Presented in occasion of the 43° Nexa Lunch Seminar (Politecnico di Torino). More information available at: http://nexa.polito.it/mercoledi-43.

1. Big Data e tecnologie semantiche -
Utilizzare i Linked Data come driver
d'integrazione di dati
Giuseppe Futia
Nexa Center for Internet and Society, Politecnico di Torino
(DAUIN)
27 July 2016

2. Outline
• Information management challenges and Big Data
• Linked Data framework (explained with examples)
• Linked Data approach for Big Data community
• The impact of Big Structured Data

3. Enterprise/Research Information
Management Challenges
• Disparate data sources and data silos
• Data sources with similar/inconsistent information
• Most of the knowledge is hidden in texts (unstructured data)
• Difficult to integrate and analyse structured and unstructured
data

4. The 3 V’s of Big Data
• Velocity
• Volume
• Variety

5. The 3 V’s of Big Data
• Velocity
• Volume
• Variety (Veracity and Value)

6. From Big Linked Data to
Linked Big Data

7. Big Linked Data

8. Linked Data Cloud Diagram
(2014)
Big Linked Data

9. Linked Data Vision (W3C)
• Extend principles of the Web from documents to data
• Data should be accessed using the general Web architecture
(e.g., URIs, HTTP, …)
• Data should be linked each other just as documents
• Creation of a common framework that allows:
– Data to be shared and reused across applications
– Data to be processed automatically
– New relationships between pieces of data to be
inferred

10. Resource Description Framework
• Everything is a triple – Subject (resource), Predicate
(relation), Object (resource or literal)
•The Resource Description Framework (RDF) graph is a
collection of triples predicate subject object

11. SPARQL
11
• SQL-like query language for RDF data
• Simple protocol for querying remote databases over
HTTP
• Query types
– select: query data by complex graph pattern
– ask: whether a query returns results (result is true/false)
– describe: returns all triples about a particular resource
– construct: create new triples based on query results

12. Nexa projects

13. Contratti pubblici

14. Le PEC dei comuni italiani con
più di 100 mila abitanti che
pubblicano contratti con
anomalie

15. ?

26. TellMeFirst
A Knowledge Discovery Application

27. TellMeFirst Architecture http://tellmefirst.polito.it

28. “The final work of legendary director Stanley Kubrick, who died
within a week of completing the edit, is based upon a novel by
Arthur Schnitzler. Tom Cruise and Nicole Kidman play William and
Alice Harford, a physician and a gallery manager who are wealthy,
successful, and travel in a sophisticated social circle.”

30. Linked Big Data

31. Linked Data approach adopted by
the Big Data community
• RDF data model for Variety
– Flexible, easy to evolve data model
– Efficiently integrate structured and unstructured data
• Enrich Big Data with metadata and semantics
–More powerful analytics on top of it
–Discover implicit links and relationships
• Interlink Big Data sets
–Information interchange across a value chain

32. Semantic technologies for Big Data

33. Blazegraph and DASL
• Blazegraph is a high performance graph database platform
that supports RDF/SPARQL APIs
• In 2016 Blazegraph introduced a programming environment
called DASL
• DASL supports the development of graph algorithms within
the Apache Spark ecosystem specifically optimised for GPUs
• Complex graph analytic environments, especially where
relationships are unknown in advance

34. EP-SPARQL
• Event processing provides on-the-fly analysis of event
streams, but cannot combine streams with background
knowledge and cannot performing reasoning tasks
• Semantic tools can effectively handle background
knowledge and perform reasoning tasks, but cannot deal
with rapidly changing data provided by event streams
• Event Processing SPARQL (EP-SPARQL) as a new language for
complex event and stream reasoning

35. The impact of Big Structured Data

36. Google Knowledge Graph
Freebase-to-Wikidata
transition

37. Facebook’s Social Graph
(in 2013)
The Graph API is the primary
way to get (our) data in and out
of Facebook's social graph

38. Facebook Web is progressively
smarter than the Web of data…

39. Open source, libre contents, and
linked data as a framework to build
an open linked big data graph

40. Grazie!
Mail
giuseppe.futia@polito.it
Repository GitHub
https://github.com/giuseppefutia/