• 제목/요약/키워드: Equation of state

검색결과 2,238건 처리시간 0.036초

BIFURCATIONS IN A DISCRETE NONLINEAR DIFFUSION EQUATION

  • Kim, Yong-In
    • 대한수학회보
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    • 제35권4호
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    • pp.689-700
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    • 1998
  • We consider an infinite dimensional dynamical system what is called Lattice Dynamical System given by a discrete nonlinear diffusion equation. By assuming the nonlinearity to be a general nonlinear function with mild restrictions, we show that as the diffusion parameter changes the stationery state of the given system undergoes bifurcations from the zero state to a bounded invariant set or a 3- or 4-periodic state in the global phase space of the given system according to the values of the coefficients of the linear part of the given nonlinearity.

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Molecular Spinless Energies of the Morse Potential Energy Model

  • Jia, Chun-Sheng;Cao, Si-Yi
    • Bulletin of the Korean Chemical Society
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    • 제34권11호
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    • pp.3425-3428
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    • 2013
  • We solve the Klein-Gordon equation with the Morse empirical potential energy model. The bound state energy equation has been obtained in terms of the supersymmetric shape invariance approach. The relativistic vibrational transition frequencies for the $X^1{\sum}^+$ state of ScI molecule have been computed by using the Morse potential model. The calculated relativistic vibrational transition frequencies are in good agreement with the experimental RKR values.

리튬 이온 전지의 전기적 등가 회로에 관한 연속시간 및 이산시간 상태방정식 연구 (Continuous Time and Discrete Time State Equation Analysis about Electrical Equivalent Circuit Model for Lithium-Ion Battery)

  • 한승윤;박진형;박성윤;김승우;이평연;김종훈
    • 전력전자학회논문지
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    • 제25권4호
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    • pp.303-310
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    • 2020
  • Estimating the accurate internal state of lithium ion batteries to increase their safety and efficiency is crucial. Various algorithms are used to estimate the internal state of a lithium ion battery, such as the extended Kalman filter and sliding mode observer. A state-space model is essential in using algorithms to estimate the internal state of a battery. Two principal methods are used to express the state-space model, namely, continuous time and discrete time. In this work, the extended Kalman filter is employed to estimate the internal state of a battery. Moreover, this work presents and analyzes the estimation performance of algorithms consisting of a continuous time state-space model and a discrete time state-space model through static and dynamic profiles.

POSITIVE SOLUTION AND GROUND STATE SOLUTION FOR A KIRCHHOFF TYPE EQUATION WITH CRITICAL GROWTH

  • Chen, Caixia;Qian, Aixia
    • 대한수학회보
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    • 제59권4호
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    • pp.961-977
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    • 2022
  • In this paper, we consider the following Kirchhoff type equation on the whole space $$\{-(a+b{\displaystyle\smashmargin{2}{\int\nolimits_{{\mathbb{R}}^3}}}\;{\mid}{\nabla}u{\mid}^2dx){\Delta}u=u^5+{\lambda}k(x)g(u),\;x{\in}{\mathbb{R}}^3,\\u{\in}{\mathcal{D}}^{1,2}({\mathbb{R}}^3),$$ where λ > 0 is a real number and k, g satisfy some conditions. We mainly investigate the existence of ground state solution via variational method and concentration-compactness principle.

Necessary and Sufficient Stability Condition of Discrete State Delay Systems

  • Suh, Young-Soo;Ro, Young-Shick;Kang, Hee-Jun;Lee, Hong-Hee
    • International Journal of Control, Automation, and Systems
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    • 제2권4호
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    • pp.501-508
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    • 2004
  • A new method to solve a Lyapunov equation for a discrete delay system is proposed. Using this method, a Lyapunov equation can be solved from a simple linear equation and N-th power of a constant matrix, where N is the state delay. Combining a Lyapunov equation and frequency domain stability, a new stability condition is proposed for a discrete state delay system whose state delay is not exactly known but only known to lie in a certain interval.

유도전동기 축소모델을 이용한 센서리스 칼만 필터 속도 추정기 (Sensorless Velocity Estimation using the Reduced-order State Equation of Induction Motor based on Kalman Filter)

  • 이승현;정교범
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1998년도 전력전자학술대회 논문집
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    • pp.245-248
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    • 1998
  • This paper proposes a sensorless velocity estimator using the reduced-order state equation of induction motor based on Kalman Filter. The electrical transients in the stator voltage equations of induction motor are neglected in the reduced-order model. The advantage of using the reduced-order model is to reduce the required number of numerical integrations for filtering the rotor speed. As changing the operating points and the parameters of the induction motor in simulation studies, the behavior of the sensorless velocity estimator as predicted by the reduced-order state equation of induction machine is compared with the behavior predicted by the complete state equation of induction machine.

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압축성 이상(二相) 충격파관 문제에 대한 엄밀 리만해법 (EXACT RIEMANN SOLVERS FOR COMPRESSIBLE TWO-PHASE SHOCK TUBE PROBLEMS)

  • 염금수;장근식
    • 한국전산유체공학회지
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    • 제15권3호
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    • pp.73-80
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    • 2010
  • In this paper, we present the exact Riemann solver for the compressible liquid-gas two-phase shock tube problems. We hereby consider both isentropic and non-isentropic two-phase flows. The shock tube has a diaphragm in the mid-section which separates the liquid medium on the left and the gas medium on the right. By rupturing the diaphragm, various waves are observed on the phasic field variables such as pressure, density, temperature and void fraction in the form of rarefaction wave, shock wave and material interface (contact discontinuity). Both phases are treated as compressible fluids using the linearized equation of state or the stiffened-gas equation of state. We solve several shock tube problems made of a high/low pressure in the liquid and a low/high pressure in the gas. The wave propagations are well resolved by the exact Riemann solutions.

Stability of discrete state delay systems

  • Suh, Young-Soo;Lee, Won-Gu;Lee, Man-Hyung
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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    • pp.112-115
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    • 1999
  • A new method to solve a Lyapunov equation for a discrete delay system is proposed. Using this method, a Lyapunov equation can be solved from a simple linear equation and N-th power of a constant matrix, where N is the state delay. Combining a Lyapunov equation and frequency domain stability, a new stability condition is proposed. The proposed stability condition ensures stability of a discrete state delay system whose state delay is not exactly known but only known to lie in a certain interval.

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