Now showing items 1-12 of 12

    • A New Method to Index and Store Spatio-Temporal Data 

      Bernardo, Guillermo de; Casares, Ramón; Gómez-Brandón, Adrián; Paramá, José R. (2016-11-16)
      [Abstract] We propose a data structure that stores, in a compressed way, object trajectories, which at the same time, allow to efficiently response queries without the need to decompress the data. We use a data structure, ...
    • A succinct data structure for self-indexing ternary relations 

      Álvarez García, Sandra; Bernardo, Guillermo de; Brisaboa, Nieves R.; Navarro, Gonzalo (Elsevier BV, 2016-10-27)
      [Abstract] The representation of binary relations has been intensively studied and many different theoretical and practical representations have been proposed to answer the usual queries in multiple domains. However, ternary ...
    • Aggregated 2D range queries on clustered points 

      Bernardo, Guillermo de; Konow, Bernardo; Navarro, Gonzalo; Brisaboa, Nieves R.; Seco, Diego (Elsevier Ltd, 2016-09)
      [Abstract] Efficient processing of aggregated range queries on two-dimensional grids is a common requirement in information retrieval and data mining systems, for example in Geographic Information Systems and OLAP cubes. ...
    • Classic distance join queries using compact data structures 

      Bernardo, Guillermo de; Penabad, Miguel R.; Corral, Antonio; Brisaboa, Nieves R. (Elsevier, 2024-07)
      [Abstract]: Distance-based Join Queries (DJQs) have multiple applications in spatial databases, Geographic Information Systems, and other areas. The K Closest Pairs Query (KCPQ) and the 𝜀� Distance Join Query (𝜀� DJQ) ...
    • Compressed and queryable self-indexes for RDF archives 

      Cerdeira-Pena, Ana; Bernardo, Guillermo de; Fariña, Antonio; Fernández, Javier D.; Martínez-Prieto, Miguel A. (Springer Nature, 2023-08)
      [Abstract]: RDF compression and querying are consolidated topics in the Web of Data, with a plethora of solutions to efficiently store and query static datasets. However, as RDF data changes along time, it becomes necessary ...
    • Extending general compact querieable representations to GIS applications 

      Brisaboa, Nieves R.; Cerdeira-Pena, Ana; Bernardo, Guillermo de; Navarro, Gonzalo; Pedreira, Óscar (Elsevier, 2020-01)
      [Abstract]: The raster model is commonly used for the representation of images in many domains, and is especially useful in Geographic Information Systems (GIS) to store information about continuous variables of the space ...
    • Improved Compressed String Dictionaries 

      Brisaboa, Nieves R.; Cerdeira-Pena, Ana; Bernardo, Guillermo de; Navarro, Gonzalo (ACM, 2019-11-03)
      [Abstract] We introduce a new family of compressed data structures to efficiently store and query large string dictionaries in main memory. Our main technique is a combination of hierarchical Front-coding with ideas from ...
    • Revisiting Compact RDF Stores Based on k2-Trees 

      Brisaboa, Nieves R.; Cerdeira-Pena, Ana; Bernardo, Guillermo de; Fariña, Antonio (IEEE Xplore, 2020-03)
      [Abstract]: We present a new compact representation to efficiently store and query large RDF datasets in main memory. Our proposal, called BMatrix, is based on the k 2 -tree, a data structure devised to represent binary ...
    • Space-Efficient Representations of Raster Time Series 

      Silva-Coira, Fernando; Paramá, José R.; Bernardo, Guillermo de; Seco, Diego (Elsevier, 2021)
      [Abstract] Raster time series, a.k.a. temporal rasters, are collections of rasters covering the same region at consecutive timestamps. These data have been used in many different applications ranging from weather forecast ...
    • Space/time-efficient RDF stores based on circular suffix sorting 

      Brisaboa, Nieves R.; Cerdeira-Pena, Ana; Bernardo, Guillermo de; Fariña, Antonio; Navarro, Gonzalo (Springer Nature, 2023-03)
      [Abstract]: The resource description framework (RDF) has gained popularity as a format for the standardized publication and exchange of information in the Web of Data. In this paper, we introduce RDFCSA, a compressed ...
    • Tool for SPARQL Querying over Compact RDF Representations 

      Ramos-Vidal, Delfina; Bernardo, Guillermo de (MDPI, 2021)
      [Abstract] We present an architecture for the efficient storing and querying of large RDF datasets. Our approach seeks to store RDF datasets in very little space while offering complete SPARQL functionality. To achieve ...
    • Towards a Compact Representation of Temporal Rasters 

      Cerdeira-Pena, Ana; Bernardo, Guillermo de; Fariña, Antonio; Paramá, José R.; Silva-Coira, Fernando (Springer Nature, 2018-09)
      [Abstract]: Big research efforts have been devoted to efficiently manage spatio-temporal data. However, most works focused on vectorial data, and much less, on raster data. This work presents a new representation for raster ...