• Title/Summary/Keyword: Spin mode

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TEMPERATURE DEPENDENCE OF SPIN WAVE RESONANCE IN AMORPHOUS FILMS

  • Kim, Y.Y.;Baek, J.S.;Lee, S.J.;Lee, T.G.;Lim, W.Y.;Yu, S.C.;Lee, S.H.;Jang, P.W.
    • Journal of the Korean Magnetics Society
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    • v.5 no.5
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    • pp.524-527
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    • 1995
  • The temperature dependence of spin wave mode separation in amorphous $Co_{89.5}Zr_{10.5}$ thin film has been investigated at temperatures between 100 K and 300 K. The magnetization and the spectroscopic splitting factor were obtained for the main resonance mode in parallel and perpendicular magnetic field. ${\Delta}H_{2-3}$, the difference between resonance field of mode 2 and the resonance field of mode 3, increases with decreasing temperature. The linewidth increases for all the modes with decreasing temperature. Especially in mode 3 it increases rapidly below 200 K. This phenomenon could be caused by the increase of exchange stiffness constant or the decrease of surface magnetic anisotropy constant with decreasing temperature.

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SYNTHESIS AND APPLICATION OF NEW SPIN PROBES

  • Kim, S.D.;Freeman, H.S.;Mcgregor, R.
    • Proceedings of the Korean Fiber Society Conference
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    • 1990.06b
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    • pp.67-67
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    • 1990
  • Three non-ionic and two anioinic spin probes, differing in size and substituent, were synthesized. Their mobility in dried nylon 6 film was investicated by the spin probe technique using electron spin resonance spectrometer. When the size of a spin probe was large and the interaction between the probe molecules and polymer chains existed, the mobility of spin probes decreased. From Arrhenius plots of rotational correlation time, one discontinuity point ($T_d$) was determined. The activation energies for rotation below and above $T_d$ were discussed in terms of the mode of probe rotation. Three spin probes could be viewed as azo dyes having a built-in nitroxide radical. Photolysis of them in dimethylformamide and in nylon 6 film was performed by exposure to 254 nm UV light in the presence of air. It was found that dyes having a built-in nitroxide radical showed better photostability than dyes derived from ${\bata}-naphthol$..

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Impact Analysis of the Cervical Spin using a Finite Element Model (유한요소 모델을 이용한 충격력에 따른 경추부의 응답특성 해석)

  • 김영은;박덕용;이춘기
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.5
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    • pp.249-257
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    • 1999
  • A three dimensional finite model of a human neck has been developed in an effort to study the mechanics of cervical spin while subjected to vertical impact. This model consisting of the vertebrae from C1 through C7 including posterior element and ligaments was constructed by 2mm thick transverse CT cross-sections and X-ray film taken at lateral side. Geometrical nonlinearity was also considered for the large deformation on the disc. ABAQUS package was used for calculation and its results were verified comparing with responses of a model under static loading condition with published in-vitro experimental data. There were more cervical fracture in the restrained (compression) mode than in the nonrestrained (flexion-compression and extension-compression) mode. Upper cervical(C1-C2) injuries were observed under compression-extension modes, while lower cervical injuries occurred undjer compression-flexion modes. Posterior ligament distraction without bony damage at the upper cervical spin(C1-C2) were observed secondary to C5-C7 trauma in compression-flexion modes.

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The Analysis of Device Models and the Method of Increasing Compatibility Between Device Models for M&S V&V of NetSPIN (NetSPIN M&S 모델 V&V를 위한 장비 모델 및 모델간 호환성 증진방안 분석)

  • Park, In-Hye;Kang, Seok-Joong;Lee, Hyung-Keun;Shim, Sang-Heun
    • Journal of Information Technology Services
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    • v.11 no.sup
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    • pp.51-60
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    • 2012
  • In this paper, we provide the analysis of device model and method between device models for compatible M&S V&V of the NetSPIN. First of all, we analysis features, structure, and classification of the NetSPIN. The second, as a part of reliable V&V process, we analysis network system modeling process, correlation between device modeling process for M&S of the NetSPIN. The third, we suggest making a kind of pool of reference model and module of devices for the increase factor of reuse between device model. We also, at the point view of M&S V&V, conclude that there is the validity of the fidelity in device modeling process. Through the analysis of the NetSPIN device model and suggestion of the method for higher compatibility between device modes, the development process of device model be clearly understood. Also we present the effective method of the development for reliable device mode as the point of V&V.

Near-resonant attitude motion analysis of a spinning satellite via multiple scales method

  • Kang, Ja-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 1994.10a
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    • pp.213-217
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    • 1994
  • The attitude stability of a satellite in spin-stabilized injection mode which contains a liquid pool is investigated. The satellite model for investigation is a two-body system consisting of a the main body, which is symmetric and rigid, representing the spacecraft, and a spherical pendulum, representing the liquid pool. Assuming that both spacecraft and pendulum are in states of steady spin about the symmetry axis of the spacecraft, the coupled nonlinear equations of motion for the system are simplified. In this paper, by using the multiple scales method, the possible resonance conditions in terms of the system parameters are determined and the corresponding near-resonant solutions are derived.

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Analysis of the Antenna Pointing Instability of a Satellite in Spin-Stabilized Injection Mode

  • Kang, Ja-Young;Shin, Kwang-Keun
    • ETRI Journal
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    • v.16 no.2
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    • pp.27-41
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    • 1994
  • A new mathematical model to predict the beam pointing instability of a nonconservative two-body satellite system in spinning injection mode has been developed by using Newton-Euler and projection methods. Since the on-axis and null axis of the omni antenna with toroidal pattern beam form a right angle, wobbling of the antenna on-axis is measured by determining the Euler angles which represent the orientation of the satellite's spin axis. Because of the complexity of the system which is a time varying, nonstationary, nonlinear dynamical system, a numerical method is used for the analysis. Computer simulation results present the effects of the mass distribution and internal mass motion on the antenna beam pointing.

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