Fig. 5. Flows in experiment 1 for GET requests.Fig. 6. Flows in experiment 1 for POST requests.
Experiment 1: semantic interoperability
The SGAM framework was previously used to demonstrate how a semantic
interoperability implementation may be assessed and quantified in the
context of DR schemes [49]. The semantic interoperability of the CIM
was specifically evaluated to demonstrate how payloads defined in RDF,
independent of serialization, and using alternative ontologies (SAREF
[51] or SAREF4ENER22) could be successfully and accurately
translated into JSON-LD using the DELTA ontology. Nonetheless, such
results did not demonstrate how the CIM can also cope with payloads
written in formats other than RDF and with models that are not
ontologies.
The collection of test scenarios presented in the previous study was
expanded in this experiment to evaluate the CIM semantic compatibility
in those uncovered circumstances. To that goal, two payloads were
specified in XML using the OpenADR XML format. The payloads were then
shared using CIMs, which transformed them into their corresponding
JSON-LD format. The GET (xml to json-ld), POST (json-ld to xml), and
POST (xml to json-ld) messages are depicted in Figs. 5 and 6.
The DELTA ontology SHACL shapes were used to evaluate the payload
converted to JSON-LD. 23 A manual validation was also undertaken to
guarantee that the translation was done appropriately. Table 2 shows the
outcomes of this exploration after delivering 100 payloads in each test
case (GET (xml to json-ld), POST (json-ld to xml), and POST (xml to
json-ld)).
Table 2 :Results of the semantic interoperability experiments.