Invited Speakers
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Invited Speakers
Nikolaos Bekiaris-Liberis
Technical University of Crete, Greece
© Nikolaos Bekiaris-Liberis
Talk: “Micro-macro PDE control under implementation limitations of large-scale transport systems”
Abstract:
Although “transport” may imply different notions for different scientific fields, the feature of incorporation
of interacting system components through which “information” is propagated remains invariant.
I will present control-theoretic results for biological transport systems, which describe epidemic-spreading dynamics
via people transport and cardiovascular-flow dynamics via blood transport. In particular, I will present numerical
implementations of macroscopic, coupled crowd-flow and epidemic-spreading processes, subject to different macro-
control measures, while studying blood-transport stability in the presence of stenosis.
I will then present computationally tractable control designs for large-scale hyperbolic PDEs, whose complexity does
not grow with the number of PDE-system components. I will also present averaged and quantized predictor-feedback
designs for ODE systems subject to switching and quantization.
Lucas Brivadis
The Laboratory of Signals and Systems (L2S), Centre national de la recherche scientifique (CNRS), Paris, France
© Lucas Brivadis
Talk: “A Backstepping-KKL observer for a cascade of a nonlinear ODE with
a linear PDE”
Abstract:
In this talk, we propose an observer design for a cascade of an arbitrary nonlinear ODE with a linear
PDE, specifically a one-dimensional heat equation. The nonlinear output of the ODE imposes a boundary condition
on one side of the PDE, while the measured output is on the other side.
The observer design combines an infinite-dimensional Kazantzis–Kravaris/Luenberger (KKL) observer for the ODE
with a backstepping observer for the heat equation. This construction is the first extension of the KKL methodology
to infinite-dimensional systems. We establish convergence of the observer under a differential-observability condition
on the ODE. We will also give some insights into generalizations of the results to other PDEs.
Emilia Fridman
Tel Aviv University (TAU), Israel
© Emilia Fridman
Talk: “Constructive Methods for Robust Control of Distributed Parameter
Systems”
Abstract:
Many important plants, such as flexible manipulators or heat-transfer processes, are governed by partial
differential equations (PDEs) and are often described by models with a significant degree of uncertainty. Some
PDEs may not be robust with respect to arbitrarily small time delays in the feedback. Robust finite-dimensional
controller design for PDEs is therefore a challenging problem.
In this talk, two constructive methods for finite-dimensional control will be presented. The first is a spatial-
decomposition, or sampling-in-space, method, where the spatial domain is divided into N subdomains with N
sensors and actuators located in the subdomains. The second is a modal-decomposition method, where the
controller is designed on the basis of a finite-dimensional system that captures the dominant dynamics of the
infinite-dimensional one.
Sufficient conditions ensuring stability and performance of the closed-loop system are established in terms of simple
linear matrix inequalities that are always feasible for an appropriate choice of controllers. Delayed and sampled-data
implementations will also be discussed.
Jochen Glück
University of Wuppertal, Germany
© Jochen Glück
Talk: “Positivity in infinite-dimensional systems theory”
Abstract:
For linear partial differential equations, it is a classical question whether positive initial values lead to
positive solutions. This property occurs naturally in many models from, for example, physics and biology and,
remarkably, is often very helpful in the mathematical analysis of such models.
If an input term is added to the differential equation – that is, if we consider an infinite-dimensional linear control
system – a comprehensive theory of positivity is still under development. In this talk, we give an overview of some
central ideas in this area and demonstrate how positivity can help in the analysis of such systems.
Martin Gugat
FAU Erlangen-Nürnberg, Germany
© Martin Gugat
Talk: “Stabilizability of hyperbolic systems by boundary control:
The influence of time-delay and the quasi-linear case”
Abstract:
A celebrated example by Bastin and Coron illustrates the limits of stabilizability by boundary control
for hyperbolic systems; see the book “Stability and Boundary Stabilization of 1-D Hyperbolic Systems“.
We discuss the effect of time delay in the control loop in this context. Since many systems in engineering are
governed by nonlinear PDEs, we also discuss sufficient conditions for the stabilizability of quasi-linear hyperbolic
systems by boundary controls.
Rami Katz
Tel Aviv University, Israel
© Rami Katz
Talk: “Spectral reconstruction of 1D reaction-diffusion systems from measurements via algebraic super-resolution method”
Abstract:
Stabilization of one-dimensional reaction-diffusion systems is a ubiquitous task in numerous applications
in physics and electrical engineering. A common assumption in various stabilization schemes, such as modal
decomposition, is that the spatial differentiation operator is known, and hence its spectrum is available for
control-input design.
In many applications, however, the exact form of the spatial differentiation operator is not known and only a finite
number of system measurements is available, thereby requiring estimation of the spectrum of the differentiation
operator. In this talk, I will present a novel method for performing such a spectral estimation, based on tools
from algebraic super-resolution theory and signal processing. I will also provide rigorous theoretical guarantees for
reconstruction in the presence of structured measurement noise.
Joint work with Dmitry Batenkov (Tel Aviv University) and Giulia Giordano (University of Trento).
Volker Mehrmann
TU Berlin, Germany
© Volker Mehrmann
Talk: “Long- and short-time decay of solutions of evolution equations”
Abstract:
The long- and short-time behaviour of solutions to dissipative Hamiltonian evolution equations is studied
by applying the concept of hypocoercivity. The analysis is performed for general evolution equations that allow for
a modal decomposition with a scaled family of generators. We also present an analysis for finite-dimensional linear
and nonlinear systems.
Kirsten Morris
University of Waterloo, Canada
© Kirsten Morris
Talk: “Establishing uniform stability of approximated infinite-dimensional systems”
Abstract:
The abstract of this invited talk will be added when available.
Cristina Pignotti
University of L'Aquila, Italy
© Cristina Pignotti
Talk: “Generalized Korteweg–de Vries–Burgers equations with time-varying delay: Well-posedness and exponential stability”
Abstract:
We investigate a generalized Korteweg–de Vries–Burgers equation on the real line with indefinite
damping and a time-varying delay. By combining semigroup techniques with suitable Lyapunov functionals, we
establish global well-posedness of the problem under appropriate growth assumptions on the nonlinear term,
assuming only that the delay is continuous.
We then derive exponential-stability estimates under suitable assumptions on the model parameters, thereby
improving existing results in the literature. For sufficiently regular time-varying delays, these conditions are
independent of the delay magnitude.
Nathanael Skrepek
University of Twente, The Netherlands
© Nathanael Skrepek
Talk: “Boundary stabilization of Maxwell’s equations”
Abstract:
The abstract of this invited talk will be added when available.