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Πλοήγηση ανά Θέμα "Quad trees"

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    • The deletion operation in xBR-trees 

      Roumelis, G.; Vassilakopoulos, M.; Corral, A. (2012)
      In order to design a spatial index, the most important operations are: insertion, deletion and search. We focus on the deletion operation over the xBR-tree, a spatial data secondary memory structure that belongs to the ...

    • Efficient processing of all-k-nearest-neighbor queries in the MapReduce programming framework 

      Moutafis P., Mavrommatis G., Vassilakopoulos M., Sioutas S. (2019)
      Numerous modern applications, from social networking to astronomy, need efficient answering of queries on spatial data. One such query is the All k Nearest-Neighbor Query, or k Nearest-Neighbor Join, that takes as input ...

    • Efficient query processing on large spatial databases: A performance study 

      Roumelis G., Vassilakopoulos M., Corral A., Manolopoulos Y. (2017)
      Processing of spatial queries has been studied extensively in the literature. In most cases, it is accomplished by indexing spatial data using spatial access methods. Spatial indexes, such as those based on the Quadtree, ...

    • Nearest Neighbor Algorithms using xBR-Trees 

      Roumelis, G.; Vassilakopoulos, M.; Corral, A. (2011)
      One of the common queries in spatial databases is the (K) Nearest Neighbor Query that discovers the (K) closest objects to a query object. Processing of spatial queries, in most cases, is accomplished by indexing spatial ...

    • The xbr+-tree: An efficient access method for points 

      Roumelis G., Vassilakopoulos M., Loukopoulos T., Corral A., Manolopoulos Y. (2015)
      Spatial indexes, such as those based on Quadtree, are important in spatial databases for efficient execution of queries involving spatial constraints. In this paper, we present improvements of the xBR-tree (a member of the ...