To IEEE NTUA Student Branch διοργανώνει στις **17-1-2013**, στις **12.30 μ.μ.**, στο **Αμφιθέατρο Πολυμέσων** του κτιρίου βιβλιοθήκης ομιλία με θέμα **“Structural Transformations of Passive Electrical Networks and System Properties”** με ομιλητή τον καθηγητή Νίκο Καρκανιά. Περισσότερες λεπτομέρειες για το θέμα θα βρείτε παρακάτω.

**Nicos Karcanias**

Professor of Control Theory and Design, Associate Dean for Research,

Systems and Control Centre, Dept of Electrical Electronic and Information Engineering

School of Engineering and Mathematical Sciences

CITY UNIVERSITY LONDON, *N.Karcanias@city.ac.uk*

The paper examines the problem of systems redesign within the context of passive electrical networks and through analogies provides also the means of addressing issues of re-design of mechanical networks. The problem addressed here are special cases of the more general network redesign problem. Redesigning autonomous passive electric networks involves changing the network natural dynamics by modification of the types of elements, possibly their values, interconnection topology and possibly addition, or elimination of parts of the network. We investigate the modelling of systems, whose structure is not fixed but evolves during the system lifecycle. As such, this is a problem that differs considerably from a standard control problem, since it involves changing the system itself without control and aims to achieve the desirable system properties, as these may be expressed by the natural frequencies by system re-engineering. In fact, this problem involves the selection of alternative values for dynamic elements and non-dynamic elements within a fixed interconnection topology and/or alteration of the network interconnection topology and possible evolution of the cardinality of physical elements (increase of elements, branches). The aim of the paper is to define an appropriate representation framework that allows the deployment of control theoretic tools for the re-engineering of properties of a given network. We use impedance and admittance modelling for passive electrical networks and develop a systems framework that is capable of addressing “life-cycle design issues” of networks where the problems of alteration of existing topology and values of the elements, as well as issues of growth, or death of parts of the network are addressed.

We use the Natural Impedance/ Admittance (NI-A) models and we establish a representation of the different types of transformations on such models. This representation provides the means for an appropriate formulation of natural frequencies assignment using the Determinantal Assignment Problem framework defined on appropriate structured transformations. The developed natural representation of transformations are expressed as additive structured transformations. For the simpler case of RL or RC networks it is shown that the single parameter variation problem (dynamic or non-dynamic) is equivalent to Root Locus problems.

*Professor Nicos Karcanias is a graduate of NTUA of Athens in Electrical Engineering and has M.Sc. and Ph.D. in Control Engineering from UMIST (UK) and the DSc from City University. He is Professor of Control Theory and Design, Associate Dean for Research and Director of the Systems and Control Engineering Centre of the School of Engineering and Mathematical Sciences of City University London. He has published over 240 research papers and has supervised the completion of 27 Ph.D thesis. He is a Fellow of IET and IMA (UK), Editor of IMA Journal of Mathematical Control and Information. His research interests are in the areas of Control Theory, Algebraic and Geometric Methods, Systems Theory, Complex Systems, Systems Integration and Approximate Algebraic Computations and Linear Algebra. He has managed a number of EU research projects in the areas Process Systems and Control using Control ideas to problems such as Systems Integration and Design, study of Complex systems. His current research is focused on the development of systems and control methodology for complex systems, by developing the theory required for the new systems paradigms of “structure evolving systems”,the challenging notion of “system of systems” and developing an approximate and robust framework to exact algebraic synthesis problems.*

**UPDATE !**

**Παρακάτω μπορείτε να βρείτε την παρουσίαση της ομιλίας όπως πραγματοποιήθηκε από τον κ. Καρκανιά**