Searched for: author:"Verhaegen, M.H.G."
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Wilding, D. (author), Soloviev, O.A. (author), Pozzi, P. (author), Vdovine, G.V. (author), Verhaegen, M.H.G. (author)
A methodology for retrieving the unknown object distribution and point-spread functions (PSFs) from a set of images acquired in the presence of temporal phase aberrations is presented in this paper. The method works by finding optimal complimentary linear filters for multi-frame deconvolution. The algorithm uses undemanding computational...
journal article 2017
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Sinquin, B. (author), Verhaegen, M.H.G. (author)
In this paper we address the identification of (2D) spatial-temporal dynamical systems governed by the Vector Auto-Regressive (VAR) form. The coefficient-matrices of the VAR model are parametrized as sums of Kronecker products. When the number of terms in the sum is small compared to the size of the matrix, such a Kronecker representation...
conference paper 2017
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Gong, H. (author), Soloviev, O.A. (author), Verhaegen, M.H.G. (author), Vdovine, G.V. (author)
We present a quantitative phase imaging microscope based on a Shack-Hartmann sensor, that directly reconstructs the optical path difference (OPD) in reflective mode. Comparing with the holographic or interferometric methods, the SH technique needs no reference beam in the setup, which simplifies the system. With a preregistered reference, the...
journal article 2017
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Yu, C. (author), Ljung, Lennart (author), Verhaegen, M.H.G. (author)
Gray-box identification is prevalent in modeling physical and networked systems. However, due to the non-convex nature of the gray-box identification problem, good initial parameter estimates are crucial for a successful application. In this paper, a new identification method is proposed by exploiting the low-rank and structured Hankel matrix...
conference paper 2017
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Yu, C. (author), Verhaegen, M.H.G. (author)
Abstract:<br/>This note studies the identification of individual systems operating in a large-scale distributed network by considering the interconnection signals between neighboring systems to be unmeasurable. The unmeasurable interconnections act as unknown system inputs to the individual systems in a network, which poses a challenge for the...
journal article 2017
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Wilding, D. (author), de Iongh, Gijs (author), Soloviev, O.A. (author), Pozzi, P. (author), Vdovine, G.V. (author), Verhaegen, M.H.G. (author)
By taking multiple input-output measurements, it is shown how to determine the input to an optical system that corrects unknown phase aberrations without interferometric measurements or online iterative optimization within a couple of seconds. It is shown to work in simulations and experiment. This technique may also be used to acquire the...
conference paper 2017
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Gunes, B. (author), van Wingerden, J.W. (author), Verhaegen, M.H.G. (author)
The major bottleneck in state-of-the-art Linear Parameter Varying (LPV) subspace methods is the curse-of-dimensionality during the first regression step. In this paper, the origin of the curse-of-dimensionality is pinpointed and subsequently a novel method is proposed which does not suffer from this bottleneck. The problem is related to the...
journal article 2017
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Pozzi, P. (author), Quintavalla, M. (author), Verstraete, H.R.G.W. (author), Bijlsma, Hielke (author), Bonora, S. (author), Verhaegen, M.H.G. (author)
conference paper 2017
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Yu, C. (author), Verhaegen, M.H.G. (author)
This note studies the identification of a network comprised of interconnected clusters of LTI systems. Each cluster consists of homogeneous dynamical systems, and its interconnections with the rest of the network are unmeasurable. A subspace identification method is proposed for identifying a single cluster using only local input and output data...
journal article 2017
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Doelman, R. (author), Verhaegen, M.H.G. (author)
We analyse the very general class of uncertain systems that have Linear Fractional Representations (LFRs), and uncertainty blocks in a convex set with a finite number of vertices. For these systems we design static output feedback controllers. In the general case, computing a robust static output feedback controller with optimal performance...
journal article 2017
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Taballione, Caterina (author), Agbana, T.E. (author), Vdovin, Gleb (author), Hoekman, Marcel (author), Wevers, Lennart (author), Kalkman, J. (author), Verhaegen, M.H.G. (author), van der Slot, Peter J.M. (author), Boller, Klaus-Jochen (author)
Wavelength meters are central for many applications such as in telecommunication systems or laser monitoring. The primary function of a wavelength meter is to provide an output signal that changes sensitively with the wavelength of the input light. Of central importance is the reproducibility of the output signal even in the presence of external...
conference paper 2017
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Pozzi, P. (author), Wilding, D. (author), Soloviev, O.A. (author), Vdovine, G.V. (author), Verhaegen, M.H.G. (author)
This proceeding reports early results in the development of a new technique for adaptive optics in confocal microscopy. The term adaptive optics refers to the branch of optics in which an active element in the optical system is used to correct inhomogeneities in the media through which light propagates. In its most classical form, mostly used in...
conference paper 2016
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Doelman, R. (author), Verhaegen, M.H.G. (author)
We consider the use of the nuclear norm operator, and its tendency to produce low rank results, to provide a convex relaxation of Bilinear Matrix Inequalities (BMIs). The BMI is first written as a Linear Matrix Inequality (LMI) subject to a bi-affine equality constraint and subsequently rewritten into an LMI subject to a rank constraint on a...
conference paper 2016
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Wilding, D. (author), Pozzi, P. (author), Soloviev, O.A. (author), Vdovine, G.V. (author), Verhaegen, M.H.G. (author)
Aberrations, scattering and absorption degrade the performance light-sheet fluorescence microscopes (LSFM). An adaptive optics system to correct for these artefacts and to optimize the light-sheet illumination is presented. This system allows a higher axial resolution to be recovered over the field-of-view of the detection objective. It is...
conference paper 2016
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Verhaegen, M.H.G. (author), Hansson, A (author)
The identification of multivariable state space models in innovation form is solved in a subspace identification framework using convex nuclear norm optimization. The convex optimization approach allows to include constraints on the unknown matrices in the data-equation characterizing subspace identification methods, such as the lower triangular...
journal article 2016
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Yu, C. (author), Verhaegen, M.H.G. (author)
In this paper, we study the deterministic blind identification of multiple channel state-space models having a common unknown input using measured output signals that are perturbed by additive white noise sequences. Different from traditional blind identification problems, the considered system is an autoregressive system rather than an FIR...
journal article 2016
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Sinquin, B. (author), Verhaegen, M.H.G. (author)
We consider the problem of identifying 1D spatially-varying systems that exhibit no temporal dynamics. The spatial dynamics are modeled via a mixed-causal, anti-causal state space model. The methodology is developed for identifying the input-output map of e.g a 1D flexible beam described by the Euler-Bernoulli beam equation and equipped with a...
conference paper 2016
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Verstraete, H.R.G.W. (author), Almasian, M. (author), Pozzi, P. (author), Bilderbeek, R (author), Kalkman, J. (author), Faber, DJ (author), Verhaegen, M.H.G. (author)
In this manuscript, we present a lens setup for large defocus and astigmatism correction. A deformable defocus lens and two rotational cylindrical lenses are used to control the defocus and astigmatism. The setup is calibrated using a simple model that allows the calculation of the lens inputs so that a desired defocus and astigmatism are...
conference paper 2016
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Yoo, H.W. (author), van Royen, M.E. (author), van Cappellen, WA (author), Houtsmuller, AB (author), Verhaegen, M.H.G. (author), Schitter, G (author)
The pinhole plays an important role in confocal laser scanning microscopy (CLSM) for adaptive optics (AO) as well as in imaging, where the size of the pinhole denotes a trade-off between out-of-focus rejection and wavefront distortion. This contribution proposes an AO system for a commercial CLSM with an adjustable square pinhole to cope with...
conference paper 2016
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Gong, H. (author), Pozzi, P. (author), Soloviev, O.A. (author), Verhaegen, M.H.G. (author), Vdovine, G.V. (author)
We present a reference-less and time-multiplexing phase retrieval method by making use of the digital micromirror device (DMD). In this method, the DMD functions not only as a flexible binary mask which modulates the optical field, but also as a sampling mask for measuring corresponding phases, which makes the whole setup simple and robust. The...
conference paper 2016
Searched for: author:"Verhaegen, M.H.G."
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