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



1994

491.

Breidohr, R.; Shestakov, Oleg; Fink, Ewald H.
The a \(^{3}\)\(\Sigma\)\(^{+}\) (a\(_{1}\) 1) → X \(^{1}\)\(\Sigma\)\(^{+}\) (X 0\(^{+}\)) Transitions of BiP, BiAs, and BiSb
Journal of Molecular Spectroscopy, 168 (1) :126-135
1994
Herausgeber: Academic Press

490.

Breidohr, R.; Shestakov, Oleg; Fink, Ewald H.
The a \(^{3}\)\(\Sigma\)\(^{+}\) (a\(_{1}\) 1) → X \(^{1}\)\(\Sigma\)\(^{+}\) (X 0\(^{+}\)) Transitions of BiP, BiAs, and BiSb
Journal of Molecular Spectroscopy, 168 (1) :126-135
1994
Herausgeber: Academic Press

489.

Breidohr, R.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.; Zyrnicki, W.
The a \(^{3}\)\(\Sigma\)\(_{u}\)\(^{+}\) (a\(_{1}\) 1\(_{u}\)) → X \(^{1}\)\(\Sigma\)\(_{g}\)\(^{+}\) (X 0\(_{g}\)\(^{+}\)) Transition of Bi\(_{2}\)
Journal of Molecular Spectroscopy, 166 (2) :251-263
1994
Herausgeber: Academic Press

488.

Breidohr, R.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.; Zyrnicki, W.
The a \(^{3}\)\(\Sigma\)\(_{u}\)\(^{+}\) (a\(_{1}\) 1\(_{u}\)) → X \(^{1}\)\(\Sigma\)\(_{g}\)\(^{+}\) (X 0\(_{g}\)\(^{+}\)) Transition of Bi\(_{2}\)
Journal of Molecular Spectroscopy, 166 (2) :251-263
1994
Herausgeber: Academic Press

487.

Breidohr, R.; Shestakov, Oleg; Fink, Ewald H.
The a \(^{3}\)\(\Sigma\)\(_{u}\)\(^{+}\)(a\(_{1}\) 1\(_{u}\)) → X \(^{1}\)\(\Sigma\)\(_{g}\)\(^{+}\) (X 0\(_{g}\)\(^{+}\)) transition of Sb\(_{2}\)
Chemical Physics Letters, 218 (1-2) :13-16
1994

486.

Breidohr, R.; Shestakov, Oleg; Fink, Ewald H.
The a \(^{3}\)\(\Sigma\)\(_{u}\)\(^{+}\)(a\(_{1}\) 1\(_{u}\)) → X \(^{1}\)\(\Sigma\)\(_{g}\)\(^{+}\) (X 0\(_{g}\)\(^{+}\)) transition of Sb\(_{2}\)
Chemical Physics Letters, 218 (1-2) :13-16
1994

485.

Breidohr, R.; Setzer, Klaus-Dieter; Shestakov, Oleg; Fink, Ewald H.; Zyrnicki, W.
The a 3Σu+ (a1 1u) → X 1Σg+ (X 0g+) Transition of Bi2
Journal of Molecular Spectroscopy, 166 (2) :251-263
1994
Herausgeber: Academic Press

484.

Breidohr, R.; Shestakov, Oleg; Fink, Ewald H.
The a 3Σu+(a1 1u) → X 1Σg+ (X 0g+) transition of Sb2
Chemical Physics Letters, 218 (1-2) :13-16
1994

483.

Breidohr, R.; Shestakov, Oleg; Fink, Ewald H.
The a 3Σ+ (a1 1) → X 1Σ+ (X 0+) Transitions of BiP, BiAs, and BiSb
Journal of Molecular Spectroscopy, 168 (1) :126-135
1994
Herausgeber: Academic Press

482.

Shestakov, Oleg; Fink, Ewald H.
The a\(^{1}\)\(\Delta\)(a2) state of BiF
Chemical Physics Letters, 229 (3) :273-278
1994

481.

Shestakov, Oleg; Fink, Ewald H.
The a\(^{1}\)\(\Delta\)(a2) state of BiF
Chemical Physics Letters, 229 (3) :273-278
1994

480.

Shestakov, Oleg; Fink, Ewald H.
The a1Δ(a2) state of BiF
Chemical Physics Letters, 229 (3) :273-278
1994

479.

Tashkun, Sergey A.; Jensen, Per
The low-energy part of the potential function for the electronic ground state of NO\(_{2}\) derived from experiment
Journal of Molecular Spectroscopy, 165 (1) :173-184
1994
Herausgeber: Academic Press

478.

Tashkun, Sergey A.; Jensen, Per
The low-energy part of the potential function for the electronic ground state of NO\(_{2}\) derived from experiment
Journal of Molecular Spectroscopy, 165 (1) :173-184
1994
Herausgeber: Academic Press

477.

Tashkun, Sergey A.; Jensen, Per
The low-energy part of the potential function for the electronic ground state of NO2 derived from experiment
Journal of Molecular Spectroscopy, 165 (1) :173-184
1994
Herausgeber: Academic Press

476.

Jensen, Per; Bunker, Philip R.
The Molecular Symmetry Group for Molecules in High Angular Momentum States
Journal of Molecular Spectroscopy, 164 (1) :315-317
1994
Herausgeber: Academic Press

475.

Jensen, Per; Bunker, Philip R.
The Molecular Symmetry Group for Molecules in High Angular Momentum States
Journal of Molecular Spectroscopy, 164 (1) :315-317
1994
Herausgeber: Academic Press

474.

Jensen, Per; Bunker, Philip R.
The Molecular Symmetry Group for Molecules in High Angular Momentum States
Journal of Molecular Spectroscopy, 164 (1) :315-317
1994
Herausgeber: Academic Press

473.

Bednarek, G.; Wayne, R.P.; Wildt, J{ü}rgen; Fink, E.H.
The yield of O\(_{2}\)(b \(^{1}\)\(\Sigma\)\(_{g}\)\(^{+}\), v=0) produced by quenching of O\(_{2}\)(A \(^{3}\)\(\Sigma\)\(_{u}\)\(^{+}\), v=8) by O\(_{2}\)
Chemical Physics, 185 (2) :251-261
1994

472.

Bednarek, G.; Wayne, R.P.; Wildt, J{ü}rgen; Fink, E.H.
The yield of O\(_{2}\)(b \(^{1}\)\(\Sigma\)\(_{g}\)\(^{+}\), v=0) produced by quenching of O\(_{2}\)(A \(^{3}\)\(\Sigma\)\(_{u}\)\(^{+}\), v=8) by O\(_{2}\)
Chemical Physics, 185 (2) :251-261
1994

471.

Bednarek, G.; Wayne, R.P.; Wildt, Jürgen; Fink, E.H.
The yield of O2(b 1Σg+, v=0) produced by quenching of O2(A 3Σu+, v=8) by O2
Chemical Physics, 185 (2) :251-261
1994

470.

Auwera, J. Vander; Holland, J. K.; Jensen, Per; Johns, John W. C.
The ν6 band system of C3O2 near 540 cm-1
Journal of Molecular Spectroscopy, 163 (2) :529-540
1994
Herausgeber: Academic Press
1993

469.

Graf, J.; Jensen, Per
A Theoretical Model for the Rotation and Vibration of Symmetrical Triatomic Molecules with Strong Coupling Between the Local Stretching Modes
Journal of Molecular Spectroscopy, 159 (1) :175-191
1993
Herausgeber: Academic Press

468.

Graf, J.; Jensen, Per
A Theoretical Model for the Rotation and Vibration of Symmetrical Triatomic Molecules with Strong Coupling Between the Local Stretching Modes
Journal of Molecular Spectroscopy, 159 (1) :175-191
1993
Herausgeber: Academic Press

467.

Graf, J.; Jensen, Per
A Theoretical Model for the Rotation and Vibration of Symmetrical Triatomic Molecules with Strong Coupling Between the Local Stretching Modes
Journal of Molecular Spectroscopy, 159 (1) :175-191
1993
Herausgeber: Academic Press