2 research outputs found

    reSearch : enhancing information retrieval with images

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    Combining image and text search is an open research question. The main issues are what technologies to base this solution on, and what measures of relevance to employ. Our reSearch prototype mashes up papers indexed using information retrieval techniques (Terrier) with Google image search for faces and Google book search. The user can interactively employ query expansion with additional terms suggested by Terrier, and use those terms to expand both the text and image search. We test this solution with a selection of recent publications and queries concerning people engaged in research. We report on the effectiveness of this solution. It seems that the combination works to a large extent, as testified by our observations

    Algebraic methods for incremental maintenance and updates of views within XML databases

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    Within XML data management the performance of queries has been improved by using materialised views. However, modifications to XML documents must be reflected to these views. This is known as the view maintenance problem. Conversely updates to the view must be reflected on the XML source documents. This is the view update problem. Fully recalculating these views or documents to reflect these changes is inefficient. To address this, a number of distinct methods are reported in the literature that address either incremental view maintenance or update. This thesis develops a consistent incremental algebraic approach to view maintenance and view update using generic operators. This approach further differs from related work in that it supports views with multiple returned nodes. Generally the data sets to be incrementally maintained are smaller for the view update case. Therefore, it was necessary to investigate the circumstances in which converting view maintenance into view update gave better performance. Finally, dynamic reasoning on updates was considered to determine whether it improved the performance of the proposed view maintenance and view update methods. The system was implemented using features of XML stores and XML query evaluation engines including structural identifiers for XML and structural join algorithms. Methods for incrementally handling the view maintenance and view update problem are presented and the benefits of these methods over existing algorithms are established by means of experiments. These experiments also depict the benefit of translating view maintenance updates into view updates, where applicable, and the benefits of dynamic reasoning. The main contribution of this thesis is the development of similar incremental algebraic methods which provide a consistent solution to the view maintenance and view update problems. The originality of these methods is their ability to handle statement-level updates using generic operators and views returning data from multiple nodes.Within XML data management the performance of queries has been improved by using materialised views. However, modifications to XML documents must be reflected to these views. This is known as the view maintenance problem. Conversely updates to the view must be reflected on the XML source documents. This is the view update problem. Fully recalculating these views or documents to reflect these changes is inefficient. To address this, a number of distinct methods are reported in the literature that address either incremental view maintenance or update. This thesis develops a consistent incremental algebraic approach to view maintenance and view update using generic operators. This approach further differs from related work in that it supports views with multiple returned nodes. Generally the data sets to be incrementally maintained are smaller for the view update case. Therefore, it was necessary to investigate the circumstances in which converting view maintenance into view update gave better performance. Finally, dynamic reasoning on updates was considered to determine whether it improved the performance of the proposed view maintenance and view update methods. The system was implemented using features of XML stores and XML query evaluation engines including structural identifiers for XML and structural join algorithms. Methods for incrementally handling the view maintenance and view update problem are presented and the benefits of these methods over existing algorithms are established by means of experiments. These experiments also depict the benefit of translating view maintenance updates into view updates, where applicable, and the benefits of dynamic reasoning. The main contribution of this thesis is the development of similar incremental algebraic methods which provide a consistent solution to the view maintenance and view update problems. The originality of these methods is their ability to handle statement-level updates using generic operators and views returning data from multiple nodes
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