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

616.

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

615.

Bunker, Philip R.; Jensen, Per; Yamaguchi, Yukio; Schaefer III, Henry F.
The Rovibrational Energy Levels of Quasilinear c~ 1A1 Methylene
Journal of Molecular Spectroscopy, 179 (2) :263-268
1996
Herausgeber: Academic Press

614.

Arste, J.; Klamroth, Kathrin; Mengersen, Ingrid
Three color Ramsey numbers for small graphs
Utilitas Mathematica, 49 :85--96
1996

613.

[german] Tausch, Michael W.
Ungleiche Gleichgewichte
{CHEMKON}, 3 (3) :123--127
1996
Herausgeber: Wiley
1995

612.

Mengel, Markus; Jensen, Per
A Theoretical Study of the Stark Effect in Triatomic Molecules: Application to H\(_{2}\)O
Journal of Molecular Spectroscopy, 169 (1) :73-91
1995
Herausgeber: Academic Press

611.

Mengel, Markus; Jensen, Per
A Theoretical Study of the Stark Effect in Triatomic Molecules: Application to H\(_{2}\)O
Journal of Molecular Spectroscopy, 169 (1) :73-91
1995
Herausgeber: Academic Press

610.

Mengel, Markus; Jensen, Per
A Theoretical Study of the Stark Effect in Triatomic Molecules: Application to H2O
Journal of Molecular Spectroscopy, 169 (1) :73-91
1995
Herausgeber: Academic Press

609.

Jensen, Per; Brumm, Martin; Kraemer, Wolfgang P.; Bunker, Philip R.
A Treatment of the Renner Effect Using the MORBID Hamiltonian
Journal of Molecular Spectroscopy, 171 (1) :31-57
1995
Herausgeber: Academic Press

608.

Jensen, Per; Brumm, Martin; Kraemer, Wolfgang P.; Bunker, Philip R.
A Treatment of the Renner Effect Using the MORBID Hamiltonian
Journal of Molecular Spectroscopy, 171 (1) :31-57
1995
Herausgeber: Academic Press

607.

Jensen, Per; Brumm, Martin; Kraemer, Wolfgang P.; Bunker, Philip R.
A Treatment of the Renner Effect Using the MORBID Hamiltonian
Journal of Molecular Spectroscopy, 171 (1) :31-57
1995
Herausgeber: Academic Press

606.

Jensen, Per; Brumm, Martin; Kraemer, Wolfgang P.; Bunker, Philip R.
An ab Initio Calculation of the Rovibronic Energies of the CH\(_{2}\)\(^{+}\) Molecule
Journal of Molecular Spectroscopy, 172 (1) :194-204
1995
Herausgeber: Academic Press

605.

Jensen, Per; Brumm, Martin; Kraemer, Wolfgang P.; Bunker, Philip R.
An ab Initio Calculation of the Rovibronic Energies of the CH\(_{2}\)\(^{+}\) Molecule
Journal of Molecular Spectroscopy, 172 (1) :194-204
1995
Herausgeber: Academic Press

604.

Jensen, Per; Brumm, Martin; Kraemer, Wolfgang P.; Bunker, Philip R.
An ab Initio Calculation of the Rovibronic Energies of the CH2+ Molecule
Journal of Molecular Spectroscopy, 172 (1) :194-204
1995
Herausgeber: Academic Press

603.

Gerstberger, R.; Günther, M.
Charge-oriented extrapolation methods in digital circuit simulation
Applied Numerical Mathematics, 18 (1) :115–125
1995
Herausgeber: Elsevier

602.

Gerstberger, Robert; Günther, Michael
Charge-oriented extrapolation methods in digital circuit simulation
Applied numerical mathematics, 18 (1-3) :115--125
1995
Herausgeber: North-Holland

601.

Flaud, Jean-Marie; Camy-Peyret, C.; B{ü}rger, H.; Jensen, Per; Kozin, Igor N.
Experimental evidence for the formation of fourfold rovibrational energy clusters in the \(\nu\)\(_{1}\)/\(\nu\)\(_{3}\) vibrational states of H\(_{2}\)\(^{80}\)Se
Journal of Molecular Spectroscopy, 172 (1) :126-134
1995
Herausgeber: Academic Press

600.

Flaud, Jean-Marie; Camy-Peyret, C.; B{ü}rger, H.; Jensen, Per; Kozin, Igor N.
Experimental evidence for the formation of fourfold rovibrational energy clusters in the \(\nu\)\(_{1}\)/\(\nu\)\(_{3}\) vibrational states of H\(_{2}\)\(^{80}\)Se
Journal of Molecular Spectroscopy, 172 (1) :126-134
1995
Herausgeber: Academic Press

599.

Flaud, Jean-Marie; Camy-Peyret, C.; Bürger, H.; Jensen, Per; Kozin, Igor N.
Experimental evidence for the formation of fourfold rovibrational energy clusters in the ν1/ν3 vibrational states of H280Se
Journal of Molecular Spectroscopy, 172 (1) :126-134
1995
Herausgeber: Academic Press

598.

Heilmann, Margareta
Explicit Voronovskaja-type results for linear combinations of BDT-operators
Approximation Theory and its Applications, 11 (1) :54-61
1995

597.

Ehrhardt, M.
Finite Differenzenverfahren für hyperbolische Systeme mit absorbierenden Randbedingungen
Technische Universität Berlin
1995

596.

Jensen, Per; Li, Yan; Hirsch, Gerhard; Buenker, Robert J.; Lee, Timothy J.; Kozin, Igor N.
Fourfold clusters of rovibrational energies in H\(_{2}\)Te studied with an ab initio potential energy function
Chemical Physics, 190 (2-3) :179-189
1995

595.

Jensen, Per; Li, Yan; Hirsch, Gerhard; Buenker, Robert J.; Lee, Timothy J.; Kozin, Igor N.
Fourfold clusters of rovibrational energies in H\(_{2}\)Te studied with an ab initio potential energy function
Chemical Physics, 190 (2-3) :179-189
1995

594.

Jensen, Per; Li, Yan; Hirsch, Gerhard; Buenker, Robert J.; Lee, Timothy J.; Kozin, Igor N.
Fourfold clusters of rovibrational energies in H2Te studied with an ab initio potential energy function
Chemical Physics, 190 (2-3) :179-189
1995

593.

Breidohr, R.; Shestakov, Oleg; Setzer, Klaus-Dieter; Fink, Ewald H.
High-Resolution Study of the a \(^{3}\)\(\Sigma\)\(^{+}\) (a\(_{1}\) 1) → X \(^{1}\)\(\Sigma\)\(^{+}\) (X 0\(^{+}\)) Transitions of BiP and BiAs
Journal of Molecular Spectroscopy, 172 (2) :369-377
1995
Herausgeber: Academic Press

592.

Breidohr, R.; Shestakov, Oleg; Setzer, Klaus-Dieter; Fink, Ewald H.
High-Resolution Study of the a \(^{3}\)\(\Sigma\)\(^{+}\) (a\(_{1}\) 1) → X \(^{1}\)\(\Sigma\)\(^{+}\) (X 0\(^{+}\)) Transitions of BiP and BiAs
Journal of Molecular Spectroscopy, 172 (2) :369-377
1995
Herausgeber: Academic Press