Export Citations
Save this search
Please login to be able to save your searches and receive alerts for new content matching your search criteria.
- research-articleSeptember 2024
Controlled query evaluation in description logics through consistent query answering
AbstractControlled Query Evaluation (CQE) is a framework for the protection of confidential data, where a policy given in terms of logic formulae indicates which information must be kept private. Functions called censors filter query answering so that no ...
- research-articleJune 2024
Plausible reasoning over large health datasets: A novel approach to data analytics leveraging semantics
AbstractPlausible reasoning is an interesting and viable approach for semantic data analytics as it provides a non-deterministic and exploratory approach to inferring new knowledge from large datasets. Plausible reasoning identifies meaningful ...
- research-articleAugust 2023
Polynomial combined first-order rewritings for linear and guarded existential rules
AbstractWe consider the problem of ontological query answering, that is, the problem of answering a database query (typically a conjunctive query) in the presence of an ontology. This means that during the query answering process we also need ...
- ArticleOctober 2022
GNNQ: A Neuro-Symbolic Approach to Query Answering over Incomplete Knowledge Graphs
AbstractReal-world knowledge graphs (KGs) are usually incomplete—that is, miss some facts representing valid information. So, when applied to such KGs, standard symbolic query engines fail to produce answers that are expected but not logically entailed by ...
- research-articleJune 2022
Temporal reasoning and query answering with preferences and probabilities for medical decision support
Expert Systems with Applications: An International Journal (EXWA), Volume 195, Issue Chttps://doi.org/10.1016/j.eswa.2022.116565Highlights- Decision support based on clinical guidelines is important in medicine.
- For ...
Knowledge-based decision support systems have a long tradition within the medical area. In particular, in the last decades, many Computer-Interpretable Guidelines (CIG) systems have been built to provide evidence-based and knowledge-...
-
- research-articleJune 2022
Inconsistency-tolerant query answering for existential rules
- Thomas Lukasiewicz,
- Enrico Malizia,
- Maria Vanina Martinez,
- Cristian Molinaro,
- Andreas Pieris,
- Gerardo I. Simari
AbstractQuerying inconsistent knowledge bases is an intriguing problem that gave rise to a flourishing research activity in the knowledge representation and reasoning community during the last years. It has been extensively studied in the ...
- research-articleApril 2022
Querying of several DL-Lite knowledge bases from various information sources-based polynomial response unification approach
Journal of King Saud University - Computer and Information Sciences (JKSUCIS), Volume 34, Issue 4Pages 1161–1171https://doi.org/10.1016/j.jksuci.2020.06.002AbstractThe inconsistency in the hierarchical knowledge base is due to the fact that the assertions (ABoxes) come from several sources with different levels of reliability. We introduce the management of this inconsistency problem to query the ...
- research-articleMarch 2022
Vadalog: A modern architecture for automated reasoning with large knowledge graphs
AbstractThe introduction of novel Datalog +/- fragments with good theoretical properties, together with the growing use of enterprise knowledge graphs motivated the development of Vadalog, a knowledge graph management system developed at the ...
Highlights- Growing use of enterprise knowledge graphs motivated the development of Vadalog.
- research-articleDecember 2021
- research-articleNovember 2021
KG4ASTRA: question answering over Indian Missiles Knowledge Graph
Soft Computing - A Fusion of Foundations, Methodologies and Applications (SOFC), Volume 25, Issue 22Pages 13841–13855https://doi.org/10.1007/s00500-021-06233-yAbstractNatural language, being unstructured, makes the tedious task for building a model to parse it into a query language successfully. An incorrect query for a particular question would lead to an absurd answer. As seen in many semantic parsing ...
- research-articleJune 2021
Inference from Visible Information and Background Knowledge
ACM Transactions on Computational Logic (TOCL), Volume 22, Issue 2Article No.: 13, Pages 1–69https://doi.org/10.1145/3452919We provide a wide-ranging study of the scenario where a subset of the relations in a relational vocabulary is visible to a user—that is, their complete contents are known—while the remaining relations are invisible. We also have a background theory—...
- ArticleMay 2021
Rule Injection-Based Generative Adversarial Imitation Learning for Knowledge Graph Reasoning
Advances in Knowledge Discovery and Data MiningPages 338–350https://doi.org/10.1007/978-3-030-75768-7_27AbstractKnowledge graph reasoning is a crucial part of knowledge discovery and knowledge graph completion tasks. The solution based on generative adversarial imitation learning (GAIL) has made great progress in recent researches and solves the problem of ...
- research-articleMarch 2021
Query answering DL-lite knowledge bases from hidden datasets
Annals of Mathematics and Artificial Intelligence (KLU-AMAI), Volume 89, Issue 3-4Pages 271–299https://doi.org/10.1007/s10472-020-09714-2AbstractUnifying access to data using structured knowledge is the main problem studied in ontology-based data access (OBDA). Data are often provided by several information sources, and this has led to a number of methods that merge them in order to get a ...
- ArticleNovember 2020
KnowlyBERT - Hybrid Query Answering over Language Models and Knowledge Graphs
AbstractProviding a plethora of entity-centric information, Knowledge Graphs have become a vital building block for a variety of intelligent applications. Indeed, modern knowledge graphs like Wikidata already capture several billions of RDF triples, yet ...
- ArticleSeptember 2020
A Partial Materialization-Based Approach to Scalable Query Answering in OWL 2 DL
AbstractThis paper focuses on the efficient ontology-mediated querying (OMQ) problem. Compared with query answering in plain databases, which deals with fixed finite database instances, a key challenge in OMQ is to deal with the possibly infinite large ...
- ArticleSeptember 2020
Approximate Knowledge Graph Query Answering: From Ranking to Binary Classification
Graph Structures for Knowledge Representation and ReasoningPages 107–124https://doi.org/10.1007/978-3-030-72308-8_8AbstractLarge, heterogeneous datasets are characterized by missing or even erroneous information. This is more evident when they are the product of community effort or automatic fact extraction methods from external sources, such as text. A special case ...
- research-articleSeptember 2019
Foundations of ontology-based data access under bag semantics
- Charalampos Nikolaou,
- Egor V. Kostylev,
- George Konstantinidis,
- Mark Kaminski,
- Bernardo Cuenca Grau,
- Ian Horrocks
Artificial Intelligence (ARTI), Volume 274, Issue CPages 91–132https://doi.org/10.1016/j.artint.2019.02.003AbstractOntology-based data access (OBDA) is a popular approach for integrating and querying multiple data sources by means of a shared ontology. The ontology is linked to the sources using mappings, which assign to ontology predicates views ...
- ArticleJune 2019
Reformulation-Based Query Answering for RDF Graphs with RDFS Ontologies
AbstractQuery answering in RDF knowledge bases has traditionally been performed either through graph saturation, i.e., adding all implicit triples to the graph, or through query reformulation, i.e., modifying the query to look for the explicit triples ...
- research-articleMarch 2019
Reasoning and querying web-scale open data based on DL-LiteA in a divide-and-conquer way
Web Semantics: Science, Services and Agents on the World Wide Web (WEBS), Volume 55, Issue CPages 122–144https://doi.org/10.1016/j.websem.2019.01.003AbstractWe propose to use DL-LiteA techniques to reason and query the Web-scale Open Data (knowledge bases) described by Semantic Web standards like RDF and OWL due to the low reasoning complexity and suitable expressivity of the language. ...
Highlights- We propose to use DL-LiteA techniques to reason and query the web-scale Open Data.
- ArticleSeptember 2018
A Tutorial on Query Answering and Reasoning over Probabilistic Knowledge Bases
Reasoning Web. Learning, Uncertainty, Streaming, and ScalabilityPages 35–77https://doi.org/10.1007/978-3-030-00338-8_3AbstractLarge-scale probabilistic knowledge bases are becoming increasingly important in academia and industry alike. They are constantly extended with new data, powered by modern information extraction tools that associate probabilities with knowledge ...