33 research outputs found

    Linked Stream Data: A Position Paper

    Full text link
    The amount of sensors publishing data on the Web is increasing as a result of the online availability of Sensor Web platforms that provide support for this task. With such increase in sensor data publication, new challenges arise for the identification, discovery and access to this data. Following the set of best practices to publish and link structured data on the web proposed by the Linked Data community, in this paper we introduce the concept of Linked Stream Data, a way in which the Linked Data principles can be applied to stream data and be part of the Web of Linked Data

    Formalisation and experiences of R2RML-based SPARQL to SQL query translation using Morph

    Get PDF
    R2RML is used to specify transformations of data available in relational databases into materialised or virtual RDF datasets. SPARQL queries evaluated against virtual datasets are translated into SQL queries according to the R2RML mappings, so that they can be evaluated over the underlying relational database engines. In this paper we describe an extension of a well-known algorithm for SPARQL to SQL translation, originally formalised for RDBMS-backed triple stores, that takes into account R2RML mappings. We present the result of our implementation using queries from a synthetic benchmark and from three real use cases, and show that SPARQL queries can be in general evaluated as fast as the SQL queries that would have been generated by SQL experts if no R2RML mappings had been used

    1020 steel coated with Ti/TiN by Cathodic Arc and Ion Implantation

    Get PDF
    TiN coatings have been widely studied in order to improve mechanical properties of steels. In this work, thin Ti/TiN films were prepared by plasma based immersion ion implantation and deposition (PBII&D) with a cathodic arc on AISI 1020 steel substrates. Substrates were exposed to the discharge during 1 min in vacuum for the deposition of a Tiunderlayer with the aim of improving the adhesion to the substrate. Then, a TiN layer was deposited during 6 min in a nitrogen environment at a pressure of 3xl0-4 mbar. Samples were obtained at room temperature and at 300 °C, and with or without ion implantation in order to analyze differences between the effects of each treatment on the tribological properties. The mechanical and tribological properties of the films were characterized. The coatings deposited by PBII&D at 300 °C presented the highest hardness and young modulus, the best wear resistance and corrosion performance.Fil: Bermeo, Diego Fernando. Universidad Santiago de Cali; ColombiaFil: Quintana, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física del Plasma. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física del Plasma; ArgentinaFil: Kleiman, Ariel Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física del Plasma. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física del Plasma; ArgentinaFil: Sequeda, F.. Universidad del Valle; ColombiaFil: Márquez, A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física del Plasma. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física del Plasma; Argentin

    Generating Data Wrapping Ontologies from Sensor Networks: a case study

    Get PDF
    Information coming from sensor networks is being increasingly used in a variety of systems (decision support systems, information portals, etc), normally combined with information coming from more traditional sources (e.g., relational databases, web documents, etc). However, existing ontology based information integration approaches cannot be easily used for this combination task since they are mainly focused on the integration of information coming from these traditional sources, and do not support sensor network data. In this paper we make a first step towards enabling the inclusion of sensor network data into these integration approaches, with the automatic generation of data wrapping ontologies for sensor networks. Our approach extends existing ones used for extracting data wrapping ontologies from relational databases, using the schema of sensor network queries and external ontology search and relation discovery services

    Overcoming database heterogeneity to facilitate social networks: the Colombian displaced population as a case study

    Get PDF
    In this paper we describe a two-step approach for the publication of data about displaced people in Colombia, whose lack of homogeneity represents a major barrier for the application of adequate policies. This data is available in heterogeneous data sources, mainly relational, and is not connected to social networking sites. Our approach consists in a first step where ontologies are automatically derived from existing relational databases, exploiting the semantics underlying the SQL-DDL schema description, and a second step where these ontologies are aligned with existing ontologies (FOAF in our example), facilitating a better integration of data coming from multiple sources

    Semantic Web based Container Monitoring System for the Transportation Industry

    Get PDF
    Abstract: Goods are transported around the world in containers. Monitoring containers is a complex task. In this presentation, we will present a Container Monitoring System based on Semantic Web technologies. This system is currently being developed by Ege University, Bimar Information Technology Services and Capsenta for ARKAS Holding, one of Turkey's leading logistics and transportation companies. Our presentation consists of 1) introducing the challenges of monitoring containers in the transportation industry, 2) how existing technologies and solutions do not satisfy the needs, 3) why Semantic Web technologies can address the needs, 4) how we are using Semantic Web technologies including architectural design decisions and finally 5) describe lessons learned

    The Future is Big Graphs! A Community View on Graph Processing Systems

    Get PDF
    Graphs are by nature unifying abstractions that can leverage interconnectedness to represent, explore, predict, and explain real- and digital-world phenomena. Although real users and consumers of graph instances and graph workloads understand these abstractions, future problems will require new abstractions and systems. What needs to happen in the next decade for big graph processing to continue to succeed?Comment: 12 pages, 3 figures, collaboration between the large-scale systems and data management communities, work started at the Dagstuhl Seminar 19491 on Big Graph Processing Systems, to be published in the Communications of the AC
    corecore