Applied and Computational Mathematics (ACM)

Model Order Reduction

Model Order Reduction (MOR) is the art of reducing a system's complexity while preserving its input-output behavior as much as possible.

Processes in all fields of todays technological world, like physics, chemistry and electronics, but also in finance, are very often described by dynamical systems. With the help of these dynamical systems, computer simulations, i.e. virtual experiments, are carried out. In this way, new products can be designed without having to build costly prototyps.

Due to the demand of more and more realistic simulations, the dynamical systems, i.e., the mathematical models, have to reflect more and more details of the real world problem. By this, the models' dimensions are increasing and simulations can often be carried out at high computational cost only.

In the design process, however, results are needed quickly. In circuit design, e.g., structures may need to be changed or parameters may need to be altered, in order to satisfy design rules or meet the prescribed performance. One cannot afford idle time, waiting for long simulation runs to be ready.

Model Order Reduction allows to speed up simulations in cases where one is not interested in all details of a system but merely in its input-output behavior. That means, considering a system, one may ask:

  • How do varying parameters influence certain performances ?
    Using the example of circuit design: How do widths and lengths of transistor channels, e.g., influence the voltage gain of a circuit.
  • Is a system stable?
    Using the example of circuit design: In which frequency range, e.g., of voltage sources, does the circuit perform as expected
  • How do coupled subproblems interact?
    Using the example of circuit design: How are signals applied at input-terminals translated to output-pins?

Classical situations in circuit design, where one does not need to know internals of blocks are optimization of design parameters (widths, lengths, ...) and post layout simulations and full system verifications. In the latter two cases, systems of coupled models are considered. In post layout simulations one has to deal with artificial, parasitic circuits, describing wiring effects.

Model Order Reduction automatically captures the essential features of a structure, omitting information which are not decisive for the answer to the above questions. Model Order reduction replaces in this way a dynamical system with another dynamical system producing (almost) the same output, given the same input with less internal states.

MOR replaces high dimensional (e.g. millions of degrees of freedom) with low dimensional (e.g. a hundred of degrees of freedom ) problems, that are then used instead in the numerical simulation.

The working group "Applied Mathematics/Numerical Analysis" has gathered expertise in MOR, especially in circuit design. Within the EU-Marie Curie Initial Training Network COMSON, attention was concentrated on MOR for Differential Algebraic Equations. Members that have been working on MOR in the EU-Marie Curie Transfer of Knowledge project O-MOORE-NICE! gathered knowledge especially in the still immature field of MOR for nonlinear problems.

Current research topics include:

  • MOR for nonlinear, parameterized problems
  • structure preserving MOR
  • MOR for Differential Algebraic Equations
  • MOR in financial applications, i.e., option prizing

Group members working on that field

  • Jan ter Maten
  • Roland Pulch

Publications



1996

641.

Beutel, M.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
The a\(^{1}\)\(\Delta\) → X\(^{3}\)\(\Sigma\)\(^{-}\) Transitions of AsH and AsD
Journal of Molecular Spectroscopy, 178 (2) :165-171
1996
Herausgeber: Academic Press

640.

Beutel, M.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
The a\(^{1}\)\(\Delta\) → X\(^{3}\)\(\Sigma\)\(^{-}\) Transitions of AsH and AsD
Journal of Molecular Spectroscopy, 178 (2) :165-171
1996
Herausgeber: Academic Press

639.

Beutel, M.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
The a\(^{1}\)\(\Delta\) → X\(^{3}\)\(\Sigma\)\(^{-}\) transitions of PH and PD
Chemical Physics Letters, 249 (3-4) :183-190
1996

638.

Beutel, M.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
The a\(^{1}\)\(\Delta\) → X\(^{3}\)\(\Sigma\)\(^{-}\) transitions of PH and PD
Chemical Physics Letters, 249 (3-4) :183-190
1996

637.

Beutel, M.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
The a\(^{1}\)\(\Delta\)(a2) → X\(^{3}\)\(\Sigma\)\(^{-}\)(X\(_{2}\)1) Transitions of SbH and SbD
Journal of Molecular Spectroscopy, 179 (1) :79-84
1996
Herausgeber: Academic Press

636.

Beutel, M.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
The a\(^{1}\)\(\Delta\)(a2) → X\(^{3}\)\(\Sigma\)\(^{-}\)(X\(_{2}\)1) Transitions of SbH and SbD
Journal of Molecular Spectroscopy, 179 (1) :79-84
1996
Herausgeber: Academic Press

635.

Beutel, M.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
The a\(^{1}\)\(\Delta\)(a2) States of BiCl, BiBr, and BiI
Journal of Molecular Spectroscopy, 175 (1) :48-53
1996
Herausgeber: Academic Press

634.

Beutel, M.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
The a\(^{1}\)\(\Delta\)(a2) States of BiCl, BiBr, and BiI
Journal of Molecular Spectroscopy, 175 (1) :48-53
1996
Herausgeber: Academic Press

633.

Beutel, M.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
The a1Δ → X3Σ- Transitions of AsH and AsD
Journal of Molecular Spectroscopy, 178 (2) :165-171
1996
Herausgeber: Academic Press

632.

Beutel, M.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
The a1Δ → X3Σ- transitions of PH and PD
Chemical Physics Letters, 249 (3-4) :183-190
1996

631.

Beutel, M.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
The a1Δ(a2) → X3Σ-(X21) Transitions of SbH and SbD
Journal of Molecular Spectroscopy, 179 (1) :79-84
1996
Herausgeber: Academic Press

630.

Beutel, M.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.
The a1Δ(a2) States of BiCl, BiBr, and BiI
Journal of Molecular Spectroscopy, 175 (1) :48-53
1996
Herausgeber: Academic Press

629.

Günther, Michael; Rentrop, Peter
The differential-algebraic index concept in electric circuit simulation
, Proceedings of the 3rd International Congress on Industrial and Applied MathematicsBand76, Seite 91–94
Herausgeber: Akademie Verlag Berlin
1996

628.


The differential-algebraic index concept in electric circuit simulation
Zeitschrift fur angewandte Mathematik und Mechanik, 76 (1) :91--94
1996

627.

Denk, Georg; Günther, Michael
The influence of MOSFET model and network equations on circuit simulation
Preprint (1842)
1996
Herausgeber: Technische Hochschule Darmstadt

626.

Polyansky, Oleg L.; Jensen, Per; Tennyson, Jonathan
The potential energy surface of H\(_{2}\)\(^{16}\)O
Journal of Chemical Physics, 105 (15) :6490-6497
1996

625.

Polyansky, Oleg L.; Jensen, Per; Tennyson, Jonathan
The potential energy surface of H\(_{2}\)\(^{16}\)O
Journal of Chemical Physics, 105 (15) :6490-6497
1996

624.

Polyansky, Oleg L.; Jensen, Per; Tennyson, Jonathan
The potential energy surface of H216O
Journal of Chemical Physics, 105 (15) :6490-6497
1996

623.

Polyansky, Oleg L.; Jensen, Per; Tennyson, Jonathan
The Potential Energy Surface of Hydrogen Sulfide
Journal of Molecular Spectroscopy, 178 (2) :184-188
1996
Herausgeber: Academic Press

622.

Polyansky, Oleg L.; Jensen, Per; Tennyson, Jonathan
The Potential Energy Surface of Hydrogen Sulfide
Journal of Molecular Spectroscopy, 178 (2) :184-188
1996
Herausgeber: Academic Press

621.

Polyansky, Oleg L.; Jensen, Per; Tennyson, Jonathan
The Potential Energy Surface of Hydrogen Sulfide
Journal of Molecular Spectroscopy, 178 (2) :184-188
1996
Herausgeber: Academic Press

620.

Kozin, Igor N.; Jensen, Per; Polanz, Oliver; Klee, Stefan; Poteau, Laurent; Demaison, Jean
The Rotational Spectrum of H\(_{2}\)Te
Journal of Molecular Spectroscopy, 180 (2) :402-413
1996
Herausgeber: Academic Press

619.

Kozin, Igor N.; Jensen, Per; Polanz, Oliver; Klee, Stefan; Poteau, Laurent; Demaison, Jean
The Rotational Spectrum of H\(_{2}\)Te
Journal of Molecular Spectroscopy, 180 (2) :402-413
1996
Herausgeber: Academic Press

618.

Kozin, Igor N.; Jensen, Per; Polanz, Oliver; Klee, Stefan; Poteau, Laurent; Demaison, Jean
The Rotational Spectrum of H2Te
Journal of Molecular Spectroscopy, 180 (2) :402-413
1996
Herausgeber: Academic Press

617.

Bunker, Philip R.; Jensen, Per; Yamaguchi, Yukio; Schaefer III, Henry F.
The Rovibrational Energy Levels of Quasilinear c\verb=~= \(^{1}\)A\(_{1}\) Methylene
Journal of Molecular Spectroscopy, 179 (2) :263-268
1996
Herausgeber: Academic Press