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© Fraunhofer IPSI

Semantic Web Application Models

Invited Talk at the ER 2003 - 22nd International Conference on ConceptualModeling, Chicago, Illinois13-16 October, 2003

Erich NeuholdClaudia Niederée

Michael FuchsFraunhofer Institute IPSI

Darmstadt Germanyhttp://ipsi.fhg.de



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Content

Trends for the next generation of theWeb

• Web Services

• The Semantic Web

Challenges for Web applications inthe NextGeneration of the WWW

Semantic Web Application Models and

related Standards

Operationalization: A Semantic WebApplication Development Framework

Open Issues



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The Next Generation of the Web

Central trends for the next Generation of the World Wide Web

The Web as “Programming

Interface”:Web Service Paradigm

Semantic Enrichment for animproved information and servicemediation: Semantic Web



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Semantic Web - Vision

Calendar

…

Preferences

…

User

Information and ServiceProvider

Ratings,Signatures,

Certificates

„Trust“-Services

S+

Agents

Request/Task

Communication, Negotiation,Planning, Decisions, Proofs

Semanticallyenrichedinformation

Interpretation

Interpretation

Interpretation

S+

S+

S+

S+

S+

Interpretation

S+

Calendar

Preferences



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The Web Services Architecture

Servicecomponent

SOAP*wrapping

Service

Registry

UDDI*

1. register

Service clientService provider

2. locate service in the Web

4. call, exploit

WSDL*descriptio

n

Application

3. compose,orchestrate

Web Services support the flexible and dynamicconfiguration of IT and service infrastructures

*SOAP = Simple Object Access Protocol*WSDL = Web Service Description Language*UDDI = Universal Description, Discovery and Integration



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Challenges for Web Applications

For effective operation in the Semantic Web, Webapplicationshave to

move from a purely human user community of theWWW towards a mixed user community (humans as

well as software agents);support information to enable automatic

interpretation of delivered Web page content;(interlinking local data and content with globallydefined interpretation schemes like vocabularies and

ontologies);

Exploitation of Web service paradigm for flexiblecomposition of Web Applications; General Challenges

Service Discovery

Service Composition




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Application Layer

WebClient(HTML)

Challenges for Web Applications

User Interface Layer

JSP*, ASP*, …

ODBC*, JDBC*, …

What?How?

Software Agent

not nodel-based,

semi-structured document (HTML),butwithout explicit Schemata

*JDBC/ODBC = Java/Open Database Connectivit*JSP/ASP = Java/Active Sever Pages




HTML-based UI Dialog Models -Shortcomingsno (or little) client side validation

restricted client side interaction

restricted control of submitted data

strong bias towards one userinterface agent (Web Browser)

static form composition

HTML has not to be "well formed"

(not parseable)mixed layout and structure

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Application Layer


Software Agent




HTML – Properties andShortcomings

<html>

<BODY bgcolor=yellow>

<form action=followUpPage.cgi><p>

<CENTER><h2><font color=red>Travel Tours </h2></font>

<P><img src="palm.gif"></p>

<font face=Arial size="2"> Please enter the <br><i><b> start date </i></b> <br> of your

Journey in the following field

<br> > <input type=text name='start'><br>

and the <br><i><b> end date </i></b><BR> here <br>

> <input type="input" name='end'> <BR> After filling the

form please press <br>

<p><input type='submit' value="submit"></P>

</FORM>

</Body>

</Html>




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Application Layer

Semantic Web Applications Models (1)

Conceptual User Interface Model

Web User Interface Agent Interface

Conceptual UI Model


Software Agent

What?

How?What?

How

WebClient(HTML)




Requirements for Conceptual UIModel

conceptual model for form-based User Interfacesrequires

design of forms on a more abstract level independence of specific user interface agents

rich set of UI component types

more powerful client-side interaction model

dynamic client side behavior

Operationalization

processors for different user interface agents comfortable editors for form authoring

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Application Layer


Software Agent




Conceptual UI Model - XForms

XForms - the next generation of form-based userinterfaces:

design of forms on a more abstract level independence of specific user interface agents

rich set of UI component types

more powerful client-side interaction model

dynamic client side behavior (e.g. add newfields or exchange form blocks while using the

form)

Operationalization (not supported by XForms)

processors for different user interface agents

comfortable editors for form authoring

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Application Layer


Software Agent




XForms Example –SCHOLNETProject (1) <SearchForm>

...

<fields><field name="dc:creator" type="string"><rel-ops selected="equal">

<rel-op name="equal" symbol="" position="infix"/...</rel-ops> ...

</fields> ...</SearchForm><xforms:repeat nodeset="SearchForm/fields/field"/>

<xforms:select1 ref="field-operators/@selected"><xforms:itemset nodeset="field-operators/field-

operator"><xforms:caption ref="@name"/><xforms:value

ref ="@name"/></xforms:itemset>

</xforms:select1> <xforms:button value="Add" onclick="new:rptName"/>

<xforms:button value="Delete" onclick="delete:rptName"/><xforms:group nodeset="rel-ops"/>

<xforms:select1 ref="@selected" appearance="min"><xforms:itemset nodeset="rel-op">

<xforms:caption ref="@name"/><xforms:value ref="@name"/>

</xforms:itemset></xforms:select1>

Instance of

Data Model

Conceptual

User Interface Model




XForms Example –SCHOLNETProject <SearchForm>

...

<fields><field name="dc:creator" type="string"><rel-ops selected="equal">



<xforms:select1 ref="field-operators/@selected"><xforms:itemset nodeset="field-operators/field-

operator"><xforms:caption ref="@name"/><xforms:value

ref ="@name"/></xforms:itemset>

</xforms:select1> <xforms:button value="Add" onclick="new:rptName"/>








XForms Example – SCHOLNETProject

<SearchForm> ...<fields>

<field name="dc:creator" type="string"><rel-ops selected="equal">



<xforms:select1 ref="field-operators/@selected"><xforms:itemset nodeset="field-operators/field-operator">

<xforms:caption ref="@name"/><xforms:valueref ="@name"/>

</xforms:itemset>

</xforms:select1> <xforms:button value="Add" onclick="new:rptName"/




</xforms:itemset></xforms:select1><xforms:input ref="value"/>[<xforms:output











</xforms:itemset></xforms:select1><xforms:button value="Add" onclick="new:rptName"/><xforms:button value="Delete" onclick="delete:rptName"/>

<xforms:group nodeset="rel-ops"/><xforms:select1 ref="@selected" appearance="min"<xforms:itemset nodeset="rel-op">













</xforms:itemset>

</xforms:select1><xforms:button value="Add" onclick="new:rptName"/><xforms:button value="Delete" onclick="delete:rptName"/><xforms:group nodeset="rel-ops"/>

<xforms:select1 ref="@selected" appearance="min"<xforms:itemset nodeset="rel-op">













</xforms:itemset>

</xforms:select1><xforms:button value="Add" onclick="new:rptName"/><xforms:button value="Delete" onclick="delete:rptName"/><xforms:group nodeset="rel-ops"/>




<xforms:input ref="value"/>[<xforms:output




How to use XForms?

Edit XForms Model

(Form Dialog Manager)

MapXForms Model

Data Model(VizCo *)

TransformXForm Model

Client Interface

FormsPLayer © x-por

hs, Niederée, Hemmje, Neuhold,pporting Model-based Construction of Semantic-enabled Web Applications ”,ppear in Proceedings of the 4th International Conference on Web Information Systems Engineering (

e, December 2003

Run timeDesign time




Use of Models for User InterfaceCreation

J. Eisenstein, J. Vanderdonckt, A. Puerta

Applying Model-Based Techniques to the Development of UIs for Mobile Comp(2001)

Intelligent User Interfaces




What How

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Semantic Web Application Models (2)

Semantic Domain Model



Application Layer

Conceptual UI Model


Flight Departure

Flight Departure

Flight Departure

Flight Departure

Ontology

Software Agent

What?How

WebClient(HTML)




Requirements for SemanticDomain Model

Support of modeling primitives

Flexible definition of relationships to globalconceptual models

Representation of concept hierarchies Systematic support of data types

Representation of additional domainknowledge and constraints

Consistent support of domain/ontology

evolution

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Application Layer


Software Agent




Conceptual Modeling in SoftwareDesign

Example: UnifiedModeling Language(UML*)

Travel

BusTravel TrainTravel

DirectFlight CompositeFlight

PlaneTravel

City

name : String

Flight

number : String

0..*

1

0..*

1start

0..*

0..*0..*

0..*

destination

contains

*UML Specification, Object Managent Group (OMG),

see http://www.omg.org/technology/documents/formal/uml.htm




Fulfillment of Requirements - UML


• Definition of entities (class centric approach)

• Definition of relationships (association, aggregation,composition)

• Properties of relationships (multiplicities, association +role names, association classes)

Flexible definition of relationships to global conceptualmodels

• not supported

Representation of concept hierarchies

• subclass relationship

Systematic support of data types• imported from DB Schema or Programming Language

Representation of additional domain knowledge andconstraints

• in textual form

Domain/Ontology evolution

• not supported

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Application Layer


Software Agent




Conceptual Modeling in the Semantic Web –RDF & Co

The Resource Description Framework (RDF + RDFSchema):

Defines a framework for structuring anddescribing resources in the Semantic Web

Enables the definition of vocabularies for thedescription of resources in an applicationdomain;

Goals:

Extensibility, interoperability, and reuse of vocabularies;

Improved support for interpretation of data bymachines

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Application Layer


Software Agent




Resource Description Framework –Example

RDF Schema

RDF

travel:City

travel:destination

travel:Flight

travel:contains

travel:PlaneTravel

MyTravel

travel:TrainTraveltravel:BusTravel

travel:Travel

ThisFlight

Rome

r d f s : r a n g e

contains

r df s

: d o

m a

i n

r d f s : s u b

C l a

s s O f

r d f s

: s u

b C l a

s s

O f

r d f s : s u b C l a s s O f

r d f s : r a

n g

e

r d

f :

t y p

e

r d f : t y p

e

r d f s

: d o m

a i n

rdf:Property

r d f : t

y p e

rdfs:Class

r d f : t y p e

r d

f : ty

p e

rdf:Resource

r d f s : s u b C

la s s O f

r d f s :

s u b C

l a s s O

f

LH27

d e s t i

n a t i o

nf l i g

h t N

o

travel:flightNo

rdf:Literal

r d f s

: d o m

a i n

r d f s

: r a n g e

r d f : t y

p e




Fulfillment of Requirements - RDFSchema


• Definition of entities (classes + property centricapproach)

• Definition of relationships (via properties)

• Properties of relationships (properties are also

resources) Flexible definition of relationships to global conceptual

models

• use of URI references, subclasses relationship (seenext slide)

Representation of concept hierarchies• yes, subclass relationship

Systematic support of data types

• only on the instance level (typed literal), use of XML Schema data types


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Application Layer


Software Agent




What is still missing?

RDF contains only limited set of predefinedconcepts with defined semantics; conceptsare missing for:

predefined concepts for the

definition of richer types of relationships between conceptualmodels

representation of domain constraintsand further domain knowledge

ontology/domain model evolutionsupport

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Application Layer


Software Agent




Defining Domain Ontologies -OWL

„ An ontology is a specification of aconceptualization.” *

OWL (Web Ontology Language) is

• is a language for defining ontologies for theSemantic Web

• is currently developed by the W3C Web OntologyGroup (Status: Working Draft) - successor of DAML + OIL

• is building upon RDF and RDF Schema• enables the representation of additional domain

knowledge (compared with RDF)

*T. R. Gruber. A translation approach to portable ontologies. Knowledge

Acquisition,

5 2 :199-220 1993




Ontology Definition - Protégé

The Protégé Ontology Editor and Knowledge Acquisition Systemsee http://protege.stanford.edu/index.html




Fulfillment of Requirements - OWL


• Definition of entities (property centric approach likeRDF)

• Definition of relationships (via class properties)

• Properties of relationships (cardinalities, transitivity,symmetry, ...)

Flexible definition of relationships to global conceptualmodels

• additional to RDF: disjoint, union, intersection,equivalent class, equivalent property

Representation of concept hierarchies

• yes like RDF + additional relationships, e.g. disjoint

classes Systematic support of data types

• on schema level (“data type properties”)


• supported by predefined concepts, examples see next

slides

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Application Layer


Software Agent




Relationships to global Conceptual

Models - OWLExample

“A Travel is defined a bus travel, a planeor a train travel, assuming that this threetypes of travel are defined in other global

schemes”

<owl:class rdf:about = “#Travel” >

<owl:unionOf rdf:parseType= “Collection”>

<owl:Class rdf:about = “airWays:Flight”

<owl:Class rdf:about = “busWorld:Travel”<owl:Class rdf:about = “railway:TrainTravel”>

</owl:unionOf>

</owl:class>

Travel

BusTravel TrainTravel PlaneTravel

“definition of new superclass”




Additional Requirements for Semantic WebApplications

flexible (e.g. Caching)

bidirectional

Mappings between:

Conceptual UI Model


Data Modeli d n a me

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Application Layer



Conceptual UI Model

Software Agent




Mapping and Semantic Domain Model -VizCo

R 1 7 : i s A

R

1 6 : h

a s

R 1 8 :

b o o k

R 11: b e lo ng sT o

R 9 : h a s

R 1

0 : r e

g i s

t e r

R4:

has

R 5 : s F r o

m

mn

number

person address

person name

coursedomain name

pricetitleauthor name

affiliation address

provider name

affiliation name

No of persons

R 3 : h a s

R 1 : h

a s

R 2 0 : h

a s

R 7 : h a s

R 2 1 : h

a s

R 1 5

: h a s

R 1 3 : h a s

R 2 : h a s

R1 9: h a s

R 8 : h

a s R

6 : h a s

R 1 4 : h

a s

affiliation

coursetransaction

vehicle

student

coursedomain

person

courseauthor

provider

a3: person name

R 2 0 : h

a s

a2: mn

R 1 4 : h a s

R 1 7 : i s A c4: student

R 1 8 : b

o o k

c3: person

R 1

0 :

r e g

i s t e

r

a1: title

c2: coursetransaction

c1: course

a4: person address

R 2 1

: h a s

R 1 1 : b e l o n g s T o c5: coursedomain

a5: coursedomain name

R 1 3 : h a s

Fuchs, Niederée, Hemmje, Neuhold,“Supporting Model-based Construction of Semantic-enabled WebApplications ”,to appear in Proceedings of the 4th International Conference on WebInformation S stems En ineerin (WISE'03), Rome, December 2003




Operationalization: Model Authoring +Mapping Definition

System Authoring

Tool Suite

Publishing Tools- Form Dialog Manager

- Menu Manager

Task-specificTools- Booking Manager - User Manager

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Application Layer



Conceptual UI Model

Software Agent

SystemAuthoringTool Suite

VizCo

Web Services

ProcessModel

Manager




Open Issues

Development of globally acceptedOntologies

Extended support for domain modeland ontology evolution

Systematic Handling of Multilinguality Development of adequate processors

for the transformation of conceptual UImodel into different agent-specific UI

formats




Thanks!




In the following some Backup Slides




Use of Models for User Interface Creation

Mecano and MOBI-D (Model-based Interface Designer)

The Mecano Interface Models [Puerta 1997]

User Model

User-Task Model

Domain ModelPresentation Model

Dialog Model

Design Model

Uses object oriented

modeling language:

MIMIC




The Semantic Web

"The Semantic Web is an extension of the current Web in which information isgiven well-defined meaning, better

enabling computers and people to work incooperation."

Tim Berners-Lee, James Hendler, Ora Lassila, The Semantic Web,Scientific American, May 2001


W b




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Application Layer

Conceptual UI Model


Software Agent<xforms:repeat nodeset="flights">

<xforms:select ref="start"/>

<xforms:select ref="end"/>

</xforms:repeat>

WebClient(HTML)




Defining Semantics on the Web

There is a need to describe resources on theWebin a form that can be interpretedby machines across the Web

Interpretation depends on the context of a

resourcee.g. Jaguar (car vs. beast);

Using their experience and cognitive abilitieshumans may infer the context of a resourcein many ways even if it is not made explicit;

Software can interpret contextonly if it is described explicitly and formally;

RDF and the ontology languages buildingupon RDFprovide means to explicate (part of) thiscontext.

i d n a me

1 R udar

2 B e s t

3 Glue

4 H ol low

authors

i d n a me

1 R udar

2 B e s t

3 Glue

4 H ol low

authors i d n a me

1 Rudar

2 Best

3 G l ue

4 Hollow

5 Rudar 6 Best

7 G l ue

8 Hollow9 Rudar

10 Best

11 Glue

authors

i d n a me

1 Rudar

2 Bes t

3 G lue

4 Hollow

authors

i d n a me

1 Rudar

2 Best

3 Glue

4 Hollow

5 Rudar 6 Best

7 Glue

8 Hollow9 Rudar

10 Best

11 Glue

authors

Application Layer


Software Agent




RDF Schema Example

Flight

Person

hasPassenger

Ticket

Plane

isFor

owns

assignedTo

r d f s

: r a n

g e

r d f s :

d o m a i n r

d f s : r a n g e

rdfs:range

r d f s : d o m a i n

r d f s : d o m a i n

FlightNumber

DepatureDate

rdf:Literal

rdf:Literal

r d f s

: d o m

a i n

r d f s : d o

m a i n

r d f s : r a n g e

rdfs:range

r d f s : r a n g e

r d f s

: d o m a

i n




Ontology Languages

OWL is language for defining ontologies

DAML+OIL is a combination of the twopredecessor ontology languages

DAML – DARPA Agent Markup Language

OIL - Ontology Inference Layer

OWL (Web Ontology Language) is thesuccessor DAML + OIL currently developed bythe W3C Web Ontology Group (Status:

Working Draft) Building on RDF ideas

OWL Lite is a subset of OWL




OWL Characteristics

OWL enables the definition of various types of relationships between

classes(in addition to subclass hierarchies)

additional restrictions for property valuesadditional types of relationships between

properties

different kinds of properties

OWL distinguishes betweenclasses and instances (objects) on the oneside,and data types and value on the other side(XML Schema datatypes)




Additional Requirements for Semantic WebApplications

Mappings between the ModelsConceptual UI Model


Domain Model (represented by DatabaseSchema)

Mappings which are

bidirectionalflexible (e.g. caching)

id n a me

1 R udar

2 Bes t

3 Glue

4 H ol low

authors

i d n a me

1 R udar

2 Bes t

3 Glue

4 H ol low

authors i d n a me

1 Rudar

2 Best

3 Glue

4 Hollow

5 Rudar

6 Best

7 Glue

8 Hollow

9 Rudar

10 Best11 Glue

authors

i d n a me

1 Rudar

2 Bes t

3 G lue

4 Hollow

authors

i d n a me

1 Rudar

2 Best

3 Glue

4 Hollow

5 Rudar

6 Best

7 Glue

8 Hollow

9 Rudar

10 Best11 Glue

authors

Application Layer


Software Agent

er2003-invitedtalkv27

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