Reasoning Web Semantic Technologies For The Web Of Data

The Semantic Web aims at enriching the existing Web with meta-data and processing methods so as to provide web-based systems with advanced capabilities, in particular with context awareness and decision support. The objective of this book is to provide a coherent introduction to semantic web methods and research issues with a particular emphasis on reasoning. The 7th reasoning web Summer School, held in August 2011, focused on the central topic of applications of reasoning for the emerging “Web of Data”. The 12 chapters in the present book provide excellent educational material as well as a number of references for further reading. The book not only addresses students working in the area, but also those seeking an entry point to various topics related to reasoning over Web data.

This volume contains the lecture notes of the 9th Reasoning Web Summer School 2013, held in Mannheim, Germany, in July/August 2013. The 2013 summer school program covered diverse aspects of Web reasoning, ranging from scalable lightweight formalisms such as RDF to more expressive ontology languages based on description logics. It also featured foundational reasoning techniques used in answer set programming and ontology-based data access as well as emerging topics like geo-spatial information handling and reasoning-driven information extraction and integration.

This book contains a collection of revised tutorial papers based on lectures given by researchers at the 5th International Summer School on the Reasoning Web. It introduces semantic web methods and research issues with a particular emphasis on reasoning.

Linked Data publishing has brought about a novel “Web of Data”: a wealth of diverse, interlinked, structured data published on the Web. These Linked Datasets are described using the Semantic Web standards and are openly available to all, produced by governments, businesses, communities and academia alike. However, the heterogeneity of such data – in terms of how resources are described and identified – poses major challenges to potential consumers. Herein, we examine use cases for pragmatic, lightweight reasoning techniques that leverage Web vocabularies (described in RDFS and OWL) to better integrate large scale, diverse, Linked Data corpora. We take a test corpus of 1.1 billion RDF statements collected from 4 million RDF Web documents and analyse the use of RDFS and OWL therein. We then detail and evaluate scalable and distributed techniques for applying rule-based materialisation to translate data between different vocabularies, and to resolve coreferent resources that talk about the same thing. We show how such techniques can be made robust in the face of noisy and often impudent Web data. We also examine a use case for incorporating a PagerRank-style algorithm to rank the trustworthiness of facts produced by reasoning, subsequently using those ranks to fix formal contradictions in the data. All of our methods are validated against our real world, large scale, open domain, Linked Data evaluation corpus.

Semantic Web technologies enable people to create data stores on the Web, build vocabularies, and write rules for handling data. They have been in use for several years now, and knowledge extraction and knowledge discovery are two key aspects investigated in a number of research fields which can potentially benefit from the application of semantic web technologies, and specifically from the development and reuse of ontologies. This book, Applications and Practices in Ontology Design, Extraction, and Reasoning, has as its main goal the provision of an overview of application fields for semantic web technologies. In particular, it investigates how state-of-the-art formal languages, models, methods, and applications of semantic web technologies reframe research questions and approaches in a number of research fields. The book also aims to showcase practical tools and background knowledge for the building and querying of ontologies. The first part of the book presents the state-of-the-art of ontology design, applications and practices in a number of communities, and in doing so it provides an overview of the latest approaches and techniques for building and reusing ontologies according to domain-dependent and independent requirements. Once the data is represented according to ontologies, it is important to be able to query and reason about them, also in the presence of uncertainty, vagueness and probabilities. The second part of the book covers some of the latest advances in the fields of ontology, semantics and reasoning, without losing sight of the book’s practical goals.

Welcome to the proceedings of Reasoning Web 2010 which was held in Dresden. Reasoning Web is a summer school series on theoretical foundations,contemporary approaches, and practical solutions for reasoning in a Web of Semantics. It has est- lished itself as a meeting point for experts from research institutes and industry, as well as students undertakingtheir PhDs in related ?elds. This volume contains tutorial notes of the sixth school in the series, held from August 30 to September 3, 2010. This year, the school focused on applications of semantic technologies in software engineeringandthereasoningtechnologiesappropriateforsuchanendeavor. Asit turns out, semantic technologies in software engineering are not so easily applied, and s- eral issues mustbe resolvedbeforesoftware modelingcanbene?t fromreasoning. First, reasoning has to be fast and scalable, since models and programscan be quite large and voluminous. SincemanyreasoninglanguagesareexponentialorNP-complete,appro- mation, incrementalization,and other optimizationtechniques are extremelyimportant. Second, software engineering needs to model software systems, in contrast to mod- ing domains of the world. Thus, the modeling techniques are prescriptive rather than descriptive [1], which in?uences the way models are reasoned about. When a software system is modeled, its behavior is prescribed by the model, that is, “the truth is in the model”[2]; when a domainof the world is described,its behaviorcannotbe prescribed, only described by the model (“the truth is in the world”). Therefore, reasoning has to distinguish between prescriptiveness and descriptiveness, leading to different assu- tions about the closeness or openness of the world (closed-world assumption, CWA vs. open-world assumption, OWA).

The Semantic Web is a new area of research and development in the field of computer science that aims to make it easier for computers to process the huge amount of information on the web, and indeed other large databases, by enabling them not only to read, but also to understand the information. Based on successful courses taught by the authors, and liberally sprinkled with examples and exercises, this comprehensive textbook describes not only the theoretical issues underlying the Semantic Web, but also algorithms, optimisation ideas and implementation details. The book will therefore be valuable to practitioners as well as students, indeed to anyone who is interested in Internet technology, knowledge engineering or description logics. Supplementary materials available online include the source code of program examples and solutions to selected exercises.