Andrew Parkes

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We make a change of field variables in the J formulation of self-dual Yang–Mills theory. The field equations for the resulting algebra valued field are derivable from a simple cubic action. The cubic interaction vertex is different from that considered previously from the N=2 string, however, perturbation theory with this action shows that the only(More)
Alcohol-induced hangover, defined by a series of symptoms, is the most commonly reported consequence of excessive alcohol consumption. Alcohol hangovers contribute to workplace absenteeism, impaired job performance, reduced productivity, poor academic achievement, and may compromise potentially dangerous daily activities such as driving a car or operating(More)
This study examined the legibility of information presented on head-up displays (HUDs) for automotive application as a function of background scene complexity, the position of the HUD within field of view relative to the background scene, and the perceptual capacity of the perceiver. Groups of field-dependent and field-independent subjects viewed video(More)
The driving performance of 15 subjects in a simulated road environment has been studied both with and without a hands-free telephone conversation. Previous research on the interference of the manual use of handsets while driving, or when looking at handsfree conversations, has tended to focus on the operational control performance of the driver. This study(More)
This paper discusses the limitations and potential of using an occlusion test to assess visual distraction and the suitability of an in-vehicle information system (IVIS) task for driving. This discussion was expanded from issues raised during a UK workshop on occlusion. The paper describes the research history and empirical foundations of occlusion. It(More)
Train driving is primarily a visual task; train drivers are required to monitor the dynamic scene visually both outside and inside the train cab. Poor performance on this visual task may lead to errors, such as signals passed at danger. It is therefore important to understand the visual strategies that train drivers employ when monitoring and searching the(More)
This paper reports the results of a pilot study designed to evaluate the effect of an energy drink on mental performance and driving. 24 healthy subjects were tested after consumption of a placebo or an energy drink in a double-blind crossover study. Measures included a laboratory test of Adaptive Tracking (AT), and a simulated drive involved a 40 Km(More)
Ooguri and Vafa have shown that the open N=2 string corresponds to self-dual Yang-Mills (SDYM) and also that, in perturbation theory, it has has a vanishing four particle scattering amplitude. We discuss how the dynamics of the three particle scattering implies that on shell states can only scatter if their momenta lie in the same self-dual plane and then(More)
Towards optimal Newton-type methods for nonconvex smooth optimization Coralia Cartis Coralia.Cartis (at) ed.ac.uk School of Mathematics, Edinburgh University We show that the steepest-descent and Newton methods for unconstrained non-convex optimization, under standard assumptions, may both require a number of iterations and function evaluations arbitrarily(More)
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