RDF data evolution: efficient detection and semantic representation of changes

ABSTRACT Many RDF data sources are constantly changing for both data and vocabulary (ontology) levels. Many integration tasks are impacted by these changes. In this context, it is important to develop approaches to detect and represent these changes. Many studies have focused on the detection, the representation and the management of changes at the ontology level. In this paper, we present an approach which allows to detect and represent elementary and complex changes that can be detected when we focus only on the data level. A first experiment was conducted on different versions of DBpedia

Represent Changes of Knowledge Organization Systems on the Semantic Web

Traditional knowledge organization systems (KOS) including thesauri, classification schemes, taxonomies, subject heading systems, name authorities, and other lists of terms and codes have been playing important roles in indexing, information organization, and retrieval. With the advent of the semantic web, a large number of them have been converted into Linked Open Data (LOD) datasets. Since the Simple Knowledge Organization Systems (SKOS) and SKOS eXtension for Labels (SKOS-XL) are languages for representation of knowledge organization systems, they have been applied to knowledge organization systems. In this article, the issues surrounding changes, versioning control, and evolution of KOS are investigated. From KOS services providers and consumers perspectives, this study focuses on representation of changes on the semantic web

Ontology evolution: a process-centric survey

Ontology evolution aims at maintaining an ontology up to date with respect to changes in the domain that it models or novel requirements of information systems that it enables. The recent industrial adoption of Semantic Web techniques, which rely on ontologies, has led to the increased importance of the ontology evolution research. Typical approaches to ontology evolution are designed as multiple-stage processes combining techniques from a variety of fields (e.g., natural language processing and reasoning). However, the few existing surveys on this topic lack an in-depth analysis of the various stages of the ontology evolution process. This survey extends the literature by adopting a process-centric view of ontology evolution. Accordingly, we first provide an overall process model synthesized from an overview of the existing models in the literature. Then we survey the major approaches to each of the steps in this process and conclude on future challenges for techniques aiming to solve that particular stage

On Computing Deltas of RDF/S Knowledge Bases

The ability to compute the differences that exist between two RDF/S Knowledge Bases (KB) is an important step to cope with the evolving nature of the Semantic Web (SW). In particular, RDF/S deltas can be employed to reduce the amount of data that need to be exchanged and managed over the network in order to build SW synchronization and versioning services. By considering deltas as sets of change operations, in this article we introduce various RDF/S differential functions which take into account inferred knowledge from an RDF/S knowledge base. We first study their correctness in transforming a source to a target RDF/S knowledge base in conjunction with the semantics of the employed change operations (i.e., with or without side-effects on inferred knowledge). Then we formally analyze desired properties of RDF/S deltas such as size minimality, semantic identity, redundancy elimination, reversibility, and composability, as well as identify those RDF/S differential functions that satisfy them. Subsequently, we experimentally evaluate the computing time and size of the produced deltas over real and synthetic RDF/S knowledge bases

An evaluation of the challenges of Multilingualism in Data Warehouse development

In this paper we discuss Business Intelligence and define what is meant by support for Multilingualism in a Business Intelligence reporting context. We identify support for Multilingualism as a challenging issue which has implications for data warehouse design and reporting performance. Data warehouses are a core component of most Business Intelligence systems and the star schema is the approach most widely used to develop data warehouses and dimensional Data Marts. We discuss the way in which Multilingualism can be supported in the Star Schema and identify that current approaches have serious limitations which include data redundancy and data manipulation, performance and maintenance issues. We propose a new approach to enable the optimal application of multilingualism in Business Intelligence. The proposed approach was found to produce satisfactory results when used in a proof-of-concept environment. Future work will include testing the approach in an enterprise environmen