Hera: Development of Semantic Web Information Systems

steelsquareInternet and Web Development

Oct 20, 2013 (4 years and 2 months ago)

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TU
/
e



technische universiteit eindhoven

Hera: Development of Semantic
Web Information Systems

Geert
-
Jan Houben

Peter Barna

Flavius Frasincar

Richard Vdovjak


hera@wwwis.win.tue.nl

TU
/
e



technische universiteit eindhoven

Overview


WIS design


Hera methodology, RDF(S)


Conceptual model and integration


Application model and adaptation


User interaction

TU
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e



technische universiteit eindhoven

Motivation


From Web pages to Web information
system (WIS)


Technologies from Semantic Web: RDF(S)


Hera uses RDF(S) for effective support of
WIS design

TU
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e



technische universiteit eindhoven

WIS Design


Generation of hypermedia presentations:
navigation structure


Presentation objects, e.g. pages


Navigation connections, e.g. hyperlinks


Integration from different sources: transparent
repository


Management of semi
-
structured data


Personalization: user adaptation

TU
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e



technische universiteit eindhoven

Adaptation


Presentations must be adaptable to different

users/user platforms



Devices
(PC, PDA, WAP Phone, WebTV etc.)


Device capabilities (display size, memory size,
network speed, etc.)


User preferences (desired layout, navigation
patterns, etc.)


User browsing history

TU
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e



technische universiteit eindhoven

HERA
A
rchitecture

TU
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e



technische universiteit eindhoven

Hera: WIS Design Methodology


RMM, OOHDM, WebML, etc.


Sequence of steps in designing a web application


Model
-
driven approach:


data/navigation/presentation


Data transformations:


towards HTML, WML, SMIL, etc.


Use of RDF(S) to specify different models and
XSLT to transform (meta)data


subclass/subproperty


extensibility, e.g. CC/PP vocabulary

TU
/
e



technische universiteit eindhoven

TU
/
e



technische universiteit eindhoven

TU
/
e



technische universiteit eindhoven

Conceptual Model (CM)


Provides a uniform semantic view over
different data sources that are integrated
within a given Web application


Consists of hierarchies of concepts relevant
within the given domain, their properties,
and relations


Encoded in RDF(S)

TU
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e



technische universiteit eindhoven

Conceptual Model Example

TU
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e



technische universiteit eindhoven

Source Clusters

Equipment Catalogue

Photo Rental

Photo Stock Agency

Sources are


Autonomous


(Virtually) grouped to clusters
based on the content they
provide


RDF(S), RQL capable

TU
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e



technische universiteit eindhoven

Integration Model

IM decouples the CM and Sources


Articulations


actual links between the CM and the source ontologies


(a part of it) serves as a query on the source side


Decorations


offer a way to rank sources within the same cluster


capture explicitly designer’s knowledge about sources


open possibilities for queries with constraints


e.g. “I’m interested in the answer within 1s, otherwise
forget it”

TU
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e



technische universiteit eindhoven

Integration Model Ontology


Path expression


Articulation


Decoration


Processing instruction

TU
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e



technische universiteit eindhoven

Application Model (AM)


Captures navigational view over CM, describing
hypermedia aspects


S
lices

are meaningful presentation units:


Associated to concepts from CM


Containing properties/
attributes and possibly other
slices


Slices are linked together with slice relationships:


Aggregation relationships: index, tour, indexed guided
tour etc.


Reference relationships: link with an anchor specified


Encoded in RDF(S)

TU
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e



technische universiteit eindhoven

Application Model Example



TU
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technische universiteit eindhoven

Adaptation


WIS are accessed through multitude of devices
and by different users


Device capabilities


User preferences


Browsing history



Adaptation based on conditioning the appearance
of slices in AM

TU
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e



technische universiteit eindhoven

Adaptation/User Model


Captures two kinds of adaptation


Adaptability

takes into account the context in which the user
will use the presentation (e.g. the browsing platform)


Adaptivity

means that the presentation changes itself
according to the “state of the user’s mind” while being
browsed


Consists of


Device/User Profile

captures “static” visual and platform
preferences encoded in CC/PP


User Model

represents the dynamic user’s state, e.g. did the
user visit (learn) this slice (concept)


Application and Update Rules

describe the behavior of the
presentation (e.g. conditional slices in AM) and keep the user
model up
-
to
-
date (AHAM rules)

TU
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e



technische universiteit eindhoven

TU
/
e



technische universiteit eindhoven

Profile Example

Device/User Profile (CC/PP encoding)


Screen size: 100x80


Preferred language: English

<ccpp:component>


<up:UserPreferences>


<up:Language>English</up:Language>





</up:UserPreferences>

</ccpp:component>

</rdf:Description>

<rdf:Description rdf:about=“Profile”>

<ccpp:component>


<prf:HardwarePlatform>


<prf:ImageCapable>No</prf:ImageCapable>


<prf:ScreenSize>100x80</prf:ScreenSize>





</prf:HardwarePlatform>

</ccpp:component>


TU
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e



technische universiteit eindhoven

TU
/
e



technische universiteit eindhoven

Adaptation Model Syntax

Adaptability Condition




Adaptivity Condition

<rdfs:Class rdf:ID=“Slice.painter.main”


slice:condition=“um:Biography = false”>


<rdf:subClassOf rdf:resource=“#Slice”/>

</rdfs:Class>


<rdfs:Class rdf:ID=“Slice.painting.picture”


slice:condition=“prf:ImageCapable=Yes”>


<rdf:subClassOf rdf:resource=“#Slice”/>

</rdfs:Class>


<rdfs:Class rdf:ID=“Slice.painting.main”


slice:condition=“um:Painter > 10”>


<rdf:subClassOf rdf:resource=“#Slice”/>

</rdfs:Class>


TU
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e



technische universiteit eindhoven

User Interaction


E
-
commerce applications often require WIS with
broader functionality than just navigation through
static web sites (known patterns: shopping carts,
on
-
line payments, searches, etc.)


The functionality includes also richer means of
interaction with users via interaction elements:
buttons, text entry forms, checkboxes, etc.


Navigation objects (slices) with data content may
depend on the interaction and/or system business
logic, so it cannot be static




TU
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e



technische universiteit eindhoven

User Interaction Specification


Extension of AM specification:


Structural: interaction elements as “active” attributes
capturing user actions (buttons, text fields, etc.)


Behavioural: operations assigned to interaction
elements (dynamic navigation, data manipulation,
adaptation, call of external Web Services, etc.)


Consequence on WIS architecture: need for an
engine providing the operations (as AHA! for
adaptivity)

TU
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e



technische universiteit eindhoven

Shopping Cart: example of CM
data manipulations

TU
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technische universiteit eindhoven

Conclusion & Future Work


Explicit semantics in models, expressing
concepts, their hierarchies and relationships


Adaptation in all design steps including the CM
and IM, and full support of adaptivity


Experiment with higher ontology languages (e.g.
OWL) as the basis for the different models


Further development of authoring tools helping
the designer to build models in all design steps


Query and transformation language, e.g. RAL

TU
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e



technische universiteit eindhoven