• Title/Summary/Keyword: Maxwell

Search Result 833, Processing Time 0.025 seconds

멀티그리드 고정용 전자석 해석 및 설계

  • Kim, Hoe-Seop
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • v.6 no.2
    • /
    • pp.99-108
    • /
    • 2002
  • 그리드 고정용 전자석은 절단금형에서 여러 조각으로 나누어진 매우 얇고 가벼운 그리드를 전자석에 흡착시켜 그리드를 부착한 장소까지 이송하는 역할을 하는 전자석이다. 설계목표는 (1)그리드 고정용 전자석이 착자, 탈자 및 이동시 전자석에 흡착된 그리드 조각의 정렬상태가 동요되지 않는 전자석의 설계, (2)금형(그리드 흡착면)에 잔류자기가 최소화되는 설계, (3)전자석이 탈자되었을 때, 잔류자기가 최소화되는 설계에 초점을 두었다. 자장분포는 유한요소법으로 계산하였고, 전자력 계산은 Maxwell stress tensor법을 사용하였다.

  • PDF

A study on the movement of Liquid DMPE and DLPE monolayer on a water subphase by Maxwell Displacement Currents (변위전류에 의한 DMPE, DLPE 지질막의 수면상 거동 연구)

  • ;;;;M. Iwamoto
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1996.11a
    • /
    • pp.191-194
    • /
    • 1996
  • Maxwell displacement current clearly shows the onset of a first order phase transition from gaseous to gaseous-fluid phase, and polar ordering of liquid molecules in the solid phase coexisting with fluid. For further monolayer compression in the fluid/solid phase transition, the condensation of domains was suggested.

  • PDF

Effects of Fission Neutron Spectra in Reactor Calculations (핵분열 중성자스펙트럼이 핵계산에 미치는 영향)

  • 김정도;이종태
    • Nuclear Engineering and Technology
    • /
    • v.15 no.4
    • /
    • pp.280-285
    • /
    • 1983
  • Effects of fission neutron spectra in the reactor calculations have been analysed through applications of several cases of spectra in the criticality calculations of fast critical assemblies. They were the application of Maxwellian or Watt-Cranberg type formulae, of region dependent spectrum, of composition dependent spectrum, of fission transfer matrix, and the effects due to the selection of nuclear temperature in Maxwellian formula.

  • PDF

A Study on the Electrical Properties of Organic Miked Films (유기혼합막의 전기특성에 관한 연구)

  • 조수영;이경섭
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2000.07a
    • /
    • pp.503-506
    • /
    • 2000
  • Molecular switching in azobenzene mixed monolayers on a water surface was investigated by means of Maxwell displacement current(MDC) measurement. It was found that the change in the vertical component of the dipolemoment of the mixed monolayer during visible light irradiation was almost the same as that flowing during UV light irradiation. Also MDC was generated but it depended on the molar ratio. As a result. It's phtoisomerization progressed by 8A5H in mixed films.

  • PDF

An improved Maxwell creep model for salt rock

  • Wang, Jun-Bao;Liu, Xin-Rong;Song, Zhan-Ping;Shao, Zhu-Shan
    • Geomechanics and Engineering
    • /
    • v.9 no.4
    • /
    • pp.499-511
    • /
    • 2015
  • The creep property of salt rock significantly influences the long-term stability of the salt rock underground storage. Triaxial creep tests were performed to investigate the creep behavior of salt rock. The test results indicate that the creep of salt rock has a nonlinear characteristic, which is related to stress level and creep time. The higher the stress level, the longer the creep time, the more obvious the nonlinear characteristic will be. The elastic modulus of salt rock decreases with the prolonged creep time, which shows that the creep damage is produced for the gradual expansion of internal cracks, defects, etc., causing degradation of mechanical properties; meanwhile, the creep rate of salt rock also decreases with the prolonged creep time in the primary creep stage, which indicates that the mechanical properties of salt rock are hardened and strengthened. That is to say, damage and hardening exist simultaneously during the creep of salt rock. Both the damage effect and the hardening effect are considered, an improved Maxwell creep model is proposed by connecting an elastic body softened over time with a viscosity body hardened over time in series, and the creep equation of which is deduced. Creep test data of salt rock are used to evaluate the reasonability and applicability of the improved Maxwell model. The fitting curves are in excellent agreement with the creep test data, and compared with the classical Burgers model, the improved Maxwell model is able to precisely predict the long-term creep deformation of salt rock, illustrating our model can perfectly describe the creep property of salt rock.

Subcell Maxwell-Boltzmann FDTD Method for Analyzing Thin Plasma Layer (얇은 플라즈마 층의 전자기 해석을 위한 Subcell 맥스웰-볼츠만 유한 차분 시간 영역 기법)

  • Jung, Inkyun;Kim, Yuna;Hong, Yongjun;Yook, Jong-Gwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.26 no.3
    • /
    • pp.326-332
    • /
    • 2015
  • Analyzing electromagnetic properties in plasma medium, it is difficult to numerically solve electromagnetic problem with thin plasma. In this paper, subcell Maxwell-Boltzmann FDTD method was proposed which is combined with Maxwell-Boltzmann FDTD and subcell FDTD method for analyzing plasma and electrically thin materials, respectively. Calculations of reflection coefficient and absorption rate error were performed by using 1D FDTD method. Reflection coefficient computed by applying the proposed method is in agreement with analytic solution. Absorption rate error analyzed by employing the proposed method is 1/10 times less than one by using conventional method.

The Development of Electromagnetic Field Analysis Software for Virtual Training (가상 교육용 전자장 해석 프로그램 개발)

  • Wee, Sang Bong;Kim, Ki Beom
    • The Journal of Korean Institute for Practical Engineering Education
    • /
    • v.2 no.2
    • /
    • pp.55-60
    • /
    • 2010
  • We usually encounter Electro-magnetics phenomenons and only feel some part of that, but it is hard to feel it visually. Moreover understanding physically and quantitatively is not a easy work. These electrostatic field theory, magnetostatic field theory and interchange magnetic field theory combined with electromagnetic field are formulated experimentally and theoretically by James Clerk Maxwell in 1873. Electromagnetic field takes electro-magnetic phenomenons as a expansion of formula originated in Maxwell equations. Since this is based on expansion of formula, it is hard to understand for many students not only middle school and high school students learning it at the first time but also college students studying physics as a elementary class and even majors in electromagnetic field. The program is developed as a visual aid to cope with these problems, and even to deal with complex problem to estimate solution using numerical method.

  • PDF

Development of Wall Slip Models for Rarefied Gas and MEMS Thermal Fluid Flows (희박기체 및 MEMS 열유동장 해석을 위한 벽면 슬립모델 개발)

  • Myong, Rho-Shin;Cho, Soo-Yong
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.30 no.7
    • /
    • pp.90-97
    • /
    • 2002
  • Wall slip models are essential to the study of nonequilibrium gas transport in rarefied and microscale condition that can be found in gas flows associated with aerospace vehicle, propulsion system, and MEMS. The Maxwell slip model has been used for this type of problem, but it has difficulty in defining the so-called accommodation coefficient and has not been very effective in numerical implementation. In the present study, on the basis of Langmuir's theory of the adsorption of gases on metals, a physical slip model is developed. The concept of the accommodation coefficient and the difference of gas particles are clearly explained in the new model. It turned out that the Langmuir model recovers the Maxwell model in the first-order approximation. The new models are also applied to various situations including internal flow in a microchannel. Issues of validation of models are treated by comparing analytic results with experiment.

Likelihood based inference for the ratio of parameters in two Maxwell distributions (두 개의 맥스웰분포의 모수비에 대한 우도함수 추론)

  • Kang, Sang-Gil;Lee, Jeong-Hee;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
    • /
    • v.23 no.1
    • /
    • pp.89-98
    • /
    • 2012
  • In this paper, the ratio of parameters in two independent Maxwell distributions is parameter of interest. We proposed test statistics, which converge to standard normal distribution, based on likelihood function. The exact distribution for testing the ratio is hard to obtain. We proposed the signed log-likelihood ratio statistic and the modified signed log-likelihood ratio statistic for testing the ratio. Through simulation, we show that the modified signed log-likelihood ratio statistic converges faster than signed log-likelihood ratio statistic to standard normal distribution. We compare two statistics in terms of type I error and power. We give an example using real data.

Iterative Cumulant Moment Method for solution of Boltzmann Equation and its Application to Shock Wave Structure (반복적 Cumulant 모멘트 방법에 의한 Boltzmann 방정식의 해법과 충격파구조에 관한 연구)

  • Ohr, Young Gie
    • Journal of the Korean Chemical Society
    • /
    • v.42 no.4
    • /
    • pp.398-410
    • /
    • 1998
  • For non-linear solution of the Boltzmann equation, the cumulant moment method has been studied. To apply the method to the normal shock wave problem, we restricted ourselves to the monatomic Maxwell molecular gases. The method is based on the iterative approach developed by Maxwell-Ikenberry-Truesdell (MIT). The original MIT approach employs the equilibrium distribution function for the initial values in beginning the iteration. In the present work, we use the Mott-Smith bimodal distribution function to calculate the initial values and follow the MIT iteration procedure. Calculations have been carried out up to the second iteration for the profiles of density, temperature, stress, heat flux, and shock thickness of strong shocks, including the weak shock thickness of Mach range less than 1.4. The first iteration gives a simple analytic expression for the shock profile, and the weak shock thickness limiting law which is in exact accord with the Navier-Stokes theory. The second iteration shows that the calculated strong shock profiles are consistent with the Monte Carlo values quantitatively.

  • PDF