The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
Zhong Wan-xie - One of the best experts on this subject based on the ideXlab platform.
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Numerical Solutions of LQ Control for Time-Varying Systems Via Symplectic Conservative Perturbation
Applied Mathematics and Mechanics-english Edition, 2007Co-Authors: Zhong Wan-xieAbstract:Optimal control system of state space is a conservative system, whose approximate method should be symplectic conservation. Based on the precise integration method, an algorithm of symplectic conservative perturbation was presented. It gives a uniform way to solve the LQ control problems for linear time-varying systems accurately and efficiently, whose key points are solutions of differential Riccati Equation and the state Feedback Equation with variable coefficient. The method is symplectic conservative and has a good numerical stability and high precision. Numerical examples demonstrate the effectiveness of the proposed method.
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Numerical solutions of linear quadratic control for time-varying systems via symplectic conservative perturbation
Applied Mathematics and Mechanics, 2007Co-Authors: Tan Shu-jun, Zhong Wan-xieAbstract:Optimal control system of state space is a conservative system, whose approximate method should be symplectic conservation. Based on the precise integration method, an algorithm of symplectic conservative perturbation is presented. It gives a uniform way to solve the linear quadratic control (LQ control) problems for linear time-varying systems accurately and efficiently, whose key points are solutions of differential Riccati Equation (DRE) with variable coefficients and the state Feedback Equation. The method is symplectic conservative and has a good numerical stability and high precision. Numerical examples demonstrate the effectiveness of the proposed method.
Michael K. Salemi - One of the best experts on this subject based on the ideXlab platform.
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Revealed Preference of the Federal Reserve: Using Inverse-Control Theory to Interpret the Policy Equation of a Vector Autoregression
Journal of Business & Economic Statistics, 1995Co-Authors: Michael K. SalemiAbstract:How close is observed Federal Reserve policy to policy that would be optimal in the control-theory sense? The question is addressed by using an inverse-control methodology. Federal Reserve policy is characterized by a Feedback Equation for either changes in the interest rate or money stock. Optimal policy is characterized by solution of the Ricatti Equation. Parameters are estimated that characterize the relative importance to the Federal Reserve of stabilizing output, inflation, interest rates, and money growth. The period of study is 1947 through 1992. Evidence is uncovered that policy is optimal within distinct regimes.
H. G. Khajah - One of the best experts on this subject based on the ideXlab platform.
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Tau method treatment of a delayed negative Feedback Equation
Computers & Mathematics With Applications, 2005Co-Authors: H. G. KhajahAbstract:The step-by-step Tau method is applied to find polynomial approximations to the solution of the nonlinear functional Equation, [email protected]?(t)[email protected](t-1)[1+x(t)],t>0, which arises in population dynamics. The behavior of the approximate solutions is consistent with the theoretical results obtained elsewhere.
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Tau method treatment of a delayed negative Feedback Equation
Computers & Mathematics with Applications, 2005Co-Authors: H. G. KhajahAbstract:AbstractThe step-by-step Tau method is applied to find polynomial approximations to the solution of the nonlinear functional Equation, x˙(t)=−αx(t−1)[1+x(t)],t>0, which arises in population dynamics. The behavior of the approximate solutions is consistent with the theoretical results obtained elsewhere
Haiping Fang - One of the best experts on this subject based on the ideXlab platform.
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lattice boltzmann model with nearly constant density
Physical Review E, 2002Co-Authors: Haiping FangAbstract:An improved lattice Boltzmann model is developed to simulate fluid flow with nearly constant fluid density. The ingredient is to incorporate an extra relaxation for fluid density, which is realized by introducing a Feedback Equation in the equilibrium distribution functions. The pressure is dominated by the moving particles at a node, while the fluid density is kept nearly constant and explicit mass conservation is retained as well. Numerical simulation based on the present model for the (steady) plane Poiseuille flow and the (unsteady) two-dimensional Womersley flow shows a great improvement in simulation results over the previous models. In particular, the density fluctuation has been reduced effectively while achieving a relatively large pressure gradient.
Jiandong Zhu - One of the best experts on this subject based on the ideXlab platform.
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a necessary and sufficient condition for local asymptotic stability of a class of nonlinear systems in the critical case
Automatica, 2018Co-Authors: Jiandong Zhu, Chunjiang QianAbstract:By the theory of linear differential Equations, a system described by a chain of integrators with a linear Feedback is globally asymptotically stable if and only if the characteristic polynomial is Hurwitz, which implies that all the coefficients in the linear Feedback Equation are negative. However, negative coefficients may not guarantee the local asymptotic stability of the linear system. In this paper, we reveal that, by monotonizing the powers of the integrators, the strict negativity of the Feedback coefficients is not only necessary but also sufficient for the local asymptotic stability of the system. A dual result is also obtained for the dual power integrator systems.
