Browsing Institut für Mathematik by Title
Now showing items 132-151 of 329
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2011-09-20BuchIterative operator-splitting with time overlapping algorithms In this article we consider wave equations with constant and linear time dependent diffusion-coefficients which are solved numerically by iterative operator splitting with interval overlapping algorithms. The benefits of ...
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2001-10-12BuchJacobi theta embedding of a hyperbolic 4-space with cusps Starting from a fixed elliptic curve with complex multiplication we compose lifted quotients of elliptic Jacobi theta functions to abelian functions in higher dimension. In some cases, where complete Picard-Einstein metrics ...
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2011-09-20BuchKinetic processes and Phase-transition of CVD processes for Ti₃SiC₂ In this paper we present a kinetic model based on numerical simulations of a chemical vapor deposition (CVD) process. We discuss a model that is based on kinetics of the deposition rates to the material. Such a simple ...
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2006-09-20BuchLaGO - a (heuristic) Branch and Cut algorithm fornonconvex MINLPs We present a Branch and Cut algorithm of the software package LaGO to solve nonconvex mixed-integer nonlinear programs. A linear outer approximation is constructed from a convex relaxation of the problem. Since we do not ...
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2002-05-31BuchLagrangian Decomposition of Mixed-Integer All-Quadratic Programs The purpose of this paper is threefold. First we show that the Lagrangian dual of a block-separable mixed-integer all-quadratic program (MIQQP) can be formulated as an eigenvalue optimization problem keeping the block-separable ...
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2002-05-28BuchLagrangian Smoothing Heuristics for Max-Cut This paper presents smoothing heuristics for an NP-hard combinatorial problem based on Lagrangian relaxation. We formulate the Lagrangian dual for this nonconvex quadratic problem and propose eigenvalue nonsmooth unconstrained ...
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2005-11-07BuchLarge time asymptotics of solutions to the anharmonic oscillator model from nonlinear optics The anharmonic oscillator model describing the propagation of electromagnetic waves in an exterior domain containing a nonlinear dielectric medium is investigated. The system under consideration consists of a generally ...
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2005-11-07BuchLevel Zero Types and Hecke Algebras for Local Central Simple Algebras Let D be a central division algebra and Ax = GLm(D) the unit group of a central simple algebra over a p-adic field F. The purpose of this paper is to give types (in the sense of Bushnell and Kutzko) for all level zero ...
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2003-09-15BuchLinear boundary value problems for differential algebraic equations By the use of the corresponding shift matrix, the paper gives a criterion for the unique solvability of linear boundary value problems posed for linear differential algebraic equations up to index 2 with well-matched leading ...
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2005-11-09BuchLinear differential algebraic equations of index 1 and their adjoint equations For linear differential algebraic equations of tractability index 1 the notion of the adjoint equation is analysed in full detail. Its solvability is shown at the lowest possible smoothness. The fundamental matrices of ...
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2011-07-13BuchLinear differential-algebraic equations with properly stated leading term We examine in this paper so-called B-critical points of linear, time-varying differential-algebraic equations (DAEs) of the form A(t)(D(t)x(t))' + B(t)x(t) = q(t). These critical or singular points, which cannot be handled ...
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2005-11-03BuchLinear index-1 DAEs: regular and singular problems Several features and interrelations of projector methods and reduction techniques for the analysis of linear time-varying differential-algebraic equations (DAEs) are addressed in this work. The application of both methodologies ...
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1995-10-25BuchLinear spaces for index 2 differential-algebraic equations In this paper we consider solution spaces of linear index-2-tractable differential algebraic equations. Relations between the solutions of the adjoint equations and the corresponding solution spaces are derived and, thus, ...
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2004-07-01BuchLineare Algebra individuell Diese Aufgabensammlung zur linearen Algebra ist der fachliche Teil des Schlussberichts zum BMBF-Projekt 01NM075D zur interaktiven Mathematik- und Informatikgrundausbildung an der Humboldt-Universität zu Berlin. Sie beinhaltet ...
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2005-11-17BuchLocal error control for general index-1 and index-2 differential-algebraic equations This paper presents an error test function usable for the local error control and the automatic stepsize selection in the numerical integration of general index-1 and index-2 differential-algebraic equations (DAEs). This ...
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2006-01-01BuchLocal Error Estimates for Moderately Smooth ODEs and DAEs We discuss an error estimation procedure for the local errors of low order methods applied to solve initial value problems in ordinary differential equations (ODEs) and index 1 differential-algebraic equations (DAEs). The ...
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2011-07-13BuchLocal error estimates for moderately smooth problems The paper consists of two parts. In the first part of the paper, we proposed a procedure to estimate local errors of low order methods applied to solve initial value problems in ordinary differential equations (ODEs) and ...
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2005-11-16BuchLocally Exact Lower Bounds and Optimality Cuts for All-Quadratic Programs with Convex Constraints A central problem of branch-and-bound methods for global optimization is that lower bounds are often not exact even if the diameter of the subdivided regions shrinks to zero. This can lead to a large number of subdivisions ...
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2011-08-11BuchMacro- And Micor-Simulations For A Sublimation Growth Of Sic Single Crystals The numerous technical applications in electronic and optoelectronic devices, such as lasers, diodes, and sensors demand high-quality silicon carbide (SiC) bulk single crystal for industrial applications. We consider a SiC ...
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2011-09-27BuchMagnus integrator and successive approximation for solving time-dependent problems Magnus integrator and successive approximation for solving time-dependent problems. The Magnus expansion has been intensely studied and widely applied for solving explicitly time-dependent problems. Due to its exponential ...
