• Boosting Perturbation-Based Iterative Algorithms to Compute the Median String 

      Mirabal, Pedro; Abreu Salas, José Ignacio; Seco, Diego; Pedreira, Óscar; Chávez, Edgar (IEEE, 2021)
      [Abstract] The most competitive heuristics for calculating the median string are those that use perturbation-based iterative algorithms. Given the complexity of this problem, which under many formulations is NP-hard, the ...
    • Combining Multiple Granularity Variability in a Software Product Line Approach for Web Engineering 

      Horcas Aguilera, José Miguel; Cortiñas, Alejandro; Fuentes, Lidia; Rodríguez Luaces, Miguel (Elsevier, 2022)
      [Abstract] Context: Web engineering involves managing a high diversity of artifacts implemented in different languages and with different levels of granularity. Technological companies usually implement variable artifacts ...
    • Compact and indexed representation for LiDAR point clouds 

      Ladra, Susana; Rodríguez Luaces, Miguel; Paramá, José R.; Silva-Coira, Fernando (Taylor & Francis, 2022)
      [Abstract]: LiDAR devices are capable of acquiring clouds of 3D points reflecting any object around them, and adding additional attributes to each point such as color, position, time, etc. LiDAR datasets are usually large, ...
    • 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 ...
    • Compressed Data Structures for Binary Relations in Practice 

      Quijada Fuentes, Carlos; Penabad, Miguel R.; Ladra, Susana; Gutiérrez Retamal, Gilberto (Institute of Electrical and Electronics Engineers, 2020-01-31)
      [Abstract] Binary relations are commonly used in Computer Science for modeling data. In addition to classical representations using matrices or lists, some compressed data structures have recently been proposed to represent ...
    • Efficient Processing of Raster and Vector Data 

      Silva-Coira, Fernando; Paramá, José R.; Ladra, Susana; López, Juan R.; Gutiérrez, Gilberto (Public Library of Science, 2020-01-10)
      [Abstract] In this work, we propose a framework to store and manage spatial data, which includes new efficient algorithms to perform operations accepting as input a raster dataset and a vector dataset. More concretely, we ...
    • Energy Consumption in Compact Integer Vectors: A Study Case 

      Fuentes Sepúlveda, José; Ladra, Susana (Institute of Electrical and Electronics Engineers, 2019-10-25)
      [Abstract] In the field of algorithms and data structures analysis and design, most of the researchers focus only on the space/time trade-off, and little attention has been paid to energy consumption. Moreover, most of the ...
    • 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 ...
    • Fed-mRMR: A lossless federated feature selection method 

      Hermo González, Jorge; Bolón-Canedo, Verónica; Ladra, Susana (Elsevier, 2024-05)
      [Abstract]: Feature selection has become a mandatory task in data mining, due to the overwhelming amount of features in Big Data problems. To handle this high-dimensional data and avoid the well-known curse of dimensionality, ...
    • From Coarse to Fine-Grained Parcellation of the Cortical Surface Using a Fiber-Bundle Atlas 

      López-López, Narciso; Vázquez, Andrea; Houenou, Josselin; Poupon, Cyril; Mangin, Jean-François; Ladra, Susana; Guevara, Pamela (Frontiers Research Foundation, 2020-09-10)
      [Abstract] In this article, we present a hybrid method to create fine-grained parcellations of the cortical surface, from a coarse-grained parcellation according to an anatomical atlas, based on cortico-cortical connectivity. ...
    • GraCT: A Grammar-based Compressed Index for Trajectory Data 

      Brisaboa, Nieves R.; Gómez-Brandón, Adrián; Navarro, Gonzalo; Paramá, José R. (Elsevier Ltd, 2019)
      [Abstract]: We introduce a compressed data structure for the storage of free trajectories of moving objects that efficiently supports various spatio-temporal queries. Our structure, dubbed GraCT, stores the absolute positions ...
    • Grammar compressed sequences with rank/select support 

      Ordóñez, Alberto; Navarro, Gonzalo; Brisaboa, Nieves R. (Elsevier BV, 2016-10-14)
      [Abstract] Sequence representations supporting not only direct access to their symbols, but also rank/select operations, are a fundamental building block in many compressed data structures. Several recent applications need ...
    • Graph Compression for Adjacency-Matrix Multiplication 

      Francisco, Alexandre P.; Gagie, Travis; Köppl, Dominik; Ladra, Susana; Navarro, Gonzalo (Springer, 2022)
      [Abstract] Computing the product of the (binary) adjacency matrix of a large graph with a real-valued vector is an important operation that lies at the heart of various graph analysis tasks, such as computing PageRank. In ...
    • Local features: Enhancing variability modeling in software product lines 

      Castro, David de; Cortiñas, Alejandro; Rodríguez Luaces, Miguel; Pedreira, Óscar; Saavedra Places, Ángeles (Elsevier, 2024-07)
      [Abstract]: Context and motivation: Software Product Lines (SPL) enable the creation of software product families with shared core components using feature models to model variability. Choosing features from a feature model ...
    • Lossless Compression of Industrial Time Series With Direct Access 

      Gómez-Brandón, Adrián; Paramá, José R.; Villalobos, Kevin; Illarramendi, Arantza; Brisaboa, Nieves R. (Elsevier, 2021)
      [Abstract] The new opportunities generated by the data-driven economy in the manufacturing industry have causedmany companies opt for it. However, the size of time series data that need to be captured creates theproblem ...
    • Map algebra on raster datasets represented by compact data structures 

      Silva-Coira, Fernando; Paramá, José R.; Ladra, Susana (John Wiley and Sons, 2023-06)
      [Abstract]: The increase in the size of data repositories has forced the design of new computing paradigms to be able to process large volumes of data in a reasonable amount of time. One of them is in-memory computing, ...
    • Modeling the Number of People Infected With SARS-COV-2 From Wastewater Viral Load in Northwest Spain 

      Vallejo, J. A.; Trigo Tasende, Noelia; Rumbo-Feal, Soraya; Conde-Pérez, Kelly; López-Oriona, Ángel; Barbeito, Inés; Vaamonde, Manuel; Tarrío-Saavedra, Javier; Reif López, Rubén; Ladra, Susana; Rodiño-Janeiro, Bruno Kotska; Nasser-Ali, Mohammed; Cid, Ángeles; Veiga, María Carmen; Acevedo, Antón; Lamora, Carlos; Bou, Germán; Cao, Ricardo; Poza, Margarita (Elsevier, 2022)
      [Abstract] The quantification of the SARS-CoV-2 RNA load in wastewater has emerged as a useful tool to monitor COVID–19 outbreaks in the community. This approach was implemented in the metropolitan area of A Coruña (NW ...
    • Multilevel Modeling of Geographic Information Systems Based on International Standards 

      Alvarado, Suilen H.; Cortiñas, Alejandro; Rodríguez Luaces, Miguel; Pedreira, Óscar; Saavedra Places, Ángeles (SpringerLink, 2021)
      [Abstract] Even though different applications based on Geographic Information Systems (GIS) provide different features and functions, they all share a set of common concepts (e.g., spatial data types, operations, services), ...
    • New machine learning approaches for real-life human activity recognition using smartphone sensor-based data 

      García-González, Daniel; Rivero, Daniel; Fernández-Blanco, Enrique; Rodríguez Luaces, Miguel (Elsevier B.V., 2023)
      [Abstract]: In recent years, mainly due to the application of smartphones in this area, research in human activity recognition (HAR) has shown a continuous and steady growth. Thanks to its wide range of sensors, its size, ...
    • Optimization in Sanger sequencing 

      Carpente, Luisa; Cerdeira-Pena, Ana; Lorenzo Freire, Silvia; Saavedra Places, Ángeles (Elsevier, 2019-09)
      [Abstract]: The main objective of this paper is to solve the optimization problem that is associated with the classification of DNA samples in PCR plates for Sanger sequencing. To achieve this goal, we design an integer ...