Now showing items 1-8 of 8

    • Efficient and Compact Representations of Some Non-canonical Prefix-Free Codes 

      Fariña, Antonio; Gagie, Travis; Manzini, Giovanni; Navarro, Gonzalo; Ordóñez, Alberto (Springer, 2016-09-21)
      [Abstract] For many kinds of prefix-free codes there are efficient and compact alternatives to the traditional tree-based representation. Since these put the codes into canonical form, however, they can only be used when ...
    • Compact Trip Representation over Networks 

      Brisaboa, Nieves R.; Fariña, Antonio; Galaktionov, Daniil; Rodríguez, M. Andrea (Springer, 2016-09-21)
      [Abstract] We present a new Compact Trip Representation ( CTRCTR ) that allows us to manage users’ trips (moving objects) over networks. These could be public transportation networks (buses, subway, trains, and so on) where ...
    • GraCT: A Grammar Based Compressed Representation of Trajectories 

      Brisaboa, Nieves R.; Gómez Brandón, Adrián; Navarro, Gonzalo; Paramá, José R. (Springer, 2016-09-21)
      [Abstract] We present a compressed data structure to store free trajectories of moving objects (ships over the sea, for example) allowing spatio-temporal queries. Our method, GraCT, uses a k2k2 -tree to store the absolute ...
    • Efficient Representation of Multidimensional Data over Hierarchical Domains 

      Brisaboa, Nieves R.; Cerdeira Pena, Ana Belén; López López, Narciso; Navarro, Gonzalo; Penabad, Miguel R.; Silva Coira, Fernando (Springer, 2016-09-21)
      [Abstract] We consider the problem of representing multidimensional data where the domain of each dimension is organized hierarchically, and the queries require summary information at a different node in the hierarchy of ...
    • A new method to index and store spatio-temporal data 

      Bernardo Roca, 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, ...
    • Navigational Rule Derivation: An algorithm to determine the effect of traffic signs on road networks 

      Galaktionov, Daniil; Luaces, Miguel R.; Places, Ángeles S. (2016-11-17)
      [Abstract] In this paper we present an algorithm to build a road network map enriched with traffic rules such as one-way streets and forbidden turns, based on the interpretation of already detected and classified traffic ...
    • Design of Mutation Operators for Testing Geographic Information Systems 

      Alvarado, Suilen H. (M D P I AG, 2019-08-06)
      [Abstract] In this article, we propose the definition of specific mutation operators for testing Geographic Information Systems. We describe the process for applying the operators and generating mutants, and present a case ...
    • Improved Compressed String Dictionaries 

      Brisaboa, Nieves R.; Cerdeira Pena, Ana Belén; De Bernardo Roca, Guillermo; 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 ...