• 제목/요약/키워드: Maxwell

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Simulation of Electrorheological Fluids by the Extended Maxwell-Wagner Polarization Model with Onsager Theory (Onsager 이론으로 확장한 Maxwell-Wagner 분극 모델에 의한 전기유변 현상 모사)

  • Kim, Young Dae
    • Korean Chemical Engineering Research
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    • v.58 no.3
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    • pp.480-485
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    • 2020
  • The extended Maxwell-Wagner polarization model is employed to describe the ER behavior of the conducting particle ER suspensions, and solutions to the equation of motion are obtained by dynamic simulation. The simulation results show the nonlinear ER behavior (Δτ∝En, n≈1.5) of the conducting particle ER suspensions. The response point, where shear stress reaches steady-state, is the point where stable break-up and rebuild of the chain-like structure of particles reaches. Also, it shows the minimum of shear stress, which corresponds the start-up of random particle configuration. The shear stress reaches plateau as particle volume fraction increases.

Extended Maxwell-Wagner Polarization Model with Onsager Theory for the Electrorheological Phenomena (전기유변현상 해석을 위하여 Onsager 이론으로 확장한 Maxwell-Wagner 분극 모델)

  • Kim, Young Dae
    • Korean Chemical Engineering Research
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    • v.56 no.5
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    • pp.767-772
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    • 2018
  • Among various mechanisms for ER phenomena, the electrostatic polarization and conduction models were known as the most promising theoretical models. However, many inherited defects have limited their uses for the development of effective ER fluids. To resolve these problems, extended Maxwell-Wagner polarization model with Onsager theory was developed. It was observed that the extended model resolved the problems, suggesting that the extended model can be used for the development of effect ER fluids.

Development of a Modified Maxwell Bridge for Precise Measurement of a 10 mH, 100 mH Inductance Standards (10 mH, 100 mH 인덕턴스 표준기 정밀측정용 Modified Maxwell Bridge 개발)

  • Kim, Han-Jun;Lee, Rae-Duk;Kang, Jeon-Hong;Semenov, Yu.P.;Han, Sang-Ok
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.840-842
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    • 2003
  • 저 주파수에서 인덕턴스 단위(H, Henry)는 전기용량의 단위(F, Farad)로부터 Maxwell bridge 또는 LC를 이용한 resonance 방법으로써 유도가 된다. 이중 Maxwell bridge 방법은 국가의 단위표준을 유지하는 연구소 또는 기관에서 가장 많이 사용되는 "product arm" 형의 bridge로 잘 알려져 있다. 개발된 bridge는 ratio-transformer를 전압공급 쪽(source)과 신호검출 쪽(detector)에 사용하여 종래의 Maxwell bridge 평형조절 시 main balance와 Wagner balance의 2개 과정을 진행하던 것과는 달리 main balance, source balance, detector balance의 과정을 진행함으로서 기존 bridge의 불안정한 ground admittance들의 영향에 의해 나타나는 불확도를 완전히 제거하였다. 한편 개발된 bridge는 10 mH, 100 mH를 10 nF의 전기용량표준기와 $1\;k{\Omega}$, $10\;k{\Omega}$의 저항표준기로부터 유도 되도록 제작되었으며. 10 mH의 경우 $400\;Hz{\sim}5\;kHz$의 주파수 영역에서 약 $2.2{\times}10^{-6}$(k=1)의 불확도로 인덕턴스 단위를 유도할 수가 있게 되었다.

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Nanometer-scale Imaging in Thin Films by Scanning Maxwell-stress Microscopy (주사형 맥스웰 응력 현미경을 이용한 박막의 Nanometer-scale 이미지)

  • 신훈규;유승엽;권영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.11a
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    • pp.133-136
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    • 1998
  • The scanning Maxwell-stress microscopy (SMM) is a dynamic noncontact electric force microscopy that allows simultaneous access to the electrical properties of molecular system such as surface potential, surface charge, dielectric constant and conductivity along with the topography. Here we report our recent results of its application to nanoscopic study of domain structures and electrical functionality in organic thin films prepared by the Langmuir-Blodgett technique.

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Parameter design optimization of solenoid type magnetic actuator using response surface methodology (반응표면법을 이용한 솔레노이드형 자기액추에이터의 치수 최적화 설계)

  • Soh, Hyun-Jun;Yoo, Jeong-Hoon
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.579-584
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    • 2003
  • Solenoid type magnetic actuator is the device, which could translate the electromagnetic energy to mechanical force. The force generated by magnetic flux, could be calculated by Maxwell stress tensor method. Maxwell stress tensor method is influenced by the magnetic flux path. Thus, magnetic force could be improved by modification of the iron case, which is the route of the magnetic flux. Modified design is obtained by parameter optimization using by Response surface methodology.

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Macroalgal Flora of Maxwell Bay, King George Island, Antarctica: I. Chlorophyta, Chrysophyta and Phaeophyta

  • Kim, Ji-Hee;Chung, Ho-Sung;Oh, Yoon-Sik;Lee, In-Kyu
    • Ocean and Polar Research
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    • v.23 no.3
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    • pp.209-221
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    • 2001
  • Taxonomic composition of marine benthic algal flora was investigated in an Antarctic bay. Specimens of chlorophyte, chrysophyte and phaeophyte were collected and examined over the period from January 1988 to January 1995 from Maxwell Bay, King George Island. A total of 19 genera and 23 species (7 chlorophytes, 1 chrysophyte and 15 phaeophytes) were identified and described. A chlorophyte Lambia antarctica (Skottsberg) Delepine and a phaeophyte Alethocladus corymbosus (Dickie) Sauvageau were recorded in Maxwell Bay for the first time. Taxonomic keys for the chlorophytes and the phaeophytes were also provided.

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Noninformative priors for the ratio of parameters of two Maxwell distributions

  • Kang, Sang Gil;Kim, Dal Ho;Lee, Woo Dong
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.3
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    • pp.643-650
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    • 2013
  • We develop noninformative priors for a ratio of parameters of two Maxwell distributions which is used to check the equality of two Maxwell distributions. Specially, we focus on developing probability matching priors and Je reys' prior for objectiv Bayesian inferences. The probability matching priors, under which the probability of the Bayesian credible interval matches the frequentist probability asymptotically, are developed. The posterior propriety under the developed priors will be shown. Some simulations are performed for identifying the usefulness of proposed priors in objective Bayesian inference.

Comparison of Two Dependent Agreements Using Test of Marginal Homogeneity (주변동질성검정법을 이용한 종속된 두 일치도의 비교)

  • Oh, Myong-Sik
    • Communications for Statistical Applications and Methods
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    • v.15 no.4
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    • pp.605-614
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    • 2008
  • Oh (2008) has proposed the one-sided likelihood ratio test of the equality of two agreement measures. However the use of this test may be limited since the computations of test statistic and critical value are not easy. We propose a test for comparing two dependent agreements using some well known tests for marginal homogeneity, for instance, Bhapkar test, Stuart-Maxwell test. Data obtained from 2008 world figure skating championship ladies single is analyzed for illustration purposes.

Measurement of Maxwell Displacement Current of Polyamic Acid Containing p-Cyanoazobenzene of the Water Surface (p-Cyanoazobenzene을 함유한 Polyamic Acid의 수면상의 Maxwell 변위 전류 측정)

  • Park, Keun-Ho;Shon, Byung-Chung
    • Journal of the Korean Applied Science and Technology
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    • v.14 no.3
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    • pp.55-61
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    • 1997
  • Maxwell displacement current(MDC) measuring technique has been applied on the study of monolayers of polyamic acid containing p-cyanoazobenzene. The displacement current was generated from monolayers on the water surface by monolayer compression and expansion. Displacement current was generated when the area per molecule was about $140{\AA}^2$ and $100{\AA}^2$. Maxwell displacement currents were investigated in connection with monolayer compression cycles. It was found that the maximum of MDC appeared at the molecular area just before the initial rise of surface pressure in compression cycles.