Creating an ontology

“An Ontology is a formal explicit description of concepts oc a domain of discourse […], and restrictions on slots […]. An ontology together with a set of individual instances of classes constitutes a knowledge base” (Noy und McGuinness, 2001)

To create an ontology for the whole model we had two different approaches. The first approach was to merge each of the single ontologies or single models into a collective one that combine them all together and provides a holistic approach in which we see the whole compound as one entity rather than four different projects or model. While the second approach preserves more the singularity of each model, and in the same time provide the relations and correspondences between the different parts of the models.

First approach

For the first approach we tried to identify all interfaces of the given models. When working through the ontologies we found that the ontologies derived in four main classes. All of our models where build up in a similiar way. We all used classes describing the physical and environmental components. With those classes the hole part of the compound can be described. The main classes are:

• Components and Functunality,
• Construction and Structural Components,
• Infrastructure,
• Materials.

Under each one of these we can categorize the different parts of the different components, because every sublcass relates to one of the classes. This is how it looks using Protégé:

This models advantage is that dont have to implement a hole new main class for new parts of the infrastructre. The structure is allready set and you can arrange new models or submodels in the given setup. When defining the infrastructure, we e.g. created the class “Main Roads” only one time and then used relations to relate it to the different parts of the project. We will come to see that it was more effort to include new parts of infrastrucutre to the ontology with the set up of the second approach. The relations we had for this approach were:

The hole model looks like this:

Second approach

For the second approach we defined each model as one main class. Here the idea is when adding more infrastructure to add a new main class that describes a new model. This way the individuality of each model is being maintained. The combined classes looks like this:

Also when the classes are set up in individual classes there can be relations defined with protege. For this example we generally kept all the previos relations intact. Then we created interrelation or correlated relation that connects the main classes with eachother.  For example if two buildings are connected with each other by a road than we used the Property ‘Connected by Road’. Or in cases that we need to connect a certain department in the hospital directly to the school or riding hall we used the property ‘HasDirectAccessto’. Here is how the relations we used in Protégé:

The hole model of the second approach looks like this:

The individuals

The individuals were already set as several options in the earlier assignments. There was no need deleting them as they still work within the combined model. Keeping the parametric model in mind, however we created some individuals that we will use as input parameters for the model in blender. The indiviudals are shown in the figure below: