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What are Geospatial Ontologies Good For? Geospatial Ontologies Workshop National Science Foundation 20–22 June, 2006. Richard Waldinger Artificial Intelligence Center SRI International. Choreographing Multiple Resources. Software and data. Local and Web-based.
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What are Geospatial Ontologies Good For?Geospatial Ontologies WorkshopNational Science Foundation 20–22 June, 2006 Richard Waldinger Artificial Intelligence Center SRI International
Choreographing Multiple Resources • Software and data. • Local and Web-based. • Not intended to work together; disagree in • names. • units. • coordinate systems. How to get them to cooperate on a common task? Waldinger
Deductive Choreography • Phrase task as theorem to be proved. • Extract solution from proof. • Use deductive inference to • Identify relevant resources. • Compose them to solve the task at hand. Waldinger
Subject Domain Theories • An ontology is a (sometimes impoverished) axiomatic theory. • Subject domain theory provides knowledge necessary to • Describe task. • Characterize capabilities of resources. • Relate task description to resource characterizations. Waldinger
Axiomatic Advertisement An axiom that describes the capabilities of a resource: • What it produces. • What it requires. Waldinger
Procedural Attachment • Link symbol in theory to external resource. • When symbol appears in proof search, resource may be invoked. • Information provided by resource may be used to complete proof. Theory virtually extended to include the information provided by the resource. • e.g., multiplication, gazetteer. Waldinger
Translation Resources Translate information in the form produced by one resource into the form required by another resource. E.g., • multiplication by a constant (unit conversion). • coordinate system transformation. • name translation (Kabul -> Kabol) Waldinger
Strategic Controls • Use control strategies tailored to the specific subject domain. E.g., • symbol weights (determine which agenda item to attack first). • symbol ordering (determine which subexpression of an agenda item to attack first). • Theorem prover with an appropriate control strategy can exhibit high performance on the selected subject domain. Waldinger
Combining Theories • Need to incorporate theories developed by others. • Disparate theories may use • different symbols with same meaning. • same symbol with different meaning. • Use category-theory ideas (colimit, Burstall/Goguen) to combine disparate theories. • diagram links concepts to be identified. • unlinked concepts are kept distinct. • new axioms relate concepts from different theories. Waldinger
Applications of Deductive Choreography • Amphion (planetary astronomy; Lowry, NASA). • Quark (intelligence analysis). • GeoLogica (earth systems science). • BioDeducta (molecular biology). • Infomaster (real estate search; Genesereth, Stanford). • Ariadne (travel agent; Minton/Knoblock, ISI). Waldinger
Logical form of an English Query show(?y) & petrified.forest(?y) & in(?y, zimbabwe) & within(?y, ?z, feature(city, lusaka, zambia)) & measure.of(?u, ?z) mile.unit(?u) & value.of(?u, 200) & north.of (?y, ?v) & capital.of(?v, botswana) Show a petrified forest in Zimbabwe within 200 miles of Lusaka, Zambia and north of the capital of Botswana. Waldinger
Geographical Theory: Names • Hierarchical place-naming scheme: feature(city,portland, feature(state, oregon, united-states)) • Internal representation, not visible to user. “Portland, Oregon, United States.” • use of functional terms (not just relations). Waldinger
Multiple Geographical Sources • Alexandria Digital Library Gazetteer. • CIA World Factbook. • Semantic Web Browser (ASCS). • NASA Data Sources (Landsat, GDAAC). • Information Extraction Engine (TextPro). • easy to add new sources. Waldinger
An Axiomatic Advertisement region-to-bounding-box(?country) = bounding-box(?north, ?south, ?east, ?west) name(?region-name, ?country) & region-latlong(?region-name, “country”, ?north, ?south, ?east, ?west) Waldinger
Procedural Attachment to ADL Gazetteer region-latlong(“Afghanistan”, “country”, ?north, ?south, ?east, ?west) region-latlong(“Afghanistan”, “country”, 39.11, 28.65, 75.65, 59.9) • use of 5-place relation symbol. Waldinger
Some Translation Resources inch = 254/10000 * meter foot = 12 * inch …. lat-long-real(?lat-real, ?long-real) = lat-long-compass(lat-comp-r(?lat-real), long-comp-r(?long-real)) lat-long-real(39.28, -76.6) = lat-long-compass(39°17’ N, 76°36’ W) • use of equality Waldinger
Resource Cooperation in the Petrified Forest • CIA World Factbook found capital of Botswana • ADL supplied bounding boxes or latitudes and longitudes for Zimbabwe, Botswana, Zambia, Lusaka, and Gabarone. • ADL found “Makuku Fossil Forest” in Zimbabwe. • Geographical computation agent checked north/south relation • Translation agent transformed latitudes and longitudes. • Geographical agent checked distance between forest and Lusaka (112 miles). • TerraVision 3d terrain viewer displayed forest. Waldinger
Makuku Fossil Forest Show a petrified forest in Zimbabwe north of Lusaka, Zambia and within 200 miles of the capital of Botswana. Show a petrified forest in Zimbabwe within 200 miles of Lusaka, Zambia and north of the capital of Botswana. Waldinger
Requirements on Formalism • n-place relations. • function symbols and equality. • full logical connectives and quantifiers. • true negation. • temporal primitives. • optional closed-world assumption. Waldinger
Requirements on Inference • Answer extraction. • Procedural attachment. • Large theory. • Theory-specific control strategy. • Temporal Inference Facility. • SNARK (SRI, Stickel) Waldinger
How to Formulate Query? • English • used in Quark, GeoLogica • hard to tell user what the system can understand. • Interactive guided query formulation • elicit query from user • used in Amphion, BioDeducta (soon). • can be clunky. Waldinger
Reference http://www.ai.sri.com/project/aquaint Waldinger