A theoretical study of the gamma-ray scattering technique for measuring atmospheric density Final report

Theoretical modeling study of gamma ray scattering technique for measuring atmospheric densit

Mathematical model predictions and optimization study of the gamma ray atmospheric density sensor

Mathematical model predictions and optimization study of gamma ray atmospheric density senso

Experimental verification of gamma ray atmospheric density sensor mathematical model predictions

Experimental verification of mathematical model performance predictions for gamma ray atmospheric density sensor

A Bayesian approach for determining player abilities in football

We consider the task of determining a football player’s ability for a given event type, for example, scoring a goal. We propose an interpretable Bayesian model which is fit using variational inference methods. We implement a Poisson model to capture occurrences of event types, from which we infer player abilities. Our approach also allows the visualisation of differences between players, for a specific ability, through the marginal posterior variational densities. We then use these inferred player abilities to extend the Bayesian hierarchical model of Baio and Blangiardo (2010, Journal of Applied Statistics, 37(2), 253–264) which captures a team’s scoring rate (the rate at which they score goals). We apply the resulting scheme to the English Premier League, capturing player abilities over the 2013/2014 season, before using output from the hierarchical model to predict whether over or under 2.5 goals will be scored in a given game in the 2014/2015 season. This validates our model as a way of providing insights into team formation and the individual success of sports teams

Managing crime and the fear of crime at railway stations––a case study in South Wales (UK)

Rail users consistently perceive their risks from crime to be significantly higher than official statistics suggest, discouraging many from using rail transport. The aims of the paper include a discussion of Crime Prevention Through Environmental Design (CPTED) and current policy initiatives for reducing crime and the fear of crime on the railways. This exploratory study focuses on adult passengers' perceptions of crime and nuisance as they relate to the management, design and maintenance of railway stations and their immediate access routes. The study innovatively utilises interactive virtual reality (VR) scenes of ‘representative' stations as the environmental stimulus and concludes that such an approach provides an analytical and pragmatic framework for managers of railway stations that are unlikely to receive Secure Station accreditation

Tackling Crime and Fear of Crime Whilst Waiting at Britain's Railway Stations

Crime on the railways in Britain is an increasing concern for train operating companies,the British Transport Police (BTP), passengers, and local residents. Significantly,rail users consistently perceive their risks from crime to be considerably higher thanofficial crime statistics indicate, having a negative affect on levels of patronage. Thisarticle presents an exploratory study of passengers’ fear of crime while waiting atrailway stations using Quick Time Virtual Reality (QTVR) walkthrough scenes. QTVRarguably represents an innovative, dynamic, and interactive environmental stimulusfor gaining insights into passengers’ fear of crime. Visibility at stations was identifiedas a crucial factor in determining levels of fear of crime. The design of the stationshelter is analyzed as an example of how crime prevention through environmentaldesign (CPTED) is being implemented on railway stations by Valley Lines (Wales and Borders Trains) on its network in South Wales (UK)

Vortex Structures Formed by the Interference of Sliced Condensates

We study the formation of vortices, vortex necklaces and vortex ring structures as a result of the interference of higher-dimensional Bose-Einstein condensates (BECs). This study is motivated by earlier theoretical results pertaining to the formation of dark solitons by interfering quasi one-dimensional BECs, as well as recent experiments demonstrating the formation of vortices by interfering higher-dimensional BECs. Here, we demonstrate the genericity of the relevant scenario, but also highlight a number of additional possibilities emerging in higher-dimensional settings. A relevant example is, e.g., the formation of a "cage" of vortex rings surrounding the three-dimensional bulk of the condensed atoms. The effects of the relative phases of the different BEC fragments and the role of damping due to coupling with the thermal cloud are also discussed. Our predictions should be immediately tractable in currently existing experimental BEC setups.Comment: 8 pages, 6 figures (low res). To appear in Phys. Rev. A. Full resolution preprint available at: http://www-rohan.sdsu.edu/~rcarrete/publications

Characterization of a 5-eV neutral atomic oxygen beam facility

An experimental effort to characterize an existing 5-eV neutral atomic oxygen beam facility being developed at Princeton Plasma Physics Laboratory is described. This characterization effort includes atomic oxygen flux and flux distribution measurements using a catalytic probe, energy determination using a commercially designed quadrupole mass spectrometer (QMS), and the exposure of oxygen-sensitive materials in this beam facility. Also, comparisons were drawn between the reaction efficiencies of materials exposed in plasma ashers, and the reaction efficiencies previously estimated from space flight experiments. The results of this study show that the beam facility is capable of producing a directional beam of neutral atomic oxygen atoms with the needed flux and energy to simulate low Earth orbit (LEO) conditions for real time accelerated testing. The flux distribution in this facility is uniform to +/- 6 percent of the peak flux over a beam diameter of 6 cm