Results 191 to 200 of about 32,178 (242)

Efficient and Effective SPARQL Autocompletion on Very Large Knowledge Graphs

International Conference on Information and Knowledge Management, 2022
We show how to achieve fast autocompletion for SPARQL queries on very large knowledge graphs. At any position in the body of a SPARQL query, the autocompletion suggests matching subjects, predicates, or objects.
Hannah Bast, J. Kalmbach, Theresa Klumpp, F. Kramer, N. Schnelle   +4 more
semanticscholar   +1 more source

Federated SPARQL Query Processing over Heterogeneous Linked Data Fragments

The Web Conference, 2022
Linked Data Fragments (LDFs) are Web interfaces that enable querying knowledge graphs on the Web. These interfaces, such as SPARQL endpoints or Triple Pattern Fragment servers, differ in the SPARQL expressions they can evaluate and the metadata they ...
Lars Heling, Maribel Acosta
semanticscholar   +1 more source

An Efficient RDF Converter and SPARQL Endpoint for the Complete OpenStreetMap Data

SIGSPATIAL/GIS, 2021
We present osm2rdf, a tool for converting OpenStreetMap (OSM) data to RDF triples, along with an efficient SPARQL endpoint and a convenient user interface for formulating SPARQL queries on that data.
Hannah Bast, P. Brosi, J. Kalmbach, A. Lehmann   +3 more
semanticscholar   +1 more source

Discovery and diagnosis of wrong SPARQL queries with ontology and constraint reasoning

Expert systems with applications, 2021
The discovery and diagnosis of wrong queries in database query languages have gained more attention in recent years. While for imperative languages well-known and mature debugging tools exist, the case of database query languages has traditionally ...
J. Almendros-Jiménez, A. Becerra-Terón
semanticscholar   +1 more source

SPARQL-RW

Proceedings of the 15th International Conference on Extending Database Technology, 2012
The Web of Data is an open environment consisting of very large, inter-linked RDF datasets from various domains (e.g., DBpedia, GeoNames, ACM, PubMed, etc.) accessed through SPARQL queries. Establishing interoperability in this environment has become a major research challenge.
Konstantinos Makris, Nikos Bikakis, Nektarios Gioldasis, Stavros Christodoulakis   +3 more
openaire   +1 more source

LLM-based SPARQL Query Generation from Natural Language over Federated Knowledge Graphs

HGAIS@ISWC
We introduce a Retrieval-Augmented Generation (RAG) system for translating user questions into accurate federated SPARQL queries over bioinformatics knowledge graphs (KGs) leveraging Large Language Models (LLMs).
Vincent Emonet, Jerven T. Bolleman, S. Duvaud, T. M. Farias, A. Sima   +4 more
semanticscholar   +1 more source

SPINACH: SPARQL-Based Information Navigation for Challenging Real-World Questions

Conference on Empirical Methods in Natural Language Processing
Large Language Models (LLMs) have led to significant improvements in the Knowledge Base Question Answering (KBQA) task. However, datasets used in KBQA studies do not capture the true complexity of KBQA tasks.
Shicheng Liu, Sina J. Semnani, Harold Triedman, Jialiang Xu, I. Zhao, Monica S. Lam   +5 more
semanticscholar   +1 more source

Experiments with text-to-SPARQL based on ChatGPT

International Computer Science Conference
Currently, large language models (LLMs) are the state of the art for pre-trained language models. LLMs have been applied to many tasks, including question and answering over Knowledge Graphs (KGs) and text-to-SPARQL, that is, the translation of Natural ...
Caio Viktor S. Avila, V. Vidal, Wellington Franco, Marco A. Casanova   +3 more
semanticscholar   +1 more source

SPBERT: An Efficient Pre-training BERT on SPARQL Queries for Question Answering over Knowledge Graphs

International Conference on Neural Information Processing, 2021
In this paper, we propose SPBERT, a transformer-based language model pre-trained on massive SPARQL query logs. By incorporating masked language modeling objectives and the word structural objective, SPBERT can learn general-purpose representations in ...
H. Tran, Long Phan, J. Anibal, B. Nguyen, Truong-Son Nguyen   +4 more
semanticscholar   +1 more source

G-SPARQL

Proceedings of the 21st ACM international conference on Information and knowledge management, 2012
We propose a SPARQL-like language, G-SPARQL, for querying attributed graphs. The language expresses types of queries which of large interest for applications which model their data as large graphs such as: pattern matching, reachability and shortest path queries.
Sherif Sakr, Sameh Elnikety, Yuxiong He
openaire   +1 more source