TRM - Learning Dependencies between Text and Structure with Topical Relational Models -- A Confidentiality Model for Ontologies -- Pattern Based Knowledge Base Enrichment -- Controlled Query Evaluation over OWL 2 RL Ontologies -- Completeness Statements about RDF Data Sources and Their Use for Query Answering -- Empirical Study of Logic-Based Modules: Cheap Is Cheerful -- The Logic of Extensional RDFS -- Indented Tree or Graph? A Usability Study of Ontology Visualization Techniques in the Context of Class Mapping Evaluation -- Real-Time RDF Extraction from Unstructured Data Streams -- One License to Compose Them All: A Deontic Logic Approach to Data Licensing on the Web of Data -- Federated Entity Search Using On-the-Fly Consolidation -- ProSWIP: Property-Based Data Access for Semantic Web Interactive Programming -- Simplified OWL Ontology Editing for the Web: Is Web Protégé Enough -- A Query Tool for EL with Non-monotonic Rules -- Incremental Reasoning in OWL EL without Bookkeeping -- Secure Manipulation of Linked Data -- A Decision Procedure for SHOIQ with Transitive Closure of Roles -- Elastic and Scalable Processing of Linked Stream Data in the Cloud -- Towards Constructive Evidence of Data Flow-Oriented Web Service Composition -- The Combined Approach to OBDA: Taming Role Hierarchies Using Filters -- A Snapshot of the OWL Web -- Semantic Rule Filtering for Web-Scale Relation Extraction -- Semantic Message Passing for Generating Linked Data from Tables -- Bringing Math to LOD: A Semantic Publishing Platform Prototype for Scientific Collections in Mathematics -- ORCHID - Reduction-Ratio-Optimal Computation of Geo-spatial Distances for Link Discovery -- Simplifying Description Logic Ontologies -- Fed Search: Efficiently Combining Structured Queries and Full-Text Search in a SPARQL Federation -- Getting Lucky in Ontology Search: A Data-Driven Evaluation Framework for Ontology Ranking -- Exploring Scholarly Data with Rexplore -- Personalized Best Answer Computation in GraphDatabases -- Towards an Automatic Creation of Localized Versions of DBpedia -- Type Inference on Noisy RDF Data -- What's in a 'nym'? Synonyms in Biomedical Ontology Matching -- Knowledge Graph Identification -- Ontology-Based Data Access: On top of Databases -- DAW: Duplicate-AWare Federated Query Processing over the Web of Data -- On the Status of Experimental Research on the Semantic Web -- A Graph-Based Approach to Learn Semantic Descriptions of Data Sources -- QODI: Query as Context in Automatic Data Integration -- TRank: Ranking Entity Types Using the Web of Data -- DynamiTE: Parallel Materialization of Dynamic RDF Data -- Discovering Missing Semantic Relations between Entities in Wikipedia -- Infrastructure for Efficient Exploration of Large Scale Linked Data via Contextual Tag Clouds -- Statistical Knowledge Patterns: Identifying Synonymous Relations in Large Linked Datasets -- Complete Query Answering over Horn Ontologies Using a Triple Store.

The two-volume set LNCS 8218 and 8219 constitutes the refereed proceedings of the 12th International Semantic Web Conference, ISWC 2013, held in Sydney, Australia, in October 2013. The International Semantic Web Conference is the premier forum for Semantic Web research, where cutting edge scientific results and technological innovations are presented, where problems and solutions are discussed, and where the future of this vision is being developed. It brings together specialists in fields such as artificial intelligence, databases, social networks, distributed computing, Web engineering, information systems, human-computer interaction, natural language processing, and the social sciences. Part 1 (LNCS 8218) contains a total of 45 papers which were presented in the research track. They were carefully reviewed and selected from 210 submissions. Part 2 (LNCS 8219) contains 16 papers from the in-use track which were accepted from 90 submissions. In addition, it presents 10 contributions to the evaluations and experiments track and 5 papers of the doctoral consortium.