Browsing Preprints aus dem Institut für Mathematik by Subject "27 Mathematik"
Now showing items 120 of 99

20051021Buch1Semiquasihomogeneous Singularities of Hypersurfaces in Characteristic 2 In arbitrary characteristic different from 2, the singularities with semiquasihomogeneous equations characterized by the condition to have Saitoinvariant 1 are the "classical" quasihomogeneous ones, known over the field ...

20060101BuchA 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 ...

20060101BuchA 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 ...

19950426BuchA Dual Method for the Unit Commitment Problem In this paper a method for solving a midterm 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 ...

20060101BuchA 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 ...

20051021BuchA global L kgradient estimate on weak solutions to nonlinear stationary NavierStokes equations under mixed boundary conditions

20051020BuchA Global LpGradient 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 ...

19961001BuchA nonstandard finite difference method for the solution of linear second order boundary value problems with nonsmooth coefficients A new three point highly accurate finite difference method for solving linear second order differential equations is proposed. The coefficients of the scheme are constructed via differentiations of the differential equation. ...

20051021BuchA Shooting Method for Fully Implicit Index2 DifferentialAlgebraic Equations A shooting method for twopointboundary value problems for fully implicit index1 and 2 differentialalgebraic equations is presented. A combination of the shooting equations with a method of the calculation of consistent ...

20060101BuchA Spectral Gap Mapping Theorem and Smooth Invariant Center Manifolds for Semilinear Hyperbolic Systems Although the spectral mapping property in general fails it is shown that a ``spectral gap mapping theorem'', which characterizes exponential dichotomy, holds for a general class of semilinear hyperbolic systems of PDEs in ...

20060623BuchA unifying theory of a posteriori error control for nonconforming finite element methods Residualbased a posteriori error estimates were derived within one unifying framework for lowestorder conforming, nonconforming, and mixed finite element schemes in [C. Carstensen, Numerische Mathematik 100 (2005) 617637]. ...

20011005BuchAbelian approach to modular forms of neat 2ball lattices In previous papers [HoEis], [Ho2000] we found neat Picard modular surfaces with abelian minimal model and, conversely, a divisor criterion on abelian surfaces A for such a situation. For the corresponding ball lattices ...

20060101BuchAdditive Schwarz DomainDecomposition method with embedded small scales for Diffusion Equation We present a convergence and error bound study for domaindecomposition methods with very small domains. The idea is to apply very fast solver methods for strips with $h

20051109BuchAnalyzing the stability behaviour of DAE solutions and their approximations New stability results are proved for linear index2 differential algebraic equations (DAE). They are obtained by means of an improved projector decoupling. On the background of logarithmic norms related to invariant ...

20051020BuchAsymptotic properties of regularized differentialalgebraic equations

20060101BuchBilateral Gamma Distributions and Processes in Financial Mathematics We present a class of Lévy processes for modelling financial market fluctuations: Bilateral Gamma processes. Our starting point is to explore the properties of bilateral Gamma distributions, and then we turn to their ...

20051026BuchCharacterization of stability for cone increasing constraint mappings We investigate stability (in terms of metric regularity) for the specific class of cone increasing constraint mappings. This class is of interest in problems with additional knowledge on some nondecreasing behavior of the ...

20000704BuchComputing Green Currents via the Heat Kernel Let X be a compact Kähler manifold. We show that there exists a unique Green current gY for any cycle Y in X. We show that the current gY is a form with L1coefficients. The heat kernel applied to the Dirac distribution ...

20051109BuchConsistent initial values for DAE systems in circuit simulation One of the difficulties of the numerical integration methods for differentialalgebraic equations (DAEs) is computing consistent initial values before starting the integration, i.e. calculating values that satisfy the given ...

20060101BuchConvergence of adaptive FEM for a class of degenerate convex minimization problems A class of degenerate convex minimization problems allows for some adaptive finite element method (AFEM) to compute strongly converging stress approximations. The algorithm AFEM consists of successive loops of the form ...