EMMC The European Materials Modelling Council

Introduction to Ontologies Part I

Alexandra Simperler

On-line 29.4.2019

https://emmc.info/ EMMC The EMMO round table

Emanuele Ghedini (University of Bologna)

Gerhard Goldbeck Adham Hashibon (Goldbeck Consulting) (Fraunhofer Institut)

Georg J. Schmitz Jesper Friis (Access) (SINTEF) EMMC Outline

• Taxonomy vs Ontology • The value of ontologies • Semantic Technologies • Representation of Ontologies What’s the difference between an EMMC ontology and a taxonomy?

TAXONOMY ONTOLOGY

• Like a tree with branches • Like a spiderweb • Parent – Child relation, • Manifold of relations, is_a adds non is_a relations • Generally limited to a • Not limited to a specific specific subject area subject area • Hierarchy of (simple) • Complex relations with concepts complex concepts EMMC The Value of Semantic Technologies

• Natural perspective of human communication • Greater expressivity than a database • Improved logical structure • Knowledge layer is separated from data layer • Flexibility, reusability, interoperability • Hierarchies, relationships and annotation • Search patterns can be stored, share, reused • Reasoning – answers to what-if, if-then questions • Accessible to Artificial Intelligence EMMC The Value of Ontology in the Materials Field

Artificial Intelligence Materials Ontology will contribute to: Systems Engineering • High throughput experiments Biomedical Informatics • High throughput characterization Library Science • Cost reduction Enterprise Bookmarking Information Architecture • Reliable results • Standard operation procedures (SOPs) • Design of materials with improved characteristics All these fields create Ontologies to limit • Classification of techniques and complexity and acceleration of results organize information. The Ontology can then • Uniform query interface be applied to problem solving. EMMC Examples/Use of Ontologies

• Database integration – Connected data! Discover new trends – Takahashi, et al (2018). Redesigning the Materials and Catalysts Database Construction Process Using – New materials candidates Ontologies. J Chem Inf Mod 58, 1742 . • Easier Database queries – Ontology organises data by domain knowledge: contrast to database which is organised by IT need. Schott presentation, EMMC Workshop, – Querying can be done by scientist using scripts! Vienna 2019 • Integration of analytical processes and equipment • Integration/collaboration/PLM in complex engineering projects (e.g. ISO 15926 for Oil/Gas industry) • Avoid misunderstanding about concepts Airbus 380

7 Semantic Spectrum of Knowledge EMMC Organization Systems Semantics and allow a resource to be understood by both humans and machines ‰ promote interoperability.

Machine can Ontology Logics, OWL interpret information semantic and reason. interoperability Taxonomy formal hierarchy, RDFS

syntactic Thesaurus synonyms, association relations interoperability Machine can process Informal hierarchy table of contents, information due to List glossary, catalogue ID compatible syntax.

Adapted from: Leo Obrst “The Ontology Spectrum”. Book section in of Roberto Poli, Michael Healy, Achilles Kameas “Theory and Applications of Ontology: Computer Applications”. Springer Netherlands, 17 Sep 2010. EMMC A flower, by any name?

Cowslip or cuy lippe, herb peter, paigle, peggle, key flower, key of heaven, fairy cups, petty mulleins, crewel, buckles, palsywort, plumrocks, ….

All these words for one and the same thing … EMMC “Set” means …?

All these meanings for one and the same word … EMMC Speaking the same language

Review of Materials Definitions of concepts and a harmonised language Modelling (RoMM) VI Categorizes the models in an interpretable way

Together the physics or chemistry equations and materials relations are called governing equations and they form one model

April 2018: The CEN (European Committee for Standardization) Workshop Agreement CWA 17284 “Materials modelling – terminology, classification and metadata”

The “lingua franca” of materials modelling EMMC Modelling-Data (MODA)

MODEL User Case Model Physics

Solver Post Processing

Finding a common language and formal approach how to log a simulation project

At some point we want a machine to understand it. This is where Ontologies enter! EMMC What is A ‘Semantic Knowledge System’?

• Semantics is the linguistic and philosophical study of meaning • Logics is the systematic study of the form of valid inference – Predicate: • “Elasticity is a materials property ” – Subject Predicate Object: • “Material has a materials property ” – First order logic • “There exist materials with elasticity ”

13 EMMC ML vs AI

Machine Learning Artificial Intelligence • “Big Data”, Statistics • Logics + Data/Statistics/ML • Leads to knowledge • Leads to intelligence • Learns new things • Makes decisions • Allows computer programs • Mimics the human brain to automatically improve through experience EMMC How is an Ontology represented?

OWL () EMMC How is an Ontology represented

Protégé is a free, open-source ontology editor

A reasoner is a piece of software able to infer logical consequences from a set of asserted facts or axioms. EMMC How is an Ontology represented?

OWL DL (description logic): maximum expressiveness without losing computational completeness, decidability of reasoning systems. includes restrictions such as type separation (a class can not also be an individual or property, a property can not also be an individual or class, …

I. Horrocks, P.F. Patel-Schneider, and F. van Harmelen. J. of Web Semantics, 1(1):7-26, 2003.

representation examples ; there are other way to represent an ontology EMMC

EMMC-CSA project has received funding from the European Union's Horizon 2020 research and innovation programme, under Grant Agreement No. 723867.