A Gaussian Theory of Superfluid--Bose-Glass Phase Transition

We show that gaussian quantum fluctuations, even if infinitesimal, are sufficient to destroy the superfluidity of a disordered boson system in 1D and 2D. The critical disorder is thus finite no matter how small the repulsion is between particles. Within the gaussian approximation, we study the nature of the elementary excitations, including their density of states and mobility edge transition. We give the gaussian exponent $\eta$ at criticality in 1D and show that its ratio to $\eta$ of the pure system is universal.Comment: Revtex 3.0, 11 pages (4 figures will be sent through airmail upon request

Dynamic properties of models of modulated systems in condensed matter

SIGLEAvailable from British Library Document Supply Centre- DSC:DX92268 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The DIATS project: Deployment of inter-urban ATT test scenarios

Describes the DIATS project which is concerned with the development of scenarios describing the deployment of interurban and periurban ATT measures based on co-operative driving concepts, DGVII Task 7.3/20. The main output of the project will be an assessment of these scenarios (including an indication of the robustness of the likely forecasts), in terms of both content and timing, with key alternatives and issues being identified, and their implications considered. To achieve this output, research activities will address three interim goals that divide the project into its main functional stages<br/

Development of a fuzzy logic based microscopic motorway simulation model

Reports on progress in the development of a new microscopic model of interurban traffic, uses fuzzy modelling techniques to describe behavioural processes. Emphasis is placed on work undertaken in establishing, implementing and calibrating a new set of driving rules for both car following and lane changing, using both 'traditional' and new methods, such as the use of an instrumented vehicle