Synergies

Mutual seminars
APR 17 2018
Georg-August-Universität Göttingen, Institute for Numerical and Applied Mathematics
Estimating the spectral information of an exponential sum plays an important role in many signal processing applications. In particular, we mention nuclear magnetic resonance (NMR) spectroscopy and the direction of arrival (DOA) problem in smart antenna technology. We present a parametric method that can circumvent the Shannon-Nyquist sampling rate and break the curse of dimensionality. Read More
JAN 25 2018
Université de Lille
The first part of the presentation is a tutorial introduction to sum-of-exponentials modeling from a numerical linear algebra point of view. The problem considered is related to the rational approximation, linear time-invariant system realization, and model reduction problems. Three classed of solution methods are reviewed: convex relaxations based on the nuclear norm heuristic, subspace methods, and local optimization methods. Read More
DEC 21 2017
Universiteit Antwerpen, Department of Mathematics and Computer Science
NOV 17 2017
Universiteit Antwerpen, Department of Mathematics and Computer Science
In signal processing data are traditionally sampled according to the Shannon-Nyquist theorem in order to prevent aliasing effects. Here we focus on parametric methods and introduce a procedure that allows these methods to work with sub-sampled data. We actually make use of the aliasing effect to regularize the problem statement rather than that we avoid it. Read More
NOV 7 2017
Georg-August-Universität Göttingen, Institute for Numerical and Applied Mathematics
MAY 16 2017
Georg-August-Universität Göttingen, Institute for Numerical and Applied Mathematics
Rational functions like for instance Padé approximants play an important role in signal processing, sparse interpolation and exponential analysis. They have good theoretical properties in approximation and modeling. However, for a successful modeling with help of rational functions we want to make sure that there is no ”similar” rational function being degenerate, i.e., having strictly smaller degree of both degrees of numerator and denominator. Read More
DEC 13 2016
Georg-August-Universität Göttingen, Institute for Numerical and Applied Mathematics
NOV 21 2016
Universiteit Antwerpen, Department of Mathematics and Computer Science
OCT 24 2016
Universiteit Antwerpen, Department of Mathematics and Computer Science
State-of-the-art data processing methods are model based and require a model identification step prior to solving the data processing problem. Starting with a review of classical system identification, this talk presents a model-free data processing approach, in which model parameters need not be explicitly estimated. Read More
OCT 18 2016
Georg-August-Universität Göttingen, Institute for Numerical and Applied Mathematics
System identification is a fast growing research area that encompasses a broad range of problems and solution methods. The expansion of methods and applications makes it difficult to maintain a common theoretical framework. This talk shows the potential of the structured low-rank approximation setting to unify problems of data modeling from diverse application areas. Read More
SEP 15 2016
Imperial College of Science, Technology and Medicine, EEE Department
JUN 16 2016
Vrije Universiteit Brussel, Department ELEC seminar
A mathematical model is called t-sparse if it is a combination of only t generating elements. In sparse interpolation, the aim is to determine both the support of the sparse linear combination and the scalar coefficients in the representation, from a small or minimal amount of data samples. Read More
MAY 20 2016
Université de Lille
MAR 17 2016
Imperial College of Science, Technology and Medicine
DEC 10 2015
Université des Sciences et Technologies de Lille - Lille I
Reconstructing a digital signal from its measurements is an inverse problem that can be extremely ill-posed. Meanwhile, sampling a signal uniformly below the Shannon-Nyquist rate leads to aliasing, an unwanted effect causing different signals to become indistinguishable. Read More
NOV 23 2015
Universiteit Antwerpen, Department of Mathematics and Computer Science
Rational functions like for instance Padé approximants play an important role in signal processing, sparse interpolation and exponential analysis. However, for a successful modeling with help of rational functions we want to make sure that there is no ”similar” rational function being degenerate, i.e., having strictly smaller degree of both degrees of numerator and denominator. Read More
NOV 12 2015
Universiteit Antwerpen, Department of Mathematics and Computer Science
Padé approximants play an important role in signal processing, sparse interpolation and exponential analysis. In this talk we will report about recent results concerning the forward and backward conditioning of the (real) Padé map, which sends a vector of Taylor coefficients onto the normalized vector of coefficients of the Padé numerator and denominator. Read More
OCT 26 2015
Universiteit Antwerpen, Department of Mathematics and Computer Science
Modelling signals as sparse in a proper domain has proved fruitful in many signal and image processing applications. Recently, the notion of sparsity has lead to new sampling theories that have demonstrated that the prior knowledge that signals can be sparsely described in a basis or in a parametric space can be used to sample and perfectly reconstruct such signals at a significantly reduced rate. Read More
OCT 19 2015
Universiteit Antwerpen, Department of Mathematics and Computer Science
We derive a new generalization of Prony's method to reconstruct M-sparse expansions of (generalized) eigenfunctions of linear operators from only O(M) suitable values in a deterministic way. Read More
JAN 20 2015
Georg-August-Universität Göttingen, Institute for Numerical and Applied Mathematics
JAN 15 2015
Vrije Universiteit Brussel, Department ELEC seminar
JUN 25 2013
Universiteit Antwerpen, Department of Mathematics and Computer Science
Tutorials
SEP 18 2017
Computer Algebra in Scientific Computing (CASC 2017)
A mathematical model is called sparse if it is a combination of only a few non-zero terms. In sparse interpolation, the aim is to determine both the support of the sparse linear combination and the scalar coefficients in the representation, from a small or minimal amount of data samples. Read More
SEP 9 - 12 2014
Dolomites Research Week on Approximation (DRWA14)
Within the last time, various adaptive methods for signal and image approximation have been suggested. Instead of choosing a priori a basis or a frame to approximate an image, one tries to adapt the approximation scheme to the image geometry. Read More
SEP 8 - 11 2014
Dolomites Research Week on Approximation (DRWA14)
Throughout computational science and engineering, several attempts have been made to represent data in a parsimonious way. Mathematical models are proposed in which the major features of the data are represented using only a few terms, in other words, models that use a sparse combination of generating elements instead of a linear combination of all basis elements. Read More
Research visits

December 21-22, 2017

Visit of Gerlind Plonka (Georg-August-Universität Göttingen, Germany) to Universiteit Antwerpen.

November 7-8, 2017

Visit of Mariya Ishteva (Vrije Universiteit Brussel, Belgium) to Georg-August-Universität Göttingen.

May 15-17, 2017

Visit of Ana Matos (Université des Sciences et Technologies de Lille - Lille I, France) to Georg-August-Universität Göttingen.

December 13-14, 2016

Visit of Pier Luigi Dragotti (Imperial College of Science, Technology and Medicine, United Kingdom) to Georg-August-Universität Göttingen.

October 18-19, 2016

Visit of Ivan Markovsky (Vrije Universiteit Brussel, Belgium) to Georg-August-Universität Göttingen.

September 15-16, 2016

Visit of Ivan Markovsky (Vrije Universiteit Brussel, Belgium) to Imperial College of Science, Technology and Medicine.

November 11-12, 2015

Visit of Bernhard Beckermann and Ana C. Matos (Université des Sciences et Technologies de Lille - Lille I, France) to Universiteit Antwerpen.

October 28, 2015

Visit of Pier Luigi Dragotti (Imperial College of Science, Technology and Medicine, United Kingdom) to Vrije Universiteit Brussel.

October 26-27, 2015

Visit of Pier Luigi Dragotti (Imperial College London, United Kingdom) to Universiteit Antwerpen.

October 19-21, 2015

Visit of Gerlind Plonka (Georg-August-Universität Göttingen, Germany) to Universiteit Antwerpen.

September 14-18, 2015

Visit of Giovanni Lo Bianco (Universiteit Antwerpen, Belgium) to University of Strathclyde.

August 18-19, 2015

Visit of David Li (University of Strathclyde, United Kingdom) to Universiteit Antwerpen.

Organized events

June 28-July 4, 2018

Curves and Surfaces (CS18): Minisymposium on Advances on Prony's method @ Arcachon, France.

May 31-June 1, 2018

International conference on Approximation and Matrix Functions (amf18) @ Université de Lille, France.

September 4-8, 2017

Dolomites Research Week on Approximation (DRWA17): Working group "Multi-exponential analysis and tensor methods" @ Alba di Canazei, Val di Fassa (Trento), Italy.

July 31-August 4, 2017

SIAM conference on Applied Algebraic Geometry (SIAM AG 17): Minisymposium on From Approximation Theory to Tensor Decomposition, Part I and Part II @ Georgia Institute of Technology, Atlanta, Georgia (USA).

October 30-November 4, 2016

CMO Workshop 16w5038: Sparse Interpolation, Rational Approximation and Exponential Analysis @ Casa Matemática Oaxaca, Mexico.

September 15-16, 2016

London Workshop on Sparse Signal Processing @ Imperial College of Science, Technology and Medicine, United Kingdom.

September 8-13, 2016

4th Dolomites Workshop on Constructive Approximation and Applications: Session "Sparse approximation" @ Alba di Canazei, Val di Fassa (Trento), Italy.

May 20, 2016

5èmes Journées Approximation, International conference on constructive complex approximation @ Université des Sciences et Technologies de Lille - Lille I, France.

September 5-8, 2015

Dolomites Research Week on Approximation (DRWA15): Working group "Interpolation: dimensionality, sparsity, orthogonality" @ Alba di Canazei, Val di Fassa (Trento), Italy.

June 14-19, 2015

Dagstuhl Seminar 15251: Sparse Modelling and Multi-exponential Analysis @ Schloss Dagstuhl, Dagstuhl, Germany.