UNCERTML%20-%20DESCRIBING%20AND%20COMMUNICATING%20UNCERTAINTY

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UNCERTML - DESCRIBING AND COMMUNICATING
UNCERTAINTY

• Matthew Williams
• williamw_at_aston.ac.uk

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OVERVIEW

• Introduction.
• Motivation the Semantic and Sensor Webs.
• UncertML overview.
• Use case The INTAMAP project.
• Conclusions.

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MOTIVATION

• The semantic and sensor webs

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THE SENSOR WEB
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SENSOR WEB ENABLEMENT (SWE)

• Open Geospatial Consortium (OGC) initiative
• Interoperability interfaces and metadata
  encodings.
• Real time integration of heterogeneous sensor
  webs into the information infrastructure.
• Current SWE standards
• Observations Measurements
• SensorML
• SWE Common
• No formal standard for quantifying uncertainty

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HOW UNCERTAINTY IS USED WITHIN THE SEMANTIC WEB

• PR-OWL a Bayesian Ontology Language for the
  Semantic Web
• Extends OWL to allow probabilistic knowledge to
  be represented in an ontology.
• Used for reasoning with Bayesian inference.
• Random variables are described by either a PR-OWL
  table (discrete probability) or using a
  proprietary format.
• Other standards looking at similar concepts
• BayesOWL.
• FuzzyOWL.

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What next?

• A formal open standard for quantifying complex
  uncertainties
• Extend to allow continuous distributions
• More powerful reasoning, richer representations

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UNCERTML
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OVERVIEW

• Split into three distinct packages
  (distributions, statistics realisations).

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DISTRIBUTIONS
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UNCERTML

• An overview

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WEAK VS. STRONG

• Weak-typed

• Strong-typed

• Benefits
• Generic features have generic properties
  extensible
• Drawbacks
• Validation becomes less meaningful

• Benefits
• Produces relatively simple XML features
• Drawbacks
• Not easily extended all domain features must be
  known a priori

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THE UNCERTML DICTIONARY

• Weak-typed designs rely on dictionaries.
• Includes definitions of key distributions
  statistics.
• URIs link to dictionary entry and provide
  semantics.
• Could be written in Semantic Web standards (OWL,
  RDF etc).

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UNCERTML DICTIONARY EXAMPLE
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SEPARATION OF CONCERNS

• Several competing standards already exist
  addressing the issue of units and location.
• Geospatial information not always relevant
  Systems biology.
• Do what we know do it well!

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UNCERTML

• An applied case study

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THE INTAMAP PROJECT

• An automatic, interoperable service providing
  real time interpolation between observations.
• EURDEP providing radiological data as a case
  study.
• Provide real time predictions to aid risk
  management through a Web Processing Service
  interface.

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UNCERTML IN INTAMAP
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COMPARING PREDICTIONS WITH AND WITHOUT UNCERTML

• Without UncertML

• With UncertML

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CONCLUSIONS

• Currently no interoperable standard which fully
  describes random variables.
• UncertML provides an extensible, weak-typed,
  design that can quantify uncertainty using
• Distributions.
• Statistics.
• Realisations.
• Provide richer information for use in decision
  support systems.

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UNCERTML IN INTAMAP