Exploiting Tournament Selection for Efficient Parallel Genetic Programming

Genetic Programming (GP) is a computationally intensive technique which is naturally parallel in nature. Consequently, many attempts have been made to improve its run-time from exploiting highly parallel hardware such as GPUs. However, a second methodology of improving the speed of GP is through efficiency techniques such as subtree caching. However achieving parallel performance and efficiency is a difficult task. This paper will demonstrate an efficiency saving for GP compatible with the harnessing of parallel CPU hardware by exploiting tournament selection. Significant efficiency savings are demonstrated whilst retaining the capability of a high performance parallel implementation of GP. Indeed, a 74% improvement in the speed of GP is achieved with a peak rate of 96 billion GPop/s for classification type problems

Considering flexibility in the evolutionary dynamic optimisation of airport security lane schedules

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Airports face pressures to reduce costs at the security lane area by reducing lane opening hours whilst maintaining a passenger service level. Evolutionary methods have been shown to design schedules that minimise both objectives. However, by reducing lane opening hours schedules have a tendency to over-fit the expectation of passenger arrivals at security resulting in long delays with deviations from this forecast. Evolutionary dynamic re-optimisation can mitigate for this reducing passenger waiting times but the security lane problem is an example of a constrained problem in that schedules cannot be significantly altered. Consequently, this paper will investigate the consideration of flexibility when evolving initial schedules to facilitate the evolutionary dynamic re-optimization process. Several differing methods of measuring flexibility will be investigated alongside reducing security lane opening hours and passenger waiting times. Results demonstrate that considering flexibility in the initial design of schedules improves the effectiveness of evolutionary dynamic re-optimisation of schedules