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Transcript of 1 Foundations V: Infrastructure and Architecture, Middleware Deborah McGuinness and Peter Fox...
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Foundations V: Infrastructure and Architecture, Middleware
Deborah McGuinness and Peter Fox
CSCI-6962-01
Week 9, October 27, 2008
Contents• Review of reading, questions, comments
• Technology and how to use it
• Summary
• Next week
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Semantic Web Methodology and Technology Development Process
• Establish and improve a well-defined methodology vision for Semantic Technology based application development
• Leverage controlled vocabularies, et c.
Use Case
Small Team, mixed skills
Analysis
Adopt Technology Approach
Leverage Technology Infrastructur
e
Rapid PrototypeOpen World:
Evolve, Iterate, Redesign, Redeploy
Use Tools
Science/Expert Review & Iteration
Develop model/
ontology
EvaluationEvaluation
Architecture• Importance of state
– Grids– Web
• Existing infrastructure– Catalogs– Data sources– User interfaces– Services
• Wrapping these syntactic interface
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Inventory• Refer to the Resources
– Files– Databases– Catalogs– Existing UI– Services– User database/ security– Logging– Backup/ archive
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… … … …
Geo App1Geo App2
App3
DB2 DB3DBn
DB1
WSCommon
Web Coverage Service
Web Feature Service
Web Mapping Service
Limited interoperability
Fox WHOI: Semantic Data Frameworks March 20, 2008
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The Astronomy approach; data-types as a service
… … … …
VO App1
VO App2VO App3
DB2 DB3DBn
DB1
VOTable
Simple Image
Access Protocol
Simple Spectrum
Access Protocol
Simple Time
Access Protocol
VO layer
Limited interoperability
Lightweight semantics
Limited meaning, hard coded
Limited extensibility
Under review
… … … …
Web Portal
Web Serv.
API
DB2 DB3DB…
DB1
Semantic mediation layer: Ontology - capturing concepts of Parameters, Instruments, Date/Time, Space, Event, Feature, Data Product (and associated classes, properties) and Service Classes. Maps queries to underlying data. Generates access requests for metadata, data. Allows queries, reasoning, analysis, new hypothesis generation, testing, explanation, etc.
Semantic mediation layer - mid-upper-level
Education, clearinghouses, other services, disciplines, etc.
Metadata, schema, data
Query, access and use of data
Semantic interoperability
Data as Service
Implementing• Let’s take an example
– VSTO– Representative but does not exercise all
semantic web capabilities
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Fox RPI: Semantic Data Frameworks May 14, 2008
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Web Service
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Additional middleware• Web server, Tomcat are essential (Axis)
• MySQL (or similar) is very handy to have
• OPeNDAP – for data access and transport
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Fox RPI: Semantic Data Frameworks May 14, 2008
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Web Service
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Infrastructure• Protégé-OWL-API
– http://protege.stanford.edu/plugins/owl/api/index.html
– http://protege.stanford.edu/plugins/owl/api/guide.html
• Jena (Java API for RDF and OWL)– http://protege.stanford.edu/plugins/owl/jena-
integration.html
– http://jena.sourceforge.net/
– Migrate to other triple stores when needed
Using Protégé• Load VSTO into Protégé 3.4beta
• Generate Java-OWL classes from Tool menu
• Review other tools for generating code stubs
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Examine some of the code• Java Factory class
• Code stubs and ‘myclass’
• VSTO code base will be made available for browsing
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Jena
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Infrastructure• Reasoner – DIG/Pellet
– http://protegewiki.stanford.edu/index.php/ProtegeReasonerAPI
• SPARQL– http://www.w3.org/2001/sw/DataAccess/tests/
implementations
• Spring (Application Framework - optional)– http://www.springframework.org/
• Eclipse (IDE)– http://www.eclipse.org/
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Infrastructure• Rules
– SWRL – plug-in for Protégé– Jess rules– Jess rules engine -
http://herzberg.ca.sandia.gov/jess/
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Software development• Junit (generated in Eclipse)
– http://smi-protege.stanford.edu/repos/protege/owl/trunk/junit.properties.template
• Faceted browsing – mspace
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Metadata• Migrate metadata into ontologies – instances,
choose how you will populate them– Manual – okay to start with sufficient annotation– Scripted – preferred – rdfs_comment: essential
• Choose what you will not, cannot move
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Services• If you are going to put up services, include an
end-point and a link to your WSDL (or SAWSDL)
• At this point, developing a full services ontology, e.g. in OWL-S may be beyond the initial implementation
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Fox RPI: Semantic Data Frameworks May 14, 2008
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Semantic Web Services
Fox RPI: Semantic Data Frameworks May 14, 2008
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Semantic Web Services
OWL document returned using VSTO ontology - can be used both syntactically or semantically
Result/ outcome• Refer to the use case document
• Check the expected outcome and see if the test (to verify outcome) is complete
• Document all variations, note alternate flows
• Document in sufficient detail that someone else could come along and re-produce your work
• Include URLs for access, etc.
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Metrics• Next week we will cover evaluation but
already be thinking of things you can measure– Could not do before– Faster, more complete, less mistakes, etc.– Wider range of users
• Estimate the baseline before you start
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Summary• Architectural design needs to take into
account existing resources that you will leverage
• Keeping it simple is also very important as you begin to implement
• Take time to learn the tools and the supporting APIs; look at existing examples and working code
• Being prepared to iterate is really essential
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Next week• This weeks assignment:
– Reading: Evaluation– Assignment 3: Team Use Case Implementation
(on the class wiki later today)
• Next class (week 10 – November 3): – Class Presentation II: Use Case Implementation
• Office hours this week – Thursday afternoon 1-2, Winslow 1140
• Questions?
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