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

541.

Jensen, Per; Tashkun, Sergey A.; Tyuterev, Vladimir G.
A Refined Potential Energy Surface for the Electronic Ground State of the Water Molecule
Journal of Molecular Spectroscopy, 168 (2) :271-289
1994
Herausgeber: Academic Press

540.

Jensen, Per; Tashkun, Sergey A.; Tyuterev, Vladimir G.
A Refined Potential Energy Surface for the Electronic Ground State of the Water Molecule
Journal of Molecular Spectroscopy, 168 (2) :271-289
1994
Herausgeber: Academic Press

539.

Jensen, Per; Tashkun, Sergey A.; Tyuterev, Vladimir G.
A Refined Potential Energy Surface for the Electronic Ground State of the Water Molecule
Journal of Molecular Spectroscopy, 168 (2) :271-289
1994
Herausgeber: Academic Press

538.

Polyansky, Oleg L.; Jensen, Per; Tennyson, Jonathan
A spectroscopically determined potential energy surface for the ground state of H\(_{2}\)\(^{16}\)O: A new level of accuracy
The Journal of Chemical Physics, 101 (9) :7651-7657
1994

537.

Polyansky, Oleg L.; Jensen, Per; Tennyson, Jonathan
A spectroscopically determined potential energy surface for the ground state of H\(_{2}\)\(^{16}\)O: A new level of accuracy
The Journal of Chemical Physics, 101 (9) :7651-7657
1994

536.

Polyansky, Oleg L.; Jensen, Per; Tennyson, Jonathan
A spectroscopically determined potential energy surface for the ground state of H216O: A new level of accuracy
The Journal of Chemical Physics, 101 (9) :7651-7657
1994

535.

Kraemer, Wolfgang P.; Jensen, Per; Bunker, Philip R.
An ab initio calculation of the vibronic energies of the CH\(_{2}\)\(^{+}\) molecule
Canadian Journal of Physics, 72 (11-12) :871-878
1994
Herausgeber: NRC Research Press Ottawa, Canada

534.

Kraemer, Wolfgang P.; Jensen, Per; Bunker, Philip R.
An ab initio calculation of the vibronic energies of the CH\(_{2}\)\(^{+}\) molecule
Canadian Journal of Physics, 72 (11-12) :871-878
1994
Herausgeber: NRC Research Press Ottawa, Canada

533.

Kraemer, Wolfgang P.; Jensen, Per; Bunker, Philip R.
An ab initio calculation of the vibronic energies of the CH2+ molecule
Canadian Journal of Physics, 72 (11-12) :871-878
1994
Herausgeber: NRC Research Press Ottawa, Canada

532.

Tausch, Michael W.
Atom, Molekül, Mol - eine Schulbuchsynopse über 80 Jahre
Praxis der Naturwissenschaften (Chemie), 43 (7) :32
1994

531.

Günther, M.
Charge-oriented modelling of electric circuits and Rosenbrock-Wanner methods
Journal of Computing and Information, 4 :41–53
1994

530.

Alml{ö}f, Jan; Jensen, Per; Northrup, F. J.; Rohlfing, Celeste Michael; Rohlfing, E. A.; Sears, T. J.
Comment on ''The \(\nu\)\(_{1}\) + \(\nu\)\(_{3}\) combination mode of C\(_{3}\) in Ar and Kr matrices: Evidence for a bent structure'' [J. Chem. Phys. 99, 7371 (1993)]
The Journal of Chemical Physics, 101 (6) :5413-5413
1994

529.

Alml{ö}f, Jan; Jensen, Per; Northrup, F. J.; Rohlfing, Celeste Michael; Rohlfing, E. A.; Sears, T. J.
Comment on ''The \(\nu\)\(_{1}\) + \(\nu\)\(_{3}\) combination mode of C\(_{3}\) in Ar and Kr matrices: Evidence for a bent structure'' [J. Chem. Phys. 99, 7371 (1993)]
The Journal of Chemical Physics, 101 (6) :5413-5413
1994

528.

Almlöf, Jan; Jensen, Per; Northrup, F. J.; Rohlfing, Celeste Michael; Rohlfing, E. A.; Sears, T. J.
Comment on "The ν1 + ν3 combination mode of C3 in Ar and Kr matrices: Evidence for a bent structure" [J. Chem. Phys. 99, 7371 (1993)]
The Journal of Chemical Physics, 101 (6) :5413-5413
1994

527.

Denk, Georg; Selting, Petra A
Efficient numerical methods in electronic circuit simulation
Report TUM-M9413
1994
Herausgeber: Technische Universität München

526.

Denk, Georg; Selting, Petra A
Efficient numerical methods in electronic circuit simulation
1994

525.

Tausch, Michael W.; Wambach, H.
Entropie - was ist wissenschaftlich vertretbar und didaktisch sinnvoll?
Praxis der Naturwissenschaften (Chemie), 43 (2) :35
1994

524.

Skov, H.; Benter, Thorsten; Schindler, Ralph N.; Hjorth, J.; Restelli, G.
Epoxide formation in the reactions of the nitrate radical with 2,3-dimethyl-2-butene, cis- and trans-2-butene and isoprene
Atmospheric Environment, 28 (9) :1583-1592
1994

523.

Skov, H.; Benter, Thorsten; Schindler, Ralph N.; Hjorth, J.; Restelli, G.
Epoxide formation in the reactions of the nitrate radical with 2,3-dimethyl-2-butene, cis- and trans-2-butene and isoprene
Atmospheric Environment, 28 (9) :1583-1592
1994

522.

Skov, H.; Benter, Thorsten; Schindler, Ralph N.; Hjorth, J.; Restelli, G.
Epoxide formation in the reactions of the nitrate radical with 2,3-dimethyl-2-butene, cis- and trans-2-butene and isoprene
Atmospheric Environment, 28 (9) :1583-1592
1994

521.

Kozin, Igor N.; Jensen, Per
Fourfold clusters of rovibrational energy levels for H\(_{2}\)S studied with a potential energy surface derived from experiment
Journal of Molecular Spectroscopy, 163 (2) :483-509
1994
Herausgeber: Academic Press

520.

Kozin, Igor N.; Jensen, Per
Fourfold clusters of rovibrational energy levels for H\(_{2}\)S studied with a potential energy surface derived from experiment
Journal of Molecular Spectroscopy, 163 (2) :483-509
1994
Herausgeber: Academic Press

519.

Kozin, Igor N.; Jensen, Per
Fourfold clusters of rovibrational energy levels for H2S studied with a potential energy surface derived from experiment
Journal of Molecular Spectroscopy, 163 (2) :483-509
1994
Herausgeber: Academic Press

518.

Fink, Ewald H.; Setzer, Klaus-Dieter; Ramsay, D. A.; Zhu, Q.-S.
High-resolution study of the emission system of \(^{80}\)Se\(_{2}\) in the near infrared
Canadian Journal of Physics, 72 (11-12) :919-924
1994
Herausgeber: NRC Research Press Ottawa, Canada

517.

Fink, Ewald H.; Setzer, Klaus-Dieter; Ramsay, D. A.; Zhu, Q.-S.
High-resolution study of the emission system of \(^{80}\)Se\(_{2}\) in the near infrared
Canadian Journal of Physics, 72 (11-12) :919-924
1994
Herausgeber: NRC Research Press Ottawa, Canada