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Research group: Semantic Web and Ontological Engineering (SWOE)

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The SWOE acronym can also be read – according to several web sources, referring to hybridization of (Wilkinson) “Sword” and “hoe” – as „long-handled weeder“ or „very lightweight, many angled weeding tool“. In our context, we can refer to the metaphor of weeding in view of long-term fruit in the semantic web garden. Consequently, also SWOE’s color among the KIZI groups is green.

Go to: Research focus; Team and Collaborations; Publications; Education


(For older news see page bottom)

Research focus

The Semantic Web and Ontological Engineering (SWOE) group at KIZI (one of its four research groups, over-arched by the virtual Knowledge Engineering Group) undertakes research in knowledge and data representation and management, in particularly in connection with the semantic web. The focal areas of the group currently are:

  • Linked data modeling, publishing, matchmaking and exploitation, especially for public sector, e-commerce and encyclopedic (Wikipedia etc.) domains
  • Ontology and data vocabulary design and management
  • Ontology and data vocabulary analysis, evaluation and matching
  • Ontology and linked data visualization
  • Linked data mining


The seed of the group had been gradually formed since approx. 2000, the initial topics having been the computerization of clinical guidelines (e.g., in the EU FP4 MGT project, where the Stepper tool for text-centric guideline formalization was developed) and modest contributions to the initial phase of the semantic web research (via non-funded partnership in EU FP5 projects such as OntoWeb and Knowledge Web).  In EU FP6, the team had been involved, among other, in the design of the Core Ontology of Multimedia (COMM), in the frame of the K-Space Network of Excellence (2006-2008). The group also hosted the EKAW 2006 conference (with V. Svátek as Co-Chair).


  • An ongoing activity, started around 2006, is ontology tool benchmarking, with special focus on Ontology Matching. Most notably, O. Zamazal has been engaged in this community as co-organizer of the OAEI campaigns, as main provider of the ‘conference’ benchmark (OntoFarm dataset) used in these campaigns, as well as the author and maintainer of the OOSP tool allowing for building multi-ontology corpora (as potential benchmark collections) on the fly.
  • Since 2010, the SWOE flagship in software artifact development has been the PatOMat project, which provides a rich machinery for pattern-based transformation of OWL/RDFS ontologies and data vocabularies.  PatOMat components are in use by several external parties, and embedded into tools such as ORE (Univ. Leipzig) or XDtools (ISTC/CNR Rome). PatOMat use cases include unification of ontology/vocabulary modeling style (for example, for e-commerce ontologies), ontology complexity downgrading, ontology adaptation to Linked Data best practices, or support of matching or merging of ontologies with heterogeneous structure. User-oriented tools, such as the GUIPOT Protégé plugin for OWL2OWL pattern-based ontology transformation, have been developed.
  • A closely interconnected effort is that of applying ontological background models (OBMs), expressed in a modeling language called PURO, in ontology analysis and design. The central artifact thereof is PURO Modeler, a graphical editor of OBMs allowing to build ontology fragments in various OWL styles through the associated OBOWLMorph tool. This view of OWL ontologies, which abstracts from the particular encoding style, also led to new research sub-project on studying the focused categorization power of ontologies across multiple OWL encoding patterns.
  • In recent years, linked data have become another major topic for the group. In 2011-2014 the group has been responsible for a particular use case in the EU FP7 LOD2 project, namely, that on Public Procurement. A Public Contracts Ontology has been designed and numerous RDFization efforts are taking place (mostly in collaboration with the XRG group at Charles University, Prague, using LOD2 Stack tools such as UnifiedViews). A follow-up EU project is H2020, which is devoted to RDFization (mostly via LinkedPipesETL) and subsequent analytics of public budget and spending data.
  • A related effort in linked data processing relates to linked data analytics, using both data mining tools and visualization tools (such as our LODSight). In 2013, the first edition of the Linked Data Mining Challenge was organized, with significant involvement of the SWOE team, and then another three, associated to the Know@LOD workshop (2014, 2015 and 2016) collocated with the ESWC conference. V. Svátek also co-chaired the LOD Track of ESWC 2014.
  • SWOE is also managing the Czech DBpedia and develops applications (lately, in particular, games such as DB-quiz by J. Mynarz) that exploit both the Czech and English dataset.
  • Finally, the education of linked data is now being supported by SPARQLab, a web-based exercise-book for SPARQL, already in use for the 4IZ440 – Linked data on the web course, and awarded as Best Student Application in the Czech OpenData Application contest.

As summary, the current core vision of the group is:

  • To promote the linked data and open data principles (with special respect to the public sector), and train specialists for dealing with such data
  • To help bridge the gap between the linked data and ontological world using a “reactive ontological engineering” approach: trying to make sense of data structures that people create intuitively rather than enforcing them a “single best model”
  • To investigate the interplay between different modalities of web data/schema semantics: natural language, graph structure, logical entailment etc.


Group leaders: Vojtěch Svátek, Ondřej (Šváb-)Zamazal

Other group members:

  • Faculty: Petr Strossa (NLP expert), Miroslav Vacura (primarily at the Dept. of Philosophy, but collaborating on numerous projects).
  • Project workers: Jakub Klímek (also XRG group at Charles University and WI group at CTU), Petr Škoda (primarily XRG group at Charles University)
  • PhD students: Marek Dudáš, Jindřich Mynarz, Václav Zeman (also in the DMKD group), Daniel Vodňanský (primarily in the IIS group).
  • MSc students: Pavel Suk, Bohuslav Koukal (primarily in the DMKD group).
  • External members – still collaborating alumni: Tomáš Hanzal, Petr Hazuza.

Important group alumni (ex-PhD, MSc or project collaborators): Václav Belák, Martin Kavalec, Martin Labský, Marek Nekvasil, Jan Nemrava, Josef Petrák, Štěpán Pilař, Michal Pomykacz, Simone Serra, Šárka Turečková, Jan Zemánek.


Within the University, the SWOE group mainly cooperates with

  • The Data Mining and Knowledge Discovery (DMKD) group within the same department. In particular, SWOE promotes the achievements of TMWE, such as the Linked Hypernym Dataset (LHD), in the semantic web and Linked Data community. There is also joint research in the field of background knowledge for text mining (e.g. the, Ex information extractor project). The collaboration also regards the use of background knowledge in KDD (EasyMiner project) and data mining from linked data.
  • The open data group (led by Dr. Dušan Chlapek) at the neighboring Dept. of Information Technology. The overlaping interest is in government linked data; for example, the two groups cooperated in creating the CKAN-based Czech data catalog; from January 2014 on, they jointly represent the University in the SharePSI EU (PSP) project. The joint activities of both groups are overarched by the hub (currently in Czech only).

Within the Czech Republic, there is lasting cooperation with the XRG group at Charles University. In particular, XRG members have been directly involved in research activities of EU projects:

At the international level, the group collaborates with numerous foreign partners, either in connection with EU projects (in particularly, the recently ended EU FP7 IP LOD2 and currently running or on informal basis, yielding a decent number of joint publications. Examples of such joint research are:

  • Ontology/vocabulary repair based on naming patterns, with Univ. Leipzig, Germany, within the LOD2 project
  • Management of e-commerce ontologies, with UNIBW, Munich, Germany
  • Ontological patterns and anti-patterns, with ISTC-CNR, Rome, Italy, UPM, Spain, and CEMAGREF, France
  • Background models for ontologies and vocabularies, with Comenius Univ., Bratislava, Slovakia, within the bi-lateral LAAOS project
  • Multilingual ontology matching, with Univ. of Mannheim
  • Public procurement linked data, with I2G, Poznan, Poland, within the LOD2 project
  • Linked data analytics, with Univ. of Mannheim and Univ. of Bonn
  • Linked data matchmaking, with Polytechnic Univ. of Bari, Italy

Selected recent publications

Only a selection of prestigious ones; many others can be found on the homepage of V. Svátek (only the older ones at the moment…) or in the UEP publications database: for V. Svátek, O. Zamazal, or analogously for other members

Zamazal O., Svátek V.: The Ten-Year OntoFarm and its Fertilization within the Onto-Sphere. J. Web Semantics, Elsevier, Volume 40, in Press, online 18 January 2017.

Svátek V., Zamazal O., Vacura M.: Categorization Power of Ontologies with Respect to Focus Classes. In: EKAW 2016, Springer LNCS. Best paper award nomination.

Svátek V., Dudáš M., Zamazal O.: Adapting ontologies to best-practice artifacts using transformation patterns: Method, implementation and use cases. J. Web Semantics, Elsevier, Volume 40, October 2016, 52-64.

Vacura M., Svátek V., Gangemi A.: An ontological investigation over human relations in linked data. Applied Ontology 11(3): 227-254 (2016).

Svátek V., Zamazal O., Dudáš M.: Using ODPs for Ontology Transformation. In: Hitzler et al. (eds.): Ontology Engineering with Ontology Design Patterns. IOS Press, 2016.

Kliegr T., Zamazal O.: LHD 2.0: A text mining approach to typing entities in knowledge graphs. J. Web Semantics, Volume 39, August 2016, 47-61.

Mynarz J., Zeman V.: DB-quiz: a DBpedia-backed knowledge game. In: SEMANTiCS 2016, ACM, 121-124.

Hanzal T., Svátek V., Vacura M.: Event Categories on the Semantic Web and Their Relationship/Object Distinction. In: FOIS 2016: 183-196.

Svátek V., Kompuš P., Dudáš M., Nečaský M., Klímek J.: Procurement notice enrichment using product ontologies. In: SEMANTiCS 2015, ACM, 200-203. Honorary mention.

Zamazal O.: Online ontology shortest paths searcher. In: SEMANTiCS 2015, ACM, 204-206. Honorary mention.

Dudáš M., Svátek V., Mynarz J.: Dataset Summary Visualization with LODSight. In: ESWC 2015 (Demo Session), Springer LNCS 9341, 2015, 36-40.

Dudáš M., Zamazal O., Svátek V.: Roadmapping and Navigating in the Ontology Visualization Landscape. In: EKAW 2014, Linköping, Springer, LNCS 8876, 2014, 137-152.

Scharffe F., Zamazal O., Fensel D.: Ontology alignment design patterns. Knowledge and Information Systems. Springer, 40(1): 1-28 (2014).

Kliegr T., Zamazal O: Towards Linked Hypernyms Dataset 2.0: complementing DBpedia with hypernym discovery. In: LREC 2014: 3517-3523.

Dudáš M., Zamazal O., Mynarz J., Svátek V.: Exploiting Freebase to Obtain GoodRelations-Based Product Ontologies. In: EC-Web 2014, Munich, Springer LNBIP 188, 2014, 34-45.

Mynarz J.: Validator and Preview for the JobPosting Data Model of In: EC-Web 2014, Munich, Springer LNBIP 188, 2014, 58-63 .

Nečaský M., Klímek J., Mynarz J., Knap T., Svátek V., Stárka J.: Linked data support for filing public contracts. J. Computers in Industry, Elsevier, Volume 65, Issue 5, June 2014, 862–877.

Dudáš M., Svátek V., Török L., Zamazal O., Rodriguez-Castro B., Hepp M.: Semi-automated Structural Adaptation of Advanced E-Commerce Ontologies. In: EC-Web 2013, Prague, Springer LNBIP 152, 2013, 51-58 .

Nekvasil M., Svátek V.: Towards savvy adoption of semantic technology: From published use cases to category-specific adopter readiness models. J. Web Semantics, Elsevier, Volume 21, August 2013, 61-74.

Svátek V., Homola M., Kluka J., Vacura M.: Mapping structural design patterns in OWL to ontological background models. In: K-CAP 2013, ACM, 117-120.

Šváb-Zamazal O., Schlicht A., Stuckenschmidt H., Svátek V.: Constructs Replacing and Complexity Downgrading via a Generic OWL Ontology Transformation Framework. In: SOFSEM 2013, Springer LNCS 7741, 2013, 528-539.

Šváb-Zamazal O., Dudáš M., Svátek V.: User-Friendly Pattern-Based Transformation of OWL Ontologies. In: EKAW 2012, Springer, LNCS 7603, 2012, 426-429. Best demo award.

Meilicke C., García-Castro R., Freitas F., van Hage W. R., Montiel-Ponsoda E., Ribeiro de Azevedo R., Stuckenschmidt H., Šváb-Zamazal O., Svátek V., Tamilin A., Trojahn C., Wang S.: MultiFarm: A benchmark for multilingual ontology matching. J. Web Semantics, Elsevier, Volume 15, September 2012, Pages 62-68.


Activities of the group are reflected in several courses taught at the University, most notably the MSc level courses:

A certain primer to relevant knowledge representation methods is also provided in the Bc level course:

Older news:

  • December 2015: The fifth Know@LOD workshop was accepted to be held within the ESWC 2016 conference in Crete, June 2016.
  • December 2015: The Czech TV showed a news story (on December 2) on the “Mapy bez bariér” (Maps without barriers) project, with Petr Hazuza demonstrating the building accessibility categories on his own flesh. Petr participates in this project as member of the Charter 77 Foundation and transfers there the ongoing results of his MSc thesis on the Building Accessibility Vocabulary.
  • November-December 2015: The first plenary meeting of the EU project took place in Berlin (November 30 – January 1). Even before (September 26) Jindřich Mynarz co-presented a widely attended talk on “Self-decribing fiscal data” at the Berlin workshop of the SharePSI 2.0 project.
  • November 2015: Marek Dudáš was awarded the Josef Hlávka Prize for outstanding PhD students and young academics, by the Hlávka Foundation. Congratulations!
  • November 2015: Jindřich Mynarz and Václav Zeman talked about Czech DBpedia and  DB-quiz at the Czech annual Wikimedia conference (page is in Czech).
  • September-December 2015: Papers have been presented by the group members at: SEMANTiCS (2 demos: of PCFA tool for ontology-augmented procurement data management from LOD2 WP9a, and of ontology path metrics from COSOL), ODBASE (procurement linked data matchmaking, also from LOD2 WP9a), WOP@ISWC (OBM2OWL transformation patterns), VOILA@ISWC (discovering issues in datasets using visual summaries created in enhanced LODSight), OWLED (OBM2OWL transformation using the OBOWLMorph tool), KEOD (ontology richness analysis using path metrics from COSOL), Data&Znalosti (2 student papers, by P. Hazuza and Š. Turečková).
  • October 2015: Vojtěch Svátek moderated the panel on PhD research & industrial cooperation, at the annual national database and knowledge engineering conference, Data&Znalosti (pages are in Czech).
  • September 2015: Out of the 32 poster/demo papers accepted to the SEMANTiCS conference, only six outstanding ones have been selected for the main ACM volume and obtained a Honorary Mention… including both papers authored by SWOE
  • July 2015: The group started to cooperate with the team of the newly started project, “Mapy bez bariér” (Maps without barriers), undertaken by the Charter 77 Foundation. The project (to be formally completed by end 2015) aims to provide machine-readable data on building accessibility for handicapped on the background of common map servers. Petr Hazuza is member of the project team on behalf of the Foundation, and develops the Building Accessibility Vocabulary as part of his MSc thesis. A poster on the project has been presented at the Data&Znalosti conference in October.
  • June 2015: Šárka Turečková defended her MSc thesis focused on DBpedia-powered quizz generator and strategic game (the programs are downloadable). From September she will be working towards another MSc, on Serious Games, at University of Skövde, Sweden.
  • June 2015: Václav Zeman defended his PhD project progress on “Data mining on linked data” (after first year).
  • May 2015: The EU Horizon 2020 project started. The SWOE team is responsible for the WP related to budget/spending open data modeling.
  • May 2015: The ESWC 2015 conference featured three SWOE-based outcomes: the successful Know@LOD workshop (most attended of all!) with 3rd Linked Data Mining Challenge (LDMC), co-chaired by V. Svátek; the presentation of the LODSight (vocabulary-centric) linked dataset summarizer in the conference demo session, by M. Dudáš, and presentation of OOSP, Online Ontology Set Picker, within the SumPre workshop, by O. Zamazal.
    February 2015: Marek Dudáš has been awarded a new PhD research support project, this time under the name ‘Generation of style variants of semantic data schemas using generalized data visualization’. 4 permanent staff members and 3 other students will collaborate on the project.
  • January 2015: The Czech DBpedia has been significantly enhanced. New extraction using an extended set of mapping rules has been made, new support datasets added, and the visualization interface enhanced.
  • January 2015: Vojtěch Svátek became Editorial Board Member of Elsevier’s Journal of Web Semantics.
  • January 2015: Jindřich Mynarz spent a month on internship in the Knowledge Engineering group at the University of Göttingen, mainly working on library data RDFization.
  • November 2014: In the Annual Rector’s Award for best publications in 2014, Jindřich Mynarz’s paper from EC-Web conference placed 2nd in the PhD student work category.
  • November 2014  (primarily relates to the DMKD group): The paper on the Linked Hypernym Dataset, by Tomáš Kliegr, has been accepted to Elsevier’s Journal of Web Semantics (see preprint).
  • November 2014: A full paper (18% acceptance rate) on ‘Roadmapping and Navigating in the Ontology Visualization Landscape’, by Marek Dudáš, Ondřej Zamazal and Vojtěch Svátek, was presented at the EKAW 2014 conference in Linköping.
  • October 2014: Jindřich Mynarz started a 2,5-month PhD internship at the Information Systems Laboratory of the Polytechnic University of Bari (upon invitation from Dr. Tommaso Di Noia). The internship is focused on combining the linked data technology with recommendation/matchmaking techniques
  • October 2014: Ondřej Zamazal co-authored a chapter on multilingual ontology matching in the Towards the Multilingual Semantic Web book.
  • October 2014  (primarily relates to the DMKD group): The Linked Hypernym Dataset (LHD), a large collection of type assignments to RDF entities built by THD tool co-developed by Tomáš Kliegr, has been integrated into the official version of German DBpedia.
  • September 2014: The 13th edition of the Czecho-Slovak knowledge technology conference, Znalosti, was co-chaired by Vojtěch Svátek and Ondřej Zamazal. It was probably the last edition, as from 2015 on, there will be a new conference combining the topics of Znalosti and Datakon (the Czecho-Slovak database conference). This witnesses the constant assimilation of database and knowledge/semantic technologies in the last decade.
  • September 2014: The EU LOD2 Integrated project, where the team led by V. Svátek was responsible for the Public Procurement Linked Data use case, was concluded by a successful final review. The rating of the project eventually was ‘Excellent Progress’ (i.e., the best possible). The results of the project are summarized in the book Linked Open Data – Creating Knowledge Out of Interlinked Data published by Springer; two chapters are co-authored by SWOE members: Ondřej Zamazal, Vojtěch Svátek and Jindřich Mynarz (plus Milan Dojchinovski from the DMKD group).
  • August 2014: Two papers by the SWOE team were presented at the EC-Web 2014 conference in Munich and appear in the Springer LNBIP volume: a full paper (24% acceptance rate) by Marek Dudáš et al., and a short paper by Jindřich Mynarz.
  • July 2014: Article on Ontology alignment design patterns, co-autored by O. Zamazal, was published in Springer’s Knowledge and Information Systems (impact factor 2.6)
  • June 2014: The Linked data support for filing public contracts article, co-authored by Jindřich Mynarz and Vojtěch Svátek, was published in Elsevier’s J. Computers in Industry (impact factor 1.7).
  • May 2014: Vojtěch Svátek co-chaired the LOD track at the ESWC 2014 conference (Anissaras, Crete), plus the collocated Know@LOD workshop.
  • April 2014: Czech DBpedia, maintained by Václav Zeman, is online.
  • March 2014: Marek Dudáš has been awarded a PhD research support project (as best rated proposal within the faculty), under the name ‘Semantic web data visualization exploiting the ontological schema structure’.
  • January 2014: Ondřej Zamazal succeeded, in a sharp competition, in obtaining a 3-year (2014-2016) post-doctoral project from the Czech Science Foundation: ‘COSOL – Categorization of Ontologies in Support of Ontology Life Cycle’.
  • January 2014: The SharePSI 2.0 European network, focused on the exchange of experience and ideas around implementing open data policies in the public sector, started. A joint group, led by colleagues from the Dept. of Information Technology (but with participation of SWOE, via Jindřich Mynarz) is one of the partners.