Grid-enabled Workflows for Industrial Product Design

This paper presents a generic approach for developing and using Grid-based workflow technology for enabling cross-organizational engineering applications. Using industrial product design examples from the automotive and aerospace industries we highlight the main requirements and challenges addressed by our approach and describe how it can be used for enabling interoperability between heterogeneous workflow engines

Accessing Patient Records in Virtual Healthcare Organisations

The ARTEMIS project is developing a semantic web service based P2P interoperability infrastructure for healthcare information systems that will allow healthcare providers to securely share patient records within virtual healthcare organisations. Authorisation decisions to access patient records across organisation boundaries can be very dynamic and must occur within a strict legislative framework. In ARTEMIS we are developing a dynamic authorisation mechanism called PBAC that provides a means of contextual and process oriented access control to enforce healthcare business processes. PBAC demonstrates how healthcare providers can dynamically share patient records for care pathways across organisation boundaries

Meteorological information in GPS-RO reflected signals

Vertical profiles of the atmosphere can be obtained globally with the radio-occultation technique. However, the lowest layers of the atmosphere are less accurately extracted. A good description of these layers is important for the good performance of Numerical Weather Prediction (NWP) systems, and an improvement of the observational data available for the low troposphere would thus be of great interest for data assimilation. We outline here how supplemental meteorological information close to the surface can be extracted whenever reflected signals are available. We separate the reflected signal through a radioholographic filter, and we interpret it with a ray tracing procedure, analyzing the trajectories of the electromagnetic waves over a 3-D field of refractive index. A perturbation approach is then used to perform an inversion, identifying the relevant contribution of the lowest layers of the atmosphere to the properties of the reflected signal, and extracting some supplemental information to the solution of the inversion of the direct propagation signals. It is found that there is a significant amount of useful information in the reflected signal, which is sufficient to extract a stand-alone profile of the low atmosphere, with a precision of approximately 0.1 %. The methodology is applied to one reflection case

Effects of Selected Roofing Materials and Angle of Incidence on Navaids Signal Strength

Interference that causes partial loss of intelligence in air navigation signal is largely dependent on the environment around radio navigation aids (navaids). Buildings around airports have been restricted partly because they pose a technical threat to flight navigation. Previous studies have shown that about 50% of air accidents occur during landing. However no data has been availed to determine the contribution of navaids to these accidents. The purpose of this paper was to determine the effects of roofing materials on air navigation signal strength. Radio transmitters, receivers and computers were used in a laboratory to measure signal level transmitted through six different roofing materials at a frequency of 9.4GHz. Decra offered the highest attenuation whereby 90% of the signal propagated was lost, out of which 60% was due to reflection. The equivalent transmission path field strength was 57dBmV/M against an International Civil Aviation Organization (ICAO) recommended minimum specification of minus 28dBmV/M. Similarly decra exhibited desired-to-undesired signal ratio of minus 16dB against ICAO recommended value of 20dB. Highest and lowest reflections occurred at angles of incidence of 90 and 135 degrees respectively. Generally roofing materials had little effect on navaids signal strength in the transmission paths but had significant effect in the reflection paths. Highly reflective roofing materials such as steel and decra are not recommended for use in aerodrome areas. Based on these findings, building industry and flight navigation authorities have been challenged to develop a compromise roofing material. Keywords: Interference, Navaids, Propagation, Signal strength, Aerodrom