## 3 Interconnecting Interdisciplinary Emotional Knowledge
### Keeping Track of Provenance Metadata
#### 4.4.3 AI4 EU H2020 European Project-Knowledge Extraction for the Web of Things (KE4 WoT) Challenge

To encourage research collaborations to automatically extract the knowledge from ontologies and scientific publication describing the ontology, we designed the Knowledge Extraction for the Web of Things (KE4 WoT) Challenge supported by the AI4 EU project and by the Web Conference Conference (WWW 2018) [90]. The KE4 WoT challenge encourages processing the expertise published by domain experts and making the domain knowledge usable, interoperable, and integrated by machines. We released the set of ontologies in various domains (including emotion) as dumps, web services, and tutorials and made them available for the challenge. Furthermore, the Linked Open Reasoning tool, introduced in Section 4.3, is referenced on the AI4 EU platform ([[https://www.ai4](https://www.ai4) europe.eu/research/ai-catalog/linked-open-reasoning]([https://www.ai4](https://www.ai4) europe.eu/research/ai-catalog/linked-open-reasoning) accessed on 18 September 2022). #### 4.4.4 Other Emotional Use Cases

* Taxonomy of mood states (see Figure 10) (e.g., based on [PERSON] et al. [86] references eight mood states: Excited, Happy, Calm, Tired, Bored, Sad, Stressed, Angry). * IAMHAPPY: an IoT knowledge-based well-being recommendation system to encourage happiness [55]. * **Naturopathy Recommender System extended for Emotion**: We extended our natural-opathy knowledge graph to cover better emotion-related knowledge and to enhance mental health, for instance:
* Food that contains magnesium is recommended for depression (e.g., chocolate) (Figure 11). * Food that contains Vitamin D is recommended for depression (Figure 11). * Heartbeat data to deduce fear emotion (Figure 12). * Skin conductance data to deduce anxiety emotion (Figure 13). * Luminosity data to deduce weather (cloud cover) (Figure 14). ## 5 Evaluation: Applying Semantic Web Best Practices to Enhance the Emotional Knowledge Graph

We employed our designed PerfectO methodology [91] that references a set of semantic web best practices and collection of tools providing web services to evaluate ontologies to enhance our emotional knowledge graph: (1) Syntactic Ontology Evaluation in Section 5.1, (2) ontology design evaluation in Section 5.2, (3) LOV4 IoT-Emotion Ontology Catalog statistics in Section 5.3, and (4) the emotional knowledge graph evaluated with emotion scenarios in Section 5.4. ### Syntactic Ontology Evaluation

The ontology can be loaded with Jena version 2.11, Protege 4.3 (Figures 5 and 6), and GraphDB 9.10 (Figure 7). We evaluated our emotion ontology with the **TripleChecker** syntax validator in May 2022. Mistakes found such as \"Literal value does not match datatype\" (data format and decimal format) have been fixed. We also used the W3C RDF Validator ([[https://www.w3.org/RDF/Validator/rdfval](https://www.w3.org/RDF/Validator/rdfval)]([https://www.w3.org/RDF/Validator/rdfval](https://www.w3.org/RDF/Validator/rdfval)) accessed on 18 September 2022) and OWL Manchester Validator ([[http://mowl-power.cs.man.ac.uk:8080/validator/validate](http://mowl-power.cs.man.ac.uk:8080/validator/validate)]([http://mowl-power.cs.man.ac.uk:8080/validator/validate](http://mowl-power.cs.man.ac.uk:8080/validator/validate)) accessed on 18 September 2022), and no errors have been found. ### Ontology Design Evaluation

We evaluated our emotion ontology with **OOPS! OntOlogy Pitfall Scanner! **[92], which detects pitfalls. We have identified eleven pitfalls, which are classified as critical, important or minor:

* One **critical pitfall**: P31 Defining wrong equivalent classes. * Four **important pitfalls**: P10 Missing disjointness, P34 Untyped class, P38 No owl ontology declaration, and P30 Equivalent classes not explicitly declared. * Six **minor pitfalls**: P04 Creating unconnected ontology elements, P08 Missing annotation, P20 Missing ontology annotations, P22 Using different naming conventions in the ontology, P32 Several classes with the same label, P36 URI contains file extension.