Semantic Web Applications: Past, Present and Future

Semantic Web Applications: Past, Present and Future

Oscar Corcho ([email protected])

Universidad Politécnica de Madrid

Florianópolis, August 31st 2010(OntoBras 2010)

Acknowledgements: Asunción Gómez-Pérez, Jesús Barrasa, Angel López Cima, Oscar Muñoz, Jose Angel Ramos Gargantilla, María del Carmen Suárez de Figueroa, Boris Villazón, Mariano Fernández López, Luis Vilches, Carlos Ruíz Moreno

Work distributed under the license Creative Commons Attribution-Noncommercial-Share Alike 3.0

Overview

• Coming to terms: The Web (1.0 and 2.0), the Semantic Web, the Web of Linked Data and all its applications• The Web (1.0 and 2.0)

• Web applications

• The Semantic Web (pre-SemanticWeb, SW1.0 and SW3.0)• Semantic Web Applications Or [Semantic | Web]+ Applications

• The Web of Linked Data• Linked Data Applications

• Semantic-based Applications• preSemanticWeb Applications

• Annotation

• Semantic Web 1.0 Applications• Annotation, Data Integration and Decision Support Systems

• Semantic Web 3.0 Applications• (Collaborative) Annotation and Data Integration

• Conclusions and Trends

Health and Safety Notice

ClassificationDisclaimer: This is not the only way that applications can be classified or grouped. In fact, many other possibilities exist for the classification of Semantic Web application.

Overview






• Annotation




The beginning: Web 1.0

WWWHTTPURI

From Web1.0 to Web2.0

More than30M pages

More than1000M users

WWWHTTP, HTML, URI

New requirements start arising• Cooperation• Dynamicity• Decentralised change• Heterogeneity• Multimedia content

Web2.0 basic sites and services

Web1.0 vs Web2.0

• Cooperation• Dynamicity• Decentralised change• Heterogeneity• Multimedia content

Web Applications

• Who doesn’t know what is a Web application?• Let’s define it

• A web application is an application that is accessed over a network such as the Internet or an intranet.

• The term may also mean a computer software application that is…

• … hosted in a browser-controlled environment (e.g. a Java applet)

• … or coded in a browser-supported language (such as JavaScript, combined with a browser-rendered markup language like HTML)

• … and reliant on a common web browser to render the application executable.

• Some comments• Too many technology-related terms in the definition

• No mentions to the evolution of user-generated content (Web1.0 Web2.0), although it is already well understood.

Overview






• Annotation




(Syntactic) Web Limitations

• A place where computers do the presentation (easy) and people do the linking and interpreting (hard).

• Why not get computers to do more of the hard work?

Resource

ResourceResource Resource Resource

ResourceResource Resource

Resource

Resource

hrefhrefhref

hrefhrefhref

hrefhrefhref

href href

href

What is the Semantic Web?

• An extension of the current Web…• … where information and services

are given well-defined and explicitly represented meaning, …

• … so that it can be shared and used by humans and machines, ...

• ... better enabling them to work in cooperation

• How? • Promoting information exchange

by tagging web content with machine processable descriptions of its meaning.

• And technologies and infrastructure to do this

Need to Add “Semantics”

• Agreement on the meaning of annotations• Shared understanding of a domain of interest• Formal and machine manipulable model of a domain of interest

• An ontology is an engineering artifact, which provides: • A vocabulary of terms• A set of explicit assumptions regarding the intended meaning of the

vocabulary. • Almost always including concepts and their classification• Almost always including properties between concepts

• Besides...• The meaning (semantics) of such terms is formally specified• New terms can be formed by combining existing ones• Can also specify relationships between terms in multiple ontologies

Ontology Languages

• A large amount of work on Semantic Web has concentrated on the definition of a collection or “stack” of languages.

• Used to support the representation and use of metadata• Basic machinery that we can use to represent the extra semantic

information needed for the Semantic Web

RDF(S)

Integrating information sources

Associating metadata to resources (bindings)

OWL

Integration

RDFS

RDF

XMLA

nnotation

Integration

Inference

Reasoning over the information we haveCould be light-weight (taxonomy)Could be heavy-weight (logic-style)

SWRL

The evolution of the Semantic Web

• Cooperation Dynamicity• Decentralised change• Heterogeneity Multimedia

Semantic Web 1.0 Semantic Web 3.0pre-Semantic Web

2004 2008

No standardised formatse.g., (KA)2

RDFS, OWL

Semantic WebChallenge

[Semantic | Web]+ Applications (I)

• No definition in Wikipedia… ;-(

• Why [Semantic | Web]+ application?

[Semantic | Web]+ Applications (II)

• Why [Semantic | Web]+ application?• Most of them are focused on the use of semantics

• In fact, probably it would be better to useSemantic [Web]* application

• However, many of them are not so Web-oriented• E.g., very common in data integration approaches

• http://www.readwriteweb.com/archives/10_semantic_apps_to_watch.php• A key element [of a Semantic Web App] is that the apps all

try to determine the meaning of text and other data, and then create connections for users. Besides, data portability and connectibility are keys to these new semantic apps - i.e. using the Web as platform.

Overview






• Annotation




What is the Web of Linked Data?

• An extension of the current Web…• … where information and services

are given well-defined and explicitly represented meaning, …

• … so that it can be shared and used by humans and machines, ...

• ... better enabling them to work in cooperation

• How? • Promoting information exchange by

tagging web content with machine processable descriptions of its meaning.

• And technologies and infrastructure to do this

• And clear principles on how to publish data

data

What is a Linked Data application

• Again, no definition yet

• Linked Data is a term used to describe a recommended best practice for exposing, sharing, and connecting pieces of data, information, and knowledge on the Semantic Web using URIs and RDF.

• So every element from the definition of SW application applies

Overview






• Annotation




The Web

Semantic Webs

The web

Metadata <RDF triple><RDF triple><RDF triple><RDF triple><RDF triple><RDF triple><RDF triple>

<RDF triple><RDF triple><RDF triple><RDF triple><RDF triple><RDF triple><RDF triple>


Ontologies

The Web of Data

The Web of Data

Resources

Metadata




AlignmentsAlignmentsOnto. - SchemaOnto. - SchemaData SourcesData Sources

Ontologies

Overview






• Annotation




Annotation-focused applications: key characteristics

• Available at all stages (pre-Semantic Web, SW1.0 and SW3.0), although predominantly in the early ones

• Single (usually small) ontologies, many of them built manually

• Centralised ontologies• Instances stored in a centralised manner, together

with the ontologies, or in separate files/DBs• Low heterogeneity and relatively small scale• Homogeneous quality in data

Annotation in the pre-Semantic Web

• (KA)2

O1

O2

Oi

Oj

Portal AdministratorsOntologies and Software

Extranet Users

Agents

Permission-based

Semantic Driven

User Oriented

External resources

Semantic Web Portals

Extranet view

Content Edition

Workpackage

Deliverable

has associated

has Q.A. partneris generated by

Organization

Semantic-based Visualisation

Extranet View (RDF lives behind)

Overview






• Annotation




Data integration applications: key characteristics

• Available at later stages (SW1.0 and SW3.0). • Still single (usually small) ontologies, many of them

built manually• Although sometimes mappings between local and global

ontologies

• Still centralised ontologies• Instances live in distributed DBs, with a focus on run-

time queries, although also data warehousing approach

• Medium heterogeneity and medium scale• Heterogeneous quality in data

Migrating IGN (Instituto Geográfico Nacional) sources

38

NC NGN

BCN200 BCN25

Query:¿Edif. Religioso

de Soria?

Response:Catedral SoriaIg. Sto. TomásCatedral Soria

Ermita N.S. NievesCatedral SoriaSoria

Cated.Ig. Sto.

Cated.

Soria

Soria

Cated.

NS NievesEdif. Religioso

Construcción Rel.

Catedral

Ermita

IGN Catalogue Integration: Exploitation of Mappings

Slide 40

UN FAO Example

Alignments between ontologies and the DB

Land areas

Fishingareas

Biologicalentities

Fisheriescommodities

Vessel typesand size

Geartypes

R2ODocument

R2ODocument

R2ODocument

R2ODocument

R2ODocument

R2ODocument

FAOFIGIS DB

http://www.fao.org/aims/aos/fi/

Overview






• Annotation




Decision support applications: key characteristics

• Again, available at later stages (SW1.0 and SW3.0). • Still predominantly single (usually small) ontologies,

many of them built manually• But mostly heavyweight (they are the ones taking decisions)• Heavy use of logic

• Still centralised ontologies• Instances may live together with the ontologies, in

distributed DBs, or in separate RDF files/triplestores. • Annotation phases are common

• Medium heterogeneity and low/medium scale• Heterogeneous quality in data

Satellite Image Processing

SpaceSegment

Ground Segment

DMOP files

Product files

SATELLITE FILES:

Comparison between planning and product generation

...Instr#n(RA_2)planning

DMOP_File#n(StartTime) DMOP_File#n(StopTime)

DMOP_File#(n+1)StartTime

DMOP#(n+1)_File(StopTime)

DMOP_er (ORBIT_NUMBER,ELAPSED_TIME)

Instr#1planning

DURATION

PRODUCT_FILEStart_time(SENSING_START)

PRODUCT_FILEStop_time(SENSING_STOP)

...

Instr#n(RA_2)ProductGeneration

RA2_CAL_1PStop_time(SENSING_STOP)

RA2_CAL_1PStart_time(SENSING_START)

PRODUCT_data_gap... ...

Generating files in RDFFILE ; DMOP (generated by FOS Mission Planning System) RECORD fhr FILENAME="DMOP_SOF__VFOS20060124_103709_00000000_00001215_20060131_014048_20060202_035846.N1" DESTINATION="PDCC" PHASE_START=2 CYCLE_START=44 REL_START_ORBIT=404 ABS_START_ORBIT=20498

ENDRECORD fhr................................ RECORD dmop_er RECORD dmop_er_gen_part RECORD gen_event_params

EVENT_TYPE=RA2_MEA EVENT_ID="RA2_MEA_00000000002063" NB_EVENT_PR1=1 NB_EVENT_PR3=0 ORBIT_NUMBER=20521 ELAPSED_TIME=623635 DURATION=41627862 ENDRECORD gen_event_params ENDRECORD dmop_erENDLIST all_dmop_erENDFILE

RECORD ID

RECORD parameters

RECORD parameters corresponding to other

RECORD structure.

<?xml version='1.0' encoding='ISO-8859-1'?><rdf:RDF xmlns:rdf='http://www.w3.org/1999/02/22-rdf-syntax-ns#' xmlns:rdfs='http://www.w3.org/2000/01/rdf-schema#' xmlns:NS0='http://protege.stanford.edu/kb#' > <rdf:Description rdf:about='http://protege.stanford.edu/kb#10822'> <rdf:type rdf:resource='http://protege.stanford.edu/kb#Instrument_mode'/> <NS0:instrument_mode_id>MS</NS0:instrument_mode_id> </rdf:Description> <rdf:Description rdf:about='http://protege.stanford.edu/kb#11224'> <rdf:type rdf:resource='http://protege.stanford.edu/kb#DMOP_ER'/> <NS0:event_id>"GOM_OCC_00000000541299"</NS0:event_id> <NS0:duration rdf:datatype='http://www.w3.org/2001/XMLSchema#int'>53000</NS0:duration> <NS0:orbit_number rdf:datatype='http://www.w3.org/2001/XMLSchema#int'>20552</NS0:orbit_number> <NS0:elapsed_time rdf:datatype='http://www.w3.org/2001/XMLSchema#int'>2452293</NS0:elapsed_time> <NS0:event_type rdf:resource='http://protege.stanford.edu/kb#10713'/> </rdf:Description>

The planningfiles



The productfiles

1 reference ontology for annotating all filesRDF files are distributed

DistributedMetadata for Planning files

DistributedMetadata for Product files

1 Ontology

Satellite Use Case (System Infrastructure): S-OGSA Scenario

48

WS-DAIOnt

SatelliteDomain Ontology

Grid-KP

XML SummaryFile

Annotationfront-end

Atlas

MetadataQueryService

QUARC-SG client JSP

3

4

6

1

1

3

Annotate file

Obtain ontology

Create

Query

Input criteria

Select files to be annotated

Metadata generation processMetadata querying process

RDF

RDF

RDF

RDF

Planning fileserverGermany

Product fileserver

ItalyGT4GT4

File directorySpain

1a Get file names

Get file summaries2

ONTO-DSI ONTO-DSI

WebDAV

5RDF File Upload

SemanticBinding Service

7Store

2’ Upload XML Summary file

OverlapCheckingService

8Store (start-time, stop-time, gen-time, EPR)

8

Notify (start-time, stop-

time)

9

Destroy (if needed)

Fraud detection in car insurance

Fraud Diagnosis

Overview






• Annotation




Collaborative SW applications: key characteristics

• Fully-fledged in the last stage (SW3.0). • Networks of heterogeneous ontologies

• Some of them built manual, some automatically• Some of the lightweight and some others heavyweight

(although normally not used in a heavyweight form)• Dynamic finding of ontologies and terms

• Decentralised ontologies (available in URLs or search engines)

• Distributed instances living anywhere• Annotation and integration phases are common

• Instances are created by users• Large heterogeneity (in domains, quality, provenance, forms

– RDF, tags, etc. -, etc.)• Large scale

GeoBuddies: A pilgrim in St. James’ Way

• Diverse routes for pilgrims

• Self-emergent community of pilgrims• People that talk about their experiences during the

way

• People that join together in the joy of walking

• Mobile users

• People want to• Find interesting locations

• Find community services

• Provide information

GeoBuddies: architecture and main themes

• Agile methods for Web2.0 data integration• Facebook

• Flickr

• …

• Mobile applications exploiting user generated content

• Evolution of folksonomies and ontologies

Servidor de anotaciones

El usuario ve un punto de interés y envía una foto

con sus correspondientes anotaciones

walk sun tired

cathedralhuge

peaceful

Las anotacionesse guardan y los

objetos se consolidancon bases de datos geográficas

y anotaciones existentes

BBDD geográficas

Motor de recomendaciones(geográfico + tags + ontologías)

Servidor de anotaciones

(todos los usuarios)

Servidor de ontologías

mezcla

El usuario quiere saberqué puntos de interés le

pueden interesar en la zonaen la que se encuentra

Motor de recomendaciones(sólo geográfico)

Camino Personalizado

Catalogue Integration in the Geographical domain

• Monolingual Knowledge bases of IGN (spanish):

• NC (Nomenclátor Conciso), • NGN (Nomenclátor Geográfico Nacional), • BCN200 (Base Cartográfica Nacional

escala 1:200.000),• BCN25 (Base Cartográfica Nacional

escala 1:25.000)

• Monolingual Knowledge bases of CC.AA. (spanish, basque, galician): Castilla y León, Cataluña, Euskadi, Extremadura, Galicia, La Rioja, Madrid, Murcia, Navarra.

• Creation of an ontology from IGN resources and creation of mappings with IGN knowledge bases

Geobuddies Networks of Ontologies

• Generation of the Phenomen ontology from IGN catalogues using linguistic analysis

• Art ontologies, Building ontologies and artistic styles built from standardized resources

• Community building ontologies built from Web resources

• Instances are distributed and kept in their original sources

• Alignments between ontologies and resources are first class citizens

OrganizationOntology

Art

PersonalizationOntology

BuildingsOntology

Artistic Styles

Community Services

GeographicalOnt.

Core

NC NGN

BCN200 BCN25

Query:¿Edif. Religioso

de Soria?

Response:Catedral SoriaIg. Sto. TomásCatedral Soria

Ermita N.S. NievesCatedral SoriaSoria

Cated.Ig. Sto.

Cated.

Soria

Soria

Cated.

NS NievesEdif. Religioso

Construcción Rel.

Catedral

Ermita

IGN Catalogue Integration: Exploitation of Mappings

Users request information using their own tags-The system provides hints about commonly used tags on a predictive style (like SMSs)-Collaborative filtering techniques can be used to recommend the most closely-related tags-Requests can be extended with ontology-based annotations

When folksonomies meet ontologies

Overview






• Annotation




Reflections: which are the characteristics of these applications in terms of…?

• Ontologies• Single versus network of ontologies?

• Are ontologies built from scratch or reusing knowledge-aware resources?

• Are mappings used for solving conceptual mistmaches?

• Instances• Where are the data/instances?

• Instances are in the ontology• Instances are in independent RDF files or databases• Data are kept in the original sources

• Are instances distributed or centralized?

• Have instances a very high rate of changes?

• Heterogeneous provenance of instances

• Degrees of data quality

• Permissions

Where are the instances?

or

Reflections: which are the characteristics of these applications in terms of…?

• Amount of semantic markup• Conceptual Heterogeneity (semantic markup based

on different ontologies)• Interoperability with other semantic resources• Open to Web resources• Open to Web services• Web 2.0 like• Mobile devices• Geo-spatial information

ConclusionsWe are moving into a new generation of semantic

applications • Open to web resources• Open to semantic resources and Linked Data• Open to the physical world and having an impact on it.

• (I have not talked too much about this: check at http://www.semsorgrid4env.eu/)

where …data integration at large scale and user-generated annotations are some of the main challenges that are being faced

and... everything combined with 1. Social communities2. Mobile devices3. Ubiquitous computing

Semantic Web Applications: Past, Present and Future

Oscar Corcho ([email protected])

Universidad Politécnica de Madrid

Florianópolis, August 31st 2010

Acknowledgements: Asunción Gómez-Pérez, Jesús Barrasa, Angel López Cima, Oscar Muñoz, Jose Angel Ramos Gargantilla, María del Carmen Suárez de Figueroa, Boris Villazón, Mariano Fernández López, Luis Vilches, Carlos Ruíz Moreno

Work distributed under the license Creative Commons Attribution-Noncommercial-Share Alike 3.0

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Semantic Web Applications: Past, Present and Future