© Copyright 2007 STI - INTERNATIONAL www.sti2.org

An Introduction to The Semantic Web: a knowledge

modelling perspective John Domingue

President STI International

www.sti2.org

Caveat

•  Not an historical overview •  Singular perspective of some underlying

motivations and issues related to the Semantic Web

www.sti2.org

MOTIVATION & APPLICATION SCENARIO

www.sti2.org

Agenda

•  Building K-HAL v1.0 –  Influences –  Ontology –  Conceptualisation –  Knowledgebase –  Critique

•  Building K-HAL v2.0 –  Ontologies –  Data –  Getting help

•  Building K-HAL v3.0 •  Conclusions

www.sti2.org

BUILDING K-HAL V1.0

Spacecraft piloting and navigation only – the reasoning and knowledge parts

5/12/2007 - Vienna

www.sti2.org

INFLUENCES

www.sti2.org

8/59

Cognitive Psychology

www.sti2.org

9/59

Semantic Network Collins and Quillian 1967

www.sti2.org

10/59

Knowledge Level (Allen Newell, 1982)

Knowledge Level

Symbol Level

Physical Level

.

.

.

.

.

www.sti2.org

11/59

Knowledge Level

Symbol Level

Physical Level

.

.

.

.

.

Knowledge

Goals

Principle of Rationality

Agent

Observer

Knowledge Level (Allen Newell, 1982)

www.sti2.org

ONTOLOGY

www.sti2.org

Informal Ontology Explanation

•  Used to structure knowledge •  Facilitates interoperability •  Formal explicit shared

conceptualisation of a domain •  A set of concepts, relationships

and individuals over which there is an agreed consensus

www.sti2.org

14/59

Ontology Construction

www.sti2.org

CONCEPTUALISATION

www.sti2.org

16/59

Let’s talk to some smart people…

www.sti2.org

17/59

Conceptualisation

www.sti2.org

18/59

Conceptualisation

1 3

5

7 9

2

4 6

8

www.sti2.org

19/59

Re-conceptualisaiton

5

2

4 6

8 1

7

3

9

www.sti2.org

20/59

Re-conceptualisaiton

5

2

4 6

8 1

7

3

9

www.sti2.org

21/59

Re-conceptualisaiton

5

2

4 6

8 1

7

3

9

www.sti2.org

22/59

Re-conceptualisaiton

5

2

4 6

8 1

7

3

9

www.sti2.org

23/59

Re-conceptualisaiton

5

2

4 6

8 1

7

3

9

www.sti2.org

24/59

Re-conceptualisaiton

5

2

4 6

8 1

7

3

9

www.sti2.org

25/59

Re-conceptualisaiton

5

2

4 6

8 1

7

3

9

www.sti2.org

26/59

Re-conceptualisaiton

5

2

4 6

8 1

7

3

9

www.sti2.org

27/59

K-HAL v 1.0 Ontology (small portion)

Space Ship

Has Component

Rocket Generates Thrust

Concepts Relations

Star

Engineered Artifact

Celestial Body

Planet Asteroid

Crew

Human Crew

Onboard AI

Agent

Has Name

Has Mass

Has Volume

www.sti2.org

K-HAL V1.0 KNOWLEDGE BASE

www.sti2.org

29/59

K-HAL v 1.0 Ontology (small portion)

Space Ship

Has Component

Rocket Generates Thrust

Concepts Relations

Star

Engineered Artifact

Celestial Body

Planet Asteroid

Crew

Human Crew

Onboard AI

Agent

Has Name

Has Mass

Has Volume

www.sti2.org

30/59

K-HAL v 1.0 Ontology/KB (small portion)

Space Ship

Has Component

Rocket Generates Thrust

Concepts Relations

Star

Engineered Artifact

Celestial Body

Planet Asteroid

Crew

Human Crew

Onboard AI

Agent

Has Name

Has Mass

Has Volume

HAL

Dave Boorman

The Sun Jupiter

www.sti2.org

31/59

Knowledge Base

www.sti2.org

32/59

CYC Open CYC v 4.0 239,000 concepts and 2,093,000 facts

www.sti2.org

33/59

K-HAL v 1.0

Ontology

Knowledge Base

Input/Output Vision system

Speech Generation Speech Understanding

User Reasoner

www.sti2.org

What’s wrong with K-HAL v 1.0?

•  ????

www.sti2.org

BUILDING K-HAL V2.0

5/12/2007 - Vienna

www.sti2.org

36/59

Underlying Principles

Be Lazy

Be kind and share

www.sti2.org

K-HAL V2.0 ONTOLOGIES

www.sti2.org

38/59

Why work when you can Google?

www.sti2.org

39/59

DBpedia

www.sti2.org

41/59

Astronomical Objects

www.sti2.org

42/59

Astronomical Ontology (portion)

www.sti2.org

43/59

Space Shuttle Ontology

Aft-Fusulage Air-Sampling-System Airlock Auxilliar-Power-Unit Avionics-System Body-Flap Caution-And-Warning-System Communication Crew-Apparel Crew-Compartment Crew-Equipment Crew-Equipment-Stowage Eletrical-Power-Distribution Eletrical-Power-System Emergency-Egress-Slide Environmental-Control-and-Life-Support-System Exercise-Equipment External-Tank External-Tank-Hardware Food-System-and-Dining Forward-Fuselage Hold-Down-Post Housekeeping Hydaraulic-System Hydarulic-Power-Units

Inflyght-Crew-Escape-System Intertank Landing-Gear-System Liquid-Hydrogen-Tank Liquid-Oxygen-Tank Main-Propulsion-System Microcassete-Recorder Midfuselage Operational-Bioinstrumentation-System Orbial-Manuevering-System Orbital-Maneuvering-System Orbiter-External-Tank-Seperation-System Orbiter-Flight-Crew-Escape-System Orbiter-Passive-Contro-Systeml Orbiter-Purge-Vent-Drain-System Orbiter-Structure OrbiterManufacturingandAssembly Payload-Bay-Doors Personal-Hygiene-Provision Photographic-Equipment Radiation-Equipement Range-Safety-Siystem Range-Safety-Siystem-Tank Reach-Aid Reaction-Control-System Restraints-And-Mobility-Aids

RSB-Descent-and-Recovery Secondary-Emergency-Egress Shuttle Shuttle-Orbiter-Medical-System ShuttleName Sighiting-Aids Sleeping-Provision Solid-Roket-Boosters Sound-Level-Meter Space-Shuttle-Coordinate-System Space-Shuttle-Orbiter-System Space-Transportation-System SRB-Ignition SRB-Rate-Gyro-Assemblies SRB-Separation Thermal-Protection-System Thermal-Protection-System-Orbiter Thrust-Vector-Control Vertical-Tail Water-Spray-Boilers Wicket-Tabs Windows Wing

www.sti2.org

Problems to be resolved (ontology)

•  Finding ontologies •  Understanding ontologies •  Connecting ontologies •  Adapting ontologies •  Version control •  Agility

–  New ontologies, changes in used ontologies …

•  …….

www.sti2.org

45/59

Building and Using Ontologies

Elena Simperl Tutorial 10:45am Tuesday

www.sti2.org

K-HAL V2.0 DATA

Be Lazy

www.sti2.org

47/59

Solar Objects > 400km Radius

www.sti2.org

48/59

www.sti2.org

49/59

Spacecraft component data

www.sti2.org

Problems to be resolved

•  Finding semantic data •  Transforming unstructured data to a semantic

format •  Transforming structured data to a semantic format •  Connecting semantic datasets •  Querying/reasoning over connected semantic data •  Sharing new data •  Agility

–  New datasets, changes in used datasets…

www.sti2.org

Linked Data Basics

•  Fundamentals of Linked Data: main standards & technology components, motivating application scenario –  Barry Norton Tutorial 10:45am today

•  Querying Linked Data: SPARQL 101 –  Irini Fundulaki Tutorial 2pm today

•  Semantic Web languages and standards: RDF, RDFS, SPARQL –  Barry Norton & Irini Fundulaki Hands-on: 3:30pm today

www.sti2.org

Publishing and Using Linked Data

•  Providing and consuming Linked Data –  Maribel Acosta Tutorial 2:30pm Tuesday

•  Publishing and consuming Linked Open Data –  Maribel Acosta Hands-on 4pm Tuesday

www.sti2.org

Linked Data and the Unstructured World

•  Linked Data for NLP –  Barry Norton Tutorial Wednesday 10:45am

•  Using Linked Data and GATE –  Barry Norton & Isabelle Augenstein Wednesday 11:30am

www.sti2.org

54/59

Getting everybody to help…

*picture suggested by Dan Brickley

www.sti2.org

55/59

GalaxyZoo

www.sti2.org

56/59

More Zoos

www.sti2.org

57/59

Crowdsourcing AI

www.sti2.org

Getting help tutorials and hands-on

•  Social Semantic Web and crowdsourcing –  Elena Simperl Tutorial Wednesday 2pm

•  Using Mechanical Turk to solve Linked Data problems –  Maribel Acosta Hands-on Wednesday 3pm

www.sti2.org

59/59

K-HAL v 1.0

Ontology

Knowledge Base

Input/Output Vision system

Speech Generation Speech Understanding

User Reasoner

www.sti2.org

60/59

K-HAL v 2.0 Architecture

Linked Open Vocabularies

Linked Open Data

HAL Ontology

HAL Facts in RDF Store

Reasoner

Input/Output Vision system

Speech Generation Speech Understanding

Crowdsourced facts

Corporate data

www.sti2.org

BUILDING K-HAL V3.0 What about processes?

5/12/2007 - Vienna

www.sti2.org

www.sti2.org

63/59

Virtual Choir

www.sti2.org

64/59

Choir Autonomous singers Available online

www.sti2.org

65/59

Conductor Dictates song Common notation Selects performances Edits and mixes

Choir Autonomous singers Available online

www.sti2.org

66/59

Listener Has a desire Has preferences

Conductor Dictates song Common notation Selects performances Edits and mixes

Choir Autonomous singers Available online

www.sti2.org

67/59

www.sti2.org

Conclusions (1/2)

In its current state the Semantic Web/Web of Data facilitates the re-use of ontologies and data •  Other problems arise associated with

ontology and data quality, adapting/aligning ontologies and data …

•  Good SW/LD practitioners know online ontologies and datasets as a good researcher knows the related literature

Be Lazy

www.sti2.org

Conclusions (2/2)

Releasing ontologies and data •  Provides a community benefit for

expected and unexpected uses •  Can increase the value of the released

artifacts •  May be obligated depending on context

(e.g. if paid for by public funding) •  Has associated issues related to

training, quality, privacy, maintenance….

Be kind and share

www.sti2.org

THANKS