Geospatial Semantic WebHarry [email protected] Matters LLCAn invited talk at UMBC (CMSC 491/691M)March 27, 2007Outline• What’s Geospatial Semantic Web• Real world problems• State-of-the-art solutions• Demo• Q&A+??What’s Geospatial Semantic WebGeospatial + Semantic WebGeospatial Data• Geographic info• Photo imagery• GIS data• Maps• Spatial relations• Places, landmarks etc.• Locations, lat/long etc.• Time• Temporal relations• People• Organizations• Other things …Why is this interesting?• “Location” is ubiquitous on the Web• Where do you go to school or work?• Where did you take your flickr photos?• Where is the nearest gas-station from “here”?• Where are my friends now?• What’s the avg. housing price in my neighborhood?• What’s ski condition in MD and PA?• …The present Web is for humanhttp://hchen1.com/contact-me/biosketch/Your browser doesn’t know that my wife and I live in Columbia Maryland.What’s “london”?It’s “London UK” stupid!What’s “london” to a machine?http://www.geonames.org/search.html?q=london&country=USWhat did we learn?• Most of the information on the Web today is meant for human consumption. • Without an explicit semantic description, it’s difficult for machines to consume Web information. • The study of geospatial semantic web is to exploit Semantic Web and geospatial technology to improve human productivity• i.e., get machines to do more work for us.Real World ProblemsHidden Knowledge on the WebUnstructured DataStructured DataOntological SemanticsApplicationsHow to extract hidden geospatial knowledge from the existing web contents (news, photos, blogs, emails, comments, etc.)Scraping semantics from free textLocation information hidden inside unstructured free textScraping semantics from tagsKnowledge integrationUnstructured DataStructured DataOntological SemanticsApplications How to enable heterogeneous data stores to integrate and interoperate (RDBMS, shapefiles, XML, gazetteer, photo annotations, etc.)Fuse knowledge from multiple datastoresOntology sharing & reuseUnstructured DataStructured DataOntological SemanticsApplicationsHow to encourage people to share ontologies and reuse existing GIS standards (e.g., GML, OGC standards)Many different ways to describe Geo• GML (Geographical Markup Language) backed by OGC (Open Geospatial Consortium)• W3C geo ontology backed by W3C• GeoRSS – a language for embedding location information in RSS• Geonames ontology – an open and free geographical data service• Google KML – used by Google Maps and Google EarthApplication research issuesUnstructured DataStructured DataOntological SemanticsApplicationsHow to make easy for people to publish, annotate and search geospatial semantic information on the WebA mystery to many people • Do you really believe companies can make money from products that require people to edit and query data like this…State-of-the-art SolutionsTechnology overview• Semantic Web vs. semantic web• Publishing W3C geo data on the Web • RDF, Microformats & RDFa• GeoRSS & flickr machine tags• Knowledge integration technology• Mashups and browser add-onsSemantic Web vs. semantic web• There are two different schools of thinking on how semantics should be published, exported and searched on the Web.• http://tantek.com/presentations/2004etech/realworldsemanticspres.htmlRDFXMLOWL MicroformatsRSSGeoRSSRDFaStructured BloggingGeoGMLKMLRDFSrel-taghCardXNFAtom-OWLLoosely defined. No formal semantic model.Defined by the underlying ontology model (e.g., OWL)SemanticMicroformats (based on XHTML)RDF, RDFS, OWLLanguageAnything goes, as long as its XHTMLMust be well-formed RDF documentsFormat Humans first, machines second. Encode existing Web content with special tags.Build a common data format for expressing the meaning of data. Use ontologies to help machines to understand web content.Philosophy XFN (social network), hCard(contact), hReview (opinions), rel-tag (tagging) FOAF, OWL-S, OWL-TimeExamplessemantic webSemantic WebSemantic Web vs. semantic webUsing W3C Geo (RDF)<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#" xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns="http://xmlns.com/foaf/0.1/"> <Person> <name>Dan Brickley</name><homepage dc:title="Dan's home page“rdf:resource="http://danbri.org/"/><based_near geo:lat="51.47026" geo:long="-2.59466"/><rdfs:seeAlso rdf:resource="http:/danbri.org/foaf.rdf"/> </Person></rdf:RDF> “-2.59466”geo:long:_geo:_geofoaf:base_near:_a“51.47026”geo:lat:_geo“Dan Brickley”foaf:name:_afoaf:Personrdf:type:_aObjectPredicateSubjectSource: http://www.w3.org/2003/01/geo/Using Microformats Geo (1)Using Microformats (2)…Currently he lives in Columbia, Maryland (<span class="geo"><span class="latitude"> 39.207806 </span>, <span class="longitude">-76.825475 </span>) with his wife Gigi.</span> …<p class="vcard"><a class="url fn" href="http://harry.hchen1.com">Harry Chen</a>was born in Shanghai, China. He moved to Hong Kong with his parents when he was ten. During the last year of his high school, he studied in the US as an exchange student . He completed undergraduate and graduate studies in Computer Science at the <a title="UMBC" class="org" href="http://www.umbc.edu">University of Maryland, Baltimore County</a>.He was awarded a PhD fellowship from HP Labs for his work on intelligent agents in mobile and pervasive computing.</p>Technorati: Microformats SearchNot yet understand “geo”, but that’s okay. At least it works!http://kitchen.technorati.comRDFa – embedding RDF in XHTML<html xmlns:foaf=“http://xmlns.com/foaf/0.1#”xmlns:geo=“http://www.w3.org/2003/01/geo/wgs84_pos#”> …<p class=“foaf:Person“ about=“#me”><a rel=“foaf:homepage" href="http://harry.hchen1.com">Harry Chen</a>was born in Shanghai, China. He moved to Hong Kong with his parents when he was ten. During the last year of his high school, he studied in the US as an exchange student . He completed undergraduate and graduate studies in Computer Science at the <a title="UMBC" rel=“foaf:schoolHomepage" href="http://www.umbc.edu">University of Maryland, Baltimore County</a>.He was awarded a PhD fellowship from HP Labs for his work on intelligent agents in mobile and pervasive computing.…Currently he lives in Columbia,
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