Prediction of reactionary delay and cost using machine learning

Estimating the potential propagation of delay (and its associated cost) is crucial for the management of the fleet the day of operations. As the flight departure approaches, these estimations need to be as accurate as possible to support pre-tactical and tactical interventions aiming at minimising the network disruption. Dispatcher3 project aims at the use of machine learning models for the prediction and analysis of differences between planned and executed flight plans. Models corresponding to different time-horizons (from departure time to 15 hours before) are developed to predict the flying and turnaround times. These models are combined (with other operational parameters) to estimate reactionary delay and associated expected costs (including potential breaching of curfews). The outcome (delay and costs) is presented as probability distributions. This information could be used to support the flight planning process and the management of the fleet

Crossover temperature of Bose-Einstein condensation in an atomic Fermi gas

We show that in an atomic Fermi gas near a Feshbach resonance the crossover between a Bose-Einstein condensate of diatomic molecules and a Bose-Einstein condensate of Cooper pairs occurs at positive detuning, i.e., when the molecular energy level lies in the two-atom continuum. We determine the crossover temperature as a function of the applied magnetic field and find excellent agreement with the experiment of Regal et al. [Phys. Rev. Lett. 92, 040403 (2004)] that has recently observed this crossover temperature.Comment: 4 pages, 2 figure

J06587-5558 -- A Very Unusual Polarised Radio Source

We have found a peculiar radio source in the field of one of the hottest known clusters of galaxies 1E0657-56. It is slightly extended, highly polarised (54% at 8.8GHz) and has a very steep spectrum, with alpha ~ -1 at 1.3 GHz, steepening to ~ -1.5 at 8.8GHz (S \propto nu^alpha). No extragalactic sources are known with such high integrated polarisation, and sources with spectra as steep as this are rare. In this paper, we report the unusual properties of the source J06587-5558 and speculate on its origin and optical identification.Comment: 5 pages, 6 figures, accepted by MNRAS letter

Dispatcher3 D7.1 - Project communication, dissemination and exploitation plan

This document is the Communication, Dissemination and Exploitation Plan (D7.1) of the Clean Sky 2 Innovation Action Dispatcher3. The document defines the communication and dissemination actions to be performed during the project, and the potential exploitation of the project results. A complete strategy of communication is presented, as well as the items and content already prepared for it

Analyticity of the SRB measure for a class of simple Anosov flows

We consider perturbations of the Hamiltonian flow associated with the geodesic flow on a surface of constant negative curvature. We prove that, under a small perturbation, not necessarely of Hamiltonian character, the SRB measure associated to the flow exists and is analytic in the strength of the perturbation. An explicit example of "thermostatted" dissipative dynamics is constructed.Comment: 23 pages, corrected typo

Near-surface eddy dynamics in the southern ocean

The Antarctic Circumpolar Current (ACC) is a crucial component of the global ocean conveyor belt, acting as a zonal link among the major ocean basins but, to some extent, limiting meridional exchange and tending to isolate the ocean south of it from momentum and heat income. In this work we investigate one of the most important mechanisms contributing to the poleward transfer of properties in the Southern Ocean, that is the eddy component of the dynamics. For this particular purpose, observations obtained from near-surface drifters have been used: they represent a very useful data set to analyse the eddy field because of their ability to catch a large number of scales of motion while providing a quasi-synoptic coverage of the investigated area. Estimates of the eddy heat and momentum fluxes are carried out using data taken from the Global Drifter Program databank; they refer to Surface Velocity Program drifter trajectories collected in the area south of 35°S between 1995 and 2006. Eddy kinetic energies, variance ellipses, momentum and heat fluxes have been calculated using the pseudo-Eulerian method, showing patterns in good agreement with those present in the literature based on observational and model data, although there are some quantitative differences. The eddy fluxes have been separated into their rotational and divergent portions, the latter being responsible for the meridional transports. The associated zonal and depth-exponentially integrated meridional heat transport exhibits values spanning over a range between -0.4 PW and -1.1 PW in the ACC region, consistent with previous estimates. © 2011 M. Trani et al