Multilevel mesh partitioning for heterogeneous communication networks

Multilevel algorithms are a successful class of optimisation techniques which address the mesh partitioning problem for distributing unstructured meshes onto parallel computers. They usually combine a graph contraction algorithm together with a local optimisation method which refines the partition at each graph level. To date these algorithms have been used almost exclusively to minimise the cut edge weight in the graph with the aim of minimising the parallel communication overhead, but recently there has been a perceived need to take into account the communications network of the parallel machine. For example the increasing use of SMP clusters (systems of multiprocessor compute nodes with very fast intra-node communications but relatively slow inter-node networks) suggest the use of hierarchical network models. Indeed this requirement is exacerbated in the early experiments with meta-computers (multiple supercomputers combined together, in extreme cases over inter-continental networks). In this paper therefore, we modify a multilevel algorithm in order to minimise a cost function based on a model of the communications network. Several network models and variants of the algorithm are tested and we establish that it is possible to successfully guide the optimisation to reflect the chosen architecture.

Does the medium dictate the message? Cultivating communication in an asynchronous environment

Virtual learning environments (VLEs) are often perceived by education establishments as an opportunity to widen access without traditional overheads. An integral part of most VLEs is asynchronous computer conferencing and on-line moderators must help students migrate quickly to the new virtual environment to minimize learning disruption. This paper focuses on 21 new on-line moderators and reports their changing perceptions re their role and concerns, from their first appointment through to the end of the delivery of their first on-line course. The findings suggest that it is only after socialization occurs that information can be exchanged and lead to knowledge construction. These are supported by, and extend, prior research by Z Berge, R Mason, M Paulsen and G Salmon and are reinforced by empirical work with a further 19 new on-line moderators.

Requirements and design of an integrated European environmental information communication system, (IEEICS)

The needs for various forms of information systems relating to the European environment and ecosystem are reviewed, and limitations indicated. Existing information systems are reviewed and compared in terms of aims and functionalities. We consider TWO technical challenges involved in attempting to develop an IEEICS. First, there is the challenge of developing an Internet-based communication system which allows fluent access to information stored in a range of distributed databases. Some of the currently available solutions are considered, i.e. Web service federations. The second main challenge arises from the fact that there is general intra-national heterogeneity in the definitions adopted, and the measurement systems used throughout the nations of Europe. Integrated strategies are needed.

Healthcare: rejection of privatisation and patient fees in Central Europe

Since 2006, there have been successful campaigns against commercialisation of public health services in the four central European countries – Czech Republic, Hungary, Poland and Slovakia.

Debating the division of labour in healthcare in France and England

As Larson (1990) states, professions are historically specific and ‘there is no pattern of social closure around an occupation that is not inflected by the latter’s past, its specific activity and typical context of performance or…the political context in which closure is obtained.’ Larson’s work focuses particularly on the differences between the establishment of professions in France, where there was considerable state intervention, with that in the US and UK, both of which were more market-oriented. This paper is based on data from an evaluation of a large European exchange programme of staff between Kent and Lille, from 2005 to 2008 and discusses the division of labour in healthcare between two occupational groups, medicine and nursing, in England and in France. This division of labour has been extensively discussed in the UK, particularly since from the mid 1990s the nursing role has been extended and innovations such as nurse prescribing have been introduced, whereas such extended roles have not been introduced in France. The paper draws particularly on interview data from mental health practitioners, in which it is argued that whilst the English nurses may on the surface seem to have a wider range of competences and autonomy, in reality they are more constrained, as they operate under protocols and therefore do not exercise professional judgement. Not only do these data illustrate the centrality of professional judgement in discussions about practice, they also demonstrate the circularity of many debates on extended roles.

Communication system model for information rate evaluation of differential detection over time-varying channels

A communication system model for mutual information performance analysis of multiple-symbol differential M-phase shift keying over time-correlated, time-varying flat-fading communication channels is developed. This model is a finite-state Markov (FSM) equivalent channel representing the cascade of the differential encoder, FSM channel model and differential decoder. A state-space approach is used to model channel phase time correlations. The equivalent model falls in a class that facilitates the use of the forward backward algorithm, enabling the important information theoretic results to be evaluated. Using such a model, one is able to calculate mutual information for differential detection over time-varying fading channels with an essentially finite time set of correlations, including the Clarke fading channel. Using the equivalent channel, it is proved and corroborated by simulations that multiple-symbol differential detection preserves the channel information capacity when the observation interval approaches infinity.

More public rescues for more private finance failures - a critique of the EC Communication on PPPs

A critique of the EC Communication on PPPs, challenging the scale of state aid offered to PPPs, the role of PPPs in the economic recovery strategy for the EU, and drawing attention to the damage done to public authorities by 'innovative' financing mechanisms.