Documentation-of-the-Knowledge-Graph.md

@@ -10,15 +10,17 @@ Following the RDF recommendation, the KG identifies every thing using [Internati
 
 To simplify the presentation, from now on, we will use a prefixed notation for all IRIs, according to the following prefix definitions:
 
-- @prefix hctl: <https://www.w3.org/2019/wot/hypermedia#> . # hypermedia controls ontology
-- @prefix itm: <https://ci.mines-stetienne.fr/kg/itmfactory/> . # IT'm factory
-- @prefix js: <https://www.w3.org/2019/wot/json-schema#> . # JSON schema
-- @prefix onto: <https://ci.mines-stetienne.fr/kg/ontology#> . # Our custom ontology
-- @prefix pto: <http://www.productontology.org/id/> . # The product types ontology
-- @prefix s4sys: <https://saref.etsi.org/saref4syst/> . # SAREF for system ontology
-- @prefix sosa: <http://www.w3.org/ns/sosa/> . # The sensor, observation, sample & actuator ontology
-- @prefix ssn: <http://www.w3.org/ns/ssn/> . # The semantic sensor network ontology
-- @prefix td: <https://www.w3.org/2019/wot/td#> . # Thing Descriptions
+```turtle
+@prefix hctl: <https://www.w3.org/2019/wot/hypermedia#> . # hypermedia controls ontology
+@prefix itm: <https://ci.mines-stetienne.fr/kg/itmfactory/> . # IT'm factory
+@prefix js: <https://www.w3.org/2019/wot/json-schema#> . # JSON schema
+@prefix onto: <https://ci.mines-stetienne.fr/kg/ontology#> . # Our custom ontology
+@prefix pto: <http://www.productontology.org/id/> . # The product types ontology
+@prefix s4sys: <https://saref.etsi.org/saref4syst/> . # SAREF for system ontology
+@prefix sosa: <http://www.w3.org/ns/sosa/> . # The sensor, observation, sample & actuator ontology
+@prefix ssn: <http://www.w3.org/ns/ssn/> . # The semantic sensor network ontology
+@prefix td: <https://www.w3.org/2019/wot/td#> . # Thing Descriptions
+```
 
 The most important parts of the KG are the description of the machines, especially the ones identified as [itm:bosch-apas](https://ci.mines-stetienne.fr/kg/itmfactory/bosch-apas), [itm:dx10](https://ci.mines-stetienne.fr/kg/itmfactory/dx10), [itm:vl10](https://ci.mines-stetienne.fr/kg/itmfactory/vl10), and [itm:xy10](https://ci.mines-stetienne.fr/kg/itmfactory/xy10).
 
@@ -40,7 +42,7 @@ The production line is described according to the pattern of the figure below:
 
 In practice, the blank nodes will have a specific identifier, and it may be typed with a different class than what is shown in the diagram above. However, a class hierarchy can help inferring that a given entity is of the appropriate type. For instance, here is a piece of the description of the IT'm Factory:
 
-```
+```turtle
 itm:itm a sosa:Platform;
    sosa:hosts itm:productionLine .
 itm:productionLine onto:inputMachine itm:vl10;
@@ -56,4 +58,8 @@ erm:VL10 rdfs:subClassOf onto:PotStorageRack .
 
 The four components of the production line are: a storage rack, a filling machine, a robotic arm and a packaging machine. If there exist multiple machines of the same type in the factory, we need to know which one is connected to what. The pattern for describing connections follows the SAREF for System ontology ([SAREF4SYST](https://saref.etsi.org/saref4syst/)). Each machine is a `s4syst:System` that has `s4syst:ConnectionPoint`s. A connection point is attached to a `s4syst:Connection`, which is a physical or virtual entity that represents the connection between 2 systems.
 
-![system_connection.svg](uploads/28858b23e71d2449edb405a0bf6ca1f2/system_connection.svg)
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+![system_connection.svg](uploads/28858b23e71d2449edb405a0bf6ca1f2/system_connection.svg)
+
+We simplify the situation a little by assuming that the area of the output product and the area of input material are the same as the points of connection, and we will consider that the connection is a single point. So, for the sake of this summer school, we assume that the absolute coordinates of the output location of the storage rack is exactly the same as the input location of the filling machine. Note that the blue dashed lines in the diagram are relations that one can infer from the ontologies; they are not necessarily present in the knowledge graph.
+
+In the case of the robotic arm, there is no connection, because it can move freely. The robotic arm must be able to position its arm at the output location of the filling machine, and move the pots to the input location of the packaging machine.
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