Browsing Institut für Mathematik by Title
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20110920BuchIterative operatorsplitting with time overlapping algorithms In this article we consider wave equations with constant and linear time dependent diffusioncoefficients which are solved numerically by iterative operator splitting with interval overlapping algorithms. The benefits of ...

20011012BuchJacobi theta embedding of a hyperbolic 4space 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 PicardEinstein metrics ...

20110920BuchKinetic processes and Phasetransition 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 ...

20060920BuchLaGO  a (heuristic) Branch and Cut algorithm fornonconvex MINLPs We present a Branch and Cut algorithm of the software package LaGO to solve nonconvex mixedinteger nonlinear programs. A linear outer approximation is constructed from a convex relaxation of the problem. Since we do not ...

20020531BuchLagrangian Decomposition of MixedInteger AllQuadratic Programs The purpose of this paper is threefold. First we show that the Lagrangian dual of a blockseparable mixedinteger allquadratic program (MIQQP) can be formulated as an eigenvalue optimization problem keeping the blockseparable ...

20020528BuchLagrangian Smoothing Heuristics for MaxCut This paper presents smoothing heuristics for an NPhard combinatorial problem based on Lagrangian relaxation. We formulate the Lagrangian dual for this nonconvex quadratic problem and propose eigenvalue nonsmooth unconstrained ...

20051107BuchLarge 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 ...

20051107BuchLevel 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 padic field F. The purpose of this paper is to give types (in the sense of Bushnell and Kutzko) for all level zero ...

20030915BuchLinear 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 wellmatched leading ...

20051109BuchLinear 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 ...

20110713BuchLinear differentialalgebraic equations with properly stated leading term We examine in this paper socalled Bcritical points of linear, timevarying differentialalgebraic 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 ...

20051103BuchLinear index1 DAEs: regular and singular problems Several features and interrelations of projector methods and reduction techniques for the analysis of linear timevarying differentialalgebraic equations (DAEs) are addressed in this work. The application of both methodologies ...

19951025BuchLinear spaces for index 2 differentialalgebraic equations In this paper we consider solution spaces of linear index2tractable differential algebraic equations. Relations between the solutions of the adjoint equations and the corresponding solution spaces are derived and, thus, ...

20040701BuchLineare Algebra individuell Diese Aufgabensammlung zur linearen Algebra ist der fachliche Teil des Schlussberichts zum BMBFProjekt 01NM075D zur interaktiven Mathematik und Informatikgrundausbildung an der HumboldtUniversität zu Berlin. Sie beinhaltet ...

20051117BuchLocal error control for general index1 and index2 differentialalgebraic 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 index1 and index2 differentialalgebraic equations (DAEs). This ...

20060101BuchLocal 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 differentialalgebraic equations (DAEs). The ...

20110713BuchLocal 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 ...

20051116BuchLocally Exact Lower Bounds and Optimality Cuts for AllQuadratic Programs with Convex Constraints A central problem of branchandbound 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 ...

20110811BuchMacro And MicorSimulations For A Sublimation Growth Of Sic Single Crystals The numerous technical applications in electronic and optoelectronic devices, such as lasers, diodes, and sensors demand highquality silicon carbide (SiC) bulk single crystal for industrial applications. We consider a SiC ...

20110927BuchMagnus integrator and successive approximation for solving timedependent problems Magnus integrator and successive approximation for solving timedependent problems. The Magnus expansion has been intensely studied and widely applied for solving explicitly timedependent problems. Due to its exponential ...