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



1999

816.

Bunker, Philip R.; Jensen, Per
Spherical top molecules and the molecular symmetry group
Molecular Physics, 97 (1-2) :255-264
1999

815.

Bunker, Philip R.; Jensen, Per
Spherical top molecules and the molecular symmetry group
Molecular Physics, 97 (1-2) :255-264
1999

814.

Bunker, Philip R.; Jensen, Per
Spherical top molecules and the molecular symmetry group
Molecular Physics, 97 (1-2) :255-264
1999

813.

Foster, Krishna L.; Caldwell, Tracy E.; Benter, Thorsten; Langer, Sarka; Hemminger, John C.; Finlayson-Pitts, Barbara J.
Techniques for quantifying gaseous HOCl using atmospheric pressure ionization mass spectrometry
Physical Chemistry Chemical Physics, 1 (24) :5615-5621
1999

812.

Foster, Krishna L.; Caldwell, Tracy E.; Benter, Thorsten; Langer, Sarka; Hemminger, John C.; Finlayson-Pitts, Barbara J.
Techniques for quantifying gaseous HOCl using atmospheric pressure ionization mass spectrometry
Physical Chemistry Chemical Physics, 1 (24) :5615-5621
1999

811.

Foster, Krishna L.; Caldwell, Tracy E.; Benter, Thorsten; Langer, Sarka; Hemminger, John C.; Finlayson-Pitts, Barbara J.
Techniques for quantifying gaseous HOCl using atmospheric pressure ionization mass spectrometry
Physical Chemistry Chemical Physics, 1 (24) :5615-5621
1999

810.

Beutel, M.; Setzer, Klaus-Dieter; Fink, Ewald H.
The b\(^{1}\)\(\Sigma\)\(^{+}\)(b0\(^{+}\)) → X\(^{3}\)\(\Sigma\)\(^{-}\)(X\(_{1}\)0\(^{+}\), X\(_{2}\)1) and a\(^{1}\)\(\Delta\)(a2) → X\(_{2}\)1 Transitions of AsI
Journal of Molecular Spectroscopy, 194 (2) :250-255
1999
Publisher: Academic Press

809.

Beutel, M.; Setzer, Klaus-Dieter; Fink, Ewald H.
The b\(^{1}\)\(\Sigma\)\(^{+}\)(b0\(^{+}\)) → X\(^{3}\)\(\Sigma\)\(^{-}\)(X\(_{1}\)0\(^{+}\), X\(_{2}\)1) and a\(^{1}\)\(\Delta\)(a2) → X\(_{2}\)1 Transitions of AsI
Journal of Molecular Spectroscopy, 194 (2) :250-255
1999
Publisher: Academic Press

808.

Beutel, M.; Setzer, Klaus-Dieter; Fink, Ewald H.
The b\(^{1}\)\(\Sigma\)\(^{+}\)(b0\(^{+}\)) → X\(^{3}\)\(\Sigma\)\(^{-}\)(X\(_{1}\)0\(^{+}\), X\(_{2}\)1) and a\(^{1}\)\(\Delta\)(a2) → X\(_{2}\)1 transitions of SbF, SbCl, SbBr, and SbI
Journal of Molecular Spectroscopy, 195 (1) :147-153
1999
Publisher: Academic Press

807.

Beutel, M.; Setzer, Klaus-Dieter; Fink, Ewald H.
The b\(^{1}\)\(\Sigma\)\(^{+}\)(b0\(^{+}\)) → X\(^{3}\)\(\Sigma\)\(^{-}\)(X\(_{1}\)0\(^{+}\), X\(_{2}\)1) and a\(^{1}\)\(\Delta\)(a2) → X\(_{2}\)1 transitions of SbF, SbCl, SbBr, and SbI
Journal of Molecular Spectroscopy, 195 (1) :147-153
1999
Publisher: Academic Press

806.

Beutel, M.; Setzer, Klaus-Dieter; Fink, Ewald H.
The b1Σ+(b0+) → X3Σ-(X10+, X21) and a1Δ(a2) → X21 Transitions of AsI
Journal of Molecular Spectroscopy, 194 (2) :250-255
1999
Publisher: Academic Press

805.

Beutel, M.; Setzer, Klaus-Dieter; Fink, Ewald H.
The b1Σ+(b0+) → X3Σ-(X10+, X21) and a1Δ(a2) → X21 transitions of SbF, SbCl, SbBr, and SbI
Journal of Molecular Spectroscopy, 195 (1) :147-153
1999
Publisher: Academic Press

804.

Bunker, Philip R.; Bludsk{{\'y}}, Ota; Jensen, Per; Wesolowski, Steven S.; Van Huis, T. J.; Yamaguchi, Yukio; Schaefer, Henry F.
The H\(_{2}\)O\(^{++}\) Ground State Potential Energy Surface
Journal of Molecular Spectroscopy, 198 (2) :371-375
1999

803.

Bunker, Philip R.; Bludsk{{\'y}}, Ota; Jensen, Per; Wesolowski, Steven S.; Van Huis, T. J.; Yamaguchi, Yukio; Schaefer, Henry F.
The H\(_{2}\)O\(^{++}\) Ground State Potential Energy Surface
Journal of Molecular Spectroscopy, 198 (2) :371-375
1999

802.

Bunker, Philip R.; Bludský, Ota; Jensen, Per; Wesolowski, Steven S.; Van Huis, T. J.; Yamaguchi, Yukio; Schaefer, Henry F.
The H2O++ Ground State Potential Energy Surface
Journal of Molecular Spectroscopy, 198 (2) :371-375
1999

801.

Becker, Karl Heinz; Freitas Dinis, Carlos M.; Geiger, Harald; Wiesen, Peter
The reactions of OH radicals with di-i-propoxymethane and di-sec-butoxymethane: Kinetic measurements and structure activity relationships
Physical Chemistry Chemical Physics, 1 (20) :4721-4726
1999

800.

Becker, Karl Heinz; Freitas Dinis, Carlos M.; Geiger, Harald; Wiesen, Peter
The reactions of OH radicals with di-i-propoxymethane and di-sec-butoxymethane: Kinetic measurements and structure activity relationships
Physical Chemistry Chemical Physics, 1 (20) :4721-4726
1999

799.

Becker, Karl Heinz; Freitas Dinis, Carlos M.; Geiger, Harald; Wiesen, Peter
The reactions of OH radicals with di-i-propoxymethane and di-sec-butoxymethane: Kinetic measurements and structure activity relationships
Physical Chemistry Chemical Physics, 1 (20) :4721-4726
1999

798.

Gänsheimer, S; Schilling, A
Verbesserte prätherapeutische Abschätzung des pathologischen Tumorstadiums des Prostatakarzinoms anhand eines neuen Punktsystems
Aktuelle Urologie, 30 (01) :20--27
1999
Publisher: Georg Thieme Verlag Stuttgart{\textperiodcentered} New York

797.

[german] Tausch, Michael W.; Schmidt, Andrea
β-Carotin - ein Multitalent
CHEMKON, 6 (3) :135--141
1999
Publisher: Wiley
1998

796.

Tausch, Michael W.; Lowin, P.; Übel, M.
''Materialien-Manager Chemie'' Multimedia CD-ROM zur Erstellung von Arbeitsmaterialien für den Chemieunterricht
Publisher: C. C. Buchner, Bamberg
1998

795.

Tausch, Michael W.; Wachtendonk, M.; Porth, H.-R.; Schulze, I.; Wambach, H.
''STOFF-FORMEL-UMWELT'', CHEMIE S I, 7. Schjg. in NRW
Publisher: C. C. Buchner, Bamberg
1998

794.

Jacob, Birgit
A formula for the stability radius of time-varying systems
J. Differential Equations, 142 (1) :167--187
1998

793.

Feldmann, Uwe
CAD-based electric-circuit modeling in industry II: Impact of circuit configurations and parameters
Surveys on Mathematics for Industry, 8 (2) :131--158
1998
Publisher: Wien; New York: Springer-Verlag, 1991-c2005.

792.

Jacob, Birgit; Larsen, Mikael; Zwart, Hans
Corrections and extensions of: ``Optimal control of linear systems with almost periodic inputs" [SIAM J. Control Optim. \bf 25 (1987), no. 4, 1007--1019; MR0893995 (88i:93042)] by G. Da Prato and A. Ichikawa
SIAM J. Control Optim., 36 (4) :1473--1480
1998