Now showing items 1-15 of 15

  • An approach for alert raising in real-time data warehouses 

    López, Maximiliano Ariel; Nadal Francesch, Sergi; Djedaini, Mahfoud; Marcel, Patrick; Peralta, Verónika; Furtado, Pedro (2015)
    Conference report
    Open Access
    This work proposes an approach for alert raising within a real-time data warehouse environment. It is based on the calculation of confidence intervals for measures from historical facts. As new facts arrive to the data ...
  • An integration-oriented ontology to govern evolution in big data ecosystems 

    Nadal Francesch, Sergi; Romero Moral, Óscar; Abelló Gamazo, Alberto; Vassiliadis, Panos; Vansummeren, Stijn (2019-01)
    Article
    Restricted access - publisher's policy
    Big Data architectures allow to flexibly store and process heterogeneous data, from multiple sources, in their original format. The structure of those data, commonly supplied by means of REST APIs, is continuously evolving. ...
  • An integration-oriented ontology to govern evolution in big data ecosystems 

    Nadal Francesch, Sergi; Romero Moral, Óscar; Abelló Gamazo, Alberto; Vassiliadis, Panos; Vansummeren, Stijn (CEUR-WS.org, 2017)
    Conference lecture
    Open Access
    Big Data architectures allow to flexibly store and process heterogeneous data, from multiple sources, in its original format. The structure of those data, commonly supplied by means of REST APIs, is continuously evolving, ...
  • A situational approach for the definition and tailoring of a data-driven software evolution method 

    Franch Gutiérrez, Javier; Ralyté, Jolita; Perini, Anna; Abelló Gamazo, Alberto; Ameller, David; Gorroñogoitia, Jesús; Nadal Francesch, Sergi; Oriol Hilari, Marc; Seyff, Norbert; Siena, Alberto; Susi, Angelo (Springer, 2018)
    Conference report
    Open Access
    Successful software evolution heavily depends on the selection of the right features to be included in the next release. Such selection is difficult, and companies often report bad experiences about user acceptance. To ...
  • A software reference architecture for semantic-aware big data systems 

    Nadal Francesch, Sergi; Herrero Otal, Víctor; Romero Moral, Óscar; Abelló Gamazo, Alberto; Franch Gutiérrez, Javier; Vansummeren, Stijn; Valerio, Danilo (2016-06-13)
    Article
    Open Access
    Context: Big Data systems are a class of software systems that ingest, store, process and serve massive amounts of heterogeneous data, from multiple sources. Despite their undisputed impact in current society, their ...
  • Big data management challenges in SUPERSEDE 

    Nadal Francesch, Sergi; Abelló Gamazo, Alberto; Romero Moral, Óscar; Varga, Jovan (CEUR-WS.org, 2017)
    Conference report
    Open Access
    The H2020 SUPERSEDE (www.supersede.eu) project aims to support decision-making in the evolution and adaptation of software services and applications by exploiting end-user feedback and runtime data, with the overall goal ...
  • Integration-oriented ontology 

    Nadal Francesch, Sergi; Abelló Gamazo, Alberto (Springer, 2018-02-01)
    Part of book or chapter of book
    Restricted access - publisher's policy
    The purpose of an integration-oriented ontology is to provide a conceptualization of a domain of interest for automating the data integration of an evolving and heterogeneous set of sources using Semantic Web technologies. ...
  • Intermediate results materialization selection and format for data-intensive flows 

    Munir, Rana Faisal; Nadal Francesch, Sergi; Romero Moral, Óscar; Abelló Gamazo, Alberto; Jovanovic, Petar; Thiele, Maik; Lehner, Wolfgang (2018-05-01)
    Article
    Restricted access - publisher's policy
    Data-intensive flows deploy a variety of complex data transformations to build information pipelines from data sources to different end users. As data are processed, these workflows generate large intermediate results, ...
  • Materializing aaseline views for deviation detection exploratory OLAP 

    Furtado, Pedro; Nadal Francesch, Sergi; Peralta, Verónika; Djedaini, Mahfoud; Labroche, Nicolas; Marcel, Patrick (Springer, 2015)
    Conference report
    Open Access
    Alert-raising and deviation detection in OLAP and explora-tory search concerns calling the user’s attention to variations and non-uniform data distributions, or directing the user to the most interesting exploration of the ...
  • MDM: governing evolution in big data ecosystems 

    Nadal Francesch, Sergi; Abelló Gamazo, Alberto; Romero Moral, Óscar; Vansummeren, Stijn; Vassiliadis, Panos (OpenProceedings, 2018)
    Conference lecture
    Open Access
    On-demand integration of multiple data sources is a critical requirement in many Big Data settings. This has been coined as the data variety challenge, which refers to the complexity of dealing with an heterogeneous set ...
  • Metadata-driven data integration 

    Nadal Francesch, Sergi (Universitat Politècnica de Catalunya, 2019-05-16)
    Doctoral thesis
    Open Access
    Data has an undoubtable impact on society. Storing and processing large amounts of available data is currently one of the key success factors for an organization. Nonetheless, we are recently witnessing a change represented ...
  • Multi-Objective Materialized View Selection in Data-Intensive Flows 

    Nadal Francesch, Sergi (Universitat Politècnica de Catalunya, 2015-09-04)
    Master thesis
    Open Access
    In this thesis we present Forge, a tool for automating multi-objective materialization of intermediate results in data-intensive flows, driven by a set of different quality objectives. We report initial evaluation results, ...
  • Quarry 

    Abelló Gamazo, Alberto; Romero Moral, Óscar; Jovanovic, Petar; Nadal Francesch, Sergi; Bilalli, Besim; Candón Arenas, Héctor; Mayorova, Daria; Thavornun, Varunya; Gil González, Daniel (2015-07-01)
    Computer program
    Restricted access - confidentiality agreement
  • Quarry : digging up the gems of your data treasury 

    Jovanovic, Petar; Romero Moral, Óscar; Simitsis, Alkis; Abelló Gamazo, Alberto; Candón Arenas, Héctor; Nadal Francesch, Sergi (2015)
    Conference lecture
    Open Access
    The design lifecycle of a data warehousing (DW) system is primarily led by requirements of its end-users and the complexity of underlying data sources. The process of designing a multidimensional (MD) schema and back-end ...
  • Tècniques per a la traducció d'esquemes relacionals a no relacionals 

    Nadal Francesch, Sergi (Universitat Politècnica de Catalunya, 2013-06-19)
    Master thesis (pre-Bologna period)
    Open Access
    En aquest projecte es vol buscar si existeixen tècniques o regles a l'hora de convertir un esquema relacional a no relacional. Per tal de fer-ho s'han realitzat proves de rendiment sobre un sistema relacional i les diferents ...