RDF/XML-based Generation of Adaptable Hypermedia Presentations

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RDF/XML-based Generation of Adaptable Hypermedia
Presentations

• Flavius Frasincar
• flaviusf_at_win.tue.nl
• http//wwwis.win.tue.nl/hera

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Contents

• Problem
• Hera Presentation Methodology
• Data Modeling
• Conceptual Model
• Application Model
• Adaptation Model
• Data Transformations
• Data Presentation in Different Browsers
• Conclusions

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Problem

• Present the data (possibly coming from different
  sources) on different platforms for different
  users in an automatic way

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Solution Hera

• Hera is a model-driven methodology for hypermedia
  presentation design (part of Web Information
  System design)
• Hera differentiates from other existing
  model-driven methodologies by
• The high degree of automation of the designed
  system
• The use of Semantic Web technologies (RDF, RDFS,
  RDF/XML) in system specification
• The support offered for specifying adaptation
  aspects early in the design process

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Language/Tool Support

• Models are represented in RDF and they are
  serialized in RDF/XML
• User Agent Profile (UAProf) a Composite
  Capability/Preference Profiles (CC/PP) vocabulary
  to model device capabilities and user preferences
  
• XSLT processor for transforming between different
  model instances (stylesheet-based
  transformation)
• Xalan (XSLT 1.0)
• Saxon (XSLT 2.0) multiple output files support

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Data Modeling
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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
• Concept properties are
• Attributes refer to literal values that
  characterize a concept
• Relationships refer to other concepts

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Example CM
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Example CM in RDF/XML
ltrdfsClass rdfID"Creator"/gt ltrdfsClass
rdfID"Painter"gt ltrdfssubClassOf
rdfresource"Creator"/gt lt/rdfsClassgt ltrdfProp
erty rdfID"creates"
syscardinality"multiple"
sysinverse"created_by"gt ltrdfsdomain
rdfresource"Creator"/gt ltrdfsrange
rdfresource"Artifact"/gt lt/rdfPropertygt
ltrdfsClass rdfID"Artifact"/gt ltrdfsClass
rdfID"Painting"gt ltrdfssubClassOf
rdfresource"Artifact"/gt lt/rdfsClassgt ltrdfPro
perty rdfID"year"gt ltrdfsdomain
rdfresource"Artifact"/gt ltrdfsrange
rdfresourceInteger"/gt lt/rdfPropertygt ltrdfP
roperty rdfID"picture"gt ltrdfsdomain
rdfresource"Painting"/gt ltrdfsrange
rdfresourceImage"/gt lt/rdfPropertygt
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Application Model (AM)

• Captures the logical (navigational) aspects of
  the presentation
• Based on the concept of slice, a meaningful
  presentation unit which contains attributes and
  possibly other slices
• A slice is associated to a concept from CM
• Slice properties are
• Aggregation properties embed a set of slices
  (abstraction for index, tour, indexed guided tour
  etc).
• Reference properties link abstraction

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Example AM
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Example AM in RDF/XML
ltrdfsClass rdfID"Slice.painting.main"
sliceowner"CM Painting"gt
ltrdfssubClassOf rdfresource"Slice"/gt lt/rdfsCl
assgt ltrdfProperty rdfID"slice-ref"gt
ltsliceprop-ref rdfresource"CM ex_by"/gt
ltrdfsdomain rdfresource"S.t.main"/gt
ltrdfsrange rdfresource"S.p.picture"/gt lt/rdfPr
opertygt ltrdfProperty rdfIDlink_1"gt
ltrdfssubPropertyOf rdfresource linkgt
ltrdfsdomain rdfresource" S.p.picture"/gt
ltrdfsrange rdfresource"S.p.main"/gt lt/rdfPrope
rtygt
ltrdfsClass rdfID"Slice.technique.main"
sliceownerCMTechnique"
slicemain"Yes"gt ltrdfssubClassOf
rdfresourceSlice"/gt lt/rdfsClassgt ltrdfsClass
rdfID"S.painting.picture"
sliceownerCMPainting"
sliceattr-refCMpicture"gt ltrdfssubClassOf
rdfresource"Slice"/gt lt/rdfsClassgt
ltrdfProperty rdfID"media"gt ltrdfsdomain
rdfresource"S.p.picture"/gt ltrdfsrange
rdfresourceImage"/gt lt/rdfPropertygt
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Adaptation Model

• Based on conditioning the appearance of slices
• A link referencing a slice that has the condition
  not valid
• is hidden
• Takes into account the device capabilities and
  user preferences based on two CC/PP vocabularies
• UAProf (User Agent Profile) device capabilities
• UserProfile user preferences
• The user/platform profile instantiates these two
  vocabularies for the specific platform and user
  of the system

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Adapted Application Model
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Example AM in RDF/XML
ltrdfsClass rdfID"Slice.painting.picture"
sliceownerCMPainting"
sliceattr-refCMpicture"
sliceconditionSlice"prfImageCapableYes"gt
ltrdfssubClassOf rdfresourceAMSlice"/gt lt/rdfs
Classgt ltrdfProperty rdfID"slice-ref"gt
ltrdfsdomain rdfresource"Slice.painting.main"/gt
ltrdfsrange rdfresource"Slice.painter.name
"/gt ltsliceprop-ref rdfresourceCMpainted_b
y"/gt ltsliceconditionRef"prfExpertiseLevelM
edium/gt lt/rdfPropertygt
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Data Transformations

• Step 0 Preparation
• Substep 0.1 Application Model Unfolding creates
  the skeleton of an AM instance
• Substep 0.2 Application Model Adaptation adds
  slice visibility conditions to the previous
  skeleton
• Substep 0.3 Main Transformation Specification
  Generation builds the specification for the next
  step
• Step 1 Main Transformation populates the AM with
  the input CM instance
• Step 2 Presentation Generation produces code for
  different browsers (HTML, WML, SMIL)

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Main Transformation

• Project all slices on the retrieved instances
  that correspond to the slice owner concept
• Each time a slice reference is encountered refer
  to its identifier (possibly traversing some
  instances based on concept relationship(s) from
  CM)
• Each time a media reference is encountered copy
  the media (given by a certain attribute from CM)
• Name convention
• Slice full name Slice.concept . slice
  short name
• Slice instance full name Slice full name _
  identifier of the instance projected upon

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Data Transformations
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Presentation in Browsers
WML
SMIL
HTML
Wireless Markup Language
Synchronized Multimedia Integration Language
HyperText Markup Language
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Conclusions

• Hera
• Is a model-based methodology that distinguishes
  two design tasks the CM design and the AM design
• It offers a high degree of system automation by
  specifying transformation stylesheets between
  different models
• It uses standard technology RDF, RDF/XML, XSLT
• As future work
• Support user interaction
• Experiment with high level Semantic Web languages
  like the Web Ontology Language (OWL)