Efficient data representation for XML in peer-based systems

Purpose - New directions in the provision of end-user computing experiences mean that the best way to share data between small mobile computing devices needs to be determined. Partitioning large structures so that they can be shared efficiently provides a basis for data-intensive applications on such platforms. The partitioned structure can be compressed using dictionary-based approaches and then directly queried without firstly decompressing the whole structure. Design/methodology/approach - The paper describes an architecture for partitioning XML into structural and dictionary elements and the subsequent manipulation of the dictionary elements to make the best use of available space. Findings - The results indicate that considerable savings are available by removing duplicate dictionaries. The paper also identifies the most effective strategy for defining dictionary scope. Research limitations/implications - This evaluation is based on a range of benchmark XML structures and the approach to minimising dictionary size shows benefit in the majority of these. Where structures are small and regular, the benefits of efficient dictionary representation are lost. The authors' future research now focuses on heuristics for further partitioning of structural elements. Practical implications - Mobile applications that need access to large data collections will benefit from the findings of this research. Traditional client/server architectures are not suited to dealing with high volume demands from a multitude of small mobile devices. Peer data sharing provides a more scalable solution and the experiments that the paper describes demonstrate the most effective way of sharing data in this context. Social implications - Many services are available via smartphone devices but users are wary of exploiting the full potential because of the need to conserve battery power. The approach mitigates this challenge and consequently expands the potential for users to benefit from mobile information systems. This will have impact in areas such as advertising, entertainment and education but will depend on the acceptability of file sharing being extended from the desktop to the mobile environment. Originality/value - The original work characterises the most effective way of sharing large data sets between small mobile devices. This will save battery power on devices such as smartphones, thus providing benefits to users of such devices

Wave Climate at Moffat Beach

The analysis of a series of wave recordings made at Moffat Beach, Queensland using an OSPOS wave recorder during 1963-1964 is described. This analysis included (i) the establishment of representative parameters for each wave recording; (ii) the determination of the frequency of occurrence of the representative parameters over the total recording period and (iii) the comparison of the recorded data with visual observations at Cape Moreton and the adjustment of the frequency curves to a longer more Queensland coast cannot be recommended.representative period of time.The results of the analysis provide confirmation of the\ua0applicability of the Rayleigh distribution to the short term wave\ua0height distribution within a given wave recording. On the other hand\ua0no definite conclusions are made concerning which theoretical\ua0representation of the long term wave height frequency of occurrence\ua0is to be preferred.The data analysed shows that at least four distinct types\ua0of wave conditions make up the overall wave climate in this area. The\ua0general wave height and period characteristics representative of these\ua0conditions together with seasonal variations are presented.The Moffat Beach wave data is compared with that obtained off\ua0the Gold Coast using Wave Rider buoys. Generally similar values of\ua0significant wave height are found but the wave periods are appreciably\ua0different. An analysis of possible explanations for this difference\ua0suggests that the filter effect due to pressure attenuation almost\ua0completely removes local wind generated seas from the OSPOS records.\ua0The question of a representative wave period for a given wave recording\ua0is considered and it is concluded that the use of the zero crossing\ua0period Tz\ua0for the analysis of unfiltered surface wave recordings of\ua0simultaneous sea and swell such as generally occurs off the southern\ua0Queensland coast cannot be recommended

Reef-top currents in vicinity of Heron Island boat harbour, Great Barrier Reef, Australia: 1. Overall influence of tides, winds and waves.

Heron Island is a small coral cay on the western end of a large platform reef in the southern Great Barrier Reef, Australia. In 1967 a boat access channel and a small mooring basin were dredged between the western reef-rim and the island. Since then reef-top currents have flowed out through this channel, removing sediment from the reef-flat and the island’s beaches. The mooring basin and access channel were enlarged in 1987. Offreef waves (hourly) and reef-top currents (at 10 minute intervals) were measured on either side of the island during a twelve month period (17 March 1996 – 18 March 1997). An initial analysis of the experimental data gathered during this period is presented in this report. Under mild (tidally dominated) conditions, maximum reef-top currents of about 0.3 m/s occurred during ebb spring tides when flow on the reef-flat was controlled by weir action at the harbour bund walls. There were four current reversals per tidal cycle on the northern reef-flat and two on the southern reef-flat. As offreef wave heights increased, waves breaking on the reef-rims generated wave-generated flows towards the boat harbour and these became sufficiently strong to reverse and eventually suppress the tidal flow on the reef-top around the island. The wave height required to reverse the tidal flow increased with increasing tidal range. When offreef wave heights reached 3 m there were unidirectional flows from the reef-rims into the boat harbor throughout the tidal cycle. When tidal ranges were small, the magnitudes of the wave-generated currents increased approximately linearly with increasing wave heights. A second report provides a more detailed analysis of this data set

A bilateral shear layer between two parallel Couette flows

We consider a shear layer of a kind not previously studied to our knowledge. Contrary to the classical free shear layer, the width of the shear zone does not vary in the streamwise direction but rather exhibits a lateral variation. Based on some simplifying assumptions, an analytic solution has been derived for the new shear layer. These assumptions have been justified by a comparison with numerical solutions of the full Navier-Stokes equations, which accord with the analytical solution to better than 1% in the entire domain. An explicit formula is found for the width of the shear zone as a function of wall-normal coordinate. This width is independent of wall velocities in the laminar regime. Preliminary results for a co-current laminar-turbulent shear layer in the same geometry are also presented. Shear-layer instabilities were then developed and resulted in an unsteady mixing zone at the interface between the two co-current streams.Comment: 6 pages, 7 figures. Accepted for publication in Phys. Rev.

Differential binding patterns of anti-sulfatide antibodies to glial membranes

Sulfatide is a major glycosphingolipid in myelin and a target for autoantibodies in autoimmune neuropathies. However neuropathy disease models have not been widely established, in part because currently available monoclonal antibodies to sulfatide may not represent the diversity of anti-sulfatide antibody binding patterns found in neuropathy patients. We sought to address this issue by generating and characterising a panel of new anti-sulfatide monoclonal antibodies. These antibodies have sulfatide reactivity distinct from existing antibodies in assays and in binding to peripheral nerve tissues and can be used to provide insights into the pathophysiological roles of anti-sulfatide antibodies in demyelinating neuropathies

Balancing competing policy demands: the case of sustainable public sector food procurement.

A focus on market-based green growth strategies to pursue sustainability goals neglects the pursuit of understanding how human health is interwoven with the health of eco-systems to deliver sustainability goals. The article argues that clarifying the difference between green and sustainable public sector food procurement, with political continuity that supports and enables policymakers and practitioners to take an incremental approach to change, makes an important contribution to delivering more sustainable food systems and better public health nutrition. Five European case studies demonstrate the reality of devising and implementing innovative approaches to sustainable public sector food procurement and the effects of cultural and political framings. How legislation is enacted at the national level and interpreted at the local level is a key driver for sustainable procurement. Transition is dependent on political will and leadership and an infrastructure that can balance the economic, environmental and social drivers to effect change. The development of systems and indicators to measure change, reforms to EU directives on procurement, and the relationship between green growth strategies and sustainable diets are also discussed. The findings show the need to explore how consistent definitions for green public procurement and sustainable public procurement can be refined and standardized in order to support governments at all levels in reviewing and analyzing their current food procurement strategies and practices to improve sustainability

Calculating quench propagation with ANSYS®

A commercial Finite-Element-Analysis program, ANSYS®, is widely used in structural and thermal analysis. With the program's ability to include nonlinear material properties and import complex CAD files, one can generate coil geometries and simulate quench propagation in superconducting magnets. A "proof-of-principle" finite element model was developed assuming a resistivity that increases linearly from zero to its normal value at a temperature consistent with the assumed B magnetic field. More sophisticated models could easily include finer-grained coil, cable, structural, and circuit details. A quench is provoked by raising the temperature of an arbitrary superconducting element above its T . The time response to this perturbation is calculated using small time-steps to allow convergence between steps. Snapshots of the temperature and voltage distributions allow examination of longitudinal and turn-to-turn quench propagation, quench-front annihilation, and cryo-stability. Modeling details are discussed, and a computed voltage history was compared with measurements from a recent magnet test.