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

866.

Osmann, Gerald; Bunker, Philip R.; Kraemer, Wolfgang P.; Jensen, Per
Coulomb explosion imaging and the CH2+ molecule
Chemical Physics Letters, 309 (3-4) :299-306
1999

865.

Korn, Silke; Eisel, Christian; Tausch, Michael W.
Das leuchtende Labor
{CHEMKON}, 6 (3) :142--142
1999
Publisher: Wiley

864.

Tyuterev, Vladimir G.; Tashkun, Sergey A.; Jensen, Per; Barbe, Alain; Cours, T.
Determination of the Effective Ground State Potential Energy Function of Ozone from High-Resolution Infrared Spectra
Journal of Molecular Spectroscopy, 198 (1) :57-76
1999

863.

Tyuterev, Vladimir G.; Tashkun, Sergey A.; Jensen, Per; Barbe, Alain; Cours, T.
Determination of the Effective Ground State Potential Energy Function of Ozone from High-Resolution Infrared Spectra
Journal of Molecular Spectroscopy, 198 (1) :57-76
1999

862.

Tyuterev, Vladimir G.; Tashkun, Sergey A.; Jensen, Per; Barbe, Alain; Cours, T.
Determination of the Effective Ground State Potential Energy Function of Ozone from High-Resolution Infrared Spectra
Journal of Molecular Spectroscopy, 198 (1) :57-76
1999

861.

Ehrhardt, Matthias
Discrete transparent boundary conditions for general Schrödinger-type equations
VLSI Design, 9 (4) :325–338
1999
Publisher: Hindawi Publishing

860.


Discrete transparent boundary conditions for general Schrödinger-type equations
Computer Physics Communications, 121 (4) :598--598
1999
Publisher: Hindawi

859.

[german] Tausch, Michael W.; Grolmuss, A.
Ein low-cost Selbstbau-Spektroskop
Praxis der Naturwissenschaften (Chemie), 48 (7) :36
1999

858.

Zwart, Hans; Jacob, Birgit
Equivalent conditions for stabilizability of infinite-dimensional systems with admissible control operators
SIAM J. Control Optim., 37 (5) :1419--1455
1999

857.

Chudej, Kurt; Günther, Michael
Global state space approach for the efficient numerical solution of state-constrained trajectory optimization problems
Journal of optimization theory and applications, 103 :75--93
1999
Publisher: Kluwer Academic Publishers-Plenum Publishers

856.

Kleffmann, Jörg; Becker, Karl Heinz; Lackhoff, Marion; Wiesen, Peter
Heterogeneous conversion of NO\(_{2}\) on carbonaceous surfaces
Physical Chemistry Chemical Physics, 1 (24) :5443-5450
1999
Publisher: The Royal Society of Chemistry

855.

Kleffmann, Jörg; Becker, Karl Heinz; Lackhoff, Marion; Wiesen, Peter
Heterogeneous conversion of NO\(_{2}\) on carbonaceous surfaces
Physical Chemistry Chemical Physics, 1 (24) :5443-5450
1999
Publisher: The Royal Society of Chemistry

854.

Kleffmann, Jörg; Becker, Karl Heinz; Lackhoff, Marion; Wiesen, Peter
Heterogeneous conversion of NO2 on carbonaceous surfaces
Physical Chemistry Chemical Physics, 1 (24) :5443-5450
1999
Publisher: The Royal Society of Chemistry

853.

Setzer, Klaus-Dieter; Fink, Ewald H.; Ramsay, D. A.
High-Resolution Fourier-Transform Study of the b\(^{1}\)\(\Sigma\)\(^{+}\) → X\(^{3}\)\(\Sigma\)\(^{-}\) and a\(^{1}\)\(\Delta\) → X\(^{3}\)\(\Sigma\)\(^{-}\) Transitions of SO
Journal of Molecular Spectroscopy, 198 (1) :163-174
1999
Publisher: Academic Press

852.

Setzer, Klaus-Dieter; Fink, Ewald H.; Ramsay, D. A.
High-Resolution Fourier-Transform Study of the b\(^{1}\)\(\Sigma\)\(^{+}\) → X\(^{3}\)\(\Sigma\)\(^{-}\) and a\(^{1}\)\(\Delta\) → X\(^{3}\)\(\Sigma\)\(^{-}\) Transitions of SO
Journal of Molecular Spectroscopy, 198 (1) :163-174
1999
Publisher: Academic Press

851.

Setzer, Klaus-Dieter; Fink, Ewald H.; Ramsay, D. A.
High-Resolution Fourier-Transform Study of the b1Σ+ → X3Σ- and a1Δ → X3Σ- Transitions of SO
Journal of Molecular Spectroscopy, 198 (1) :163-174
1999
Publisher: Academic Press

850.

Gänsheimer, S; Schilling, A
Improved staging of prostate cancer using a new tumorscore
Aktuelle Urologie, 30 (1) :20--26
1999
Publisher: GEORG THIEME VERLAG KG RUDIGERSTR 14, D-70469 STUTTGART, GERMANY

849.

Becker, Karl Heinz; Geiger, Harald; Schmidt, Frank; Wiesen, Peter
Kinetic investigation of NCO radicals reacting with selected hydrocarbons
Physical Chemistry Chemical Physics, 1 (23) :5305-5309
1999

848.

Becker, Karl Heinz; Geiger, Harald; Schmidt, Frank; Wiesen, Peter
Kinetic investigation of NCO radicals reacting with selected hydrocarbons
Physical Chemistry Chemical Physics, 1 (23) :5305-5309
1999

847.

Becker, Karl Heinz; Geiger, Harald; Schmidt, Frank; Wiesen, Peter
Kinetic investigation of NCO radicals reacting with selected hydrocarbons
Physical Chemistry Chemical Physics, 1 (23) :5305-5309
1999

846.

Becker, Karl Heinz; Dinis, Carlos M.; Geiger, Harald; Wiesen, Peter
Kinetics of the reaction of OH with di-n-butoxymethane (DBM) in the range 298-710 K
Chemical Physics Letters, 300 (3-4) :460-464
1999

845.

Becker, Karl Heinz; Dinis, Carlos M.; Geiger, Harald; Wiesen, Peter
Kinetics of the reaction of OH with di-n-butoxymethane (DBM) in the range 298-710 K
Chemical Physics Letters, 300 (3-4) :460-464
1999

844.

Becker, Karl Heinz; Dinis, Carlos M.; Geiger, Harald; Wiesen, Peter
Kinetics of the reaction of OH with di-n-butoxymethane (DBM) in the range 298-710 K
Chemical Physics Letters, 300 (3-4) :460-464
1999

843.

Foster, Krishna L.; Lakin, M. J.; Caldwell, Tracy E.; Hemminger, John C.; Benter, Thorsten; Finlayson-Pitts, Barbara J.
Laboratory studies of model sea-salt aerosols with HOCl.
Abstracts of Papers of The Americal Chemical Society, 217 (1) :U109
1999

842.

Foster, Krishna L.; Lakin, M. J.; Caldwell, Tracy E.; Hemminger, John C.; Benter, Thorsten; Finlayson-Pitts, Barbara J.
Laboratory studies of model sea-salt aerosols with HOCl.
Abstracts of Papers of The Americal Chemical Society, 217 (1) :U109
1999