# Professor George Halikias

## Contact

- Professor George Halikias
- +44 (0)20 7040 8930
- g.halikias@city.ac.uk

## Postal Address

Northampton Square

London

EC1V 0HB

United Kingdom

## About

### Overview

Dr Halikias was born in Athens, Greece in December 1961. He obtained his undergraduate degree in Engineering Science from Magdalen College, Oxford University in July 1983. He then studied Control Systems Engineering at the Department of Electronic and Electrical Engineering at Imperial College, London, and was awarded his M.Sc. and Ph.D. degrees in October 1984 and May 1990, respectively.

Between January 1988 and July 1991 he was a member of the Industrial Systems Group at Imperial College and worked as a Research Engineer for Greycon Consultants and as a Research Fellow at the Interdisciplinary Research Centre of Process Systems Engineering. Between July 1991 and August 2000 he was a Lecturer in Control Systems at the Department of Electronic and Electrical Engineering, University of Leeds.

In September 2000 he joined City University as Senior Lecturer in Systems, Modelling and Control Theory, and in August 2008 he was appointed Reader in Control Engineering. His main research interests are in the areas of Robust Control, Systems theory, Multivariable systems design, Model reduction, Convex Optimisation and Modelling and Control applications in the areas of Networks, Mechanical Systems, Business Processes and Supply Chains. He is a member of IEEE and IET, Academic Secretary of IMA's Control Theory Group and Associate Editor of the IMA Journal of Mathematical Control and Information.

## Research

### Research interests

- Robust and H-Infinity optimal control

- Multivariable System Design

- Filtering and Estimation

- Model Reduction

- Multiple-objective optimisation

- Dynamic Programming, Stochastic Modelling and Control

- Numerical methods

- Computer Aided Design

- Modelling and Control of Flexible Structures

- Modelling and Control of Active Suspension Systems

## Publications

### Chapters (4)

- Meintanis, I., Halikias, G., Giovenco, R., Yiotis, A. and Chrysagis, K. (2017).
**Identification and Model Predictive Control Design of a Polymer Extrusion Process.***Computer Aided Chemical Engineering*(pp. 1609–1614). - Halikias, G., Dritsas, L., Tsoulkas, V., Kontoes, C. and Leventakis, G. (2011).
**Design issues of an Operational Fire Detection System Integrated with Observation Sensors.**In Masoumeh Karimi, and Yuri Labrador, (Eds.),*in Advances in Satellite Communications*InTech. ISBN 978-953-307-562-4. - Zolotas, A.C., Goodall, R.M. and Halikias, G. (2002).
**New Control strategies for tilting trains.**In Hans True, (Ed.),*The Dynamics of Vehicles on Roads and Tracks*(pp. 171–182). - Limebeer, D.J.N., Halikias, G. and Glover, K. (1988).
**State-space algorithm for the computation of super-optimal matrix interpolating functions.**In Byrnes, C.I., Martin, C.F. and Saeks, R.E. (Eds.),*in Linear Circuits, Systems and Signal Processing: Theory and Applications*New York: North-Holland, Elsevier Science Publishers.

### Conference papers and proceedings (54)

- Meintanis, I., Halikias, G., Giovenco, R., Yiotis, A. and Chrysagis, K. (2017).
**Closed-loop Identification of an Industrial Extrusion Process.** - Mamouei, M.H., Kaparias, I. and Halikias, G. (2016).
**Using unscented particle filtering as a tool for the comparison of car-following models.***95th Annual Meeting of the Transportation Research Board*Washington, DC, USA. - Tomic, I. and Halikias, G.D. (2016).
**Performance analysis of distributed control configurations in LQR multi-agent system design.** - Tomic, I., Milonidis, E. and Halikias, G.D. (2016).
**LQR distributed cooperative control of a formation of low-speed experimental UAVs.** - Mamouei, M., Kaparias, I. and Halikias, G. (2016).
**A quantitative approach to the behavioural analysis of drivers in highways using particle filtering.** - Mamouei, M.H., Kaparias, I. and Halikias, G. (2015).
**A quantitative approach to behavioural analysis of drivers in highways using particle filtering.***47th Annual Conference of the Universities’ Transport Study Group*London, UK. - Halikias, G. (2014).
**Strong stability and the Cayley transform.** - Apostolopoulos, C., Halikias, G., Maroukian, K. and Tsaramirsis, G. (2014).
**Measuring change risk for organisational decision making through a hierarchical model process approach.** - Karcanias, N. and Halikias, G. (2011).
**Approximate Zero Polynomials of Polynomial Matrices and Linear Systems.***IEEE joint CDC-ECC Conference*December. - Michail, K., Zolotas, A., Goodall, R. and Halikias, G. (2011).
**Optimal Selection for Sensor Fault Tolerance Control of an EMS system via Loop-Shaping Robust Control.***Mediterranean Conference*Corfu, Greece. - Michail, K., Zolotas, A.C., Goodall, R.M. and Halikias, G. (2011).
**Optimal selection for sensor fault tolerant control of an EMS system via loop-shaping robust control.** - Pantelous, A. and Karcanias, N. (2010).
**Approximating distributional behaviour of linear systems using Gaussian function and its derivatives.***IFAC Symposium SSSC10*15-17 September, Ancona, Italy. - Michail, K., Zhou, Y., Zolotas, A., Goodall, R. and Halikias, G. (2010).
**Optimised sensor configurations with reduced order controllers applied to an EMS system.**29-31 July, Beijing, China. - Karcanias, N. and Fatouros, S. (2009).
**Approximate Zeros of Polynomial Matrices and Linear Systems.***European Control Conference 2009*23-26 August, Budapest, Hungary. - Karcanias, N., Halikias, G., Papageorgiou, A. and (2006), (2007).
**Strong Stability of Internal System Descriptions.***European Control Conference ECC 07*2-5 July, Kos, Greece. - Nandakumar, R., Halikias, G. and Zolotas, A. (2007).
**Robust Control of a Hydraulic Actuator using the QFT method.***European Control Conference (ECC07)*July, Kos, Greece. - Kiskiras, J., Halikias, G. and Jaimoukha, I.M. (2007).
**Robust stabilization of multivariable systems under coprime factor perturbations: Directionality and Super-optimization.***European Control Conference (ECC07)*July, Kos, Greece. - Halikias, G., Rentzos, P. and Virdi, K. (2006).
**Vibration Control of Civil Engineering structures via Linear Programming.***4rth World Conference on Structural Control and Monitoring*11-13 July, San-Diego, California, USA. - Papanagnou, C. and Halikias, G. (2006).
**Analysing different ordering policies in a series supply chain by using coloured Petri nets.**28-31 May, Bonn, Germany. - Papanagnou, C.I. and Halikias, G.D. (2006).
**Supply chain modelling and control under proportional inventory replenishment policies.**17-19 May, Saint-Etienne, France. - Halikias, G. and Jaimoukha, I.M. (2006).
**Robust stabilisation of multivariable systems: Directionality and super-optimisation.***International Conference on Modern Mathematical Methods in Science and Technology (IM3ST)*Paros, Greece. - Papanagnou, C.I. and Halikias, G.D. (2006).
**Analysing different ordering policies in a series supply chain by using Coloured Petri nets.** - Zolotas, A., Halikias, G., Goodall, R. and Wang, J. (2006).
**Model Reduction studies in LQG optimal control design for high-speed tilting railway carriages.** - Papanagnou, C. and Halikias, G. (2005).
**A state-space approach for analysing the bullwhip effect in supply chains.***5th International Conference on Technology and Automation*October, Thessaloniki, Greece. - Tougiannidis, L., Iezekiel, S., Pollard, R.D. and Halikias, G. (2005).
**An efficient two layer spiral inductor configuration.***12th International IEEE Conference on Mixed Design of Integrated Circuits and Systems*22-25 June, Krakow. - Tougiannidis, L., Iezekiel, S., Pollard, R.D. and Halikias, G. (2005).
**Design of spiral inductors using evolutionary optimization.***12th International IEEE Conference on Mixed Design of Integrated Circuits and Systems Krakow*22-25 June. - Nandakumar, R., Halikias, G.D. and Zolotas, A.C. (2003).
**A new educational software tool for robust control design using the QFT method.**9-12 December, Maui, Hawaii, USA. - Kiskiras, J. and Halikias, G. (2003).
**A Note on the Complex Matrix Procrustes Problem.**1-4 September, Cambridge, UK. - Halikias, G. and Jaimoukha, I.M. (2003).
**Design of approximately linear-phase Infinite Impulse Response filters via optimal Hankel-norm approximation.**1-4 September, Cambridge, UK. - Fatouros, S., Karcanias, N. and Halikias, G. (2003).
**Approximate greatest common divisor of many polynomials and generalised resultants.**1-4 September, Cambridge, UK. - Halikias, G., Fatouros, S. and Karcanias, N. (2003).
**Approximate Greatest Common Divisor of polynomials and the Structured Singular Value.***European Control Conference ECC 03*1-4 September, Cambridge. - Halikias, G.D. and Jaimoukha, I.M. (2003).
**Design of Infinite Impulse Response (IIR) filters with almost linear phase characteristics.** - Halikias, G., Fatouros, S. and Karcanias, N. (2003).
**Approximate greatest common divisor of polynomials and the structured singular value.** - Halikias, G.D. and Jaimoukha, I.M. (2003).
**Design of Infinite Impulse Response (IIR) filters with almost linear phase characteristics.** - Kiskiras, J. and Halikias, G.D. (2003).
**A note on the complex matrix procrustes problem.** - Karcanias, N., Fatouros, S., Mitrouli, M. and Halikias, G. (2003).
**Approximate greatest common divisor of many polynomials and generalised resultants.** - Nandakumar, R., Halikias, G. and Zolotas, A. (2002).
**An optimisation algorithm for designing fixed-structure controllers using the QFT method.***2002 International Symposium on Computer-Aided Control System Design Proceedings (IEEE CCA02-CACSD)*18-20 September, Glasgow, UK. - Karcanias, N., Fatouros, S., Mitrouli, M. and Halikias, G. (2002).
**Approximate Greatest Common Divisor of polynomials and Generalised Resultant.**25-28 June, Volos, Greece. - Gungah, S.K., Malik, U., Jaimoukha, I.M. and Halikias, G.D. (2001).
**A new upper bound for the real structured singular value.**December, Orlando, FL, USA. - Zolotas, A.C., Goodall, R.M. and Halikias, G.D. (2003).
**New control strategies for tilting trains.***International Association for Vehicle System Dynamics Symposium No17, (IAVSD 2001)*Sep 2001, Copenhagen, Denmark. - Wang, J., Wilson, D.A. and Halikias, G.D. (2001).
**H∞ robust-performance control of decoupled active suspension systems based on LMI method.**25-27 June, Arlington, VA, USA. - Tziakas, D., Stakos, D., Apostolou, E., Papadopoulos, E., Halikias, G., Kekes, A. … Hatseras, D. (2001).
**Dramatic reduction of interleukin-6 and TNF-alpha levels in hypercholesteraemic patients after 3 months treatment with cerivastatin.** - Gungah, S.K., Halikias, G.D. and Jaimoukha, I.M. (2000).
**Maximally robust controllers for multivariable systems.**December, Sydney, NSW, Australia. - Zolotas, A.C., Halikias, G. and Goodall, R.M. (2000).
**A comparison of tilt control approaches for high speed railway vehicles.**September, Coventry, UK. - Orozco-Lugo, A.G., McLernon, D.C., Halikias, G.D. and Wilson, D.A. (1999).
**A new blind identification algorithm based on cyclostationarity and the bandlimited property of the communication channel.***IEE Symposium on Novel DSP Algorithms and Computer Architectures*28 September, London. - Plummer, , Sutton, R.P., Wilson, D.A. and Halikias, G. (1998).
**Experimental results in the vibration control of a highly flexible manipulator.**25-28 August. - Sutton, R.P., Halikias, G.D., Plummer, A.R. and Wilson, D.A. (1997).
**Robust control of a lightweight flexible manipulator under the influence of gravity.***IEEE Conference on Control Applications*5-7 October, Hartford, Conneticut, USA. - Richards, G.W., Halikias, G. and Wilson, D.A. (1996).
**A robust controller for a two-link flexible manipulator with variable payload.**Singapore. - Halikias, G.D. and Jaimoukha, I.M. (1996).
**Hierarchical optimisation in H∞.** - Halikias, G.D. (1994).
**Hierarchical H∞/H2-optimal control problem.**December, Lake Buena Vista, Orlando, FL, USA. - Halikias, G.D. (1993).
**The Structured H2-optimal control problem.**December, San-Antonio, USA. - Cashmore, R.D., Halikias, G. and Wilson, D.W. (1993).
**Adaptive and Robust control of a flexible manipulator system.***Inst. Measurement and Control/PRS*June, University of Nottingham. - Limebeer, D.J.N., Halikias, G. and Glover, K. (1987).
**A state-space algorithm for the computation of super-optimal matrix interpolating functions.**15-19 June, Phoenix, AZ, US. - Halikias, G. and Limebeer, D.J.N. (1986).
**A controller degree bound for optimal control problems of the second kind.**December, Athens, Greece.

### Journal articles (44)

- Apostolopoulos, C., Halikias, G., Maroukian, K. and Tsaramirsis, G. (2016).
**Facilitating organisational decision making: a change risk assessment model case study.***Journal of Modelling in Management*,*11*(2), pp. 694–721. doi:10.1108/JM2-05-2014-0035. - Tomić, I. and Halikias, G.D. (2016).
**Robustness Properties of Distributed Configurations in Multi-Agent Systems. This work was supported by a City University scholarship held by Ivana Tomić.***IFAC-PapersOnLine*,*49*(9), pp. 86–91. doi:10.1016/j.ifacol.2016.07.500. - Berger, T., Halikias, G. and Karcanias, N. (2015).
**Effects of dynamic and non-dynamic element changes in RC and RL networks.***International Journal of Circuit Theory and Applications*,*43*(1), pp. 36–59. doi:10.1002/cta.1923. - Halikias, G., Galanis, G., Karcanias, N. and Milonidis, E. (2013).
**Nearest common root of polynomials, approximate greatest common divisor and the structured singular value.***IMA Journal of Mathematical Control and Information*,*30*(4), pp. 423–442. doi:10.1093/imamci/dns032. - Halikias, G.D., Karcanias, N. and Papageorgiou, A. (2013).
**The distance to strong stability.***Linear Algebra and Its Applications*,*439*(10), pp. 2721–2735. doi:10.1016/j.laa.2013.09.003. - Milonidis, E., Halikias, G., Galanis, G. and Karcanias, N. (2013).
**Nearest common root of polynomials, approximate Greatest Common Divisor and the structured singular value.***Journal of Mathematical Control and Information*. - Karcanias, N. and Halikias, G. (2013).
**Approximate zero polynomials of polynomial matrices and linear systems.***Linear Algebra and Its Applications*,*439*(4), pp. 1091–1103. doi:10.1016/j.laa.2012.12.027. - Karcanias, A., Stupples, D. and Halikias, G. (2012).
**Impact of stochastic renewables on CO2levels and targets.***Carbon Management*,*3*(4), pp. 383–391. doi:10.4155/cmt.12.33. - Halikias, G., Dritsas, L., Pantelous, A. and Tsoulkas, V. (2012).
**Strong stability of discrete-time systems.***Linear Algebra and Its Applications*,*436*(7), pp. 1890–1908. doi:10.1016/j.laa.2011.09.024. - Kiskiras, J., Jaimoukha, I.M. and Halikias, G.D. (2012).
**An explicit state-space solution to the one-block super-optimal distance problem.***Mathematics of Control, Signals, and Systems*pp. 1–30. - Karcanias, N. and Halikias, G. (2011).
**Approximate zero polynomials of polynomial matrices and linear systems.***Proceedings of the IEEE Conference on Decision and Control*pp. 465–470. doi:10.1109/CDC.2011.6160302. - Papanagnou, C.I. and Halikias, G.D. (2011).
**Simulation and modelling methods in aluminium rolling industry.***International Journal of Advanced Manufacturing Technology*,*53*(9-12), pp. 993–1018. doi:10.1007/s00170-010-2880-3. - Papanagnou, C. and Halikias, G. (2011).
**Stochastic state space in supply chains under AR(1) demand profiles.***Int. J. Mathematics in Operational Research*,*3*(5), pp. 578–594. - Halikias, G., Dritsas, L., Pantelous, A. and Tsoulkas, V. (2011).
**Strong stability of discrete-time systems.***Linear Algebra and Its Applications*. - Halikias, G., Tsoulkas, V., Pantelous, A. and Milonidis, E. (2010).
**Hankel-norm approximation of FIR filters: A descriptor-systems based approach.***International Journal of Control*,*83*(9), pp. 1858–1867. doi:10.1080/00207179.2010.498059. - Halikias, G., Papageorgiou, A. and Karcanias, N. (2010).
**Non-overshooting stabilisation via state and output feedback.***International Journal of Control*,*83*(6), pp. 1232–1247. doi:10.1080/00207171003664844. - Karcanias, N., Halikias, G. and Papageorgiou, A. (2010).
**Strong stability of internal system descriptions.***International Journal of Control*,*83*(1), pp. 182–205. doi:10.1080/00207170903124669. - Papanagnou, C.I. and Halikias, G.D. (2008).
**Supply-chain modelling and control under proportional inventory- replenishment policies.***International Journal of Systems Science*,*39*(7), pp. 699–711. doi:10.1080/00207720802090898. - Halikias, G.D., Jaimoukha, I.M., Malik, U. and Gungah, S.K. (2007).
**New bounds on the unconstrained quadratic integer programming problem.***Journal of Global Optimization*,*39*(4), pp. 543–554. doi:10.1007/s10898-007-9155-z. - Halikias, G., Milonidis, E. and Jaimoukha, I.M. (2007).
**Robust stabilisation of multivariable systems: Directionality and super-optimisation.***Special Issue on Modern Mathematical Methods in Science and Technology, Bulletin of the Greek Mathematical Society*,*54*, pp. 143–166. - Kiskiras, J. and Halikias, G.D. (2007).
**A note on the complex semi-definite matrix Procrustes problem.***Numerical Linear Algebra with Applications*,*14*(6), pp. 485–502. doi:10.1002/nla.535. - Halikias, G.D., Zolotas, A.G. and Nandakumar, R. (2007).
**Design of optimal robust fixed-structure controllers using the quantitative feedback theory approach.***Proceedings of the Institution of Mechanical Engineers. Part I: Journal of Systems and Control Engineering*,*221*(4), pp. 291–312. - Zolotas, A.C., Goodall, R.M. and Halikias, G.D. (2007).
**Recent results in tilt control design and assessment of high-speed railway vehicles.***IMECHE Journal of Railway and Rapid Transit*,*221*(2), pp. 291–312. - Halikias, G.D., Zolotas, A.C. and Nandakumar, R. (2007).
**Design of optimal robust fixed-structure controllers using the quantitative feedback theory approach.***PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART I-JOURNAL OF SYSTEMS AND CONTROL ENGINEERING*,*221*(I4), pp. 697–716. doi:10.1243/09596518JSCE305. - Jaimoukha, I.M., Halikias, G.D., Malik, U. and Gungah, S.K. (2006).
**On the gap between the complex structured singular value and its convex upper bound.***SIAM Journal on Control and Optimization*,*45*(4), pp. 1251–1278. doi:10.1137/040617340. - Malik, U., Jaimoukha, I.M., Halikias, G.D. and Gungah, S.K. (2006).
**On the gap between the quadratic integer programming problem and its semidefinite relaxation.***Mathematical Programming*,*107*(3), pp. 505–515. doi:10.1007/s10107-005-0692-2. - Karcanias, N., Fatouros, S., Mitrouli, M. and Halikias, G.H. (2006).
**Approximate greatest common divisor of many polynomials, generalised resultants, and strength of approximation.***Computers and Mathematics with Applications*,*51*(12), pp. 1817–1830. doi:10.1016/j.camwa.2006.01.010. - Gungah, S.K., Halikias, G.D. and Jaimoukha, I.M. (2000).
**Maximally robust controllers for multivariable systems.***SIAM Journal on Control and Optimization*,*38*(6), pp. 1805–1829. doi:10.1137/S0363012999350559. - Sutton, R.P., Halikias, G.D., Plummer, A.R. and Wilson, D.A. (1999).
**Modelling and H∞control of a single-link flexible manipulator.***Proceedings of the Institution of Mechanical Engineers. Part I: Journal of Systems and Control Engineering*,*213*(2), pp. 85–102. - Halikias, G., Sutton, R.P., Plummer, A.R. and Wilson, D.A. (1999).
**Modelling and H-infinity control of a lightweight flexible manipulator.***Proc. Instn. Mech. Engrs. (IMECHE)*,*213*(1), pp. 85–104. - Zolotas, A.C. and Halikias, G.D. (1999).
**Optimal design of PID controllers using the QFT method.***IEE Proceedings: Control Theory and Applications*,*146*(6), pp. 595–599. - Halikias, G.D. and Jaimoukha, I.M. (1998).
**Hierarchical optimization in H∞.***IEEE Transactions on Automatic Control*,*43*(8), pp. 1123–1128. doi:10.1109/9.704986. - Davies, R. and Halikias, G.D. (1998).
**Hierarchical ℋ∞/ℋ2 optimal control:the 2-block problem.***International Journal of Control*,*70*(6), pp. 965–1017. - Halikias, G.D. and Jaimoukha, I.M. (1998).
**The two-Block Superoptimal AAK Problem.***Mathematics of Control, Signals, and Systems*,*11*(3), pp. 244–264. - Wilson, D.A., Nekoui, M.A. and Halikias, G.D. (1998).
**An LQR weight selection approach to the discrete generalized H-infinity control problem.***International Journal of Control*,*71*(1), pp. 93–101. - Halikias, G.D., Jaimoukha, I.M. and Wilson, D.A. (1997).
**A numerical solution to the matrix ℋ2/ℋ∞ optimal control problem.***International Journal of Robust and Nonlinear Control*,*7*(7), pp. 711–726. doi:10.1002/(SICI)1099-1239(199711)7:7<711::AID-RNC251>3.0.CO;2-8. - Bryant, G.F. and Halikias, G.D. (1995).
**Optimal loop-shaping for systems with large parameter uncertainty via linear programming.***International Journal of Control*,*62*(3), pp. 556–568. doi:10.1080/00207179508921556. - Halikias, G.D. (1995).
**The Structured H2-optimisation problem.***International Journal of Control*,*61*(6), pp. 1223–1232. - Halikias, G. (1993).
**An affine parametrisation of all one-block optimal matrix interpolating functions.***International Journal of Control*,*57*(6), pp. 1421–1441. - Halikias, G.D., Limebeer, D.J.N. and Glover, K. (1993).
**A State-space algorithm for the superoptimal Hankel-norm approximation problem.***SIAM Journal on Control and Optimization*,*31*(4), pp. 960–982. - Halikias, G. (1991).
**A class of optimal solutions to the matrix Nehari-extension problem.***International Journal of Robust and Nonlinear Control*,*1*(1), pp. 7–31. - Limebeer, D.I. (1989).
**State-space algorithm for the computation of superoptimal matrix interpolating functions.***International Journal of Control*,*50*(6), pp. 2431–2466. doi:10.1080/00207178908953509. - Limebeer, D.J.N. and Halikias, G.D. (1988).
**A Controller degree bound for H∞-optimal control problems of the second kind.***SIAM Journal on Control and Optimization*,*26*(3), pp. 646–677. - Limebeer, D.J.N. and Halikias, G. (1986).
**CONTROLLER DEGREE BOUND FOR H infinity -OPTIMAL CONTROL PROBLEMS OF THE SECOND KIND.***Proceedings of the IEEE Conference on Decision and Control*pp. 1802–1803.

### Report

- Newby, M.J., Halikias, G., Karcanias, N. and Khan, S. (2000).
**Train Dynamics Research: Modelling Requirements For Global Train Accident/Collision Dynamics.**.