4 research outputs found

    Distributed stream reasoning

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    Stream Reasoning is the combination of reasoning techniques with data streams. In this paper, we present our approach to enable rule-based reasoning on semantic data streams in a distributed manne

    Incremental Rule-based Reasoning on Semantic Data Streams

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    This thesis investigates the area of semantic stream processing, in which data streams are combined with semantic reasoning techniques. We have investigated techniques for rule-based reasoning over semantic streams in which reasoning is implemented natively over streams as data flow networks, and have developed an adaptive optimisation method to cope with the changing nature of streams. The contributions of this thesis include R4, a native rule-based reasoner for RDF streams using the Rete algorithm, and a cost-based adaptive plan optimiser designed for RDF streams. We have evaluated the performance of R4 and compared it to both a typical static reasoner and to the state-of-the-art in stream reasoners. The results show that R4 significantly outperforms these reasoners in terms of throughput. We have also evaluated the adaptive optimisation technique, with results that show the ability of the optimiser to devise and adopt better performing plans at runtime

    Global economic burden of unmet surgical need for appendicitis

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    Background There is a substantial gap in provision of adequate surgical care in many low- and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US 92492millionusingapproach1and92 492 million using approach 1 and 73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was 95004millionusingapproach1and95 004 million using approach 1 and 75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

    Global economic burden of unmet surgical need for appendicitis