Post on 16-Jan-2016
description
20081118 Fox OOS meeting1
Ontologies and Semantic Applications in Earth Sciences
Peter Fox (TWC/RPI; formerly HAO/NCAR)
Thanks to many.
Projects funded by NSF/OCI and NASA/ACCESS/ESTO
2
BackgroundScientists should be able to access a global, distributed
knowledge base of scientific data that:• appears to be integrated• appears to be locally available
But… data is obtained by multiple means (models and instruments), using various protocols, in differing vocabularies, using (sometimes unstated) assumptions, with inconsistent (or non-existent) meta-data. It may be inconsistent, incomplete, evolving, and distributed
And… there exist(ed) significant levels of semantic heterogeneity, large-scale data, complex data types, legacy systems, inflexible and unsustainable implementation technology
3
Data-types as 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
Open Geospatial Consortium:
Web {Feature, Coverage, Mapping} Service
Sensor Web Enablement:
Sensor {Observation, Planning, Analysis} Service
use the same approach
20080602 Fox VSTO et al.4
… … … …
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!
20080602 Fox VSTO et al.5
Semantic Web Methodology and Technology Development Process
• Establish and improve a well-defined methodology vision for Semantic Technology based application development
• Leverage any existing vocabularies
Use Case
Small Team, mixed skills
Analysis
Adopt Technology Approach
Leverage Technology
Infrastructure
Rapid Prototype
Open World: Evolve, Iterate,
Redesign, Redeploy
Use Tools
Science/Expert Review & Iteration
Develop model/
ontology
20080602 Fox VSTO et al.6
E.g. Science and technical use casesFind 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.
– Extract information from the use-case - encode knowledge– Translate this into a complete query for data - inference and
integration of data from instruments, indices and models
Provide semantically-enabled, smart data query services via a SOAP web for the Virtual Ionosphere-Thermosphere-Mesosphere Observatory that retrieve data, filtered by constraints on Instrument, Date-Time, and Parameter in any order and with constraints included in any combination.
20080602 Fox VSTO et al.7
VSTO - semantics and ontologies in an operational environment: vsto.hao.ucar.edu, www.vsto.org
Web Service
Existing OPeNDAP Service
20080602 Fox VSTO et al.8
Semantic Web Services
20080602 Fox VSTO et al.9
Semantic Web Services
OWL document returned using VSTO ontology - can be used both syntactically or semantically
10
Semantic Web Benefits• Unified/ abstracted query workflow: Parameters, Instruments, Date-Time
across widely different disciplines• Decreased input requirements for query: in one case reducing the
number of selections from eight to three• Semantic query support: by using background ontologies and a
reasoner, our application has the opportunity to only expose coherent queries (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, and 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
Fox RPI: Semantic Data Frameworks May 14, 2008
11
http://dataportal.ucar.edu/schemas/vsto_all.owl (1.0, 2.0 coming)
12
Ingest/pipelines: problem definition
• Data is coming in faster, in greater volumes and outstripping our ability to perform adequate quality control
• Data is being used in new ways and we frequently do not have sufficient information on what happened to the data along the processing stages to determine if it is suitable for a use we did not envision
• We often fail to capture, represent and propagate manually generated information that need to go with the data flows
• Each time we develop a new instrument, we develop a new data ingest procedure and collect different metadata and organize it differently. It is then hard to use with previous projects
• The task of event determination and feature classification is onerous and we don't do it until after we get the data
20080602 Fox VSTO et al.13
14
• Who (person or program) added the comments to the science data file for the best vignetted, rectangular polarization brightness image from January, 26, 2005 1849:09UT taken by the ACOS Mark IV polarimeter?
• What was the cloud cover and atmospheric seeing conditions during the local morning of January 26, 2005 at MLSO?
• Find all good images on March 21, 2008.• Why are the quick look images from March 21,
2008, 1900UT missing?• Why does this image look bad?
Use cases
20080602 Fox VSTO et al.15
20080602 Fox VSTO et al.16
17
Provenance
• Origin or source from which something comes, intention for use, who/what generated for, manner of manufacture, history of subsequent owners, sense of place and time of manufacture, production or discovery, documented in detail sufficient to allow reproducibility
• Knowledge provenance; enrich with ontologies and ontology-aware tools
18
20080602 Fox VSTO et al.19
20080602 Fox VSTO et al.20
Quick look browse
21
22
Visual browse
23
24
Search and structured query
25
Search StructuredQuery
20080602 Fox VSTO et al.26
Search
27
Data Integration Use Case• Determine the statistical signatures of both
volcanic and solar forcings on the height of the tropopause
28
Detection and attribution relations…
20080602 Fox VSTO et al.29
SWEET 2.0
31
Semantic framework indicating how volcano and atmospheric parameters and databases can immediately be plugged in to the semantic data framework to enable data integration.
Faceted Search
20080602 Fox VSTO et al.32
Summary• Level of ontology encoding relates to use, e.g.
– VSTO: – SPCDIS:– SESDI: Data integration needs higher level of
curation of ontologies and mapping to data
• Languages and tools– Rapid prototyping (PHP, Semantic MediaWiki)– Clean and simple (RDFS, Perl and SPARQL)– Complex and rich (Java, Protégé, Jena, Pellet,
ELMO, Maven, Eclipse)
33
20080602 Fox VSTO et al.34
Modified GEON Solution Framework
Level 1:
Data Registration at the Discovery Level,
e.g. Volcanolocation and activity
Level 2:
Data Registration at the Inventory Level, e.g. list of datasets by,types, times, products
Level 3:
Data Registration at the Item Detail
Level, e.g. access toindividual quantities
Ontology basedData Integration
Earth Sciences Virtual DatabaseA Data Warehouse where
Schema heterogeneity problem is Solved; schema based integration
Data Discovery Data Integration
A.K.Sinha, Virginia Tech, 2006
Spare material
20080602 Fox VSTO et al.35
20080602 Fox VSTO et al.36
Example 1: Registration of Volcanic Data
SO2 Emission from Kilauea east rift zone -
vehicle-based (Source: HVO)Abreviations: t/d=metric tonne (1000 kg)/day, SD=standard deviation, WS=wind speed, WD=wind direction east of true north, N=number of traverses
Location Codes:• U - Above the 180° turn at Holei Pali (upper Chain of Craters Road)
• L - Below Holei Pali (lower Chain of Craters Road)
• UL - Individual traverses were made both above and below the 180° turn at Holei Pali
• H - Highway 11
20080602 Fox VSTO et al.37
Registering Volcanic Data (2)
• No explicit lat/long data
• Volcano identified by name
• Volcano ontology framework will link name to location
20080602 Fox VSTO et al.38
Registering Atmospheric Data (2)
39
Building blocks
• Data formats and metadata: IAU standard FITS, with SoHO keyword convention, JPeG, GIF
• Ontologies: OWL-DL and RDF• The proof markup language (PML) provides an interlingua for
capturing the information agents need to understand results and to justify why they should believe the results.
• The Inference Web toolkit provides a suite of tools for manipulating, presenting, summarizing, analyzing, and searching PML in efforts to provide a set of tools that will let end users understand information and its derivation, thereby facilitating trust in and reuse of information.
• Capturing semantics of data quality, event, and feature detection within a suitable community ontology packages (SWEET, VSTO)