Linked Connections presentation for Ally

Linked Connections tries to solve the many data publishers problem within the public transit data world by using open data/linked data/REST techniques

Transcript

1. pieter.colpaert@ugent.be http://linkedconnections.org Scalable intermodal route planning advice @pietercolpaert ← me @linkedcons ← the project
2. pieter.colpaert@ugent.be http://linkedconnections.org Back in November 2014 Representing the Open Knowledge International Open Transport working group
3. pieter.colpaert@ugent.be http://linkedconnections.org My job used to be easy…
4. pieter.colpaert@ugent.be http://linkedconnections.org Slow #opentransport success
5. pieter.colpaert@ugent.be http://linkedconnections.org So I moved on... I’m now a PhD candidate at Ghent University - iMinds Subject: Publishing transport data in a queryable way on the Web → and this is the awesome branding (any designers here? Yes, this is a cry for help)
6. pieter.colpaert@ugent.be http://linkedconnections.org How should we publish public transport data on the Web? Trying to maximise the reuse, informing as many people as possible
7. pieter.colpaert@ugent.be http://linkedconnections.org 2 options? GTFS data dump Route planning on agency’s server User agent can download a data dump, or ask a question to the agency’s server
8. pieter.colpaert@ugent.be http://linkedconnections.org User agent When I use this word: it can both be a machine or an end-user app GET-ting things on the Web And when I say Web, I mean HTTP
9. pieter.colpaert@ugent.be http://linkedconnections.org Option 1: publishing a GTFS data dump Cheap effective solution straight-forward to keep online
10. pieter.colpaert@ugent.be http://linkedconnections.org GTFS problems Interoperability nightmare (Do I need to explain this to you?) User agents need to import your data over and over again
11. pieter.colpaert@ugent.be http://linkedconnections.org http://api.{transitcompany}/?from={A}&to={B} Option 2: a web-service e.g., a plain old HTTP+JSON API
12. pieter.colpaert@ugent.be http://linkedconnections.org Problem There’s a long tail of user needs (and they should not be addressed by just one app) Amount of people User profile: bus subscription, foldable bike owner, impaired...
13. pieter.colpaert@ugent.be http://linkedconnections.org http://api.{transitcompany}/?from={A}&to={B} &departuretime=2015-09-09T14:45Z &wheelchairaccessible=true &transit_modes=plane,railway,bus,car &algoritm_mode=shortest ... Problem Needs to handle any request possible
14. pieter.colpaert@ugent.be http://linkedconnections.org
15. pieter.colpaert@ugent.be http://linkedconnections.org Is there something in between? GTFS data dump Route planning algorithms as a service
16. pieter.colpaert@ugent.be http://linkedconnections.org Let’s take a look at the data a connection departureTime + departureStop arrivalTime + arrivalStop another connection departureTime + departureStop arrivalTime + arrivalStop © open street map -
17. pieter.colpaert@ugent.be http://linkedconnections.org time Our data is a long list of connections Squares are connections
18. pieter.colpaert@ugent.be http://linkedconnections.org time * The Basic Connection Scan Algorithm (CSA) And this is the algorithm* ~ creating a minimum spanning tree through a sorted directed acyclic graph
19. pieter.colpaert@ugent.be http://linkedconnections.org Intriguingly simple
20. pieter.colpaert@ugent.be http://linkedconnections.org That’s also the name of the paper (2013)
21. pieter.colpaert@ugent.be http://linkedconnections.org Do we need all data in memory always?
22. pieter.colpaert@ugent.be http://linkedconnections.org Page X Page ... Page 2 Page 1 time nextPage nextPage Let’s split our data dump into fragments
23. pieter.colpaert@ugent.be http://linkedconnections.org Why? You cannot put the entire Web on one page, so you fragment your datasets and create links between them Different user agents download the same pages for solving different questions → Great for caching!
24. pieter.colpaert@ugent.be http://linkedconnections.org Page X Page ... Page 2 Page 1 time nextPage nextPage When published in pages on the Web, route planning will need X requests instead of 1
25. pieter.colpaert@ugent.be http://linkedconnections.org Try it yourself at http://LinkedConnections.org And http://demo.linkedconnections.org
26. pieter.colpaert@ugent.be http://linkedconnections.org Current status Academic open-source javascript library: https://github.com/linkedconnections Next steps → Demo that supports intermodal queries → How to publish stops, transfers, accessibility & trips If you’re interested in collaborating
27. pieter.colpaert@ugent.be http://linkedconnections.org Current status Datasets published: • Dutch railways: http://iffns.linkedconnections.org/ • 1 month of Belgian rail: http://belgianrail.linkedconnections.org/connections/?departureTime=2015-10-03T15%3A20 Next steps All GTFS data converted to Linked Connections online? (WIP) If you’re interested in collaborating
28. pieter.colpaert@ugent.be http://linkedconnections.org We should stop thinking we can ask the Web only 1 question to get to the answer Thank you @pietercolpaert ← me @linkedcons ← the project