In this paper we continue systematic study of the dimension estimate of the global attractors for the chemotaxis-growth system and its finite-element approximations. Utilizing a conservative upwind finite-element sche...
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In this paper we continue systematic study of the dimension estimate of the global attractors for the chemotaxis-growth system and its finite-element approximations. Utilizing a conservative upwind finite-element scheme we managed significantly to improve dimension estimates with respect to the chemotactic parameter. (C) 2009 Elsevier Inc. All rights reserved.
We propose in this paper a fractional-step A-psi scheme for a quasi-magnetostatic 3D eddy current model by means of finite-element approximations. Bounds for continuous and discrete error in finite time are given, and...
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We propose in this paper a fractional-step A-psi scheme for a quasi-magnetostatic 3D eddy current model by means of finite-element approximations. Bounds for continuous and discrete error in finite time are given, and it is verified that provided the time step tau is sufficiently small, the proposed algorithm yields for finite time T an error of O(rooth(2) + tau(2)) in the L-2-norm for the magnetic field H(= vdel x A), where h is the mesh size. (C) 2004 Elsevier Ltd. All rights reserved.
In this paper we analyze an a posteriori error estimator based on the equilibrated residual method. We prove that this estimator is asymptotically exact in the energy norm for regular solutions and O(h(1+alpha)) (alph...
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In this paper we analyze an a posteriori error estimator based on the equilibrated residual method. We prove that this estimator is asymptotically exact in the energy norm for regular solutions and O(h(1+alpha)) (alpha > 0) meshes. Numerical examples are included to illustrate the theoretical results.
finite-element approximations for a fourth-order differential equation based on the space of piecewise linear polynomials on the uniform grid are introduced. And error estimates for the approximation are also given. (...
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finite-element approximations for a fourth-order differential equation based on the space of piecewise linear polynomials on the uniform grid are introduced. And error estimates for the approximation are also given. (c) 2006 Elsevier Ltd. All rights reserved.
In this paper we design high-order (non)local artificial boundary conditions (ABCs) which are different from those proposed by Han, H. & Bao, W. (1997 Numer. Math., 77, 347-363) for incompressible materials, and p...
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In this paper we design high-order (non)local artificial boundary conditions (ABCs) which are different from those proposed by Han, H. & Bao, W. (1997 Numer. Math., 77, 347-363) for incompressible materials, and present error bounds for the finite-element approximation of the exterior Stokes equations in two dimensions. The finite-element approximation (especially its corresponding stiff matrix) becomes much simpler (sparser) when it is formulated in a bounded computational domain using the new (non)local approximate ABCs. Our error bounds indicate how the errors of the finite-element approximations depend on the mesh size, terms used in the approximate ABCs and the location of the artificial boundary. Numerical examples of the exterior Stokes equations outside a circle in the plane are presented. Numerical results demonstrate the performance of our error bounds.
The main goal of this article is to investigate the capability of an operator-splitting/finiteelements based methodology at handling accurately incompressible viscous flow at large Reynolds number (Re) in regions wit...
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The main goal of this article is to investigate the capability of an operator-splitting/finiteelements based methodology at handling accurately incompressible viscous flow at large Reynolds number (Re) in regions with corners and curved boundaries. To achieve this goal the authors have selected a wall-driven flow in a semi-circular cavity. On the basis of the numerical experiments reported in this article it seems that the method under investigation has no difficulty at capturing the formation of primary, secondary and tertiary vortices as Re increases;it has also the capability of identifying a Hopf bifurcation phenomenon taking place around Re = 6600. (c) 2005 Elsevier Inc. All rights reserved.
This paper proposes the use of a variational framework to model fluid wetting dynamics. The central problem of infinite energy dissipation for a moving contact line is dealt with explicitly rather than by introducing ...
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This paper proposes the use of a variational framework to model fluid wetting dynamics. The central problem of infinite energy dissipation for a moving contact line is dealt with explicitly rather than by introducing a specific microscopic mechanism which removes it. We analyze this modelling approach in the context of the quasi-steady limit, where contact line motion is slower than bulk relaxation. We find that global effects enter into Tanner-type laws which relate line velocity to apparent contact angle through the role that energy dissipation plays in the bulk of the fluid. A comparison is made to the dynamics of lubrication equations that include attractive and repulsive intermolecular interactions. A Galerkin-type approximation method is introduced which leads to reduced-dimensional dynamical descriptions. Computations are conducted using these low-dimensional approximations, and a substantial connection to lubrication equation dynamics is found.
The limit analysis method for an estimation of mechanical and electrical strength safety conditions for non-linear elastic and dielectric solids, respectively, is examined. By the variational method and the duality th...
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The limit analysis method for an estimation of mechanical and electrical strength safety conditions for non-linear elastic and dielectric solids, respectively, is examined. By the variational method and the duality theory, the appropriate initial and dual limit analysis problems (LAPs) are formulated. It is demonstrated that the initial LAPs need a relaxation, but the appropriate fully relaxed problems have no clear physical interpretation. On the other hand, the dual LAPs have a clear physical interpretation. The general initial and dual LAPs for quasi-static problems of Continuum Mechanics are formulated. The appropriate 2-D finite-element approximations and numerical solutions are presented. Copyright (C) 2004 John Wiley Sons, Ltd.
Optimal control problems governed by the two-dimensional instationary Navier-Stokes equations and their spatial discretizations with finiteelements are investigated. A concept of semi-discrete solutions to the contro...
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Optimal control problems governed by the two-dimensional instationary Navier-Stokes equations and their spatial discretizations with finiteelements are investigated. A concept of semi-discrete solutions to the control problem is introduced which is utilized to prove existence and uniqueness of discrete controls in neighborhoods of regular continuous solutions. Furthermore, an optimal error estimate in terms of the spatial discretization parameter is given.
The asymptotic behavior and the Euler time discretization analysis are presented for the two-dimensional non-stationary Navier-Stokes problem. If the data nu and lim f(t) satisfy a uniqueness condition corresponding t...
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The asymptotic behavior and the Euler time discretization analysis are presented for the two-dimensional non-stationary Navier-Stokes problem. If the data nu and lim f(t) satisfy a uniqueness condition corresponding to the stationary Navier-Stokes problem, we then obtain the convergence of the non-stationary Navier-Stokes problem to the stationary Navier-Stokes problem and the uniform boundedness, stability and error estimates of the Euler time discretization for the non-stationary Navier-Stokes problem.
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