Olaf Hartig
@olafhartig.bsky.social
110 followers 49 following 19 posts
Senior Associate Professor in Computer Science at Linköping University • Amazon Scholar • research on data management topics related to graph data and data on the Web https://olafhartig.de
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olafhartig.bsky.social
Super glad to receive the Best Research Paper Award at #ESWC2025 together with Sitt Min Oo for our work on providing a formal foundation for mapping languages for Knowledge Graph construction.
olafhartig.bsky.social
The @liu.se Semantic Web gang at the #ESWC2025 conference.
olafhartig.bsky.social
Min Oo is presenting our work on providing a formal foundation for Knowledge Graph construction at #ESWC2025
olafhartig.bsky.social
Related to our approach to represent and to query lists as composite values in RDF-based Knowledge Graphs, I developed a tool to convert RDF files in which lists are represented as RDF collections (rdf:List) into files that use our cdt:List approach.

Repo and download: github.com/hartig/SPARQ...
Reposted by Olaf Hartig
tgdkjournal.bsky.social
Researching graph databases, SPARQL engines, or stores for Knowledge Graphs? Submit to TGDK Special Issue: Data Management for (Knowledge) Graphs. Deadline July 1st, 2025. Resources, experience reports and extended workshop/conference papers welcome. CfP: bit.ly/4luAUXZ
TGDK - CfP Special Issue: Data Management for (Knowledge) Graphs
TGDK - CfP Special Issue: Data Management for (Knowledge) Graphs
bit.ly
olafhartig.bsky.social
So far, declarative mapping languages for knowledge graph construction (RML and the likes) have lacked a solid formal foundation 😶‍🌫️

⚡ Our latest work, accepted for #ESWC2025, changes that: We introduce an algebra for mappings, provide a formal semantics for RML, and more.

🔎 arxiv.org/abs/2503.10385
An Algebraic Foundation for Knowledge Graph Construction (Extended Version)
Although they exist since more than ten years already, have attracted diverse implementations, and have been used successfully in a significant number of applications, declarative mapping languages fo...
arxiv.org
olafhartig.bsky.social
...now also on arXiv!

"Towards Computer-Using Personal Agents"
arxiv.org/abs/2503.15515
olafhartig.bsky.social
In a recent #Dagstuhl seminar we developed a research roadmap towards Computer-Using Personal Agents (CUPAs), automating complex tasks like today's Computer-Using Agents, but including context via controlled access to personal knowledge graphs. Our vision paper: openaccess.city.ac.uk/id/eprint/34...
City Research Online - Towards Computer-Using Personal Agents
openaccess.city.ac.uk
olafhartig.bsky.social
Nice achievement. Congratulations!
olafhartig.bsky.social
I just saw that DBLP (@dblp.org) has recently started to provide a public query service for everyone to run SPARQL queries over their database with information about computer science publications. Each author page includes links to relevant example queries. Very nice!
blog.dblp.org/2024/09/09/i...
olafhartig.bsky.social
Congratulations Elena! Very well deserved!
Reposted by Olaf Hartig
katjahose.bsky.social
Thank you all for a great week in #Dagstuhl, here's the traditional photo 😉

www.dagstuhl.de/25051
olafhartig.bsky.social
Arrived at Castle Dagstuhl for a week of discussions around "Trust and Accountability in Knowledge Graph-Based AI for Self Determination" www.dagstuhl.de/25051
olafhartig.bsky.social
Nice! I should try it with road bikes 🚴🏼‍♂️ /cc @klinovp.bsky.social
olafhartig.bsky.social
It may be a way to quickly provide GQL support on top of a Gremlin server. There is a library for it: github.com/WSaffery/GQL...
I can see, however, that the performance of such a setup may not be able to compete with any more direct implementation of GQL.
GitHub - WSaffery/GQL-Compiler: A compiler/transpiler from GQL to Gremlin, with an optimiser built for labelled subgraph queries.
A compiler/transpiler from GQL to Gremlin, with an optimiser built for labelled subgraph queries. - WSaffery/GQL-Compiler
github.com
olafhartig.bsky.social
Interested in translating from the recently-standardized graph database language GQL to Gremlin ? Next Monday (Nov.25), the Tinkerpop community has a talk for you.
discord.gg/tinkerpop?ev...
Join the Apache TinkerPop Discord Server!
Apache TinkerPop is an open source graph computing framework and the home of the Gremlin graph query language. | 1333 members
discord.gg
olafhartig.bsky.social
I have heard the waters here are calmer. Ready to start new.