• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.323-326
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• 2006

Numerical solutions for spin-up problem of a thermally stratified fluid in a cylinder with an insulating sidewall and time-dependent rotation rate are presented. Detailed results are given for aspect ratio of O(1), fixed Ekman number $10-^{4}$, Rossby number 0.05 and Prandtl number O(1). Angular velocity of a cylinder wall changes with following formula, $\Omega_f=\Omega_i+\Delta\Omega[1-\exp(-t/t_c)]$. Here, this $t_c$, value, which is very significant in present study, represents that how fast/slow the angular velocity of the cylinder wall reaches final angular velocity. The normalized azimuthal velocity and meridional flow plots for several tc value which cover ranges of the stratification parameter S(1 ~ 10) are presented. The role of viscous-diffusion and Coriolis term in present study is examined by diagnostic analysis of the azimuthal velocity equation.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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• pp.63.2-63.2
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• 2007

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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• pp.264.1-264.1
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• 2007

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2003년도 High Temperature Superconductivity Vol.XIII
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• pp.28-28
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• 2003

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2004년도 High Temperature Superconductivity Vol.XIV
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• pp.51-51
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• 2004

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2002년도 동계연구발표회 논문개요집
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• pp.148-149
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• 2002

In recent years, semiconductor spintronics has been rapidly developing due to potential device applications, in which the spin of charge carriers (electrons or holes) provides novel functionalities to carry signals and process information. Diluted magnetic semiconductors (DMSs) are well known to exhibit intriguing properties such as carrier-mediated ferromagnetism and spin-dependent transport resulting from the coupling between the charge transport states and the magnetic moments (spin) [1-3]. (omitted)

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2002년도 동계연구발표회 논문개요집
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• pp.76-77
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• 2002

최근 거대자기저항(Giant magneto resistance)과 성질상으로 닮고 spin-valve와 같은 작용을 하는 ferromagnet(FM)/semiconductor, magnetic semiconductor(MS)/semiconductor 등의 다층막이 만들어지고 있으며, 비자성반도체에 spin-injection을 통한 spin-dependent electronic devices의 제작을 위한 연구가 활발히 진행중이다. 이처럼 III-FM-V, II-FM-Ⅵ, IV-FM 구조의 자성반도체(Magnetic semiconductor)에 대한 연구는 자기적 요소에 기반을 둔 반도체로의 적용가능성을 보임으로 많은 주목을 끌고 있다. 우리가 선택한 MnGe이 다른 자성반도체에 대해 상대적으로 가지는 이점은 다음과 같다. (중략)

• Journal of Magnetics
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• 제11권3호
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• pp.108-110
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• 2006

We successfully enhanced the performance of a spin valve by inserting an ultra-thin layer of partially oxidized Fe in the pinned and free layers. With the exchange bias field kept large, the spin valve reached a GMR of 12%, which corresponded to a 55% increase in GMR when we compared it with that of spin valves without any inserted layer. The layer of partially oxidized Fe was more effective for improving the properties of the spin valve than the layer of partially oxidized $Co_{90}Fe_{10}$. Considering all the results, we can contribute the significant improvement to the combined effect of the modified local electronic structures at the Fe impurities and theenhanced spin-dependent reflections at the $\alpha-Fe_{2}O_{3} phase in the magnetic layer.

• 대한화학회지
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• 제19권3호
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• pp.149-155
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• 1975

플라스틱 결정체인 피발산의 temperature-dependent wide-line NMR line width, second monent 및 spin-lattice relaxation times 의 결과는 이 결정체의 특이한 운동학적 성질 및 수소결합에 기인된 것으로 해석된다. 이 분자의 운동학적 성질은 $C_3-C_3'$ reorientation 및 self-diffusion 으로 구성 되었음을 확인했다. Wide-line NMR 연구결과는 또한 Pople-Karasz 융해설과 비교검토되었고, 이 이론과의 차이점은 피발산의 수소결합에 기인되었음을 알아냈다.

• Korean Journal of Radiology
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• 제22권7호
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• pp.1194-1202
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• 2021

Objective: To investigate the age-dependent changes in regional cerebral blood flow (CBF) in healthy adults by fitting mathematical models to imaging data. Materials and Methods: In this prospective study, 90 healthy adults underwent pseudo-continuous arterial spin labeling imaging of the brain. Regional CBF values were extracted from the arterial spin labeling images of each subject. Multivariable regression with the Akaike information criterion, link test, and F test (Ramsey's regression equation specification error test) was performed for 7 models in every brain region to determine the best mathematical model for fitting the relationship between CBF and age. Results: Of all 87 brain regions, 68 brain regions were best fitted by cubic models, 9 brain regions were best fitted by quadratic models, and 10 brain regions were best fitted by linear models. In most brain regions (global gray matter and the other 65 brain regions), CBF decreased nonlinearly with aging, and the rate of CBF reduction decreased with aging, gradually approaching 0 after approximately 60. CBF in some regions of the frontal, parietal, and occipital lobes increased nonlinearly with aging before age 30, approximately, and decreased nonlinearly with aging for the rest of life. Conclusion: In adults, the age-related perfusion patterns in most brain regions were best fitted by the cubic models, and age-dependent CBF changes were nonlinear.