Telecon 25.09.2015

Participants

• Jean-Paul Calbimonte (Chair)
• Alejandro Llaves
• Minh
• Javier Fernandez
• Tara Athan

Agenda

• Serialization examples: https://github.com/streamreasoning/RSP-QL/blob/master/Serialization.md
• Temporal entities (ie align with time ontology concepts)
• Adapt concepts of substream and window functions
• Issues:
  • definition of “substream”
  • ordering of timestamps
  • concern about multiple triples

Resources

• Data Model Document: https://github.com/streamreasoning/RSP-QL/blob/master/Semantics.md
• Serialisation Document: https://github.com/streamreasoning/RSP-QL/blob/master/Serialization.md

Minutes

• javier: presents an example of json-ld serialization
• tara: this is a small stream example?
• javier: yes
• tara: another timestamped graph that is in between the recorded at and generated at that arrives in?
• javier: nothing prevents this from happening, nothing enforces sequence in Json-LD
• javier showing examples with internal context, shared context, and no shared context
• javier: showing bnode graph examples
• tara: json-ld may be controversial, but multiple serializations are possible.
• tara: suggestion: modify the dates. example with interleaved graphs, repeated timestamp. may serve as a good exercise.
• jp: does it match the abstract model?
• tara: actually the examples represent 4 timestamped graphs
• jp: to say this in the doc, and include examples after definition.
• tara: explicit example of transmission possibilities of Json-LD
• tara: substream vs window
• minh: could remove the finite form the definition.
• tara: That would work. Suggest to make difference between syntactic terms and relationships
• tara: It is important to distinguish terminology for classes versus property. Stream is a class. Substream is a property. Bounded stream would be another class. Window is also property.
• tara: ordering problem. default ordering function?
• minh: make it more generic.
• minh: associate the predicate to the predicate?
• minh. agree on properties that the ordering functions must comply to
• Tara Athan: For greater generality, it is possible to associate a fixed ordering with a predicate.

• Tara Athan: Some general properties that must be satisfied by any order:

• Tara Athan: 1. if one timestamp "precedes" (in the sense of Allen operators) another timestamp, then it must be less than the other timestamp.

• Tara Athan: 2. if a<c and b>d, then timestamp [a,b] < [c,d]

• Tara Athan: Correction: if a<c and b<d, then timestamp [a,b] < [c,d]

• Minh: something like this should violate the condition: [a,b] smaller [c,d], [c,d] smaller [e,f] but then [e,f] smaller [a,b]

• Tara Athan: Certainly the partial should satisfy the usual mathematical definition of partial order, including transitivity.

• Tara Athan: partial should => partial order should