Can anyone tell me the steps that are required to populate an Ontology?
I have created a domain-specific Ontology (TBox = Terminological knowledge) which consists of defined classes and relations.
On the other hand, I have an IFC file (The Industry Foundation Classes) which has the instances.
I have converted the IFC file to IFC OWL and have understood that I need to map the classes into the newly created ontology.
However, I don't understand how I can get the instances of the associated classes and relations into my created ontology.
You have created two ontology files, one with the tbox and one with the abox. Usually, in this scenario the abox would use an owl:imports annotation to refer to the tbox, and would not, itself, need class declarations - it would use the IRIs for the classes already declared in the tbox. In protégé, creating an imports is straightforward.
A common issue is incorrect IRIs: if you've created your abox without initially importing the tbox, it's possible the classes you used do not match the tbox classes (e.g., the abox classes use the abox IRI as their base IRI instead of the tbox).
Related
I am interested in finding out what are the ontologies preloaded into Graphdb by default. This will help me identify what ontologies (.ttl files) do I need to add along with my ontology as part of the package, especially in the situations when there is no Internet connection.
I know that some ontologies such as rdfs and owl are preloaded into GraphDb. but I could not find any list on preloaded ontologies.
Please keep in mind that OWL does not differentiate very clearly ontology from instance triples. Also GraphDB introduces another term "axiomatic triple" (i.e. statement that cannot be deleted with a normal user transaction) used to separate the ontology statements from the normal RDF.
There are 3 ways of loading ontologies as axiomatic triples in GraphDB:
Ruleset - will import all statements from the beginning of a PIE file as axiomatic statements. Check here for additional information.
Add imports initialisation parameter - this will safe a configuration predicate in the SYSTEM's repository See the configuration parameter
Add a special predicate in the beginning of an RDF file - the system transaction will add all following statements as ontology. Check here.
Another approach is to add every file in a different named graph. This will allow you to see which graphs are currently stored in the repository.
is there any way individual (instance) connect to class with object property? For example, individual in this case is module name: Web Programming. Object property : isClassified. Class: Network.
I've tried to define Web Programming as class, and it works because the domain and range are both classes. Same goes if I define both Web Programming & Network as individuals, it works. If the domain is a class and the range is individual, it still works. But what if the domain is individual and the range is class? Is there any way I can connect it with object property: isClassifiedIn?
Protégé is an OWL 2 DL editor (since version 4). In OWL 2 DL, an individual cannot be a class, and an object property must relate individuals to individuals only. So what you want cannot be expressed in the way you formulate it. However, you could do two things:
use an annotation property instead of an object property. This may not be ideal because an OWL DL reasoner must ignore annotation properties in the reasoning process. They are just that: annotations, similar to comments in a programming code.
relate the individual to another individual that has the same name as the class. Let me give details about this.
In OWL 2 DL, although it is not possible for individuals to be classes, it is possible for individual names to be class names at the same time. For instance, one can say (in Turtle syntax):
ex:Module a owl:Class .
ex:Network a owl:Class, owl:Thing .
ex:isClassified a owl:ObjectProperty .
ex:webProgramming a ex:Module;
ex:isClassified ex:Network .
Note that ex:webProgramming here is not related to a class. It is related to an individual of type owl:Thing. This individual has nothing to do, a priori, with the class named ex:Network, although it has the same name. This is called "punning" in the OWL 2 specification.
There is a third way: change your knowledge model such that you do not encounter this problem. I do not know your ontology, but it could be hinting at an antipattern that you should avoid.
You have to use "value".
Write your own expression using the class expression editor.
Select the class Than write:
"property" value "individual"
I'm new in ontology and i'm using protege to create my own. I have imported the Dublin core ontology (http://purl.org/dc/elements/1.1) into my own ontology using protege but only annotations were included. Upon reading the documentation of Dublin core there were classes and properties defined. how will i include these classes and properties in my ontology with the use of protege?
I think your problem is that you don't look inside the files. Dublin Core has many files. The one that you are referring to (elements) only contains annotations. You need to find the appropriate file. The DC terms contains some properties and classes. You need to read the documentation and then import the file with the modelling elements that you require.
I'm creating an ontology that is based on wordnet. I want to know what level of information I should add to my own ontology? Like, for example, if the lexica has a "instance of" and "hypernym" relation, do I need to import all this in my ontology? or it's ok to just refer to the lexica in my ontology and use namespace of wordnet as a reference?
Note that I've a list of terms that I want to somehow link to wordnet so these terms make sense.
quick question ive got a couple of sibling classes which include sub classes now what i want to do is connect a sub classes to two diffrent sibling classes, is this possible? also i want it to show in the owlviz.
example
sibling class:
rules
goals
sub class:
collect
so i want sub class collect to feature or be connected in both of the sibling classes. as the software does let me type the same name in each sibling class.
thanks
I don't quite understand the question. You can just assert the fact that collect is a subclass of both rules and goals straight from the Protege User Interface.
Make sure all of your classes are present in your isA hierarchy
Select the class collect
In Protege 4, click on the little "+" icon next to the "Superclasses" section in the Class Description Window
Assert "rules" as a superclass
Repeat and assert "goals" as a superclass.
Now "collect is a subclass of both "rules" and "goals".
AS an aside, it is not normally considered good practice to have multiple asserted inheritance in ontologies. For large ontologies, this can become a maintenance nightmare. If all you need is a small practical solution to a problem, then ok.
The visualisation of your ontology can also be done Protege - you need Graphviz installed first and point Protege to the location of the graphviz executable on your system.
Hope this helps!