Ontologies and databases on thermophysical properties of nuclear reactor materials

Abstract

A new technology for data management of a complex and irregular structure is proposed. Such a data structure is typical for the representation of the thermophysical properties of substances. This technology based on storage of data in JSON files is associated with ontologies for the semantic integration of heterogeneous sources. Advantages of JSON-formatthe ability to store data and metadata within a text document, accessible perceptions of a person and a computer and support for the hierarchical structures needed to represent semi-structured data. Availability of a multitude of heterogeneous data from a variety of sources justifies the use of the Apache Spark toolkit. When searching, it is supposed to combine SPARQL and SQL queries. The first one (addressed to the ontology repository) provides the user with the ability to view and search for adequate and related concepts. The second, accessed by JSON documents, retrieves the required data from the body of the document. The technology allows to overcome a variety of schemes, types and formats of data from different sources and implement a permanent adjustment of the created infrastructure to emerging objects and concepts not provided for at the stage of creation.