WESO SATBI 2011

  • 426 views
Uploaded on

 

More in: Technology , Education
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
426
On Slideshare
0
From Embeds
0
Number of Embeds
1

Actions

Shares
Downloads
1
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Application of the Spreading Activation Technique for RecommendingConcepts of well-known Ontologies in Medical Systems José María Álvarez Rodríguez WESO-Universidad de Oviedo http://purl.org/weso/ First International Workshop on Semantic Applied Technologies on Biomedical Informatics (SATBI 2011) In conjunction with ACM International Conference on Bioinformatics and Computational Biology (ACM-BCB) Chicago, IL, U.S.A. August 1-3, 2011
  • 2. IntroductionPsycho linguistics andSemantic priming
  • 3. Retrieve data as brain can do...a connectionist method
  • 4. New information realm...Semantic Technologies Linked Data... Different scopes...E-Health, E-procurement, etc.
  • 5. E-Health Sector Need to automate processes combine and synthesize complex related pieces of informationfacilitate access to clinical informationidentify patterns within the patient data …
  • 6. How to selectrelated concepts (symptoms & diseases)?
  • 7. Tagging of EHR CDSS
  • 8. Graph Exploration Document Retrieval Information Retrieval Annotation & TaggingRecommending enginesSemantic Search Engines
  • 9. Open GALEN“Ontologies” are consideredcategories: 23,141 concepts 950 relations… to facilitate clinical apps & statistics
  • 10. SNOMED CT765,000 active English-language descriptions 830,000 logically-defining relationships… Data retrieve & analysis, tagging…
  • 11. Summary... Concepts RelationsApps to retrieve, analyze, annotate …a huge amount of medical data
  • 12. GRAPHEXPLORATION?
  • 13. Spreading Activation (SA) 3 Stages Activation functionCalculation of activation value Constrained SA Stop condition
  • 14. 3 Stages PreadjustmentInitial nodes, weights of relations, set functions… Execution Spread the activation value, graph exploration… Postadjustment Rank nodes…
  • 15. Variables & Constants/  E E t
  • 16. Activation functionCalculation of activation value
  • 17. Graphically Activation function
  • 18. Constrained SA DistanceNodes far from an activate node should be penalized Path Path of activation built by the algorithm Fan outNodes highly connected should not be representative Activation-thresholdSpread nodes have an activation value >= threshold
  • 19. Stop ConditionThere is no node to spread with an activation value > Min Activation Value Threshold
  • 20. ONTOSPREAD http://code.google.com/p/ontospread/ API JavaExtensible (intensive use of design patterns)Add new constraints to SA Context, time, output degradation … 3 Tools library, test module & graphical debugger
  • 21. New constraints1) Context of activation2) Min activation value*3) Max & Min spread concepts4) Time of execution5) Degradation Functions
  • 22. Degradation Functions1) Generic2) Distance-Based3) Beats-based (k number of iterations)
  • 23. Converging Paths Reward
  • 24. Implementation1) Set of activated nodes2) Set of spread nodes 3) Activation value
  • 25. ONTOSPREAD in Action
  • 26. ^ Z
  • 27. Methodology1. Select well-known ontologies2. Define a set of initial concepts3. Specify the weight of relations4. Combine restrictions5. Select degradation function6. Add reward function7. Test & repeat!
  • 28. Open GALEN1. Ontology2. #Advanced-BreastCancer & NAMEDSymptom3. Default value 1.04. Constrained SA + New restrictions5. H1 H26. No | Yes
  • 29. SNOMED-CT1. Ontology2. #Articular cartilage of lunate & #Articular tissue sample3. Default value 1.04. Constrained SA + New restrictions5. H1 H26. No | Yes
  • 30. Use Cases BOPA Project (semantic searh engine of legal documents) http://www.w3.org/2001/sw/sweo/public/UseCases/CTIC/ 10ders Project(recommendation of public procurement notices) http://purl.org/weso/moldeas/
  • 31. Evaluation1. Close to the human brain behaviour2. Configurable & extensible framework3. Flexibility & scalability ..but...A domain-expert is still needed
  • 32. Further Steps1. Automatic configuration of the algorithm2. Development of Map- Reduce version of SA (to be published)
  • 33. Application of the Spreading Activation Technique for RecommendingConcepts of well-known Ontologies in Medical Systems José María Álvarez Rodríguez WESO-Universidad de Oviedo http://purl.org/weso/ First International Workshop on Semantic Applied Technologies on Biomedical Informatics (SATBI 2011) In conjunction with ACM International Conference on Bioinformatics and Computational Biology (ACM-BCB) Chicago, IL, U.S.A. August 1-3, 2011