An Empirical Evaluation of RDF Graph Partitioning Techniques.-Fuzzy Semantic Labeling of Semi-structured Numerical Datasets -- From Georeferenced Data to Socio-spatial Knowledge. Ontology Design -- Patterns to discover Domain-speci_c Knowledge from Crowdsourced Data -- Conceptual Schema Transformation in Ontology-based Data Access -- SWRL Reasoning with Decision Tables -- A framework for explaining query answers in DL-Lite -- DL-Foil: Class Expression Learning Revisited -- Requirements behaviour analysis for ontology testing -- Interactive Interpretation of serial episodes -- Network Metrics for Assessing the Quality of Entity Resolution Between Multiple Datasets -- Making Sense of Numerical Data - Semantic Labelling of Web Tables -- Towards Enriching DBpedia from Vertical Enumerative Structures using a Distant Learning Approach -- The Utility of the Abstract Relational Model and Attribute Paths in SQL -- Support and Centrality: Learning Weights for Knowledge Graph Embedding Models -- OmniScience and Extensions - Lessons Learned from Designing a Multi Domain, Multi-Use Case Knowledge Representation System -- A Semantic Use Case Simulation Framework for Training Machine Learning Algorithms -- KnIGHT: Mapping Privacy Policies to GDPR -- Automating Class / Instance Representational Choices in Knowledge Bases -- Comparative Preferences in SPARQL -- Interplay of Game Incentives, Player Profiles and Task Dificulty in Games with a Purpose -- Inferring Types on Large Datasets Applying Ontology Class Hierarchy Classifiers: The DBpedia Case -- A Framework for Tackling Myopia in Concept Learning on the Web of Data -- Boosting Holistic Ontology Matching : an Extended Linear Approach and its Evaluation on Graph Clique-based Relaxed Reference Alignments -- Prominence and Dominance in Networks -- Deploying Spatial-Stream Query Answering in C-ITS Scenarios -- Metaproperty-guided Deletion from the Instance-Level of a Knowledge Base -- On Extracting Relations using Distributional Semantics and a Tree Generalization -- A Query Model for Ontology-Based Event Processing over RDF Streams -- A Random Walk Model for Entity Relatedness -- Using SPARQL - the practitioners' viewpoint -- Combining Machine Learning and Semantics for Anomaly Detection -- EROSO: Semantic Technologies towards thermal comfort in workplaces -- Divided we stand out! Forging Cohorts for Numeric Outlier Detection in large scale knowledge graphs (CONOD) -- Decision Support Models to Assist in the Diagnosis of Meningitis -- A Framework to Conduct and Report on Empirical User Studies in Semantic Web Contexts.

This book constitutes the refereed proceedings of the 21th International Conference on Knowledge Engineering and Knowledge Management, EKAW 2018, held in Nancy, France, in November 2018. The 36 full papers presented were carefully reviewed and selected from 104 submissions. The papers cover all aspects of eliciting, acquiring, modeling, and managing knowledge, the construction of knowledge-intensive systems and services for the Semantic Web, knowledge management, e-business, natural language processing, intelligent information integration, personal digital assistance systems, and a variety of other related topics. A special focus was on "Knowledge and AI", i.e. papers describing algorithms, tools, methodologies, and applications that exploit the interplay between knowledge and Artificial Intelligence techniques, with a special emphasis on knowledge discovery.