• 전기의세계
• /
• v.42 no.9
• /
• pp.20-27
• /
• 1993

1. 철근출막은 결정자기이방성의 영향이 작기 때문에, 자기특성이 막의 기하학적구조에 의해 거의 결정되고 그것에 의하여 자성막의 설계가 가능하다. 2. 코발트 근출막은 결정자기이방성이 자기특성에 영향은 크기때문에 코발트 결정의 자화용역축(C축)의 배향에 의하여 자기특성은 크게 변한다. 따라서 이 C축의 배향성을 변화시켜 석출입자의 형태를 바꾸지 않고 작은 포아직경에서도 항자력의 제어가 가능하였다. 3. 코발트-철합금신출막은 조성변화에 의하여 자기특성을 제어할 수 있다. 또 ㅈ포화자화, 항자력도 철을 석출한 자성막에 비해서 높은 값을 나타냄을 물론, 우수한 각형화(Mr/Ms)로 얻어지는 큰 자기에너지적으로 수직 자기기록방식의 고정밀의 로타리 엔코다에의 응용이 유망하다.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2011.04a
• /
• pp.458-461
• /
• 2011

이방향 중공슬래브 시스템의 구조특성 및 성능평가 연구의 일부로 실제 건축물에 적용된 이방향 중공슬래브의 연직진동을 측정 및 분석하였다. 캡슐형 경량체를 사용한 이방향 중공슬래브가 적용된 두 건축물에서 바닥 용도상 일상적인 진동발생원이라고 가정할 수 있는 75 kg 성인의 보행, 달리기, 제자리 점프에 대해 슬래브의 연직진동을 측정하였다. 두 대상 건축물은 각각 연구소와 교육시설 용도로 설계 및 건축되었다. 측정된 수직 가속도 데이터로 일본건축학회 환경기준에 (AIJES-2004) 근거하여 진동수 범위 3~30 Hz에 대해 1/3 옥타브 밴드 분석을 실시하였다. 이 분석을 바탕으로 AIJEES-2004에 제시한 기준에 따라 바닥의 연직진동에 대한 거주 성능을 평가한 결과, 측정한 세 건축물에 적용된 이방향 중공슬래브 모두 보행과 달리기에 대해서는 피진동자의 10% 미만이 인지, 제자리 점프에 대해서는 50~70% 미만이 인지할 수 있는 것으로 나타나, 이방향 중공슬래브가 바닥의 연직 진동에 대해 거주 성능이 양호함을 보여주었다.

• Geotechnical Engineering
• /
• v.12 no.2
• /
• pp.95-106
• /
• 1996

In this study, a constitutive model which can describe the anisotropic and plastic behaviors of natural cohesive soils, was developed based on anisotropic bounding surface theory. The model was fomulated by the concepts of the improved anisotropic bounding surface function, nonassociated flow rule with new plastic potential function, anisotropic hardening rule, and new mapping rule governing the plastic behavior inside bounding sutraface. Comparing with the results of Ku consolidation and triaxial shearing tests, the predictions by the proposed model agree quite well with real soil responses.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.5 no.3
• /
• pp.178-182
• /
• 1981

쉘이 복합재로 제작되었거나 보강재를 사용하였을때에는 쉘요소의 역학적 특성은 방향성을 가지게 된다. 이 논문에서는 선형관계식을 사용하여 동적 표면가동을 받는 이방성원통쉘의 안정성을 고려하여 다루었다. 재료의 이방성을 고려하여 3방향 즉, 축방향, 둘레방향 및 반경향의 실성항이 포함된 운동방장실을 유도하였다. 동적 안전성의 해석은 Bolotin 의 방법을 따랐으며 근사해를 행렬식행으로 제시하였다. 수직열로 외압을 받는 원통쉘의 좌단을 다루었으며 본 이론과 고전이론 사이의 차이점을 검토하였다.

• Proceedings of the KAIS Fall Conference
• /
• 2000.10a
• /
• pp.185-193
• /
• 2000

이방성 습식 식각을 이용하여 멤브레인을 제작하기 위하여 KOH-IPA의 식각액을 사용하여 단결정 실리콘 기판을 이방성으로 식각을 하고, 각 용액에 대한 식각 특성을 관찰하였다. 식각률은 식각액의 온도와 농도에 의존하며, 패턴 형성 방향과 식각액의 농도에 따라 식각 형태가 다르게 나타났다. 패턴은 Primary Flat에 45°로 기울여 형성되었으며 20wt·% KOH 80℃ 이상에서는 U-groove, 그 이하의 온도와 농도에서는 V-groove 식각 형태를 관찰할 수 있었다. 각 면에 대한 식각률 차이에 의해서 생기는 Hillock은 온도와 농도가 높아짐에 따라 줄어들었고, 재식각을 퉁하여 현저하게 줄어듦을 알 수 있었다.

• Journal of the Korean Magnetics Society
• /
• v.21 no.3
• /
• pp.83-87
• /
• 2011

We have analyzed the torque signals measured in synthetic antiferromagnetic (SAF) coupled CoFeB/Ru/CoFeB thin film, which signals were drastically changed at flopping field ($H_F$) and saturation field ($H_s$). The minimum value of negative uniaxial anisotropy constant ($-\;K_1$) was appeared at HF. The $-\;K_1$ was due to the zero net magnetization by the antiferromagnetic coupling between two ferromagnetic layers. Whereas, the biaxial anisotropy constant (K2) was induced in the field range of $H_F$ < H < $H_s$. The induced $K_2$ was originated from deviation angles between magnetization directions of two ferromagnetic layers. And at H > $H_s$, intrinsic uniaxial anisotropy constant of CoFeB layer was observed. These change of the anisotropy constant with magnetic field was explained by the magnetization process of two ferromagnetic layers based on Stoner-Wohlfarth model calculation for SAF thin film.

• Geophysics and Geophysical Exploration
• /
• v.10 no.4
• /
• pp.393-398
• /
• 2007

Seismic traveltime tomography technique was conducted at a site composed of black shale. It is well known that black shale has strong anisotropic property. Therefore, the anisotropic property of black shale has to be considered to obtain the appropriate subsurface velocity model by an inversion process. To estimate the anisotropic constant of the velocity of the black shale in the survey area, the relation between the velocity, which is calculated by the straight ray path and the first arrival time, and the angle of the ray propagation was examined. The elliptically shaped relation was found and it reveals that the black shale contains the anisotropic property of velocity. It was also noticed that the horizontal velocity is faster than the vertical velocity. When the estimated anisotropic constant was applied in the process of the velocity inversion for three sets of field data, we could obtain the appropriate velocity structures of the site that is consistent with the result of the geological survey.

• Economic and Environmental Geology
• /
• v.36 no.1
• /
• pp.49-58
• /
• 2003

To analyze the anisotropic characteristics of fractured aquifer, variations of streaming potential were measured during and after pumping over several wells at the two test sites. Surface electrical resistivity survey, normal resistivity logging, and slug test were performed at the wells to identify the hydrogeological structure. Applying the results to the recently suggested model, the aquifer of the two test sites showed confined characteristics. Anisotropic direction appeared in using equi-potential maps from self-potential monitoring results matched well with the results of the hydrogeological test. The self-potential monitoring method adopted in this study would be useful for providing a more reliable information on the anisotropy of aquifer in the pumping test at single well.

• Journal of the Korean Magnetics Society
• /
• v.6 no.5
• /
• pp.329-333
• /
• 1996

We have studied the magnetoresistance and the magnetic anisotropy of Cu/(NiFe/Ni/NiFe) metallic multi layers grown on Si(100), Si(111), $4^{\circ}\;tilt-cut\;Si(111)$ or glass substrate. When the multilayer was grown on $4^{\circ}\;tilt-cut\;Si(111)$ with $50\;{\AA}$ of Cu underlayer, an in-plane uniaxial anisotropy was observed. On the other substrates such as Si(100), Si(111) or glass with Cu underlayer, however, no appreciable anisotropy was shown. The multilayer grown with NiFe or Ni underlayer or without underlayer did not show any arnsotropy even on $4^{\circ}\;tilt-cut\;Si(111)$. When $10\;{\AA}$ of NiFe was deposited prior to the Cu underlayer, the anisotropy in Cu/(NiFe/Ni/NiFe) multilayer disappeared.

• Korean Journal of Optics and Photonics
• /
• v.30 no.4
• /
• pp.159-166
• /
• 2019

The trajectory of the transmission ellipsometric pseudoconstant ${\rho}=tan{\psi}_{\mu}e^{i{\Delta}_{\mu}}$ of a uniaxially anisotropic substrate like PET forms a circle in polar coordinates, as the phase-retardation angle is varied at a fixed azimuthal angle. The radius as well as the center's position of this circle are functions of the azimuthal angle only. This circle passes through the point (1,0), and the center of this circle is located on the real axis. These characteristics of the circle are examined analytically, and are utilized to derive simple expressions for the azimuthal angle and the phase-retardation angle of the uniaxially anisotropic substrate using the measured transmission ellipsometric constant. Finally, we confirm that the derived expressions are well applied to the analysis of the optical anisotropy of a PET film.