UK Nonlinear News, Sept. 1995

Recent Theses

University of St Andrews

`Hysteresis and mode competition in Faraday waves'
by Stephen P. Decent (University of St.Andrews, 1995)

Part has already appeared as "Hysteresis in Faraday Resonance" J. Fluid Mech. 293, 237-268

Supervisor: Alex Craik (

UCL Chemical and Biochemical Engineering

`Quantification of Inverse Response for Controllability Analysis of Nonlinear Processes'
by Kenneth Trickett (University of London, 1995)
All chemical process design is currently done in terms of optimising the steady state of a continuous process. However optimised plants often are difficult to control in practice and so it is important to analyse the dynamics and controllability of the proposed plant during the design stage. Techniques from Differential Geometry are used to analyse the nonlinear behaviour directly.
David Bogle (

UCL Centre for Nonlinear Dynamics and its Applications

`Phase Locking in Nonlinear Driven Oscillators'
by Tan Ngiap Heng (University of London, 1995)
The study examines rich bifurcational behaviour and chaos in an archetypal system, the forced pendulum with torque. The stability of period one oscillations is emphasised as it has direct implications on several physical systems including the demodulating phase locked loop. Experimental results for this, and reconstructed attractors, are compared with numerical bifurcation-following predictions. Homoclinic tangencies are followed using numerical and Melnikov methods.

`Geometric Methods of Nonlinear Dynamics in Ship Capsize'
by Jesse R. de Souza, Jnr. (University of London, 1995)

Despite many accomplishments in the detailed mathematical modelling of large-amplitude ship motions, a corresponding understanding of the dynamics of these models has still to be achieved. Instead this work examines a model reduced to coupled heave-roll motion, including direct and parametric resonances. Geometric nonlinear dynamics is used to understand this model, and to follow its attractors, their bifurcations, and the transient and steady-state basin erosion phenomena. This leads to a simple yet robust method to evaluate the dynamic stability of ships.

Supervisor: J.M.T.Thompson (

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