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Use Cases and the VSTO. Fox, P. ; McGuinness, D.; Cinquini , L.; West, P., Garcia, J.; Zednik, S., Benedict, J.; Middleton, D. High Altitude Observatory, NCAR McGuinness Associates Computing and Information Systems Lab, NCAR. Virtual Solar Terrestrial Observatory (VSTO). - PowerPoint PPT Presentation
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VOiG 2007 - June 13, 20071
Use Cases and the VSTO
Fox, P.; McGuinness, D.; Cinquini , L.; West, P., Garcia, J.; Zednik, S., Benedict, J.;
Middleton, D.High Altitude Observatory, NCAR
McGuinness AssociatesComputing and Information Systems Lab, NCAR
VOiG 2007 - June 13, 20072
Virtual Solar Terrestrial Observatory (VSTO)
• a distributed, scalable education and research environment for searching, integrating, and analyzing observational, experimental, and model databases.
• subject matter covers the fields of solar, solar-terrestrial and space physics
• it provides virtual access to specific data, model, tool and material archives containing items from a variety of space- and ground-based instruments and experiments, as well as individual and community modeling and software efforts bridging research and educational use
• 3 year NSF-funded (OCI/SCI) project in its third year
VOiG 2007 - June 13, 20073
Semantic Web as a Technical Approach: Basic elements
• Use case(s)• Team - mixed skills• Perform analysis• Develop model/ontology• Use tools• Adopt technical approach and architecture• Leverage existing infrastructure; API, portal and
web services• Open World: evolve, iterate, redesign, redeploy
VOiG 2007 - June 13, 20074
Ontology Spectrum
Catalog/ID
SelectedLogical
Constraints(disjointness,
inverse, …)
Terms/glossary
Thesauri“narrower
term”relation
Formalis-a
Frames(properties)
Informalis-a
Formalinstance
Value Restrs.
GeneralLogical
constraints
Originally from AAAI 1999- Ontologies Panel by Gruninger, Lehmann, McGuinness, Uschold, Welty; – updated by McGuinness.Description in: www.ksl.stanford.edu/people/dlm/papers/ontologies-come-of-age-abstract.html
VOiG 2007 - June 13, 20075
Content: Coupling Energetics and Dynamics of Atmospheric Regions WEB
Community data archive for observations and models of Earth's upper atmosphere and geophysical indices and parameters needed to interpret them. Includes browsing capabilities by periods, instruments, models, …
VOiG 2007 - June 13, 20076
Science use casesTemplate 1: Plot the values of Parameter X as taken by
instrument description or instance Y subject to constraint Z during the time period W in style S.
Example 1: Plot the observed/measured Neutral Temperature (Parameter) looking in the vertical direction for Millstone Hill Fabry-Perot interferometer (Instrument) during January 2000 (Temporal Domain) as a time series (or: in a way that makes sense for the data).
Template 2: Find and retrieve image data of the type for images of content Y during times described by Z.
Example 2: Find and retrieve quick look and science data for images of the solar corona during a recent observation period.
VOiG 2007 - June 13, 20077
Science and technical use cases• Template 3 Find data for parameter X constrained by Y during
times described by Z. • Example 3: Find data, which represents the state of the neutral
atmosphere anywhere above 100km and toward the Arctic circle (above 45N) at any time of high geomagnetic activity.
• Template 4: Assemble a visual representation of a sequence of images X over a time period Y:
• Example 4: Create a movie of the white light solar corona during the whole-Sun campaign month in 2005.
• Template 5: Infer data representing a state of one physical domain X that changes in response to an external event Y from another physical setting Z.
• Example 5: Find and plot/animate data that represents the terrestrial ionospheric effects of a geo-effective solar storm.
VOiG 2007 - June 13, 20078
Example analysis of the use case
Input
Physical properties: State of neutral atmosphere
Spatial:
• Above 100km
• Toward arctic circle (above 45N)
Conditions:
• High geomagnetic activity
Action: Return Data
Specification needed for query to CEDARWEB
Instrument
Parameter(s)
Operating Mode
Observatory
Date/time
Return-type: data
GeoMagneticActivity has ProxyRepresentation
GeophysicalIndex is a ProxyRepresentation (in Realm of Neutral Atmosphere)
Kp is a GeophysicalIndex hasTemporalDomain: “daily”
hasHighThreshold: xsd_number = 7
Date/time when KP => 7
VOiG 2007 - June 13, 20079
Translating the Use-Case - ctd.
Input
Physical properties: State of neutral atmosphere
Spatial:
Above 100km
Toward arctic circle (above 45N)
Conditions:
High geomagnetic activity
Action: Return Data
Specification needed for query to CEDARWEB
Instrument
Parameter(s)
Operating Mode
Observatory
Date/time
Return-type: data
NeutralAtmosphere is a subRealm of TerrestrialAtmosphere
hasPhysicalProperties: NeutralTemperature, Neutral Wind, etc.
hasSpatialDomain: [0,360],[0,180],[100,150]
hasTemporalDomain:
NeutralTemperature is a Temperature (which) is a Parameter
FabryPerotInterferometer is a Interferometer, (which) is a Optical Instrument (which) is a Instrument
hasFilterCentralWavelength: Wavelength
hasLowerBoundFormationHeight: Height
ArcticCircle is a GeographicRegion
hasLatitudeBoundary:
hasLatitudeUpperBoundary:
VOiG 2007 - June 13, 200710
VOiG 2007 - June 13, 200711
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http://dataportal.ucar.edu/schemas/vsto_all.owl
VOiG 2007 - June 13, 200713
Creating Ontologies – CMAP, UML Options
• White board, text file• CMAP Ontology Editor (concept mapping tool IHMC)
– Drag/drop visual development of classes, subclass (is-a) and property relationship
– Reads and produces an OWL file (and other formats)– Support for formal convention (is-a, is-part-of, …)– Suggest avoid making your CMAP a graph (directed-
cyclic)• New release of Object Definition Metamodel
– Ontology Definition Metamodel/Meta Object Facility (OMG) for UML
– Provides standardized notation– Available from OMG -
http://www.omg.org/technology/documents/modeling_spec_catalog.htm
– Books likely to be available soon
VOiG 2007 - June 13, 200714
Software development tools
• Protégé, w/ plug-ins - some better than others• SWOOP (OWL analyzer, partitioner)• Jena (http://jena.sourceforge.net/)• Pellet reasoner• Eclipse (full integrated development environment
for Java; http://www.eclipse.org/)• SPARQL for queries• Lots of others
VOiG 2007 - June 13, 200715
VSTO - semantics and ontologies in an operational environment: vsto.hao.ucar.edu, www.vsto.org
Web Service
Existing OPeNDAP Service
VOiG 2007 - June 13, 200716
Partial exposure of Instrument class hierarchy - users seem to LIKE THIS
Semantic filtering by domain or instrument hierarchy
VOiG 2007 - June 13, 200717
Inferred plot type and return formats for data products
VOiG 2007 - June 13, 200718
… … … …
VO Portal
Web Serv.
VO API
DB2 DB3DBn
DB1
Semantic mediation layer - VSTO - low level
Semantic mediation layer - mid-upper-level
Education, clearinghouses, other services, disciplines, etc.
Metadata, schema, data
Query, access and use of data
Semantic query, hypothesis and inference
Semantic interoperability
Added value
Added value
Added value
Added value
Mediation Layer• Ontology - capturing concepts of Parameters,
Instruments, Date/Time, 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.
Standard, or not, vocabularies and schema
“Knowledge” as service!
VOiG 2007 - June 13, 200721
Technical use cases• Template 6: Expose semantically enabled,
smart data query services via a web services interface allowing composite query formation in arbitrary workflow order.
• Example 6: Provide query services for the Virtual Ionosphere-Thermospere-Mesosphere Observatory that retrieve query results and data filtered constraints on Instrument, Date-Time, and Parameter in any order and with constraints included in any combination.
VOiG 2007 - June 13, 200722
Semantic Web Services
VOiG 2007 - June 13, 200723
Semantic Web Services
OWL document returned using VSTO ontology - can be used both syntactically or semantically
VOiG 2007 - June 13, 200724
Semantic Web Services
VOiG 2007 - June 13, 200725
Semantic Web Services
VOiG 2007 - June 13, 200726
Developing ontologies• Use cases and small team (7-8; 2-3 domain experts, 2
knowledge experts, 1 software engineer, 1 facilitator, 1 scribe)• Identify classes and properties (leverage controlled vocab.)
– VSTO - narrower terms, generalized easily– Data integration - required broader terms– Adopted conceptual decomposition (SWEET) – Imported modules when concepts were orthogonal
• Minimal properties to start, add only when needed• Mid-level to depth - i.e. neither top-down nor bottom-up• Review, review, review, vet, vet, vet, publish - www.planetont.org
(experiences, results, lessons learned, AND your ontologies AND discussions)
• Only code them (in RDF or OWL) when needed (CMAP, …)• Ontologies: small and modular
VOiG 2007 - June 13, 200727
Semantic Web Benefits• Unified/ abstracted query workflow: Parameters, Instruments, Date-Time• Decreased input requirements for query: in one case reducing the
number of selections from eight to three• Generates only syntactically correct queries: which was not always
insurable in previous implementations without semantics• Semantic query support: by using background ontologies and a
reasoner, our application has the opportunity to only expose coherent query (portal and services)
• Semantic integration: in the past users had to remember (and maintain codes) to account for numerous different ways to combine and plot the data whereas now semantic mediation provides the level of sensible data integration required, now exposed as smart web services– understanding of coordinate systems, relationships, data synthesis,
transformations, etc.– returns independent variables and related parameters
• A broader range of potential users (PhD scientists, students, professional research associates and those from outside the fields)
• VSTO: http://vsto.hao.ucar.edu, http://www.vsto.org, http://www.egy.org/VOiG • Peter Fox pfox@ucar.edu, Deborah McGuinness dlm@ksl.stanford.edu
VOiG 2007 - June 13, 200728
VSTO experience • Conceptual model and architecture developed by combined
team; KR experts, domain experts, and software engineers• Semantic framework developed and built with a small,
cohesive, carefully chosen team in a relatively short time (deployments in 1st year)
• Production portal released, includes security, etc. with community migration (and so far endorsement)
• VSTO ontology version 1.0, (vsto.owl) • Web Services encapsulation of semantic interfaces • More solar-terrestrial use cases to drive the completion of the
ontologies - filling out the instrument ontology• Adding data sources, e.g. PSPT, ECHO, Hinode vector
magnetic fields• Using ontologies and data framework in other applications
(volcanoes, climate, …)
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• Scaling to large numbers of data providers• Crossing disciplines• Security, access to resources, policies• Interoperability at a variety of levels (~3)• Branding and attribution (where did this data come
from and who gets the credit, is it the correct version, is this an authoritative source?)
• Provenance/derivation (propagating key information as it passes through a variety of services, copies of processing algorithms, …)
• Data quality, preservation, stewardship
Issues for Virtual ObservatoriesMany we are addressing with new use cases
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