Slides of the course given at the KULeuven lecture of Knowledge and the Web on 2016/10/26. Examples of semantic technologies and a way of developing web apps on top of it.

1. Semantic
Technologies
in Practice
Knowledge and the Web
2016

2. Semantic technologies in practice
Some technical tidbits
Some real-world examples
A practical way of developing apps

3. High quality linked data
Five stars
- The content is free
- … in a structured format
- … which is open
- … and it uses URIs
- … which are used elsewhere
<3 stars: Manual integration
>3 stars: Automatic integration

4. Semantic integration
Mapping to linked data:
- CKAN
- schema.org
Content is linked data:
- RDFa
- Turtle
Internal use of Linked Data:
- mu.semte.ch
SPARQL endpoint
- dbpedia

5. “Are we succeeding?”

7. Search Engine Optimisation

8. Example: Best Buy
Accidental SEO
- Build blog for higher visibility
- Annotations using RDFa
+ 30% incoming search traffic ?!

9. Example: Best Buy
Best buy now uses schema.org
Where do we see this working?

10. Example: Best Buy

11. Example: Coolblue

12. SEO
Search engines are pushing for structured data
& it’s linked

13. BBC
you know, the big broadcasters

14. BBC: World cup 2010
Problem:
- Information on 32 teams, 736 players
- Roughly 750 pages of dynamic content
Solution:
- A semantic model
- Dynamically generated pages
- Minimal journalistic management
Repeated in 2012 summer olympics

15. BBC: Ontologies
BBC publishes Linked Data everywhere
Awesome ontologies
!! Agile ontologies !!
Semantic administration tools

16. “We want people to
recognise, not memorise their
way around the site”
-- Jo Kent

17. Linked Open Data Cloud

18. ESCO
bringing structure to the job market

19. ESCO
Meet Sara,
… a Spanish speaking nurse from Spain

20. ESCO
Sarah considers filling her duties in
another European country.

21. ESCO
Sarah has limited language skills
Sarah uses Google translate and finds that enfermera
translates to nurse
What Sarah doesn’t find is that a nurse in Spain performs
the duties of a nursery assistant in Great Britain.

22. “Name concepts by URI”

23. ESCO

24. ESCO

25. ESCO
This is what we do:
- ~7 full time knowledge engineers
- ~4 full time developers and architects
- Loads of tooling
- Vision for the future

27. Tea time!

28. <<<SSSHHHHHHHHH>>>
this is the start of the mu.semte.ch story

29. *COUGH*

30. mu.semte.ch
practical applications with Linked Data

31. In 60 seconds
State-of-the-art web applications fuelled by Linked Data aware microservices
- User-facing microservices
- Easy deployment using Docker
- Single Page Apps using Ember.js
- Well known requirements
=> [HTTP+JSON+SPARQL]
https://github.com/mu-semtech/
https://mu.semte.ch

32. Some history
Share code on personal projects
Rails is not über-productive
Stay light, choose later
Use microservices and semantic model

33. KISS
Keep It Super Simple

34. KISS
- Most of us aren’t microservice experts
- Most of us aren’t UI experts
- We need to get stuff done
- Maximize freedom
- Orthogonal features
- Minimize requirements
- Enforce simple mental model

35. Simple mental model
user-facing http-services

36. Simple mental model
User-facing microservices
Limit base technologies:
- HTTP
- JSON(API)
- SPARQL (one graph)

37. Simple mental model
TenForce supports publishing of open data.
- Use DCAT standard
- EDCAT 2.0 released
- mudCAT = back-end
- webCAT = front-end
- Custom configurations to match
specific customer needs.

38. webCAT

39. Semantic models
Many actors, telling parts of the same story

40. Semantic models
Services read/write the part of the world they understand.
User Registration:
- There’s a new user => add it to the triplestore.
User Login:
- Check username/password => connect user to current session.

41. Semantic models
Registration
service
Login service

42. Semantic models
Many implementations, one model
Same model for:
- Username/Password login
- OAuth login
- ECAS login

43. Semantic models
We use the ECAS login for ESCO-related projects.
ESCO is a taxonomy of all Skills Competences and Occupations in Europe.
The Dacota team finds and classifies content. Brains for hire!

44. Docker
Deployment made easy

45. Docker Container =~ Lightweight Linux Virtual Machine
Docker Compose =~ Topology of multi-container project
Each service runs in its own Docker Container
In short:
- Simple hosting on hub.docker.com
- Clean project description
- Always works
- Runs on the Big Data Europe Platform
Share using Docker

46. Share using Docker
We are part of Big Data Europe
Making Big Data:
- Easy to get started
- Cheaper to maintain
… in any domain
- Now including Smart Big Data:
=> Semantics + Big Data = <3

47. Reuse everything

48. Reuse everything
- Templates: basics for a service
- Configurable services
- mu-cl-resources
- Ember add-ons
- Hierarchy service + add-on
- Login service + add-on

49. Base templates
CatalogsIndexRoute = Ember.Route.extend
ajax: Ember.inject.service()
model: () ->
@get('ajax').request('/hello')
Hello result: {{model.value}}
get '/hello/' do
counter = query( "SELECT COUNT (*) as ?counter" +
"WHERE {" +
" ?s ?p ?o." +
"}" ).first[:counter].to_i
status 200
{ value: counter }.to_json
end
FROM semtech/mu-ruby-template:2.0.0-ruby2.3
MAINTAINER Your Name <you@provider.com>
demo:
image: you/demo-service
links:
- db:database
dispatcher:
…
links:
- demo:demo
match "/hello/*path" do
Proxy.forward conn, path, "http://demo/hello/"
end
[mu-ruby-template
]

50. Base templates [mu-ruby-template
]

51. Configurable services
(define-resource distribution ()
:class (s-prefix "dcat:Distribution")
:properties `((:title :string ,(s-prefix "dct:title"))
(:description :string ,(s-prefix "dct:description"))
(:issued :string ,(s-prefix "dct:issued"))
(:modified :string ,(s-prefix "dct:modified"))
(:license :string ,(s-prefix "dct:license"))
(:rights :string ,(s-prefix "dct:rights"))
(:access-url :string ,(s-prefix "dcat:accessURL"))
(:download-url :string ,(s-prefix "dcat:downloadURL")))
:has-one `((dataset :via ,(s-prefix "dcat:distribution")
:inverse t
:as "dataset")
(format :via ,(s-prefix "dct:format")
:as "format"))
:resource-base (s-url "http://your-data-stories.eu/distributions/")
:on-path "distributions")
[mu-cl-resources]
Full JSONAPI from abstract description

52. Configurable services [mu-cl-resources]

53. Ember add-ons
> ember install ember-async-expanding-tree
{{async-expanding-tree model=topNode config=customConfig}}
config:
labelPropertyPath: 'label'
getChildren: (model) ->
children = Ember.ajax("/hierarchy/" +
"#{@get('hierarchyId')}" +
"/target/#{model.get('id')}")
showMaxChildren: 50
includeLeafs: true
hierarchy:
image: tf-esco/hierarchy:1.2.3
links:
- db:database
dispatcher:
…
links:
- hierarchy:hierarchy
match "/hierarchy/*path" do
Proxy.forward conn, path, "http://hierarchy/"
end
[hierarchy-service]

54. Ember add-ons [hierarchy-service]

55. What we learned

56. What we learned
- Extremely productive
- Code reuse
- Easy for juniors
- Customers like front-end
- Database performance is okayish
- Conscious playing with alternative solutions

57. About the future

58. Trigger microservices by changes in
semantic model.
Example:
- Compute KPIs when a new dataset is added
- Send email/tweet by writing it to the triplestore
Reactive programming

59. More performance
- ember-fastboot:
Faster first page render
- mu-cache:
Smart caching strategies
in core microservices
- mu-cl-resources:
Partial resource caching

60. More authority
Describe authorization outside the microservices:
- Simplify mental model
- Help in sharing content
- Open gate to advanced
applications
search for Jonathan Langens if you want to know more

61. More interactivity
Push cache updates to all visiting clients.
Almost no development time to create
basic interactive applications
(eg: updating KPIs, chat applications, …)

62. More links

63. Lego Time Star Wars: https://www.flickr.com/photos/eurobricks-starwars/5223334274/in/photolist-8XyXiu-7BJ9Xp-c2btBw-davQBK-
nAQJCC-9XVSZs-a3vVhy-vPZaHw-r6NB6c-4ajSXh-rX7ezA-BBhAWf-BiWDpc-rED79Q-rX7f8u-mtctqc-wtp245-fcNzVb-CgXNsA-D4Uxps-wKj5u9-rX7fVm-
rUWnBU-uhC54v-rXeB4g-zVknPq-qxEqXx-8GSCNc-nzg79j-biFNa6-9fXjwV-biFMTa-a1kbsX-5HnKDa-dQCdnW-a54g8X-bm9TRN-8zJUzU-fbGRan-sdr4hw-
e9DMFz-q3qQqf-aAZwyV- bm9Tsw-dQCdpb-sdpUWU-rkow4K-wazJmK-bz4Md8-pyU2QM Wendelstein 7X: http://www.sciencemag.org/news/2015/10/
bizarre-reactor-might-save- nuclear-fusion 300SL: https://www.flickr.com/photos/smfan/7181631212/in/photolist-bWBJKN-o52kEN-
5pCCRH-6NezBh-oF2nYm-gHtRrE-6KAHDv-cPKKj9-2aj2ur-s3A8ua-5pH14j-bQk48B-omejVV-q2tAx7-o8yCtS-nRauVz-5pCNWB-o525H4-o9dqig-sk2we8-
o4EApo-N2NDc-o7jxQM-5pCG4c-81DnQh-exNBvp-kc9m4-exS223-cm2nm5-aPXHgc-7Tg5XD-6HQ5Q9-6w1JtR-5pCGWi-eb6dJe-pJYFdi-azFSaU-p5y4mb-
6GjCy2-q2kGp6-o52baX-9XtXDc-4GqX86-pJXbk1-8canak-q2tu1j-6HQ6eo-sjZQkD-dhaPyf-bBqucA http://www.quickmeme.com/meme/3stqet Big Data
Europe: https://www.big-data-europe.eu/ Docker Logo: http://www.silicon.de/41608942/microsoft-optimiert-windows-server-2016-fuer-die-
cloud/ webCAT: https://github.com/tenforce/webcat Banksy Van: http://artcentron.com/2016/06/22/banksy-graffiti-art-swat-van-sale/
#prettyPhoto Banksy Bananas: https://www.touchofmodern.com/sales/banksy-8a9ea26d-040f-4435-ada1-86e7a6b4a05c/pulp-fiction-bananas
Your Data Stories platoform: http://platform.yourdatastories.eu/ Star Wars Clones box: https://www.flickr.com/photos/kalexanderson/
5410769283/in/photolist-9f8Bcz-5SJTDj-55MnH2-4WEfzr-in3p6t-drf7fp-3b46gb-bKfRW4-3aYzBt-4xztdx-35E11y-9jVQVR-9wuv3f-9r3mWe-9hNTVz-
7JzMxg-7JYZFM-Hw1QSq-8FW8eh-nVj9Sc-8ytJvH-aPPKYz-dYyYWK-7fhBFE-7GgZYm-e5M9jV-bwm6S9-7fhyGd-e5SNkL-5LDPWB-e5SNdf-4MKWht-e5SLrb-
5zPWDw-74Yjyb-8xh5Vr-9Apdwp-4XUn5j-jSHfRS-9fAZ86-eueiqp-e5SPwu-e5MbcZ-9tJQdd- 5f4rJT-9HsoqF-9hud4U-e5MaQX-52mMrQ-e5M9WX/ GitHub Logo:
https://blog.adafruit.com/2012/12/31/github-has-big-dreams-for- open-source-software-and-more/ Twitter Logo:
https://en.wikipedia.org/wiki/File:Twitter_bird_logo_2012.svg mu-ruby-template: https://github.com/mu-semtech/mu-ruby-template
mu-cl-resources: https://github.com/mu-semtech/mu-cl-resources mu-project: https://github.com/mu-semtech/mu-project
Resources used & interesting links

64. More questions
right now, or ask later

65. aad.versteden@gmail.com
aad.versteden@tenforce.com
madnificent
@impulsater
http://www.tenforce.com http://dacota.one http://mu.semte.ch
You can track me down
Aad Versteden