This book constitutes the thoroughly refereed post-conference proceedings of the joint International Workshops on Semantic Web, Ontologies and Databases, SWDB-ODBIS 2007, co-located with the 33rd International Conference on Very Large Data Bases, VLDB 2007, held in Vienna, Austria, in September 2007. The 7 revised full papers presented together with 1 invited paper were carefully selected from 11 submissions. Among the topics addressed are semantics-aware data models and query languages; ontology-based views, mapping, transformations, and query reformulation; and storing and indexing semantic Web data and schemas.
An early vision in Computer Science was to create intelligent systems capable of reasoning on large amounts of data. Independent results in the areas of Semantic Web and Relational Databases have advanced us towards this vision. Despite independent advances, the interface between Relational Databases and Semantic Web is poorly understood. This dissertation revisits this early vision with respect to current technology and addresses the following question: How and to what extent can Relational Databases be integrated with the Semantic Web? The thesis is that much of the existing Relational Database infrastructure can be reused to support the Semantic Web. Two problems are studied.Can a Relational Database be automatically virtualized as a Semantic Web data source? The first contribution is an automatic direct mapping from a Relational Database schema and data to RDF and OWL. The second contribution is a method capable of evaluating SPARQL queries against the Relational Database by exploiting two existing relational query optimizations. These contributions are embodied in the Ultrawrap system. Experiments show that SPARQL query execution performance on Ultrawrap is comparable to that of SQL queries written directly for the relational data. Such results have not been previously achieved.Can a Relational Database be mapped to existing Semantic Web ontologies and act as a reasoner? A third contribution is a method for Relational Databases to support inheritance and transitivity by compiling the ontology as mappings, implementing the mappings as views, using SQL recursion and optimizing by materializing views. Ultrawrap is extended with this contribution. Empirical analysis reveals that Relational Databases are able to effectively act as reasoners.
Semantic web continues to be an increasingly important system for allowing end-users to share and communicate information online. Semantic Web: Ontology and Knowledge Base Enabled Tools, Services and Application focuses on the information systems discipline and the tools and techniques utilized for the emerging use of semantic web. Covering topics on semantic search, ontologies, and recommendation systems, this publication is essential for academics, practitioners, and industry professionals.
This book constitutes the refereed proceedings of the First European Semantic Web Symposium, ESWS 2004, held in Heraklion, Crete, Greece in May 2004. The 33 revised full papers presented were carefully reviewed and selected from 79 submissions. The papers are organized in topical sections on ontology engineering, ontology matching and mapping, ontology-based querying, ontology merging and population, infrastructure, semantic web services, service discovery and composition, data from the semantic web, knowledge presentation, applications, content management, and information management and integration.
The Semantic Web, which is intended to establish a machine-understandable Web, is currently changing from being an emerging trend to a technology used in complex real-world applications. A number of standards and techniques have been developed by the World Wide Web Consortium (W3C), e.g., the Resource Description Framework (RDF), which provides a general method for conceptual descriptions for Web resources, and SPARQL, an RDF querying language. Recent examples of large RDF data with billions of facts include the UniProt comprehensive catalog of protein sequence, function and annotation data, the RDF data extracted from Wikipedia, and Princeton University’s WordNet. Clearly, querying performance has become a key issue for Semantic Web applications. In his book, Groppe details various aspects of high-performance Semantic Web data management and query processing. His presentation fills the gap between Semantic Web and database books, which either fail to take into account the performance issues of large-scale data management or fail to exploit the special properties of Semantic Web data models and queries. After a general introduction to the relevant Semantic Web standards, he presents specialized indexing and sorting algorithms, adapted approaches for logical and physical query optimization, optimization possibilities when using the parallel database technologies of today’s multicore processors, and visual and embedded query languages. Groppe primarily targets researchers, students, and developers of large-scale Semantic Web applications. On the complementary book webpage readers will find additional material, such as an online demonstration of a query engine, and exercises, and their solutions, that challenge their comprehension of the topics presented.
This book introduces advanced semantic web technologies, illustrating their utility and highlighting their implementation in biological, medical, and clinical scenarios. It covers topics ranging from database, ontology, and visualization to semantic web services and workflows. The volume also details the factors impacting on the establishment of the semantic web in life science and the legal challenges that will impact on its proliferation.
Semantic Web for the Working Ontologist: Effective Modeling in RDFS and OWL, Second Edition, discusses the capabilities of Semantic Web modeling languages, such as RDFS (Resource Description Framework Schema) and OWL (Web Ontology Language). Organized into 16 chapters, the book provides examples to illustrate the use of Semantic Web technologies in solving common modeling problems. It uses the life and works of William Shakespeare to demonstrate some of the most basic capabilities of the Semantic Web. The book first provides an overview of the Semantic Web and aspects of the Web. It then discusses semantic modeling and how it can support the development from chaotic information gathering to one characterized by information sharing, cooperation, and collaboration. It also explains the use of RDF to implement the Semantic Web by allowing information to be distributed over the Web, along with the use of SPARQL to access RDF data. Moreover, the reader is introduced to components that make up a Semantic Web deployment and how they fit together, the concept of inferencing in the Semantic Web, and how RDFS differs from other schema languages. Finally, the book considers the use of SKOS (Simple Knowledge Organization System) to manage vocabularies by taking advantage of the inferencing structure of RDFS-Plus. This book is intended for the working ontologist who is trying to create a domain model on the Semantic Web. - Updated with the latest developments and advances in Semantic Web technologies for organizing, querying, and processing information, including SPARQL, RDF and RDFS, OWL 2.0, and SKOS - Detailed information on the ontologies used in today's key web applications, including ecommerce, social networking, data mining, using government data, and more - Even more illustrative examples and case studies that demonstrate what semantic technologies are and how they work together to solve real-world problems
This book constitutes the refereed proceedings of the joint 6th International Semantic Web Conference, ISWC 2007, and the 2nd Asian Semantic Web Conference, ASWC 2007, held in Busan, Korea, in November 2007. The 50 revised full academic papers and 12 revised application papers presented together with 5 Semantic Web Challenge papers and 12 selected doctoral consortium articles were carefully reviewed and selected from a total of 257 submitted papers to the academic track and 29 to the applications track. The papers address all current issues in the field of the semantic Web, ranging from theoretical and foundational aspects to various applied topics such as management of semantic Web data, ontologies, semantic Web architecture, social semantic Web, as well as applications of the semantic Web. Short descriptions of the top five winning applications submitted to the Semantic Web Challenge competition conclude the volume.
This is an edited volume based on the 2007 Conference on Metadata and Semantics Research (MTSR), now in its second meeting. Metadata research is a pluri-disciplinary field that encompasses all aspects of the definition, creation, assessment, management and use of metadata. The volume brings together world class leaders to contribute their research and up-to-date information on metadata and semantics applied to library management, e-commerce, e-business, information science and librarianship, to name a few. The book is designed for a professional audience composed of researchers and practitioners in industry.
