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Software

AWS

(contact: J. Polzehl, phone: +49 30/20372-481)

AWS is an Adaptive Weights Smoothing package. A reference implementation of the adaptive weights smoothing procedures (AWS) is available in form of a contributed package of the R-Project for Statistical Computing (http://www.r-project.org/ ). The package includes functions for local polynomial structural adaptive smoothing in regression models with additive errors and for local constant structural adaptive smoothing in exponential family models, the latter including binary response, Poisson regression, exponential regression, and volatility models. The special case of a grid design allows for efficient reconstruction of non-smooth images in 2D and 3D.

The package can be obtained from http://CRAN.R-project.org/ .

An extension of this package currently allows for multivariate models and contains functions for the analysis of fMRI and dMRI data.


BOP

(contact: J. Borchardt, phone: +49 30/20372-485)

The simulator BOP (Block Orientend Process simulator) is a software package for large-scale process simulation. It allows to solve dynamic as well as steady-state problems. Due to an equation-based approach, a wide range of processes as they occur in chemical process industries or other process engineering environments can be simulated.

The modeling language of BOP is a high-level language which supports a hierarchically unit-oriented description of the process model and enables a simulation concept that is based on a divide-and-conquer strategy. Exploiting this hierarchical modeling structure, the generated system of coupled differential and algebraic equations (DAEs) is partitioned into blocks, which can be treated almost concurrently. The used numerical methods are especially adopted for solving large-scale problems on parallel computers. They include backward differentiation formulae (BDF), block-structured Newton-type methods, and sparse matrix techniques.

BOP is implemented under UNIX on parallel computers with shared memory (Cray J90, SGI Origin2000, Compaq AlphaServer) but can also be run on different single processor machines as well as under Windows XP on PCs. So far it has been successfully used for the simulation of several real-life processes in heat-integrated distillation, sewage sludge combustion or gas turbine simulation for example.

Detailed information: http://www.wias-berlin.de/software/BOP


ClusCorr98®

(contact: H.-J. Mucha, phone: +49 30/20372-573)

The statistical software ClusCorr98® is an interactive statistical computing environment that performs exploratory data analysis mainly by using adaptive methods of cluster analysis, classification, and multivariate visualization. Currently, there are two new main enhancements. Firstly, an automatic validation technique of cluster analysis results was developed that becomes a general built-in validation tool for all hierarchical clustering methods that are available in the statistical software ClusCorr98®. This validation via resampling techniques is based on the adjusted Rand index. By doing so, both the appropriate number of clusters can be validated and the stability of each cluster can be assessed. Furthermore, one can compare the performance of different cluster analysis methods. Secondly, clustering methods based on nonparametric density estimation are under development. This is a joint project with U. Simon and C. Duckhorn within the framework of an application to water ecology (monitoring of phytoplankton). The special algorithms can find arbitrary-shaped clusters. Usually, they are used as a fast preclustering step for massive data sets or as stand-alone clustering methods that provide optimum solutions.

Up to now ClusCorr98® runs under the Excel spreadsheet environment taking advantage of both the data base connectivity and the object-oriented programming language Visual Basic for Applications (VBA). Now the upgrade of VBA to C# and VB.NET under the .NET framework is in progress.

Please find further information under: http://www.wias-berlin.de/software/ClusCorr98 and http://www.wias-berlin.de/people/mucha/Clustering .


DiPoG

(contact: G. Schmidt, phone: +49 30/20372-456)

The program package DiPoG (Direct and inverse Problems for optical Gratings) provides simulation and optimization of periodic diffractive structures with multilayer stacks.

The direct solver computes the field distributions and efficiencies of given gratings for TE and TM polarization as well as under conical mounting for arbitrary polygonal surface profiles. The inverse solver deals with the optimal design of binary gratings, realizing given optical functions, for example, far-field patterns, efficiency, or phase profiles. The algorithms are based on coupled generalized finite/boundary elements and gradient-type optimization methods.

For detailed information please see also http://www.wias-berlin.de/software/DIPOG .


gltools

(contact: J. Fuhrmann, phone: +49 30/20372-560)

gltools has been designed with the needs of numerical analysts in mind. Thus, unlike many other packages available, it can be used to enhance existing codes with interactive or non-interactive graphical output. It enhances the OpenGL API with the following additional functionality:

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multiple independent windows;
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basic interactive handling through mouse and keyboard;
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interactive three-dimensional rendering volume;
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character output;
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high-quality frame dump in encapsulated postscript format;
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MPEG video recording of window contents;
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piecewise linear function rendering on two- and three-dimensional simplex meshes

(landscape view of plane sections, isolevel surfaces, isolines) with an

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universal, callback-based mesh interface.

Please find further information under http://www.wias-berlin.de/software/gltools .


LDSL-tool

(contact: M. Radziunas, phone: +49 30/20372-441)

LDSL-tool (Longitudinal Dynamics in Semiconductor Lasers) is a tool for the simulation and analysis of the nonlinear longitudinal dynamics in multi-section semiconductor lasers. This software is used to investigate and to design lasers which exhibit various nonlinear effects such as self-pulsations, chaos, hysteresis, mode switching, excitability, and synchronization to an external signal frequency.

LDSL-tool combines models of different complexity, ranging from partial differential equation (PDE) to ordinary differential equation (ODE) systems. A mode analysis of the PDE system and a comparison of the different models is also possible.

Detailed information: http://www.wias-berlin.de/software/ldsl


pdelib

(contact: J. Fuhrmann, phone: +49 30/20372-560)

pdelib is a collection of software components which are useful to create simulators based on partial differential equations. The main idea of the package is modularity, based on a pattern-oriented bottom-up design. Among others, it provides libraries for

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iterative solvers;
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sparse matrix structures with preconditioners and direct solver interfaces;
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simplex grid handling;
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graphical output using gltools and OpenGL;
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user interface based on the scripting language Lua.
Further, based on the finite volume implicit Euler method, a solver for systems of nonlinear reaction-diffusion-convection equations in heterogeneous one-, two-, and three-dimensional domains has been implemented which is part of the package.

For more information please see also http://www.wias-berlin.de/software/pdelib .


WIAS-HiTNIHS

(contact: P. Philip, phone: +49 30/20372-480)

The WIAS-High Temperature Numerical Induction Heating Simulator constitutes a transient simulation tool for the temperature evolution in axisymmetric technical systems that are subject to intense heating by induction. The simulator accounts for heat transfer by radiation through cavities, and it allows for changes in the material parameters due to the rising temperature, e.g., employing temperature-dependent laws of thermal and electrical conductivity. The simulator is designed to deal with complicated axisymmetric setups having a polygonal 2D projection. The induction coil is allowed to move during the simulation. The software is based on the WIAS program package pdelib for the numerical solution of partial differential equations. WIAS-HiTNIHS has been and is further developed within the project ``Numerical simulation and optimization of SiC single crystal growth by sublimation from the gas phase'' supported by the BMBF and the DFG.

Please find further information under http://www.wias-berlin.de/software/hitnihs .


WIAS-SHarP

(contact: D. Hömberg, phone: +49 30/20372-491)

Based on pdelib, WIAS-SHarP (Surface Hardening Program) is a software for the simulation of electron and laser beam surface hardening. It contains a data bank with material parameters for 20 important steels as well as routines to describe the phase transition kinetics during one heat treatment cycle. Moreover, it allows for quite general radiation flux profiles and the implementation of two independent beam traces. To facilitate its usage, a Java-based GUI has been developed.

For more information see http://www.wias-berlin.de/software/sharp .


WIAS-TeSCA

(contact: R. Nürnberg, phone: +49 30/20372-570)

WIAS-TeSCA is a Two- and three-dimensional Semi- Conductor Analysis package. It serves to simulate numerically the charge carrier transport in semiconductor devices based upon the drift-diffusion model. This van Roosbroeck system is augmented by a vast variety of additional physical phenomena playing a role in the operation of specialized semiconductor devices, as, e.g., the influence of magnetic fields, optical radiation, temperature, or the kinetics of deep (trapped) impurities.

The strategy of WIAS-TeSCA for solving the resulting highly nonlinear system of partial differential equations is oriented towards the Lyapunov structure of the system which describes the currents of electrons and holes within the device. Thus, efficient numerical procedures, for both the stationary and the transient simulation, have been implemented, the spatial structure of which is a finite volume method. The underlying finite element discretization allows the simulation of arbitrarily shaped two-dimensional device structures.

WIAS-TeSCA has been successfully used in the research and development of semiconductor devices such as transistors, diodes, sensors, detectors, and lasers.

The semiconductor device simulation package WIAS-TeSCA operates in a UNIX environment and is available for a variety of configurations as, e.g., SUN, COMPAQ, HP, SGI, but also for Linux PC.

For more information please look up:http://www.wias-berlin.de/software/tesca .


WIAS-QW

(contact: U. Bandelow, phone: +49 30/20372-471)

WIAS-QW is a numerical code for the simulation of strained multi-quantum-well structures. Based upon multiband kp models it allows to treat band mixing effects, confinement effects, crystal symmetry, and the influence of mechanical strain.

In particular, WIAS-QW calculates the

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subband dispersion;
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eigenfunctions;
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transition matrix elements;
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miniband effects in multi-quantum-well structures.

In dependence on the sheet carrier densities and the temperature, WIAS-QW calculates the

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optical response function;
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gain spectrum;
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radiative recombination rate;
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carrier density distributions.

Furthermore, the calculations can be done selfconsistently, comprising pure kp calculations, but also calculations which include the Hartree-Coulomb potential, obtained from Poisson's equation, as well as density-dependent exchange-correlation potentials, which account for the bandgap-shift--one of the most prominent many-particle effects.

Please find further information under http://www.wias-berlin.de/software/qw .



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LaTeX typesetting by I. Bremer
2004-08-13