Knowledge Graph Web Portal for Interoperability of EU Member State

The Znalosti.gov.sk project (ʻznalostiʼ means Knowledge) is a web portal for a national knowledge graph that provides an exploration of reference data and a set of public electronic services to ensure data interoperability in the scope of an EU Member state and the EU Digital Single Market.

The knowledge graph consists of three main parts. The TBOX (Terminological Axioms), a set of ontologies, CBOX (Categories) such as taxonomies, and thesauri, and ABOX (Assertional Axioms) represented as instance data from public information systems. The TBOX contains national and international knowledge. National knowledge can be derived from base reference registers or central agenda systems such as a Register of addresses, Register of natural persons, Register of legal entities, etc., and their related code lists. International knowledge is formed mainly by ontologies for ensuring EU interoperability such as the Core Vocabularies and EU authority tables and the like. All these metadata in the form of linked data are uploaded to the RDF database, where the front end of the application provides functionalities such as search, exploration, and SPARQL querying. The solution then can serve as a central knowledge graph and knowledge hub for developing interoperability.

Examples of instance data that use the aforementioned structural metadata are also part of the knowledge graph. Such examples include selected addresses, legal entities, and public persons, and this data serves to illustrate the use of the Central Data Model. Data examples are loaded into particular knowledge graph contexts, related to source registers.