Understanding object feature binding through experimentation as a precursor to modelling

In order to explore underlying brain mechanisms and to further understand how and where object feature binding occurs, psychophysical data are analysed and will be modelled using an attractor network. This paper describes psychophysical work and an outline of the proposed model. A rapid serial visual processing paradigm with a post-cue response task was used in three experimental conditions: spatial, temporal and spatio-temporal. Using a ‘staircase’ procedure, stimulus onset asynchrony for each observer for each condition was set in practice trails to achieve ~50% error rates. Results indicate that spatial location information helps bind objects features and temporal location information hinders it. Our expectation is that the proposed neural model will demonstrate a binding mechanism by exhibiting regions of enhanced activity in the location of the target when presented with a partial post-cue. In future work, the model could be lesioned so that neuropsychological phenomena might be exhibited. In such a way, the mechanisms underlying object feature binding might be clarified

Measurements of Grain Motion in a Dense, Three-Dimensional Granular Fluid

We have used an NMR technique to measure the short-time, three-dimensional displacement of grains in a system of mustard seeds vibrated vertically at 15g. The technique averages over a time interval in which the grains move ballistically, giving a direct measurement of the granular temperature profile. The dense, lower portion of the sample is well described by a recent hydrodynamic theory for inelastic hard spheres. Near the free upper surface the mean free path is longer than the particle diameter and the hydrodynamic description fails.Comment: 4 pages, 4 figure

A Computer Graphics Head-Up Display for Air-To-Air and Air-To-Ground Flight Simulation

A computer graphics simulation of an aircraft Head-Up Display was designed using an RDS-3000 Ikonas Graphics Processor and a PDP-11/34 host computer system. The software control and display modules were accomplished using Ikonas microcode and Digital Equipment Corporation Fortran IV-PLUS. The Head-Up Display system consists of the basic flight data, which includes aerodynamic flight information, Roll/Pitch Ladder, and the Velocity Vector or Flight Path Marker. The system was designed for flexibility in modifications and evaluation of various weapons delivery systems. These will be adapted to specific needs by research scientists and engineers at the Visual Technology Research Simulator in Orlando, Florida

Recent Experiences of Tunneling and Deep Excavations in London

The paper focuses on recent developments in tunnelling and deep excavations in London and it draws on the experiences of the Jubilee Line Extension project which has just been completed. A brief historical review is given of the first tunnels and deep excavations undertaken in London some 150 years ago. Construction methods recently used for bored tunnelling include sprayed concrete linings and closed face pressurised tunnelling machines. Ground movements observed for these various tunnelling operations and for deep excavations are reviewed, and their effects on buildings are discussed. The most extensive protective measure used on the Jubilee Line Extension to control deformations and potential damage to historic buildings has been the relatively new technique of compensation grouting. Examples of its use are presented

Evaluation of existing and new methods of tracking glacier terminus change

ACKNOWLEDGEMENTS The authors thank two anonymous reviewers for constructive comments that helped to improve the manuscript. This research was financially supported by J.M.L.’s PhD funding from UK Natural Environment Research Council grant No. NE/I528742/1.Peer reviewedPublisher PD