Beyond data models (what we can do with RDF alone) David Leal

Semantic Web technologies RDF (Resource Description Framework) –making statements on the Web – N3 (Notation 3) –a simple way of writing down an RDF statement – An opportunity to: record information more simply enable others to use our concepts use the concepts of others

Jane believes Getting started Janet John loves RDF diagram N3 :Janet :loves :John. :Jane :believes { }

Getting started people:Janet relationship:loves relationships:. namespaces identify the people identify the human relationships

Traditional data exchange Blobs –Encapsulate the data that defines the shape –Encapsulate the data that is the specification of the part. –Encapulate the data that is the specification of the analysis. The data inside the blob and the data outside the blob are separate – what is inside can be specified in a contract. It is “data push” – I tell you what you need to know. The blob can be an attachment – it can be downloaded by FTP. This is what the EXPRESS data model + part 21 / 28 file methodology achieves.

What this is good for Command driven processes –I tell you what to do, and what you need to know to do it. Processes where the data within the blob can be easily defined –Shape information is a success story – it has a well defined scope –Engineering analysis has not taken off – the scope is fuzzy and much larger Processes where the blob has a particular destination system –CAD, CAE, CAM, PDM, LCA You need to know the type of destination system is before selecting the type of the blob. This is why standards define different types of blob – ISO , ISO , etc. for product data – ELCD XML for life cycle data

What we cannot do yet A user publishes data on the Web – the user makes his or her own decision about what data are published –Somebody else can use the data, if they want to. A user chooses standard vocabularies to publish data as statements –Vocabularies can be used together as required “Somebody” seeking information can follow links between one set of published data and another –Just like the ordinary Web, but the statements are semantically precise –and the “somebody” can be a computer application It is “data pull” - you go and get what you want This is what the provides. What we want to make possible

Tracking back materials information item: part:toDesign model:ABC456_v3 ; part:madeFromBatch alcom:. URI of an individual part URI of a design URI of a batch of material URI of a vocabulary about part:.

Tracking back materials alcoa:. item: part:toDesign model:ABC456_v3 ; part:madeFromBatch alcom:PQR dereference to get the next formula

Tracking back materials information a classification with respect to a materials standard the actual manufacturing process a standard vocabulary for manufacturing processes item: part:toDesign model:ABC456_v3 ; part:madeFromBatch alcom:PQR alcom:PQR mat:materialProductType mil5:XYZ2048-asSheet ; mat:manufacturingProcess alcom:LineA

Tracking back materials information item: part:toDesign model:ABC456_v3 ; part:madeFromBatch alcom:PQR alcom:PQR mat:materialProductType mil5:XYZ2048-asSheet ; mat:manufacturingProcess alcom:LineA dereference again to get the next formula

Tracking back materials information more manufacturing vocabulary facility that performed the process generic work flow vocabulary alcom:PQR mat:materialProductType mil5:XYZ2048-asSheet ; mat:manufacturingProcess alcom:LineA alcom:LineA mat:performedBy alcom:LineA ; act:startTime [ iso8601:utc “ T09:00” ] ; act:endTime [ iso8601:utc “ T17:00” ]. vocabulary for time dereference again to get the next formula

Tracking back materials information alcom:PQR mat:materialProductType mil5:XYZ2048-asSheet ; mat:manufacturingProcess alcom:LineA ; alcom:specimen part:madeFromBatch alcom:PQR ; part:toDesign test:SpecimenTypeXYZ. another use of the ISO product vocabulary a standard specimen type tabont:isMentionedIn alcom:specimen-67890/formula.n3. dereference again to get the next formula

Tracking back materials information alcom:PQR mat:materialProductType mil5:XYZ2048-asSheet ; mat:manufacturingProcess alcom:LineA ; tabont:isMentionedIn alcom:specimen-67890/formula.n3. alcom:specimen part:madeFromBatch alcom:PQR ; part:toDesign test:SpecimenTypeXYZ ; tabont:isMentionedIn alcom:Test-67890/formula.n3. dereference again to get the next formula

Tracking back materials information alcom:specimen part:madeFromBatch alcom:PQR ; part:toDesign test:SpecimenTypeXYZ ; alcom:Test obs:onSpecimen alcom:specimen ; act:toProcedure test:MaterialTestTypePQR ; obs:givesResult alcom:Result more generic workflow vocabulary a standard test method a generic measurement and observations vocabulary tabont:isMentionedIn alcom:Test-67890/formula.n3. dereference again to get the next formula

Tracking back materials information alcom:Test obs:onSpecimen alcom:specimen ; act:toProcedure test:MaterialTestTypePQR ; obs:givesResult alcom:Result alcom:Result { alcom:specimen mat:compressiveYieldStress [ iso:MPA “201.3” ] } a statement with provenance and finally dereference again to get the result of a real test

Many vocabularies are used to record the data product design units manufacture material handbook material test workflow observations inventory personnel maintain electrical networks GIS earth sciences life cycle assessment they are developed independently but used together

Data models Data models are good –they specify exactly what data should be supplied for a particular activity –they have constraints to ensure that the data is complete and correct But –different activities need different data –different activities have different ideas about what “complete” means So –There are lots of similar but overlapping data models A data model does not enable you to publish data on the Web

Vocabularies/ontologies Vocabularies/ontologies are good –precise statements can be made about things –different vocabularies can be used together to say what you want But –there is no constraint on what is said –you may not say all that needs to be said So –vocabularies are not enough to specify the data flow between activities –replacing data models with vocabularies + rules is a research activity Vocabularies work with the emerging Semantic Web technology

What next Use the past 20 years work on data models to create vocabularies –cannot be generated automatically from UML, EXPRESS or XML schemas –people have to read the words – real work All standards developments have this problems –data models in UML, EXPRESS or XML Schema product data - EXPRESS electrical networks - UML GIS - UML building and construction - UML materials information – XML and EXPRESS earth sciences – XML life cycle assessment – XML (ELCD XML schema from ISO 14048)