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

702.

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

701.

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

700.

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

699.

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

698.

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

697.

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

696.

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

695.

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

694.

Gómez, P. C.; Jensen, Per
A potential energy surface for the electronic ground state of H2Te derived from experiment
Journal of Molecular Spectroscopy, 185 (2) :282-289
1997
Publisher: Academic Press

693.

G{{\'o}}mez, P. C.; Jensen, Per
A potential energy surface for the electronic ground state of H\(_{2}\)Te derived from experiment
Journal of Molecular Spectroscopy, 185 (2) :282-289
1997
Publisher: Academic Press

692.

G{{\'o}}mez, P. C.; Jensen, Per
A potential energy surface for the electronic ground state of H\(_{2}\)Te derived from experiment
Journal of Molecular Spectroscopy, 185 (2) :282-289
1997
Publisher: Academic Press

691.

Ehrgott, Matthias; Hamacher, Horst W.; Klamroth, Kathrin; Nickel, Stefan; Schöbel, Anita; Wiecek, Margaret M.
A note on the equivalence of balance points and Pareto solutions in multiple objective programming
Journal of Optimization Theory and Applications, 92 :209-212
1997

690.

Arnold, A.; Ehrhardt, M.
A New Discrete Transparent Boundary Condition for Standard and Wide Angle 'Parabolic' Equations in Underwater Acoustics
Proceedings of the Third International Conference on Theoretical and Computational Acoustics, July 14-18, 1997, Newark, New Jersey, USA, Page 623-635
1997

689.

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

688.

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

687.

Jensen, Per; Sauer, Stephan P. A.
Theoretical calculations of the hyperfine structure in the spectra of H\(_{3}\)\(^{+}\) and its deuterated isotopomers
Molecular Physics, 91 (2) :319-332
1997

686.

Schindler, J. G.; Schindler, M. M.; Herna, K.; Kling, H.-W.
Glutardialdehyde and formaldehyde biosensors
Biomed. Tech. (Berl), 42 (9) :264
1997

685.

Kozin, Igor N.; Jensen, Per
The Effects of Nonzero Total Electron Spin in the X\verb=~= \(^{3}\)B\(_{1}\) State of Methylene CH\(_{2}\)
Journal of Molecular Spectroscopy, 183 (2) :398-406
1997
Publisher: Academic Press

684.

Kozin, Igor N.; Jensen, Per
The Effects of Nonzero Total Electron Spin in the X\verb=~= \(^{3}\)B\(_{1}\) State of Methylene CH\(_{2}\)
Journal of Molecular Spectroscopy, 183 (2) :398-406
1997
Publisher: Academic Press

683.

Bludsky, Ota; Jensen, Per
The calculation of the bound and quasibound vibrational states for ozone in its 1B2 electronic state
Molecular Physics, 91 (4) :653-662
1997

682.

Bludsky, Ota; Jensen, Per
The calculation of the bound and quasibound vibrational states for ozone in its \(^{1}\)B\(_{2}\) electronic state
Molecular Physics, 91 (4) :653-662
1997

681.

Bludsky, Ota; Jensen, Per
The calculation of the bound and quasibound vibrational states for ozone in its \(^{1}\)B\(_{2}\) electronic state
Molecular Physics, 91 (4) :653-662
1997

680.

Tausch, Michael W.
Simulation von chemischen Gleichgewichten
Computer + Unterricht, 26 :35
1997

679.

Günther, Michael; Hoschek, Markus
ROW methods adapted to electric circuit simulation packages
Journal of computational and applied mathematics, 82 (1-2) :159--170
1997
Publisher: North-Holland

678.

Schryber, Jeremy H.; Polyansky, Oleg L.; Jensen, Per; Tennyson, Jonathan
On the spectroscopically determined potential energy surfaces for the electronic ground states of NO2 and H2O
Journal of Molecular Spectroscopy, 185 (2) :234-243
1997
Publisher: Academic Press

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