Biography

I am David Chaves-Fraga, assistant professor at Universidade de Santiago de Compostela (USC, Spain). I am also a researcher at the Center for research in Intelligent Technologies (CiTIUS@USC) and research collaborator at the Declarative Languages and Artificial Intelligence Group (DTAI) at KU Leuven, Belgium. I am a former researcher at the Ontology Engineering Group (OEG) at Technical University of Madrid (UPM) where I hold my PhD with my thesis "Knowledge Graph Construction from Heterogeneous Data Sources Exploiting Declarative Mapping Rules" in July 2021. My main research lines are focused on the optimization and evaluation of data integration systems, mainly the construction of Knowledge Graphs from (semi)structured sources using declarative mapping rules.

As I really believe that research is a collaborative task, I'm continuously trying to contribute to my research community. For that reason, I'm currently co-chairing the W3C community group for Knowledge Graph Construction, I organize two workshop series (KGC and Sem4Tra) and several tutorials in semantic web conferences about the same topic. Additionally, I have been the main coordinator of Open Summer of Code in Spain from 2018 to 2021, a formative, international, and innovative program for undergrad and master students.

Education

  • Ph.D in Artificial Intelligence (2016-2021)
    Universidad Politécnica de Madrid, Spain
  • Master in Articial Intelligence (2015-2016)
    Universidad Politécnica de Madrid, Spain
  • Bachelor in Computer Science (2011-2015)
    Universidade de Santiago de Compostela, Spain

Experience

Publications

Are Knowledge Graphs Ready for the Real World? Challenges and Perspective
David Chaves-Fraga, Oscar Corcho, Anastasia Dimou and Maria-Esther Vidal.
Report from Dagstuhl Seminar, 2024
Report
KROWN: A Benchmark for RDF Graph Materialisation
Dylan Van Assche, David Chaves-Fraga, Anastasia Dimou.
International Semantic Web Conference, 2024
Nominated for the Best Paper Award in the Resources Track
Paper Code
Declarative Generation of RDF-star Graphs from Heterogeneous Data
Julián Arenas-Guerrero, Ana Iglesias-Molina, David Chaves-Fraga, Daniel Garijo, Oscar Corcho and Anastasia Dimou.
Semantic Web Journal, 2024
Paper Code
Empowering the SDM-RDFizer Tool for Scaling Up to Complex Knowledge Graph Creation Pipelines
Enrique Iglesias, Maria-Esther Vidal, Diego Collarana, David Chaves-Fraga.
Semantic Web Journal, 2024
Paper Code
An Ontological Approach for Representing Declarative Mapping Languages
Ana Iglesias-Molina, Andrea Cimmino, Edna Ruckhaus, David Chaves-Fraga, Raúl García-Castro, Oscar Corcho.
Semantic Web Journal, 2024
Paper Ontology
Morph-KGC: Scalable Knowledge Graph Materialization with Mapping Partitions
Julián Arenas-Guerrero, David Chaves-Fraga, Jhon Toledo, María S. Pérez, Oscar Corcho.
Semantic Web Journal, 2024
Paper Code
SCOOP all the Constraints’ Flavours for your Knowledge Graph
Xuemin Duan, David Chaves-Fraga, Olivier Derom, and Anastasia Dimou.
Extended Semantic Web Conference, 2024
Paper Code
SCOOP-UI: SHACL Shape Extraction in Just a Click!
Xuemin Duan, David Chaves-Fraga, and Anastasia Dimou.
Extended Semantic Web Conference (P&D), 2024
Paper Demo Code
RMLdoc: Documenting Mapping Rules for Knowledge Graph Construction
Jhon Toledo, Ana Iglesias-Molina, David Chaves-Fraga, and Daniel Garijo.
Extended Semantic Web Conference (P&D), 2024
Paper Code
When Ontologies met Knowledge Graphs: Tale of a Methodology
Romana Pernisch, María Poveda-Villalón, Diego Conde-Herreros, David Chaves-Fraga, and Lise Stork.
Extended Semantic Web Conference (P&D), 2024
Paper
Propagating Ontology Changes to Declarative Mappings in Construction of Knowledge Graphs
Diego Conde-Herreros, Lise Stork, Romana Pernisch, María Poveda-Villalón, Oscar Corcho, and David Chaves-Fraga.
5th Edition of the Knowledge Graph Construction Workshop co-located with ESWC, 2024
Paper Code
The RML Ontology: A Community-Driven Modular Redesign After a Decade of Experience in Mapping Heterogeneous Data to RDF
Ana Iglesias-Molina, Dylan Van Assche, Julián Arenas-Guerrero, Ben De Meester, Christophe Debruyne, Samaneh Jozashoori, Pano Maria, Franck Michel, David Chaves-Fraga, and Anastasia Dimou.
International Semantic Web Confernece, 2023
Nominated for the Best Paper Award in the Resources Track
Paper RML Portal
XSD2SHACL: Capturing RDF Constraints from XML Schema
Xuemin Duan, David Chaves-Fraga, and Anastasia Dimou.
International Conference on Knowledge Capture, 2023
Paper XSD2SHACL
Re-Construction Impact on Metadata Representation Models
Ana Iglesias-Molina, Jhon Toledo, Oscar Corcho, and David Chaves-Fraga.
International Conference on Knowledge Capture, 2023
Paper Resources
Human-Friendly RDF Graph Construction: Which one do you chose?
Ana Iglesias-Molina, David Chaves-Fraga, Ioannis Dasoulas, and Anastasia Dimou.
International Conference on Web Engineering, 2023
Paper Yatter
Declarative RDF construction from in-memory data structures with RML
Ioannis Dasoulas, David Chaves-Fraga, Daniel Garijo, and Anastasia Dimou.
4th Edition of the Knowledge Graph Construction Workshop co-located with ESWC, 2023
Paper Morph-KGC-RAM
Evo-KnoMo: How to Evolve with the Current Times (fiction paper)
Oscar Corcho, Ana Iglesias-Molina, Edna Ruckhaus, Jhon Toledo, ChatOEG, and David Chaves-Fraga.
Extended Semantic Web Conference, 2023 (or 2043)
Paper
Handling Qualitative Preferences in SPARQL over Virtual Ontology-Based Data Access
Marlene Goncalves, David Chaves-Fraga, Oscar Corcho.
Semantic Web Journal, 2022
Paper Code
Systematic Construction of Knowledge Graphs for Research-Performing Organizations.
David Chaves-Fraga, Oscar Corcho, Francisco Yedro, Roberto Moreno, Juan Olías and Alejandro De La Azuela
Information, 2022
Paper
Declarative Description of Knowledge Graphs Construction Automation: Status & Challenges.
David Chaves-Fraga, Anastasia Dimou.
3rd Edition of the Knowledge Graph Construction Workshop co-located with ESWC, 2022
Paper
Guía práctica para la publicación de datos enlazados
David Chaves-Fraga, Edna Ruckhaus, and Oscar Corcho.
datos.gob.es, 2022
Document (Spanish) Resources
Knowledge Graph Construction from Heterogeneous Data Sources Exploiting Declarative Mapping Rules
David Chaves-Fraga
PhD Dissertation, 2021
Document Slides
Enhancing Virtual Ontology Based Access over Tabular Data with Morph-CSV
David Chaves-Fraga, Edna Ruckhaus, Freddy Priyatna, Maria-Esther Vidal, Oscar Corcho.
Semantic Web Journal, 2021
Paper Code
A High-Level Ontology Network for ICT Infrastructures
Oscar Corcho, David Chaves-Fraga, Jhon Toledo, Julián Arenas-Guerrero, Carlos Badenes-Olmedo, Mingxue Wang, Hu Peng, Nicholas Burrett, José Mora, Puchao Zhang
International Semantic Web Conference, 2021
Paper Resource
RML-star: A Declarative Mapping Languagefor RDF-star Generation
Thomas Delva, Julián Arenas-Guerrero, Ana Iglesias-Molina, Oscar Corcho, David Chaves-Fraga, and Anastasia Dimou
International Semantic Web Conference Demos, 2021
Paper Specification
Knowledge Graph Construction with R2RML and RML: An ETL System-based Overview
Julián Arenas-Guerrero, Mario Scrocca, Ana Iglesias-Molina, Jhon Toledo, Luis Pozo-Gilo,Daniel Dona,
Oscar Corcho, David Chaves-Fraga.
2nd Edition of the Knowledge Graph Construction Workshop co-located with ESWC, 2021
Paper Resources
GTFS-Madrid-Bench: A Benchmark for Virtual Knowledge Graph Access in the Transport Domain
David Chaves-Fraga, Freddy Priyatna, Andrea Cimmino, Jhon Toledo, Edna Ruckhaus, Oscar Corcho
Journal of Web Semantics, 2020
Paper Resource
Towards a New Generation of Ontology Based Data Access
Oscar Corcho, Freddy Priyatna, David Chaves-Fraga
Semantic Web Journal, 2020
Paper
Exploiting Declarative Mapping Rules for Generating GraphQL Servers with Morph-GraphQL
David Chaves-Fraga, Freddy Priyatna, Ahmad Alobaid, Oscar Corcho
International Journal of Software Engineering and Knowledge Engineering, 2020
Paper Code (Deprecated)
FunMap: Efficient Execution of Functional Mappings for Knowledge Graph Creation
Samaneh Jozashoori, David Chaves-Fraga, Enrique Iglesias, Maria-Esther Vidal, Oscar Corcho
International Semantic Web Conference, 2020
Paper Code
SDM-RDFizer: An RML Interpreter for the Efficient Creation of RDF Knowledge Graphs
Enrique Iglesias, Samaneh Jozashoori, David Chaves-Fraga, Diego Collarana, Maria-Esther Vidal
International Conference on Information & Knowledge Management, 2020
Paper Code
Morph-Skyline: Virtual Ontology-Based Data Access for Skyline Queries
Marlene Goncalves, David Chaves-Fraga, Oscar Corcho.
IEEE/WIC/ACM International Joint Conference on Web Intelligence and Intelligent Agent Technology, 2020
Paper Code
Morph-CSV: Virtual Knowledge Graph Access for Tabular Data
David Chaves-Fraga, Luis Pozo-Gilo, Jhon Toledo, Edna Ruckhaus, Oscar Corcho
International Semantic Web Conference Demos, 2020
Paper Demo Video
Mapeathor: Simplifying the Specification of Declarative Rules for Knowledge Graph Construction
Ana Iglesias-Molina, Luis Pozo-Gilo, Daniel Dona, Edna Ruckhaus, David Chaves-Fraga, Oscar Corcho
International Semantic Web Conference Demos, 2020
Paper Demo
Morph-Skyline: Skyline Queries for Virtual Knowledge Graph Access
Marlene Goncalves, David Chaves-Fraga, Oscar Corcho
International Semantic Web Conference Demos, 2020
Paper Demo
Drugs4Covid: Drug-driven Knowledge Exploitation based on Scientific Publications
Carlos Badenes-Olmedo, David Chaves-Fraga, et al.
arXiv preprint, 2020
Paper Resource
What Are the Parameters that Affect the Construction of a Knowledge Graph?
David Chaves-Fraga, Kemele M Endris, Enrique Iglesias, Oscar Corcho, Maria-Esther Vidal.
OTM Confederated International Conferences "On the Move to Meaningful Internet Systems", 2019
Paper Resource
Morph-GraphQL: GraphQL Servers Generation from R2RML Mappings
Freddy Priyatna, David Chaves-Fraga, Ahmad Alobaid , Óscar Corcho.
International Conference on Software Engineering and Knowledge Engineering, 2019
Paper Code (Deprecated)
Conformance Test Cases for the RDF Mapping Language (RML)
Pieter Heyvaert, David Chaves-Fraga, Freddy Priyatna, Oscar Corcho, Erik Mannens, Ruben Verborgh, Anastasia Dimou.
Iberoamerican Knowledge Graphs and Semantic Web Conference, 2019
Paper Test-Cases Implementation Report
Enhancing the Maintainability of the Bio2RDF Project Using Declarative Mappings.
Ana Iglesias-Molina, David Chaves-Fraga, Freddy Priyatna, Oscar Corcho.
Semantic Web Applications and Tools for Healthcare and Life Sciences, 2019
Paper Resource
Towards the Definition of a Language-Independent Mapping Template for Knowledge Graph Creation.
Ana Iglesias-Molina, David Chaves-Fraga, Freddy Priyatna, Oscar Corcho.
Third International Workshop on Capturing Scientific Knowledge co-located with 10th K-CAP, 2019
Paper Resource
SAD Generator: Eating Our Own Dog Food to Generate KGs and Websites for Academic Events
Pieter Heyvaert, David Chaves-Fraga, Freddy Priyatna, Juan Sequeda, Anastasia Dimou.
European Semantic Web Conference (Posters & Demos), 2019
Paper Code
GraphQL Servers Generation from R2RML with Morph-GraphQL
Ahmad Alobaid, David Chaves-Fraga, Freddy Priyatna, Óscar Corcho.
International Conference on Software Engineering and Knowledge Engineering (Demo), 2019
Paper
ONETT: Systematic Knowledge Graph Generation for National Access Points.
David Chaves-Fraga, Adolfo Antón, Jhon Toledo, Oscar Corcho.
First International Workshop on Semantics for Transport co-located with SEMANTiCS, 2019
Paper Resource
Optimized Term Extraction Method Based on Computing Merged Partial C-Values
Victoria Kosa, David Chaves-Fraga, Hennadii Dobrovolskyi, Vadim Ermolayev .
International Conference on Information and Communication Technologies in Education, Research, and Industrial Applications, 2019
Paper
Similar Terms Grouping Yields Faster Terminological Saturation.
Victoria Kosa, David Chaves-Fraga, Nataliya Keberle, Aliaksandr Birukou.
International Conference on Information and Communication Technologies in Education, Research, and Industrial Applications, 2019
Paper
Virtual Statistics Knowledge Graph Generation from CSV files
David Chaves-Fraga, Freddy Priyatna, Idafen Santana-Pérez, Óscar Corcho.
International Workshop on Semantic Statistics co-located woth 17th ISWC, 2018
Paper Code
Cross-Evaluation of Automated Term Extraction Tools by Measuring Terminological Saturation.
Victoria Kosa, David Chaves-Fraga, Dmitriy Naumenko, Eugene Yuschenko, Carlos Badenes-Olmedo, Vadim Ermolayev, Aliaksandr Birukou.
International Conference on Information and Communication Technologies in Education, Research, and Industrial Applications, 2018
Paper
The Jedi Approach: Using The Force to Solve Linked Data Incompleteness.
Valentina Anita Carriero, David Chaves-Fraga, Arnaud Grall, Lars Heling, Subhi Issa, Thomas Minier, Alberto Moya Loustaunau.
International Semantic Web Summer School, 2018
Paper
Providing Reliable Access to Real-Time and Historic Public Transport Data Using Linked Connections.
Julián Rojas, David Chaves-Fraga, Pieter Colpaert, Ruben Verborgh, Erik Mannens.
International Semantic Web Conference (Posters & Demos), 2017
Paper
The tripscore Linked Data client: calculating specific summaries over large time series.
David Chaves-Fraga, Julian Rojas, Pieter-Jan Vandenberghe, Pieter Colpaert, Oscar Corcho.
International Workshop on Decentralizing the Semantic Web co-located with 16th ISWC, 2017
Paper Code
On the Role of the GRAPH Clause in the Performance of Federated SPARQL Queries
David Chaves-Fraga, Oscar Corcho Garcia, Claudio Gutiérrez.
4th International Workshop on Dataset PROFIling and fEderated Search for Web Data co-located with 16th ISWC, 2017
Paper Code

Talks

How do you construct your Knowledge Graph?
David Chaves-Fraga, Ana Iglesias-Molina.
Tutorial at ECAI 2024
Slides
The LOT4KG Methodology
David Chaves-Fraga.
Invited talk at IDLab (UGhent)
Slides
Challenges in Data Management for Evolving Knowledge Graphs
David Chaves-Fraga.
Keynote at 9th Managing the Evolution and Preservation of the Data Web Workshop at ISWC 2023
Slides
Web-Scale Semantic Data Integration: Challenges and Perspective
David Chaves-Fraga.
Keynote at 2nd International Workshop on the Semantic Web of Everything co-located with ICWE, 2023
Slides
Human-Friendly RDF Graph Construction: Which one do you chose?
Ana Iglesias-Molina, David Chaves-Fraga, Ioannis Dasoulas and Anastasia Dimou.
23rd International Conference on Web Engineering, 2023
Slides
From Data Spaces to Decentralized Knowledge Spaces: The Public Procurement use case
David Chaves-Fraga.
Panel at "Congreso Internacional de Espacios de Datos Sectoriales y Transparencia en el Sector Público", 2023
Slides
Evo-KnoMo: How to Evolve with the Current Times (fiction paper/presentation)
Oscar Corcho, Ana Iglesias-Molina, Edna Ruckhaus, Jhon Toledo and David Chaves-Fraga.
Extended Semantic Web Conference, 2023
Slides
Knowledge Graphs and Ontologies: A Practical Introduction to the Semantic Web
David Chaves-Fraga.
Universidad de Santiago de Compostela (Invited Talk), 2022
Slides
Declarative Knowledge Graph Construction: A Practical Introduction.
David Chaves-Fraga.
Ontology Engineering and Knowledge Graphs tool ecosystem Workshop (OntoCommons EU-Project), 2022
Slides Workshop Website
Declarative Description of Knowledge Graphs Construction Automation: Status & Challenges.
David Chaves-Fraga, Anastasia Dimou.
3rd Edition of the Knowledge Graph Construction Workshop co-located with ESWC, 2022
Slides
Why Mapping Rules are Important for Constructing your KG?
David Chaves-Fraga
Invited Talk at Polifonia H2020 project, 2022
Slides Project Website
Morph-KGCstar: Declarative Generation of RDF-star Datasets from Heterogeneous Data
David Chaves-Fraga David Chaves-Fragam, Julián Arenas-Guerro, Ana Iglesias-Molina, Daniel Garijo, Oscar Corcho, Anastasia Dimou
EAVISE group talk - KULeuven, 2022
Slides
Knowledge Graph Construction: From Optimization To Automation
David Chaves-Fraga
EAVISE group talk - KULeuven, 2022
Slides
Declarative Construction of Knowledge Graphs: one-year status-update
David Chaves-Fraga
OEG Internal Talk - UPM, 2022
Slides
Knowledge Graph Construction from Heterogeneous Data Sources Exploiting Declarative Mapping Rules
David Chaves-Fraga
PhD Dissertation, 2021
Slides
W3C Community Group - Knowledge Graph Construction
David Chaves-Fraga, Anastasia Dimou
Knowledge Graph Construction Workshop (ESWC), 2021
Slides
Welcome to Open Summer of Code 2021
David Chaves-Fraga
Open Summer of Code Spain, 2021
Slides
Knowledge Graph Construction Using Declarative Mapping Rules
Ana Iglesias-Molina, David Chaves-Fraga, Andrea Cimmino, Oscar Corcho
International Semantic Web Conference (Tutorial), 2020
Slides
Morph-CSV: Virtual Knowledge Graph Access for Tabular Data
David Chaves-Fraga, Luis Pozo
International Semantic Web Conference (Demo), 2020
Video
Knowledge Graph Construction and Access using Declarative Mappings
David Chaves-Fraga, Freddy Priyatna, Ahmad Alobaid, Andrea Cimmino, Ana Iglesias, Jhon Toledo, Daniel Doña, Luis Pozo, Edna Ruckhaus, Oscar Corcho
National Project Meeting, 2020
Slides
From Engineering to Research - The KG Construction Use Case
David Chaves-Fraga
Internal OEG Meeting, 2020
Slides
Generating and Querying (Virtual) Knowledge Graphs from Heterogeneous Data Sources
David Chaves-Fraga, Freddy Priyatna, Ahmad Alobaid, Andrea Cimmino, Oscar Corcho
International Semantic Web Conference (Tutorial), 2019
Slides
What are the Parameters that Affect the Construction of a Knowledge Graph?
David Chaves-Fraga
Ontologies, DataBases, and Applications of Semantics for Large Scale Information Systems (ODBASE), 2019
Slides
ONETT: Systematic Knowledge Graph Generation for National Access Point
David Chaves-Fraga
Sem4Tra Workshop, 2019
Slides
Virtual Knowledge Graph Generation from Heterogeneous Data Sources
David Chaves-Fraga
TIB Retreat, 2019
Slides
Knowledge Graph Construction
David Chaves-Fraga
Internal OEG Meeting, 2019
Slides
How to Develop Mapping Rules for Knowledge Graph Creation
Ana Iglesias-Molina, David Chaves-Fraga
Internal OEG Meeting, 2019
Slides
Lenguajes de Mapeo para el acceso datos heterogéneos (Spanish)
David Chaves-Fraga
National Project Meeting, 2019
Slides
Virtual Knowledge Graph Generation from Heterogeneous Data Sources
David Chaves-Fraga, Freddy Priyatna
Ghent University, 2018
Slides
GraphQL-Based Access to Virtual Datasets Exposed by RML Mappings
Freddy Priyatna, David Chaves-Fraga
Ghent University, 2018
Slides
The Jedi Approach: Using The Force to Solve Linked Data Incompleteness
Valentina Anita Carriero, David Chaves-Fraga, Arnaud Grall, Lars Heling, Subhi Issa, Thomas Minier, Alberto Moya Loustaunau
International Semantic Web Summer School (ISWS), 2018
Slides
RMLC: RDF Mapping Language for heterogeneous CSV files
David Chaves-Fraga
Internal OEG Meeting, 2018
Slides
Summary of Open Summer of Code 2018 (Spanish)
David Chaves-Fraga
Un año en un día - Medialab-Prado, 2018
Slides Video
Enlazando datos abiertos en el transporte público (Spanish)
David Chaves-Fraga, Oscar Corcho
Jornadas de periodismo de datos y datos abiertos - Medialab-Prado, 2018
Slides
Presentation of Open Summer of Code Spain (Spanish)
David Chaves-Fraga
Open Data Day - Medialab-Prado, 2018
Slides
On the Role of the GRAPH Clause in the Performance of Federated SPARQL Queries
David Chaves-Fraga
Profiles Workshop (ISWC), 2017
Slides
The tripscore Linked Data client: calculating specific summaries over large time series
David Chaves-Fraga
DeSemWeb Workshop (ISWC), 2017
Slides
Semantic Interoperability in the Transport Domain
David Chaves-Fraga
9th IT Combined Meeting in Cologne, 2017
Slides
Tripscore: Datos enlazados para el transporte público (Spanish)
David Chaves-Fraga
Dataton Madrid, 2017
Slides
The relevance of metadata in the transport domain: TransportDCAT-AP
David Chaves-Fraga
Civic Hack Night in Brussels, 2017
Slides

Community

Co-Chair of Knowledge Graph Construction W3C Community Group / 2020 - now
Register as a Participant
Organizer of Workshop Series on Knowledge Graph Construction / 2019-now
Visit Workshop Website
Chair of Workshops&Tutorials at SEMANTiCS / 2025
SEMTiCS Website
Organizer of Workshop on Software Lifecycle Management For Knowledge Graphs / 2024
Visit Workshop Website
Organizer of the Tutorial on Knowledge Graph Construction / ECAI 2024
Visit Tutorial Website
Organizer of Workshop Series on Semantics and the Web for Transport / 2019-2023
Visit Workshop Website
Organizer of the Tutorial on Knowledge Graph Construction / ESWC 2022
Visit Tutorial Website
Chair of Posters and Demos at SEMANTiCS / 2022
SEMTiCS Website
Organizer of the Tutorial on Knowledge Graph Construction / ISWC 2020
Resources
Organizer of the Tutorial on Knowledge Graph Construction / KG4DI 2022
Resources
Organizer of the Tutorial on Knowledge Graph Construction / ESWC 2019
Resources
Coach of Coaches on Open Summer of Code Spain / 2018-2021
Summer of Code Website

Projects

REOPEN / 2024-2027

Spanish National Project for Enhancing Process Management with KGs and LLMs

PPDS - EU / 2023-2024

Principal scientist of the European Public Procurement Data Space
Website

Datos.Gob / 2021

Spanish national guideline for creating RDF from open data portals using declarative mappings
Guidline & Videos

H2020 - SPRINT / 2019-2021

Semantics for Performant and scalable Interoperability of multimodal Transport
Project Website

Datos 4.0 / 2016-2020

Spanish National project for using semantic web technologies in data management
Project Info

EIT-SNAP / 2016-2020

Transforming transport data into EU compilance with semantic web technologies
Project Website

H2020 GoF4R / 2016-2018

Governance of the Interoperability Framework for Rail and Intermodal Mobility
Project Website

CEF-OASIS / 2016-2018

Open Applications for Semantically Interoperable Services

Blogposts

Benchmarking the EU PPDS

Performance Evaluation of Transparency Indicators for the EU Public Procurement Data Space
Entry