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On the Moving Preisach Model
(1990)

We present a deterministic simulation scheme for the Boltzmann Semiconductor Equation. The convergence of the method is shown for a simplified space homogeneous case. Numerical experiments, which are very promising, are also given in this situation. The extension for the application to the space inhomogeneous equation with a self consistent electric field is quoted. Theoretical considerations in that case are in preparation.

This paper contains the basic ideas and practical aspects for numerical methods for solving the Boltzmann Equation. The main field of application considered is the reentry of a Space Shuttle in the transition from free molecular flow to continuum flow. The method used will be called Finite Pointset Method (FPM) approximating the solution by finite sets of particles in a rigorously defined way. Convergence results are cited while practical aspects of the algorithm are emphasized. Ideas for the transition to the Navier Stokes domain are shortly discussed.

This report contains the following three papers about computations of rarefied gas flows:; ; a) Rarefied gas flow around a disc with different angles of attack, published in the proceedings of the 17th RGD Symposium, Aachen, 1990.; ; b) Hypersonic flow calculations around a 3D-deltawing at low Knudsen numbers, published in the proceedings of the 17th RGD Symposium,; Aachen, 1990.; ; c) Rarefied gas flow around a 3D-deltawing, published in the proceedings of the Workshop on Hypersonic Flows for Reentry Problems,; Part 1, Antibes, France, January 22-25, 1990.; ; All computations are part of the HERMES Research and Development Program.

Treating polyatomic gases in kinetic gas theory requires an appropriate molecule model taking into account the additional internal structure of the gas particles. In this paper we describe two such models, each arising from quite different approaches to this problem. A simulation scheme for solving the corresponding kinetic equations is presented and some numerical results to 1D shockwaves are compared.

This article describes the basic concepts of an extensible customizable knowledge-basedgraphical editor and its adoption to the DOCASE methodology and tool environment. Oneaspect in this field is the mapping of conceptual models (expressed in a specific language)to their graphical representations. This also has impacts to the semantic of the user actionsin a graphical editor tool. The ability to extend and customize the editor can be used tobuild specific graphical interfaces to various kinds of tools in the software developmentprocess. Major aspects of ODE are semantics-directed editing besides normal syntax-directed editing, support of abstraction mechanisms, multiple modeless views to attack com-plexity, semantic analization and animation. The result is an highly customizable graphicaleditor construction set that matches requirements of applications in many domains of systemdesign.