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



1988

241.

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

240.

Rahman, M. M.; Becker, Eilhard; Benter, Thorsten; Schindler, Ralph N.
A Gasphase Kinetic Investigation of the System F + HNO3 and the Determination of Absolute Rate Constants for the Reaction of the NO3 Radical with CH3SH, 2-Methylpropene, 1,3-Butadiene and 2,3-Dimethyl-2-Butene
Berichte der Bunsengesellschaft für physikalische Chemie, 92 (1) :91-100
1988

239.

Jensen, Per
A new morse oscillator-rigid bender internal dynamics (MORBID) Hamiltonian for triatomic molecules
Journal of Molecular Spectroscopy, 128 (2) :478-501
1988

238.

Jensen, Per
A new morse oscillator-rigid bender internal dynamics (MORBID) Hamiltonian for triatomic molecules
Journal of Molecular Spectroscopy, 128 (2) :478-501
1988

237.

Jensen, Per
A new morse oscillator-rigid bender internal dynamics (MORBID) Hamiltonian for triatomic molecules
Journal of Molecular Spectroscopy, 128 (2) :478-501
1988

236.

Jensen, Per; Kraemer, Wolfgang P.
A variational calculation of the rotation-vibration energies for CNC\(^{+}\) and CCN\(^{+}\)
Journal of Molecular Spectroscopy, 129 (1) :216-222
1988

235.

Jensen, Per; Kraemer, Wolfgang P.
A variational calculation of the rotation-vibration energies for CNC\(^{+}\) and CCN\(^{+}\)
Journal of Molecular Spectroscopy, 129 (1) :216-222
1988

234.

Jensen, Per; Kraemer, Wolfgang P.
A variational calculation of the rotation-vibration energies for CNC+ and CCN+
Journal of Molecular Spectroscopy, 129 (1) :216-222
1988

233.

Jensen, Per
A variational calculation of the rotation-vibration energies for H\(_{2}\)O from Ab initio data
Journal of Molecular Structure, 190 :149-161
1988

232.

Jensen, Per
A variational calculation of the rotation-vibration energies for H\(_{2}\)O from Ab initio data
Journal of Molecular Structure, 190 :149-161
1988

231.

Jensen, Per
A variational calculation of the rotation-vibration energies for H2O from Ab initio data
Journal of Molecular Structure, 190 :149-161
1988

230.

Benter, Thorsten; Schindler, Ralph N.
Absolute rate coefficients for the reaction of NO\(_{3}\) radicals with simple dienes
Chemical Physics Letters, 145 (1) :67-70
1988

229.

Benter, Thorsten; Schindler, Ralph N.
Absolute rate coefficients for the reaction of NO\(_{3}\) radicals with simple dienes
Chemical Physics Letters, 145 (1) :67-70
1988

228.

Benter, Thorsten; Schindler, Ralph N.
Absolute rate coefficients for the reaction of NO3 radicals with simple dienes
Chemical Physics Letters, 145 (1) :67-70
1988

227.

Jensen, Per
Calculation of rotation-vibration linestrengths for triatomic molecules using a variational approach
Journal of Molecular Spectroscopy, 132 (2) :429-457
1988

226.

Jensen, Per
Calculation of rotation-vibration linestrengths for triatomic molecules using a variational approach
Journal of Molecular Spectroscopy, 132 (2) :429-457
1988

225.

Jensen, Per
Calculation of rotation-vibration linestrengths for triatomic molecules using a variational approach
Journal of Molecular Spectroscopy, 132 (2) :429-457
1988

224.

Heilmann, Margareta
Commutativity of operators from Baskakov-Durrmeyer type
Constructive Theory of Functions - Proceedings of the International Conference, Varna, Bulgaria, 1987, Seite 197-206
1988

223.

[german] Tausch, Michael W.; Paterkiewicz, D.
Fluoreszenz und Phosphoreszenz
Praxis der Naturwissenschaften (Chemie), 36 :14
1988

222.

Jensen, Per
Hamiltonians for the internal dynamics of triatomic molecules
Journal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics, 84 (9) :1315-1339
1988

221.

Jensen, Per
Hamiltonians for the internal dynamics of triatomic molecules
Journal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics, 84 (9) :1315-1339
1988

220.

Jensen, Per
Hamiltonians for the internal dynamics of triatomic molecules
Journal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics, 84 (9) :1315-1339
1988

219.

Czech, C. M.; Kling, H.-W.; Hartkamp, H.
Kontinuierliche Derivatisierung von schwerflüchtigen Wasserinhaltsstoffen durch Periodat-Oxidation in Verbindung mit dem Contistrip-Verfahren
Fresenius' Journal of Analytical Chemistry, 332 (4) :341--344
1988

218.

Wildt, J{ü}rgen; Bednarek, G.; Fink, Ewald H.; Wayne, Richard P.
Laser excitation of O\(_{2}\)(b\(^{1}\)\(\Sigma\)\(_{g}\)\(^{+}\), v'=0,1,2) - rates and channels of energy transfer and quenching
Chemical Physics, 122 (3) :463-470
1988

217.

Wildt, J{ü}rgen; Bednarek, G.; Fink, Ewald H.; Wayne, Richard P.
Laser excitation of O\(_{2}\)(b\(^{1}\)\(\Sigma\)\(_{g}\)\(^{+}\), v'=0,1,2) - rates and channels of energy transfer and quenching
Chemical Physics, 122 (3) :463-470
1988