Efficient Database Evolution in Digital Library Reengineering

Cursos e Congresos, C-155[Abstract] With the advancement of internet applications, extensive information systems were created to effectively manage and provide easy access to documents, which coincided with a global initiative to convert physical documents into digital format, making them accessible through the internet. After two decades, these databases are well-structured and organized, although the software used to manage them is gradually becoming outdated. Additionally, once the initial digitization and creation of metadata are completed, it is sensible to enhance the metadata further to provide more detailed information about the documents. In this article we propose a tool to facilitate the evolution of large documentary databasesXunta de Galicia; ED431C 2021/53CITIC is funded by the Xunta de Galicia through the collaboration agreement between the Consellería de Cultura, Educación, Formación Profesional e Universidades and the Galician universities for the reinforcement of the research centres of the Galician University System (CIGUS), and by PRE2021-099351, MCIN/AEI+”FSE+”;GRC[ED431C 2021/53]: GAIN/Xunta de Galicia; TED2021-129245B-C21(PLAGEMIS): MCIN/AEI+”NextGenerationEU“/PRTR; PID2020-114635RB-I00(EXTRACompact): MCIN/AEI; PID2021-122554OB-C33 (OASSIS): MCIN/AEI+EU/ERDF A way of making Europe; PDC2021-120917-C21 (SIGTRANS): MCIN/AEI+“NextGenerationEU”/PRT

Applying an ontology on data integration

The term “Federated Databases” refers to the data integration of distributed, autonomous and heterogeneous databases. However, a federation can also include information systems, not only databases. When integrating data, several issues must be addressed. Here, we focus on the problem of heterogeneity, more specifically on semantic heterogeneity – that is problems related to semantically equivalent concepts or semantically related/unrelated concepts. In order to address this problem, we apply the idea of ontologies as a tool for data integration. In this paper, we explain this concept and we briefly describe a method for constructing an ontology by using a hybrid ontology approach.Eje: Bases de datosRed de Universidades con Carreras en Informática (RedUNCI

Grammar compressed sequences with rank/select support

An early partial version of this paper appeared in Proc. SPIRE 2014: G. Navarro, A. Ordóñez Grammar compressed sequences with rank/select support, Proc. 21st International Symposium on String Processing and Information Retrieval, LNCS, SPIRE, vol. 8799 (2014), pp. 31–44The final publication is available at Springer via http://dx.doi.org/10.1016/j.jda.2016.10.001[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 to represent highly repetitive sequences, and classical statistical compression proves ineffective. We introduce, instead, grammar-based representations for repetitive sequences, which use up to 6% of the space needed by statistically compressed representations, and support direct access and rank/select operations within tens of microseconds. We demonstrate the impact of our structures in text indexing applications.Chile. Fondo Nacional de Desarrollo Científico y Tecnológico; 140796Ministerio de Economía, Industria y Competitividad; 00645663/ITC-20133062Ministerio de Economía, Industria y Competitividad; TIN2009-14560-C03-02Ministerio de Economía, Industria y Competitividad; TIN2010-21246-C02-01Ministerio de Economía, Industria y Competitividad; TIN2013-46238-C4-3-RMinisterio de Economía, Industria y Competitividad; TIN2013-47090-C3-3-PMinisterio de Economía, Industria y Competitividad; AP2010-6038Xunta de Galicia; GRC2013/05

An ontological approach to federated data integration

During the last years a lot of projects and lines of research have emerged from different proposals trying to find the best way to reach data integration. Two powerful techniques have appeared separately – ontology and contextual information – in order to help solve semantic heterogeneity problems. In our proposal we combine both techniques exploiting the advantages of each of them. We propose a new approach, in which three main components work together in order to achieve a consistent integration. Each component contains some type of semantic information modeled by ontologies and contexts. Our approach helps the building of each of the components and address other types of heterogeneity such as ontological heterogeneity.Eje: Ingeniería de Software y Bases de Datos (ISBD)Red de Universidades con Carreras en Informática (RedUNCI

Towards an Ontology-based Integration of Federated Information Sources

Integrating data from a Federated System is a very complex process that involves a series of tasks. Characteristics such as autonomy of the information sources, their geographical distribution and heterogeneity are some of the main problems we face to perform the integration. In this paper we focus on the problem of heterogeneity, more specifically on semantic heterogeneity. The semantic heterogeneity makes the integration difficult because of its bearing problems on synonymous, generalization/specialization, etc. Here, we briefly explain our three level approach to solve these problems. Then we show the structure of software components used to implement our supporting tool.Eje: Ingeniería en SoftwareRed de Universidades con Carreras en Informática (RedUNCI