See also: IRC log
<DanhLePhuoc> https://filesender.heanet.ie/1.6/?vid=0b60067c-e7bd-c629-bacf-00005974b1bb, the link to the presentation
<scribe> scribenick: dsr
Danh presents Thing Discover on the Graph of Things see link above
Danh: I try to share my demo
Screen shows world map with heat map and locations as overlay
Danh shows how you can browse the data screens using some JavaScript effects
At the bottom there is a live display of data courtesy of a web socket connection with the server.
He returns to the slide presentation
We use HTTP content negotiation as a discovery mechanism, along with a sparql query.
The query results are returned in JSON
We’re using an RDF graph for the data models
There are plenty of ontologies available.
We also have RDF linked data streams
Static knowledge is treated as background knowledge
The sensor metadata describes the stream, with sparql 1.1 specification
We had to extend the sparql query language slightly to be able to aggregate data over a given time period
This also allows you to query the data at a specific time (in the past)
You can define a query that returns a stream for data that satisfies that query
Slide with stats on amount of data, cluster of servers and the software libraries
People ask if you can make it smaller? Yes through smart gateway
We’re working on making it work on Android and Raspberry Pi
The code foot print is in range 4-8 MB.
Memory foot print in range 4 - 64MB
Plenty of room for further improvementsto make it smaller faster and more scalable
Danh finishes
Dave: questions anybody?
Joerg: this looks like a complete solution inspired from sensor networks. We now need to identify some potential building blocks in respect to discovery, any suggestions?
Danh: we only use REST API, complexity is determined by the nature of the query
A few years ago we implemented a small query engine for simple queries
Joerg: in the task force we discussed different notions of discovery
Your presentation is about discovery of certain resource with a particular characteristic.
Dahn: yes, here we focus on data discovery
First you need to discovery the sparql endpoint
The linked data community has ideas for how to query endpoints for their metadata, e.g. their capabilities
We’ve looked at using JSON for queries as an alternative to sparql for restricted classes of queries
Dave: any other questions?
Helena: I want to understand continuuous discovery, is there an anouncement for sensors?
Danh: you first need to discover the query end point, and can then query for all sensors satisfying some constrain.
Helena: the sensors have to register with the system in some way?
Danh: yes
Dave: this is like the Compose project where queries for event streams from a set of sensors is a live query, i.e. reflects the sensors currently registered
Danh: one point - this approach doesn’t have to run on the public Internet.
Joerg: what are the steps in discovery with links to use cases, and then look at dependencies on work in othe task forces.
You have already listed some mechanisms for discovery, and should now add examples, and the relationship to thing descriptions, APIs and to security, privacy etc.
Dave asks for contributions for next week’s call
Joerg: yes we should invite contributions for the landscape analysis along with links
Dave: I could offer to provide an overview of the Compose system approach to discovery.
Joerg: yes, but you should break it down into the components/building blocks
This is scribe.perl Revision: 1.140 of Date: 2014-11-06 18:16:30 Check for newer version at http://dev.w3.org/cvsweb/~checkout~/2002/scribe/ Guessing input format: RRSAgent_Text_Format (score 1.00) Succeeded: s/Dahn/Danh/ Found ScribeNick: dsr Inferring Scribes: dsr Present: DanhLePhuoc Dave Danh Ashok_Helena Joerg Hamid Regrets: Soumya Got date from IRC log name: 01 Jul 2015 Guessing minutes URL: http://www.w3.org/2015/07/01-wot-di-minutes.html People with action items: WARNING: Input appears to use implicit continuation lines. You may need the "-implicitContinuations" option.[End of scribe.perl diagnostic output]