I have been working as a postdoc research fellow at the Faculty of Applied Science of University of the West of England (UWE) since June 2006. My research at UWE is funded by the EPSRC Novel Computation initiative and is entitled "Non-linear Media Based Computers: Chemical and Neuronal Networks through Machine Learning". It involves developing new approaches to enable desired behaviour from networks of non-linear media using the light sensitive Belousov-Zhabotinsky (BZ) reaction. This project is in collaboration with the universities of Sussex, Leeds and UWE.
I worked as a postdoc research fellow in Physical Chemistry at the University of Leeds between May 2003 and May 2006.
The EPSRC funded research project in Leeds, "Waves and Coupling in Discontinuous Excitable Media", included control of pattern formation, desynchronization and synchronization of coupled oscillator systems (small ion exchange beads loaded with the catalyst) with light intensity, density of the system or stirring.
I obtained my PhD in the Nonlinear Chemical Dynamics Group at the University of Debrecen, in Hungary in 2002.
My research involved experimental studies of pattern formation in reaction-diffusion (universal dispersion relation of target patterns in excitable BZ media; a method for initiation of chemical waves in the BZ reaction by using laser) and reaction-diffusion-convection systems (differential flow induced chemical instability and pattern formation through flow distributed oscillations in the BZ media). During my PhD I took part in several research visits to the University of Leeds, UK, and Otto-von-Guericke Universitaet in Magdeburg, Germany, funded by the BRITHUNG and ESF REACTOR programmes.
Chemical Computing through Coevolution: In this study a light-sensitive sub-excitable B-Z reaction in which a checkerboard image comprised of varying light intensity cells projected onto the surface of a catalyst loaded gel is controlled using a heterogeneous cellular automaton. Pulses of wave fragments are injected onto the gel resulting in rich spatio-temporal behaviour and a coevolved cellular automaton is shown able to either increase or decrease chemical activity through dynamic control of the light intensity within each cell in both simulated and real chemical systems. The approach is then extended to create a number of simple logic gates.
Collision based computation in the subexcitable BZ reaction. A few examples of collisions.
Exploring the use of genetic algorithms to design collision based architecture-less computers, in collaboration with UWE's Unconventional Computing Group.
Oscillations and pattern formation in BZ reaction:
Synchronization and desynchronization of coupled oscillators in BZ reaction
Gaspar V, Toth R, Belmonte A, et al.
Universal dispersion relation of chemical waves in excitable media.
Abstract of papers of the American Chemical Society 218: 11-PHYS Part 2. Aug. 22. 1999
R. Tóth, V. Gáspár, A. Belmonte, M. C. O’Connell, A. Taylor, S. K. Scott,
Wave initiation in the ferroin-catalysed Belousov-Zhabotinsky reaction with visible light.
Phys. Chem. Chem. Phys., 2, 413-416, 2000
R. Tóth, A. Papp, V. Gáspár, J. H. Merkin, S. K. Scott, A. F. Taylor,
Flow-driven instabilities in the Belousov-Zhabotinsky reaction: Modelling and experiments.
Phys. Chem. Chem. Phys., 3, 957-964, 2001
J. R. Bamforth, J. H. Merkin, S. K. Scott, R. Tóth, V. Gáspár,
Flow-distributed oscillation patterns in the Oregonator model.
Phys. Chem. Chem. Phys., 3, 1435-1438, 2001
J. R. Bamforth, R. Tóth, V. Gáspár, S. K. Scott,
Scaling and dynamics of „flow distributed oscillation patterns” in the Belousov-Zhabotinsky reaction,
Phys. Chem. Chem. Phys., 4, 1299-1306, 2002
R. Toth, AF Taylor,
The tris(2,2 '-bipyridyl)ruthenium-catalysed Belousov-Zhabotinsky reaction
Progress in reaction kinetics and mechanism, 31 (2): 59-115 2006
R. Toth, AF Taylor,
Loss of coherence in a population of diffusively coupled oscillators
Journal of Chemical Physics, 125 (22): Art. No. 224708 Dec. 14 2006
R. Toth, AF Taylor, MR Tinsley,
Collective behavior of a population of chemically coupled oscillators
Journal Physical Chemistry B, 110 (20): 10170-10176 May 25 2006
Stone, C., Toth, R., Adamatzky, A., Bull, L. & De Lacy Costello, B,
Towards the Coevolution of Cellular Automata Controllers for Chemical Computing with the B-Z Reaction.
In D. Thierens et al. (eds) GECOO-2007: Proceedings of the Genetic and Evolutionary Computation Conference. ACM Press. 2007
Rita Toth, Christopher Stone, Andrew Adamatzky, Ben de Lacy Costello, Larry Bull
Experimental validation of binary collisions between wave-fragments in the photosensitive Belousov-Zhabotinsky reaction.
Chaos, Solitons & Fractals 2007
Rita Toth, Christopher Stone, Andrew Adamatzky, Ben de Lacy Costello & Larry Bull
Chemical Computing through Coevolution.
IEEE Transactions on Evolutionary Computation 2007