## 3 Printing Information Model for Additive Manufacturing of Concrete Structures
### Verification of the Printing Information
#### 3.3.2 Competency Questions  
Applying competency questions is a well-established method for ontology checking [43]. Accordingly, competency questions are developed based on the information exchange requirements to check the PIM-O at the assertional level. SPARQL queries are used to answer the competency questions based on the structure and axioms defined in the PIM-O. The queries consist of two parts: a \"select\" clause identifying variables and a \"where\" clause providing conditions to be matched according to triple patterns (i.e., subject-predicate-object statements), as shown in the listings below. For illustration purposes, querying a competency question (CQ) is shown with the examples of competency questions CQ1 and CQ2. The competency question \"CQ1: What kind of components can be 3D-printed?\" addresses the types of components that are outputs of AM methods. CQ1 is answered by querying the class hierarchy directly, as shown in Listing 2. The results obtained in the \begin{table}
\begin{tabular}{l l l} \hline \hline
**Test** & **Description** & **Result** \\ \hline \multirow{3}{*}{Ontology consistency checking} & The PIM-O has no inconsistencies, answering the question & \\  & \"is there at least one model of the PIM-O?\" & ✓ \\  & Formal expression : \(\ PIM-O\
vDash\Gamma\sqsubseteq\L\) & \\ \hline \multirow{3}{*}{Concept satisfiability checking} & A concept expression \(\mathcal{C}\) is satisfiable with respect to the PIM \(-\) & \\  & \(\mathcal{O}\), answering the question \"is it possible to instantiate a concept \(\mathcal{C}\)?\" & ✓ \\  & Formal expression : \(\ PIM-O\vDash C\sqsubseteq\T\) & \\ \hline \multirow{3}{*}{Concept subsumption checking} & A concept expression Cis a subsumption of a concept expression \(D\) & \\  & with respect to PIM-O. & ✓ \\ \cline{1-1}  & Formal expression : \(\ PIM-O\vDash C\sqsubseteq D\) & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Model-checking results for PIM-O. query Q1 show that subclasses of the class _AMComponent_ exist for walls, beams, columns, support structures, and reinforcement structures. ```
SELECT?componentType WHERE{?componentType rdfs:subClassOfpimo:AMComponent }
```  
The competency question \"CQ2: Identify walls that are designed using concrete as main material\" addresses the relationship between components and materials. Instances of the _AMComponentWall_ class (e.g., _wall_1 OG_ and _wall_2 OG_) are queried to answer CQ2, as shown in Listing 3. The results obtained in the query Q2 show that it is possible to identify component instances according to the role of the materials. ```
SELECT?componentType WHERE{?wallrdf:typepimo:AMWallComponent.?wallpimo:hasMaterial?material.?materialrdf:typepimo:Concrete.?materialpimo:hasRole?role.?rolerdf:typepimo:Main_Material. } ```  
Further competency questions are applied to evaluate process-related, material-related, and geometry-related information of components based on instances of the _AMProcess_ class (e.g., _cp_Process1_), the _AMComponentWall_ class (e.g., _wall_1 OG_ and _wall_2 OG_), and the Concrete class (e.g., _concrete_M1B1_). The instance _cp_Process1_ has _concrete_M1B1_ as a material resource, presenting a green strength of 3.6 kPa (_property_GreenStength_) at an age of 15 min identified with a shear vane test (_test_VaneTest01_). The instance _wall_1 OG_ is an output of _cp_Process1_ and presents a bulk density of 2070 kg/m3 (_property_BulkDensity_). The queries representing competency questions 3, 4, and 5 are listed below, as shown in Listings 4-6. Table 3 summarizes the results of the illustrative competency question queries. In summary, the results show that the PIM-O correctly answers the competency questions on the assertional level. ```
SELECT?process WHERE{?wallpimo:isOutput?process.?processrdf:typepimo:AMProcess. ?wallrdf:typepimo:AMComponentWall }
```  
**Listing 4**. Example SPARQL query Q3 for competency question CQ3.