Renata Queiroz Dividino

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The Semantic Web is based on accessing and reusing RDF data from many different sources, which one may assign different levels of authority and credibility. Existing Semantic Web query languages, like SPARQL, have targeted the retrieval, combination and reuse of facts, but have so far ignored all aspects of meta knowledge, such as origins, authorship,(More)
Quite often, Linked Open Data (LOD) applications pre-fetch data from the Web and store local copies of it in a cache for faster access at runtime. Yet, recent investigations have shown that data published and interlinked on the LOD cloud is subject to frequent changes. As the data in the cloud changes, local copies of the data need to be updated. However,(More)
Recent work analyzing changes on the Linked Open Data (LOD) cloud on fine-grained weekly snapshots shows that vocabularies published on the cloud are highly static. While this result is quite expected, there is another kind of schematic information that can be observed on the LOD cloud: the use of the vocabularies in the cloud. With use, we mean the(More)
The objective of the Semiotic-based Ontology Evaluation Tool (S-OntoEval) is to evaluate and propose improvements to a given ontological model. The evaluation aims at assessing the quality of the ontology by drawing upon semiotic theory (Stamper et al., 2000), taking several metrics into consideration for assessing the syntactic, semantic, and pragmatic(More)
One of the key benefits of the Semantic Web technology is the better support of decentralized, self-organizing knowledge exchange between users. When integrating knowledge from different sources or even from the full range of the Semantic Web, we are faced with highly varying quality of information. Hence, one of the major challenges is to investigate the(More)
The Linked Open Data (LOD) cloud changes frequently. Recent approaches focus mainly on quantifying the changes that occur in the LOD cloud by comparing two snapshots of a linked dataset captured at two different points in time. These change metrics are able to measure absolute changes between these two snapshots. However, they cannot determine the dynamics(More)
Information retrieval on RDF data benefits greatly from additional provenance information attached to the individual pieces of information. Provenance information such as origin of data, certainty, and temporal information on RDF statements can be used to rank search results according to one of those dimensions. In this paper, we consider the problem of(More)
Querying Linked Data means to pose queries on various data sources without information about the data and the schema of the data. This demo shows SPACE, a tool to support autocompletion for SPARQL queries. It takes as input SPARQL query logs and builds an index structure for efficient and fast computation of query suggestions. To demonstrate SPACE, we use(More)
For many tasks, such as the integration of knowledge bases in the semantic web, one must not only handle the knowledge itself, but also characterizations of this knowledge, e.g.: (i) where did a knowledge item come from (i.e. provenance), (ii) what level of trust can be assigned to a knowledge item, or (iii) what degree of certainty is associated with it.(More)