Browsing Institut für Mathematik by Title
Now showing items 1-20 of 329
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2005-11-16Buch1-Semiquasihomogeneous Singularities of Hypersurfaces - Pathology in Characteristic 2 In a preceding paper, the classification of 1-semiquasihomogeneous singularities of hypersurfaces in arbitrary characteristic p was given. They turn out to coincide (up to quadratic suspensions) with the equations given ...
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2005-10-21Buch1-Semiquasihomogeneous Singularities of Hypersurfaces in Characteristic 2 In arbitrary characteristic different from 2, the singularities with semiquasihomogeneous equations characterized by the condition to have Saito-invariant 1 are the "classical" quasihomogeneous ones, known over the field ...
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2011-09-20BuchA combined BDF-semismooth Newton approach for time-dependent Bingham flow This paper is devoted to the numerical simulation of time-dependent convective Bingham flow in cavities. Motivated by a primal-dual regularization of the stationary model, a family of regularized time-dependent problems ...
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2006-01-01BuchA convergent adaptive finite element method for an optimal design problem Abstract. The optimal design problem for maximal torsion stiffness of an infinite bar of given geometry and unknown distribution of two materials of prescribed amounts is one model example in topology optimisation. It ...
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2005-08-05BuchA Convergent Adaptive Finite Element Method For The Primal Problem Of Elastoplasticity The boundary value problem representing one time step of the primal formulation of elastoplasticity with positive hardening leads to a variational inequality of the second kind with some non-differentiable functional. This ...
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2006-01-01BuchA Domain Decomposition method based on iterative Operator Splitting method. In this article a new approach is proposed for constructing domain decomposition methods based on iterative operator splitting methods. We study the convergence properties of such a method. The main feature of the method ...
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1995-04-26BuchA Dual Method for the Unit Commitment Problem In this paper a method for solving a mid-term unit commitment problem in a large scale thermal power system is presented. This method is based on Lagrangian relaxation and uses a bundle method for solving the nonsmooth ...
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2003-06-24BuchA first approach to generalized polar varieties Let W be a closed algebraic subvariety of the n-dimensional projective space over the complex or real numbers and suppose that W is non--empty and equidimensional. In this paper we generalize the classic notion of polar ...
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2007-04-17BuchA fourth order split scheme for elastic wavepropagation Motivated by seismological problems we have studied a 4th order split scheme for the elastic wave equation. We split in the spatial directions and obtain locally one-dimensional systems to be solved. We have analyzed the ...
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2005-11-17BuchA Generalization of the Fundamental Estimates for Wm,p- Solutions of Linear Systems with Constant Coefficients (the case 1 < p < 2) The aim of the present paper is to extent the well known fundamental estimates (w.r.t. the $L^2$-norm) for weak solutions of a linear elliptic system with constant coefficients: \[ \sum_{ j= 1}^ N \sum_{\mid \alpha\mid,\mid ...
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2006-01-01BuchA Geometric Interpretation of Reduction in the Jacobians of C ab Curves In this paper, we show that the reduction of divisors in the Jacobian of a curve $C$ can be performed by considering the intersections of a suitable projective model of $C$ with quadrics in projective space. We apply this ...
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2005-10-21BuchA global L k-gradient estimate on weak solutions to nonlinear stationary Navier-Stokes equations under mixed boundary conditions
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2005-10-20BuchA Global Lp-Gradient Estimate on Weak Solutions of Nonlinear Parabolic Systems under Mixed Boundary Conditions In this paper, we prove the integrability of the spatial gradient Du to an exponent p>2 near the boundary, u being a weak solution of a nonlinear parabolic system under mixed boundary conditions. Our method of proof relies ...
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2005-11-15BuchA Global Optimality Criterion for Nonconvex Quadratic Programming over a Simplex In this paper we propose a global optimality criterion for globally minimizing a quadratic form over the standard simplex, which in addition provides a sharp lower bound for the optimal value. The approach is based on the ...
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2011-08-11BuchA Meyers' type estimate for weak solutions to a generalized stationary Navier-Stokes system In this paper, we prove a Meyers' type estimate for weak solutions to a Stokes system with bounded measurable coefficients in place of the usual constant viscosity. Besides the perturbation argument due to Meyers, we make ...
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2005-11-03BuchA modified standard embedding for linear complementarity problems We propose a modified standard embedding for solving the linear complementarity problem (LCP). This embedding is a special one-parametric optimization problem $P(t), t\in [0,1]$. Under the conditions (A3) (the Mangasaria ...
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2005-11-03BuchA modified standard embedding with jumps in nonlinear optimization The paper deals with a combination of pathfollowing methods (embedding approach) and feasible descent direction methods (so-called jumps) for solving a non-linear optimization problem with equality and inequality constraints. ...
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2005-11-03BuchA necessary optimality condition for the linear-quadratic DAE control problem We consider the linear-quadratic optimal control problem for a controlled differential algebraic equation (DAE). Under minimal assumptions on the DAE concerning index and regularity it will be possible to prove that the ...
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2011-09-27BuchA new algorithm for the index determination in DAEs by Taylor series using Algorithmic Differentiation We present an approach for determining the tractability index using truncated polynomial arithmetic. In particular, computing the index this way generates a sequence of matrices that contains itself derivatives. We realize ...
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2005-11-15BuchA new approach to Lipschitz spaces of periodic integrable functions
