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



1997

741.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
A theoretical calculation of the absorption spectrum of CH\(_{2}\)\(^{+}\)
Chemical Physics, 225 (1-3) :33-54
1997
Publisher: North-Holland

740.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
A theoretical calculation of the absorption spectrum of CH\(_{2}\)\(^{+}\)
Chemical Physics, 225 (1-3) :33-54
1997
Publisher: North-Holland

739.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
A theoretical calculation of the absorption spectrum of CH2+
Chemical Physics, 225 (1-3) :33-54
1997
Publisher: North-Holland

738.

Kozin, Igor N.; Jensen, Per; Li, Yan; Buenker, Robert J.; Hirsch, Gerhard; Klee, Stefan
An ab initio calculation of the dipole moment surfaces and the vibrational transition moments of the H\(_{2}\)Te molecule
Journal of Molecular Spectroscopy, 181 (1) :108-118
1997
Publisher: Academic Press

737.

Kozin, Igor N.; Jensen, Per; Li, Yan; Buenker, Robert J.; Hirsch, Gerhard; Klee, Stefan
An ab initio calculation of the dipole moment surfaces and the vibrational transition moments of the H\(_{2}\)Te molecule
Journal of Molecular Spectroscopy, 181 (1) :108-118
1997
Publisher: Academic Press

736.

Kozin, Igor N.; Jensen, Per; Li, Yan; Buenker, Robert J.; Hirsch, Gerhard; Klee, Stefan
An ab initio calculation of the dipole moment surfaces and the vibrational transition moments of the H2Te molecule
Journal of Molecular Spectroscopy, 181 (1) :108-118
1997
Publisher: Academic Press

735.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
An ab Initio Study of the NH\(_{2}\)\(^{+}\) Absorption Spectrum
Journal of Molecular Spectroscopy, 186 (2) :319-334
1997

734.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
An ab Initio Study of the NH\(_{2}\)\(^{+}\) Absorption Spectrum
Journal of Molecular Spectroscopy, 186 (2) :319-334
1997

733.

Osmann, Gerald; Bunker, Philip R.; Jensen, Per; Kraemer, Wolfgang P.
An ab Initio Study of the NH2+ Absorption Spectrum
Journal of Molecular Spectroscopy, 186 (2) :319-334
1997

732.

Günther, Michael; Feldmann, Uwe
CAD based electric modeling in Industry
1997

731.

Spirko, Vladim{í}r; Mengel, Markus; Jensen, Per
Calculation of Rotation-Vibration Energy Levels in Ground State C\(_{3}\) by a Born-Oppenheimer-Type Separation of the Vibrational Motions
Journal of Molecular Spectroscopy, 183 (1) :129-138
1997
Publisher: Academic Press

730.

Spirko, Vladim{í}r; Mengel, Markus; Jensen, Per
Calculation of Rotation-Vibration Energy Levels in Ground State C\(_{3}\) by a Born-Oppenheimer-Type Separation of the Vibrational Motions
Journal of Molecular Spectroscopy, 183 (1) :129-138
1997
Publisher: Academic Press

729.

Spirko, Vladimír; Mengel, Markus; Jensen, Per
Calculation of Rotation-Vibration Energy Levels in Ground State C3 by a Born-Oppenheimer-Type Separation of the Vibrational Motions
Journal of Molecular Spectroscopy, 183 (1) :129-138
1997
Publisher: Academic Press

728.

Ehrgott, Matthias; Klamroth, Kathrin
Connectedness of efficient solutions in multiple criteria combinatorial optimization
European Journal of Operational Research, 97 :159-166
1997

727.


Discrete transparent boundary conditions for parabolic equations
ZAMM-Zeitschrift fur Angewandte Mathematik und Mechanik, 77 (2) :543--544
1997
Publisher: Berlin, Akademie Verlag [etc.]

726.

Ehrhardt, Matthias
Discrete transparent boundary conditions for parabolic equations
ZAMM-Zeitschrift fur Angewandte Mathematik und Mechanik, 77 (S2) :S543–S592
1997
Publisher: WILEY-VCH Verlag

725.

Kirchner, Ulf; Benter, Thorsten; Schindler, Ralph N.
Experimental verification of gas phase bromine enrichment in reactions of HOBr with sea salt doped ice surfaces
Berichte der Bunsengesellschaft für physikalische Chemie, 101 (6) :975-977
1997

724.

Kirchner, Ulf; Benter, Thorsten; Schindler, Ralph N.
Experimental verification of gas phase bromine enrichment in reactions of HOBr with sea salt doped ice surfaces
Berichte der Bunsengesellschaft für physikalische Chemie, 101 (6) :975-977
1997

723.

Kirchner, Ulf; Benter, Thorsten; Schindler, Ralph N.
Experimental verification of gas phase bromine enrichment in reactions of HOBr with sea salt doped ice surfaces
Berichte der Bunsengesellschaft für physikalische Chemie, 101 (6) :975-977
1997

722.

Fink, Ewald H.; Shestakov, Oleg; Setzer, Klaus-Dieter
Fine Structure Transitions of BiOH in the Near-Infrared Region
Journal of Molecular Spectroscopy, 183 (1) :163-167
1997
Publisher: Academic Press

721.

Fink, Ewald H.; Shestakov, Oleg; Setzer, Klaus-Dieter
Fine Structure Transitions of BiOH in the Near-Infrared Region
Journal of Molecular Spectroscopy, 183 (1) :163-167
1997
Publisher: Academic Press

720.

Fink, Ewald H.; Shestakov, Oleg; Setzer, Klaus-Dieter
Fine Structure Transitions of BiOH in the Near-Infrared Region
Journal of Molecular Spectroscopy, 183 (1) :163-167
1997
Publisher: Academic Press

719.

G{{\'o}}mez, P. C.; Pacios, L. F.; Jensen, Per
Fourfold Clusters of Rovibrational Energies in H\(_{2}\)Po Studied with an ab Initio Potential Energy Function
Journal of Molecular Spectroscopy, 186 (1) :99-104
1997
Publisher: Academic Press

718.

G{{\'o}}mez, P. C.; Pacios, L. F.; Jensen, Per
Fourfold Clusters of Rovibrational Energies in H\(_{2}\)Po Studied with an ab Initio Potential Energy Function
Journal of Molecular Spectroscopy, 186 (1) :99-104
1997
Publisher: Academic Press

717.

Gómez, P. C.; Pacios, L. F.; Jensen, Per
Fourfold Clusters of Rovibrational Energies in H2Po Studied with an ab Initio Potential Energy Function
Journal of Molecular Spectroscopy, 186 (1) :99-104
1997
Publisher: Academic Press