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



1992

378.

Benter, Thorsten; Becker, Eilhard; Wille, Uta; Rahman, M. M.; Schindler, Ralph N.
The Determination of Rate Constants for the Reactions of Some Alkenes with the NO\(_{3}\) Radical
Berichte der Bunsengesellschaft für physikalische Chemie, 96 (6) :769-775
1992

377.

Benter, Thorsten; Becker, Eilhard; Wille, Uta; Rahman, M. M.; Schindler, Ralph N.
The Determination of Rate Constants for the Reactions of Some Alkenes with the NO3 Radical
Berichte der Bunsengesellschaft für physikalische Chemie, 96 (6) :769-775
1992

376.

Ziebarth, K.; Breidohr, R.; Shestakov, Oleg; Fink, Ewald H.
The X\(_{2}\) \(^{2}\)\(\Pi\)\(_{3/2}\) → X\(_{1}\) \(^{2}\)\(\Pi\)\(_{1/2}\) electronic band systems of lead monohalides in the near infrared
Chemical Physics Letters, 190 (3-4) :271-278
1992

375.

Ziebarth, K.; Breidohr, R.; Shestakov, Oleg; Fink, Ewald H.
The X\(_{2}\) \(^{2}\)\(\Pi\)\(_{3/2}\) → X\(_{1}\) \(^{2}\)\(\Pi\)\(_{1/2}\) electronic band systems of lead monohalides in the near infrared
Chemical Physics Letters, 190 (3-4) :271-278
1992

374.

Ziebarth, K.; Breidohr, R.; Shestakov, Oleg; Fink, Ewald H.
The X2 2Π3/2 → X1 2Π1/2 electronic band systems of lead monohalides in the near infrared
Chemical Physics Letters, 190 (3-4) :271-278
1992

373.

Barone, Vincenzo; Jensen, Per; Minichino, Camilla
Vibro-rotational analysis of Si\(_{2}\)C from an ab initio potential energy surface. A comparison between perturbative and variational methods
Journal of Molecular Spectroscopy, 154 (2) :252-264
1992

372.

Barone, Vincenzo; Jensen, Per; Minichino, Camilla
Vibro-rotational analysis of Si\(_{2}\)C from an ab initio potential energy surface. A comparison between perturbative and variational methods
Journal of Molecular Spectroscopy, 154 (2) :252-264
1992

371.

Barone, Vincenzo; Jensen, Per; Minichino, Camilla
Vibro-rotational analysis of Si2C from an ab initio potential energy surface. A comparison between perturbative and variational methods
Journal of Molecular Spectroscopy, 154 (2) :252-264
1992
1991

370.

Fink, Ewald H.; Setzer, Klaus-Dieter; Ramsay, D. A.; Vervloet, M.
A new band spectrum of BiO in the near-infrared region
Chemical Physics Letters, 179 (1-2) :103-108
1991

369.

Fink, Ewald H.; Setzer, Klaus-Dieter; Ramsay, D. A.; Vervloet, M.
A new band spectrum of BiO in the near-infrared region
Chemical Physics Letters, 179 (1-2) :103-108
1991

368.

Fink, Ewald H.; Setzer, Klaus-Dieter; Ramsay, D. A.; Vervloet, M.
A new band spectrum of BiO in the near-infrared region
Chemical Physics Letters, 179 (1-2) :103-108
1991

367.

Becker, Eilhard; Benter, Thorsten; Kampf, R.; Schindler, Ralph N.; Wille, Uta
A Redetermination of the Rate Constant of the Reaction F + HNO\(_{3}\) → HF + NO\(_{3}\)
Berichte der Bunsengesellschaft für physikalische Chemie, 95 (10) :1168-1173
1991

366.

Becker, Eilhard; Benter, Thorsten; Kampf, R.; Schindler, Ralph N.; Wille, Uta
A Redetermination of the Rate Constant of the Reaction F + HNO\(_{3}\) → HF + NO\(_{3}\)
Berichte der Bunsengesellschaft für physikalische Chemie, 95 (10) :1168-1173
1991

365.

Becker, Eilhard; Benter, Thorsten; Kampf, R.; Schindler, Ralph N.; Wille, Uta
A Redetermination of the Rate Constant of the Reaction F + HNO3 → HF + NO3
Berichte der Bunsengesellschaft für physikalische Chemie, 95 (10) :1168-1173
1991

364.

Jensen, Per; Bunker, Philip R.; Karpfen, Alfred
An ab initio calculation of the nonadiabatic effect on the tunneling splitting in vibrationally excited (HF)\(_{2}\)
Journal of Molecular Spectroscopy, 148 (2) :385-390
1991

363.

Jensen, Per; Bunker, Philip R.; Karpfen, Alfred
An ab initio calculation of the nonadiabatic effect on the tunneling splitting in vibrationally excited (HF)\(_{2}\)
Journal of Molecular Spectroscopy, 148 (2) :385-390
1991

362.

Jensen, Per; Bunker, Philip R.; Karpfen, Alfred
An ab initio calculation of the nonadiabatic effect on the tunneling splitting in vibrationally excited (HF)2
Journal of Molecular Spectroscopy, 148 (2) :385-390
1991

361.

Jensen, Per; Marshall, Mark D.; Bunker, Philip R.; Karpfen, Alfred
An ab initio close-coupling calculation of the lower vibrational energies of the HCl dimer
Chemical Physics Letters, 180 (6) :594-600
1991

360.

Jensen, Per; Marshall, Mark D.; Bunker, Philip R.; Karpfen, Alfred
An ab initio close-coupling calculation of the lower vibrational energies of the HCl dimer
Chemical Physics Letters, 180 (6) :594-600
1991

359.

Jensen, Per; Marshall, Mark D.; Bunker, Philip R.; Karpfen, Alfred
An ab initio close-coupling calculation of the lower vibrational energies of the HCl dimer
Chemical Physics Letters, 180 (6) :594-600
1991

358.

Marshall, Mark D.; Jensen, Per; Bunker, Philip R.
An ab initio close-coupling calculation of the lower vibrational energies of the HF dimer
Chemical Physics Letters, 176 (3-4) :255-260
1991

357.

Marshall, Mark D.; Jensen, Per; Bunker, Philip R.
An ab initio close-coupling calculation of the lower vibrational energies of the HF dimer
Chemical Physics Letters, 176 (3-4) :255-260
1991

356.

Marshall, Mark D.; Jensen, Per; Bunker, Philip R.
An ab initio close-coupling calculation of the lower vibrational energies of the HF dimer
Chemical Physics Letters, 176 (3-4) :255-260
1991

355.

Karpfen, Alfred; Bunker, Philip R.; Jensen, Per
An ab initio study of the hydrogen chloride dimer: the potential energy surface and the characterization of the stationary points
Chemical Physics, 149 (3) :299-309
1991

354.

Karpfen, Alfred; Bunker, Philip R.; Jensen, Per
An ab initio study of the hydrogen chloride dimer: the potential energy surface and the characterization of the stationary points
Chemical Physics, 149 (3) :299-309
1991