Coastal Atlas Interoperability -

Ontologies

Luis BermudezStephanie Watson

Marine Metadata Interoperability Initiative 1

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Day 1

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Preparation

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Pre-paration (5 min)

•Create groups of 2.•Every group will have a number (X)•Your working ontology will be aX.owl•Example: Group 10 should work on a10.owl•One group will also be the super atlas master group - so they will add resources to this ontology if needed. (more later)

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Pre-paration (10 min)

•Make sure that:•CMAP works•TopBraidComposer works•You can access the SVN repository

CMAP• tool to create concept maps

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TopBraidComposer (TBC)

• TBC is a tool to develop Semantic Web ontologies and semantic applications in RDF

• Walk through the help system and Ch 3. of the tutorial

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Help in TopBraidComposer

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2

3

4

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Configuring Help

• Click on Help / Help Contents• Click on Search Scope hypertext•Click on New• Give a name e.g. TopBraid• Select TopBraid Composer• Click OKs

Introduction to Subversion (SVN)

• an open source version control system• allows users to keep track of changes made over time to any type of electronic data

• typical uses are versioning source code, web pages or design documents

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•Used in this tutorial to publish ontologies... simulating a distributed environment

Check that SVN is Installed in TBC

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• Window Menu• Show View• Other

Should See the SVN Repository Folder

If not, install SVN plugin

• Help Menu• Software Updates

• Find and Install

• Click on “…new features”

• Check “subclipse update site” box

• Click on “new remote site”

• Type URL of the SVN plugin and follow instructions

Create Project from SVN Repository

• Window Menu• Show View• Other

• Select SVN Repository

• A view titled “SVN Repository” should have appeared.

• Right click and select:New

Repository Location

• Type the following URL: https://ont.googlecode.com/svn/trunk/ and click on Finish

• User: mmidemo• Password: j6x4e4b8

• Right click on “ont-coastal” folder

• Choose Checkout

• “Accept permanently”

• Checkout and create a new project, for example, “ont-coastal”

• You should have a project with the ontologies available

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SVN Operations

Publish changes

Update the files in your local directory

Explore changes

Overview• Goals• Introduction to Ontologies• Ontology Components and Practical Exercise

• Advanced Ontology Concepts– Mappings– Restrictions and Description Logic– SPARQL and Rules

• MMI Tools• Ontology Engineering• Interoperability Demonstration• Discussions

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Goals

• Gain an understanding of controlled vocabularies (CVs) and ontologies

• Hands on experience developing ontologies

• Learn enough to write proposal to go further

• Have fun

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Introduction to Ontologies (20 min)Semantic

Interoperability Problems•Semantic Interoperability

•Controlled Vocabularies•Ontologies, RDF, OWL etc..

Interoperability

Diversity

Making Connections

Confusion

What happens if we are not semantically interoperable ?

•We cannot find all the data that we are seeking.

•p. 41 of Workshop 1 report: “Terminology used to describe similar data can vary between specialties or regions, which can complicate data searches and data integration.”

•We get too many results and they are hard to classify.

Semantic Interoperability Problem: Can’t find all

the data

Semantic Interoperability Problem:

Information Overload

Need Categorizations ...

Agreements on content help

solve semantic interoperabilit

y problems.

Ontologies could be a mechanism

Ontologies facilitate agreement

on:• controlled vocabularies• mappings• categories• knowledge of a domain

Controlled Vocabularies (CVs) What are they?

• a set of restricted words, used by an information community when describing resources or discovering data;

• prevents misspellings and avoids the use of arbitrary, duplicative, or confusing words that cause inconsistencies when cataloging or searching data.

• For example:– Glossary, dictionary– Classifications and categories– Relationship categories

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Examples of CVs in Use SeaDataNet -

http://www.seadatanet.org

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Examples of CVs in Use:Consortium of Universities for the Advancement of

Hydrologic Science (CUAHSI) http://www.cuahsi.org

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Examples of CVs in Use:OGC URN Resolver

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19SOAP WSDL

It is not always possible to agree on one and only one vocabulary

Ontologiesfacilitate agreement

on:• controlled vocabularies• mappings• categories• knowledge of a domain

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Interoperability

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Ontologies facilitate agreement

on:• controlled vocabularies• mappings• categories (is a type of mapping -:> )

• knowledge of a domain

Example Oregon Atlas

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Categories Example - Oregon Coastal

Atlas

Ontologies facilitate agreement

on:• controlled vocabularies• mappings• categories• knowledge of a domain

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Knowledge Domain Representation

OntologiesGood for Expressing

Formally:• controlled vocabularies

• mappings• categories• knowledge of a domain

•formal•machine friendly

how ?

Formal

RDF

ResourceDescriptionFramework

RDF

r a d a r

r a i n

m e a s u r e s

D r e x e l

d b Z

i s i n

D I X

i s a

P h i l a d e l p h i a

c o v e r s

0

V a l u e i s

p u b l i s h e s

N O A Ao p e r a t e s

M o s t r e c e n t a v e r a g e

H a s u n i t s

R a i n i n g

R e l a t e d n o u n

N o R a i n i n g

N e g a t i o n o f

m e a s u r e s

V a l u e i s

H a s u n i t s

S u b j e c tO b j e c tp r e d i c a t e

RDF Simple Graph Model

Observation

platform

observed property

Sea water Temperature

define inMBARI

SOS

bounded by

36.69 -122.338 0

Lower corner

valuecrs

EPSG:6.5:4329

urn:ogc:def:crs:EPSG:6.5:4329

Mooring feature of interest

Monterey Bay

http://geonames.usgs.gov/pls/gnispublic/f?…:234322

http://marinemetadata.org/platform#MooredBuoy

http://marinemetadata.org:9600/oostethys/sos

…

http://marinemetadata.org/2005/02/ioos#Temperature

Temperature

narrower than

http://marinemetadata.org/cf#sea_water_temperature

Water based platform

isARDF

URI

• http://somehost/absolute/URI/resource.jpg• ftp://somehost/resource.txt• urn:issn:1535-3613• mailto:infobot@ex.com?subject=suscribe• SIN://16137224697

“Most fundamental web stuff”

RDF Serialization

•RDF/XML

•Turtle

•N3

•N-Triple

•...

RDF is graph model that could be “stored” in different formats

Ontologies .. good for expressing formally

• controlled vocabularies

• mappings• categories• knowledge of a domain

•formal•machine friendly

how ?

how ?•RDF•Web Resources

Ontology Web Language (OWL)

•RDF/XML is the syntax

•is a representation language for ontologies

•extends RDFS by allowing representation of more complex relationships and more precise constraints on classes and properties

•uses URIs

•is the “lingua franca” of the Semantic Web

BREAK !• Next: SeaDataNet use case (Roy Lowry)

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