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



1989

266.

Heilmann, Margareta
On simultaneous approximation by optimal algebraic polynomials
Results in Mathematics, 16 (1-2) :77-81
1989

265.

Heilmann, Margareta; Müller, Manfred
On simultaneous approximation by the method of Baskakov-Durrmeyer operators
Numerical Functional Analysis and Optimization, 10 (1-2) :127-138
1989

264.

[german] Tausch, Michael W.; Wöhrle, D.
Photokatalyse
Praxis der Naturwissenschaften (Chemie), 38 :37
1989

263.

Becker, Karl Heinz; Engelhardt, B.; Wiesen, Peter; Bayes, Kyle D.
Rate constants for CH(X\(^{2}\)\(\Pi\)) reactions at low total pressures
Chemical Physics Letters, 154 (4) :342-348
1989

262.

Becker, Karl Heinz; Engelhardt, B.; Wiesen, Peter; Bayes, Kyle D.
Rate constants for CH(X\(^{2}\)\(\Pi\)) reactions at low total pressures
Chemical Physics Letters, 154 (4) :342-348
1989

261.

Becker, Karl Heinz; Engelhardt, B.; Wiesen, Peter; Bayes, Kyle D.
Rate constants for CH(X2Π) reactions at low total pressures
Chemical Physics Letters, 154 (4) :342-348
1989

260.

Fink, Ewald H.; Setzer, Klaus-Dieter; Ramsay, D. A.; Vervloet, M.; Xu, G. Z.
Rotational analysis of the 0-0 band of the b0\(^{+}\) → X\(_{1}\)0\(^{+}\) system of \(^{130}\)Te\(^{80}\)Se
Journal of Molecular Spectroscopy, 136 (1) :218-221
1989

259.

Fink, Ewald H.; Setzer, Klaus-Dieter; Ramsay, D. A.; Vervloet, M.; Xu, G. Z.
Rotational analysis of the 0-0 band of the b0\(^{+}\) → X\(_{1}\)0\(^{+}\) system of \(^{130}\)Te\(^{80}\)Se
Journal of Molecular Spectroscopy, 136 (1) :218-221
1989

258.

Fink, Ewald H.; Setzer, Klaus-Dieter; Ramsay, D. A.; Vervloet, M.; Xu, G. Z.
Rotational analysis of the 0-0 band of the b0+ → X10+ system of 130Te80Se
Journal of Molecular Spectroscopy, 136 (1) :218-221
1989

257.

Tausch, Michael W.; Wachtendonk, M.
STOFF-FORMEL-UMWELT, BAND 1: CHEMISCHE GLEICHGEWICHTE - ELEKTROCHEMIE, Lehrbuch für die S II (Grund- und Leistungskurse), 172 Seiten
Herausgeber: C. C. Buchner, Bamberg
1989

256.

Wildt, J{ü}rgen; Fink, Ewald H.; Biggs, P.; Wayne, Richard P.
The collision-induced radiation of O\(_{2}\)(a\(^{1}\)\(\Delta\)\(_{g}\))
Chemical Physics, 139 (2-3) :401-407
1989

255.

Wildt, J{ü}rgen; Fink, Ewald H.; Biggs, P.; Wayne, Richard P.
The collision-induced radiation of O\(_{2}\)(a\(^{1}\)\(\Delta\)\(_{g}\))
Chemical Physics, 139 (2-3) :401-407
1989

254.

Wildt, Jürgen; Fink, Ewald H.; Biggs, P.; Wayne, Richard P.
The collision-induced radiation of O2(a1Δg)
Chemical Physics, 139 (2-3) :401-407
1989

253.

Jensen, Per
The potential energy surface for the C\(_{3}\) molecule determined from experimental data. Evidence for a bent equilibrium structure
Collection of Czechoslovak Chemical Communications, 54 (5) :1209-1218
1989
Herausgeber: Institute of Organic Chemistry and Biochemistry AS CR, v.v.i.

252.

Jensen, Per
The potential energy surface for the C\(_{3}\) molecule determined from experimental data. Evidence for a bent equilibrium structure
Collection of Czechoslovak Chemical Communications, 54 (5) :1209-1218
1989
Herausgeber: Institute of Organic Chemistry and Biochemistry AS CR, v.v.i.

251.

Jensen, Per
The potential energy surface for the C3 molecule determined from experimental data. Evidence for a bent equilibrium structure
Collection of Czechoslovak Chemical Communications, 54 (5) :1209-1218
1989
Herausgeber: Institute of Organic Chemistry and Biochemistry AS CR, v.v.i.

250.

Jensen, Per
The potential energy surface for the electronic ground state of the water molecule determined from experimental data using a variational approach
Journal of Molecular Spectroscopy, 133 (2) :438-460
1989

249.

Jensen, Per
The potential energy surface for the electronic ground state of the water molecule determined from experimental data using a variational approach
Journal of Molecular Spectroscopy, 133 (2) :438-460
1989

248.

Jensen, Per
The potential energy surface for the electronic ground state of the water molecule determined from experimental data using a variational approach
Journal of Molecular Spectroscopy, 133 (2) :438-460
1989

247.

Schönfeld, J; Loennecken, I; Gückel, C
Unilateral pulsating tinnitus: paraganglioma of the glomus jugulare with predominantly vascular extension
Medizinische Klinik (Munich, Germany: 1983), 84 (9) :445--449
1989

246.

Heilmann, Margareta; Müller, Manfred
Weighted simultaneous L_p-approximation by the method of Baskakov-Durrmeyer operators
Approximation Theory VI, Proc. 6th Int. Symp., College Station/TX USA1989Band 1, Seite 331-332
1989
1988

245.

Jensen, Per; Kraemer, Wolfgang P.
A comparison of perturbative and variational rotation-vibration energies calculated for HOC\(^{+}\) and C\(_{3}\) using the nonrigid bender and MORBID Hamiltonians
Journal of Molecular Spectroscopy, 129 (1) :172-185
1988

244.

Jensen, Per; Kraemer, Wolfgang P.
A comparison of perturbative and variational rotation-vibration energies calculated for HOC\(^{+}\) and C\(_{3}\) using the nonrigid bender and MORBID Hamiltonians
Journal of Molecular Spectroscopy, 129 (1) :172-185
1988

243.

Jensen, Per; Kraemer, Wolfgang P.
A comparison of perturbative and variational rotation-vibration energies calculated for HOC+ and C3 using the nonrigid bender and MORBID Hamiltonians
Journal of Molecular Spectroscopy, 129 (1) :172-185
1988

242.

Rahman, M. M.; Becker, Eilhard; Benter, Thorsten; Schindler, Ralph N.
A Gasphase Kinetic Investigation of the System F + HNO\(_{3}\) and the Determination of Absolute Rate Constants for the Reaction of the NO\(_{3}\) Radical with CH\(_{3}\)SH, 2-Methylpropene, 1,3-Butadiene and 2,3-Dimethyl-2-Butene
Berichte der Bunsengesellschaft für physikalische Chemie, 92 (1) :91-100
1988