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



1985

125.

Lamour, R.; Hanke, M.; Winkler, R.
The program system ‘RWA’ (version 2) for the solution of TPBVP - fundamentals and algorithms
, Seminarbericht 67 der Sektion MathematikBand67
Humboldt-Universität zu Berlin
1985
1984

124.

Morillon-Chapey, M.; Guelachvili, Guy; Jensen, Per
Analysis of the high resolution spectrum of the \(\nu\)\(_{2}\) and \(\nu\)\(_{5}\) absorption bands of methyl chloride
Canadian Journal of Physics, 62 (3) :247-253
1984
Herausgeber: NRC Research Press Ottawa, Canada

123.

Morillon-Chapey, M.; Guelachvili, Guy; Jensen, Per
Analysis of the high resolution spectrum of the \(\nu\)\(_{2}\) and \(\nu\)\(_{5}\) absorption bands of methyl chloride
Canadian Journal of Physics, 62 (3) :247-253
1984
Herausgeber: NRC Research Press Ottawa, Canada

122.

Morillon-Chapey, M.; Guelachvili, Guy; Jensen, Per
Analysis of the high resolution spectrum of the ν2 and ν5 absorption bands of methyl chloride
Canadian Journal of Physics, 62 (3) :247-253
1984
Herausgeber: NRC Research Press Ottawa, Canada

121.

Kruse, H.; Winter, R.; Fink, Ewald H.; Wildt, J{ü}rgen; Zabel, Friedhelm
b\(^{1}\)\(\Sigma\)\(^{+}\) Emissions from group V-VII diatomic molecules. b0\(^{+}\) → X\(_{1}\)0\(^{+}\), X\(_{2}\)1 band systems of AsCl and AsBr
Chemical Physics Letters, 111 (1-2) :100-104
1984

120.

Kruse, H.; Winter, R.; Fink, Ewald H.; Wildt, J{ü}rgen; Zabel, Friedhelm
b\(^{1}\)\(\Sigma\)\(^{+}\) Emissions from group V-VII diatomic molecules. b0\(^{+}\) → X\(_{1}\)0\(^{+}\), X\(_{2}\)1 band systems of AsCl and AsBr
Chemical Physics Letters, 111 (1-2) :100-104
1984

119.

Winter, R.; Kruse, H.; Fink, Ewald H.; Wildt, J{ü}rgen; Zabel, Friedhelm
b\(^{1}\)\(\Sigma\)\(^{+}\) Emissions from group V-VII diatomic molecules. b0\(^{+}\) → X\(_{1}\)0\(^{+}\), X\(_{2}\)1 emissions of AsI and SbI
Chemical Physics Letters, 104 (4) :383-388
1984

118.

Winter, R.; Kruse, H.; Fink, Ewald H.; Wildt, J{ü}rgen; Zabel, Friedhelm
b\(^{1}\)\(\Sigma\)\(^{+}\) Emissions from group V-VII diatomic molecules. b0\(^{+}\) → X\(_{1}\)0\(^{+}\), X\(_{2}\)1 emissions of AsI and SbI
Chemical Physics Letters, 104 (4) :383-388
1984

117.

Kruse, H.; Winter, R.; Fink, Ewald H.; Wildt, Jürgen; Zabel, Friedhelm
b1Σ+ Emissions from group V-VII diatomic molecules. b0+ → X10+, X21 band systems of AsCl and AsBr
Chemical Physics Letters, 111 (1-2) :100-104
1984

116.

Winter, R.; Kruse, H.; Fink, Ewald H.; Wildt, Jürgen; Zabel, Friedhelm
b1Σ+ Emissions from group V-VII diatomic molecules. b0+ → X10+, X21 emissions of AsI and SbI
Chemical Physics Letters, 104 (4) :383-388
1984

115.

Jensen, Per
C\(_{3}\)O\(_{2}\) as a semirigid bender: The degenerate \(\nu\)\(_{5}\) state
Journal of Molecular Spectroscopy, 104 (1) :59-71
1984

114.

Jensen, Per
C\(_{3}\)O\(_{2}\) as a semirigid bender: The degenerate \(\nu\)\(_{5}\) state
Journal of Molecular Spectroscopy, 104 (1) :59-71
1984

113.

Jensen, Per
C3O2 as a semirigid bender: The degenerate ν5 state
Journal of Molecular Spectroscopy, 104 (1) :59-71
1984

112.

Kreglewski, Marek; Jensen, Per
Determination of the skeletal bending potential function for SiH\(_{3}\)NCO from the microwave spectrum
Journal of Molecular Spectroscopy, 103 (2) :312-320
1984

111.

Kreglewski, Marek; Jensen, Per
Determination of the skeletal bending potential function for SiH\(_{3}\)NCO from the microwave spectrum
Journal of Molecular Spectroscopy, 103 (2) :312-320
1984

110.

Kreglewski, Marek; Jensen, Per
Determination of the skeletal bending potential function for SiH3NCO from the microwave spectrum
Journal of Molecular Spectroscopy, 103 (2) :312-320
1984

109.

Glöckner, W.; Tausch, Michael W.; Autorenteam
MATERIALIEN FÜR DER KURSUNTERRICHT CHEMIE, Aufgabensammlung mit Klausur- und Abituraufgaben aus allen Bereichen der Schulchemie, 3 Bände
Herausgeber: Aulis Deubner\&Co KG, Köln
1984

108.

Winkler, R.
Numerische Behandlung von parameterabhängigen Zwei-Punkt-Randwertaufgaben unter Berücksichtigung von Verzweigungsproblemen
Humboldt-Universität zu Berlin
1984

107.

Bielefeld, M.; Elfers, G.; Fink, Ewald H.; Kruse, H.; Wildt, J{ü}rgen; Winter, R.; Zabel, Friedhelm
O\(_{2}\)(a\(^{1}\)\(\Delta\)\(_{g}\))-sensitized chemiluminescence of a\(^{1}\)\(\Delta\) → X\(^{3}\)\(\Sigma\)\(^{-}\) and b\(^{1}\)\(\Sigma\)\(^{+}\) → X\(^{3}\)\(\Sigma\)\(^{-}\) transitions of group VI-group VI and group V-group VII diatomic molecules
Journal of Photochemistry, 25 (2-4) :419-438
1984

106.

Bielefeld, M.; Elfers, G.; Fink, Ewald H.; Kruse, H.; Wildt, J{ü}rgen; Winter, R.; Zabel, Friedhelm
O\(_{2}\)(a\(^{1}\)\(\Delta\)\(_{g}\))-sensitized chemiluminescence of a\(^{1}\)\(\Delta\) → X\(^{3}\)\(\Sigma\)\(^{-}\) and b\(^{1}\)\(\Sigma\)\(^{+}\) → X\(^{3}\)\(\Sigma\)\(^{-}\) transitions of group VI-group VI and group V-group VII diatomic molecules
Journal of Photochemistry, 25 (2-4) :419-438
1984

105.

Bielefeld, M.; Elfers, G.; Fink, Ewald H.; Kruse, H.; Wildt, Jürgen; Winter, R.; Zabel, Friedhelm
O2(a1Δg)-sensitized chemiluminescence of a1Δ → X3Σ- and b1Σ+ → X3Σ- transitions of group VI-group VI and group V-group VII diatomic molecules
Journal of Photochemistry, 25 (2-4) :419-438
1984

104.

Maten, E. J. W.
Stability analysis of finite difference methods for fourth order parabolic partial differential equations
Rijksuniversiteit Utrecht
1984

103.

Becker, Karl Heinz; Horie, O.; Wiesen, Peter
The formation of CH radicals during the photolysis of CH\(_{2}\)N\(_{2}\) in the presence of hydrogen and oxygen atoms
Journal of Photochemistry, 24 (3) :293-297
1984

102.

Becker, Karl Heinz; Horie, O.; Wiesen, Peter
The formation of CH radicals during the photolysis of CH\(_{2}\)N\(_{2}\) in the presence of hydrogen and oxygen atoms
Journal of Photochemistry, 24 (3) :293-297
1984

101.

Becker, Karl Heinz; Horie, O.; Wiesen, Peter
The formation of CH radicals during the photolysis of CH2N2 in the presence of hydrogen and oxygen atoms
Journal of Photochemistry, 24 (3) :293-297
1984