Problem: I need to create an ontology (say www.example.com/ontology/ont# , with ONT prefix). This ontology consists of some other ontologies with prefixes as SSN, TIME, GEO, etc. Now, the confusion is that when I use ONT ontology for data modelling, should I use original prefix’s such as SSN,TIME and GEO or should I go with ONT prefix.
Conclusion: During data modelling, If I go with ONT namespace then I think l have to alter the prefixes of previous ontologies by using owl:sameAs, owl:equivalentClass, owl:subclass concepts. And, on using original prefixes during data modelling, care has to be taken as each modelled data item should be dereferenceable. Am I right with this conclusion? Is there any third approach to model the data when your ontology consists of several other ontologies?
I am not able to decide which approach should I use. What are pros of one over the other? Is there any tutorial or any reference which discusses this issue?
If i understand your question correctly, you're essentially asking if you should "duplicate" existing classes and properties from other ontologies into your own one.
The clear answer is: no.
The semantic web / linked data lives of the re-use of existing vocabularies, so [...] it's best to not re-invent any new schema, but just to use parts from existing ones. Your data will then even be useful without any reasoning.
See this answer for more.