LinkedGeoData and GeoKnow

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LinkedGeoData and GeoKnow

  1. 1. LinkedGeoData and GeoKnow Claus Stadler Jens Lehmann 2013-09-19 Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 1 / 55
  2. 2. Outline 1 Motivation for LinkedGeoData 2 OpenStreetMap 3 LinkedGeoData Architecture 4 Sparqlify and Tag Mappings 5 Access and Statistics 6 Use Cases 7 GeoKnow Project Overview 8 GeoKnow Achievements Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 2 / 55
  3. 3. Outline 1 Motivation for LinkedGeoData 2 OpenStreetMap 3 LinkedGeoData Architecture 4 Sparqlify and Tag Mappings 5 Access and Statistics 6 Use Cases 7 GeoKnow Project Overview 8 GeoKnow Achievements Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 3 / 55
  4. 4. Motivation Ease information integration tasks that require spatial knowledge, such as Oerings of bakeries next door Map of distributed branches of a company Historical sights along a bicycle track LOD cloud contains data sets with spatial features e.g. Geonames, DBpedia, US census, EuroStat But: they are restricted to popular or large entities like countries, famous places etc. or specic regions Therefore they lack Stadler, Lehmann (Univ. Leipzig) buildings, roads, mailboxes, etc. LinkedGeoData and GeoKnow 2013-09-19 4 / 55
  5. 5. Outline 1 Motivation for LinkedGeoData 2 OpenStreetMap 3 LinkedGeoData Architecture 4 Sparqlify and Tag Mappings 5 Access and Statistics 6 Use Cases 7 GeoKnow Project Overview 8 GeoKnow Achievements Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 5 / 55
  6. 6. OpenStreetMap - Datamodel Basic entities are: Latitude, Longitude. Sequence of nodes. Relations Associations between any number of nodes, ways and relations. Every member in a relation plays a certain role. Each entity may be described with tags (= key-value pairs) Nodes Ways A way is closed if the ID of the last referenced node equals that of the rst one. Whether a closed way denotes a linear ring or a polygon (i.e. whether the enclosed area is part of the respective OSM entity) depends on the tags. Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 6 / 55
  7. 7. Example: Leipzig's Zoo Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 7 / 55
  8. 8. Comparison: Leipzig's Zoo (OpenStreetMap) Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 8 / 55
  9. 9. Comparison: Leipzig's Zoo (GoogleMaps) Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 9 / 55
  10. 10. Outline 1 Motivation for LinkedGeoData 2 OpenStreetMap 3 LinkedGeoData Architecture 4 Sparqlify and Tag Mappings 5 Access and Statistics 6 Use Cases 7 GeoKnow Project Overview 8 GeoKnow Achievements Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 10 / 55
  11. 11. LGD Architecture Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 11 / 55
  12. 12. Tag Mappings Key-value pairs will be assigned to RDF ressources Each pair (k , v ) can be annotated with datatypes, language tags, classes Mappings are themselves tables Example table: k lgd_map_literal name name:en alt_label note ... Stadler, Lehmann (Univ. Leipzig) property rdfs:label rdfs:label skos:altLabel rdfs:comment ... LinkedGeoData and GeoKnow lang en ... 2013-09-19 12 / 55
  13. 13. View Denition RDF mapping of the data from a PostgreSQL database Create View lgd_nodes As Construct { ?n a lgdm:Node . ?n geom:geometry ?g . ?g ogc:asWKT ?o . } With ?n = uri(lgd:node, ?id) ?g = uri(lgd-geom:node, ?id) ?o = typedLiteral(?geom, ogc:wktLiteral) From nodes Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 13 / 55
  14. 14. Sparqlify SPARQL-SQL Rewriter Rewrites SPARQL Queries according to the view denition Platform module oers SPARQL Endpoint and Linked Data interface https: //github.com/AKSW/Sparqlify Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 14 / 55
  15. 15. Rest-API Oers REST methods for frequent queries Based on SPARQL (Virtuoso) endpoint Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 15 / 55
  16. 16. Downloads RDF dataset for download Generated using Construct { ?s ?p ?o } http: //downloads.linkedgeodata.org Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 16 / 55
  17. 17. Outline 1 Motivation for LinkedGeoData 2 OpenStreetMap 3 LinkedGeoData Architecture 4 Sparqlify and Tag Mappings 5 Access and Statistics 6 Use Cases 7 GeoKnow Project Overview 8 GeoKnow Achievements Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 17 / 55
  18. 18. SML Mapping Examples The following slides demonstrate how to map relational data to RDF with the Sparqlication Mapping Language (SML). Thereby, these prexes are used: prex rdfs ogc geom lgd lgd-geom IRI Prexes http://www.w3.org/2000/01/rdf-schema# http://www.opengis.net/ont/geosparql# http://geovocab.org/geometry# http://linkedgeodata.org/triplify/ http://linkedgeodata.org/geometry/ Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 18 / 55
  19. 19. SML - Mapping Example I: The Goal (1/4) Input Table id 1 2 How to map tables to RDF? nodes How to introduce the commonly used distinction in GIS between feature and geometry? geom POINT(0 0) POINT(1 1) Aimed for RDF Output @prefix rdfs: http://www.w3.org/2000/01/rdf-schema# . ... lgd:node1 geom:geometry lgd-geom:node1 . lgd:node2 geom:geometry lgd-geom:node2 . lgd-geom:node1 ogc:asWKT POINT(0 0)^^ogc:wktLiteral . lgd-geom:node2 ogc:asWKT POINT(1 1)^^ogc:wktLiteral . Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 19 / 55
  20. 20. SML - Mapping Example I: SML Syntax Outline (2/4) Input Table id 1 2 nodes geom POINT(0 0) POINT(1 1) Create View myNodesView As Construct { ... } With ... From ... Aimed for RDF Output @prefix rdfs: http://www.w3.org/2000/01/rdf-schema# . ... lgd:node1 geom:geometry lgd-geom:node1 . lgd:node2 geom:geometry lgd-geom:node2 . lgd-geom:node1 ogc:asWKT POINT(0 0)^^ogc:wktLiteral . lgd-geom:node2 ogc:asWKT POINT(1 1)^^ogc:wktLiteral . Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 20 / 55
  21. 21. SML - Mapping Example I: Construct and From (3/4) Input Table id 1 2 nodes geom POINT(0 0) POINT(1 1) Create View myNodesView As Construct { ?n geom:geometry ?g . ?g ogc:asWKT ?o } With ... From nodes Aimed for RDF Output @prefix rdfs: http://www.w3.org/2000/01/rdf-schema# . ... lgd:node1 geom:geometry lgd-geom:node1 . lgd:node2 geom:geometry lgd-geom:node2 . lgd-geom:node1 ogc:asWKT POINT(0 0)^^ogc:wktLiteral . lgd-geom:node2 ogc:asWKT POINT(1 1)^^ogc:wktLiteral . Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 21 / 55
  22. 22. SML - Mapping Example I: Complete! (4/4) Input Table id 1 2 nodes geom POINT(0 0) POINT(1 1) Create View myNodesView As Construct { ?n geom:geometry ?g . ?g ogc:asWKT ?o } With ?n = uri(lgd:node, ?id) ?g = uri(lgd-geom:node, ?id) ?o = typedLiteral(?geom, ogc:wktLiteral) From nodes Aimed for RDF Output @prefix rdfs: http://www.w3.org/2000/01/rdf-schema# . ... lgd:node1 geom:geometry lgd-geom:node1 . lgd:node2 geom:geometry lgd-geom:node2 . lgd-geom:node1 ogc:asWKT POINT(0 0)^^ogc:wktLiteral . lgd-geom:node2 ogc:asWKT POINT(1 1)^^ogc:wktLiteral . Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 22 / 55
  23. 23. SML Mapping Examples A more complex example, which demonstrates the use of an SQL mapping table and an SQL helper view. Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 23 / 55
  24. 24. SML - Mapping Example II: The Goal (1/8) Input Table id 1 1 1 1 1 node_tags k name name:en amenity addr:street addr:city v Universitaet Leipzig University of Leipzig university Augustusplatz Leipzig Aimed for RDF Output @prefix rdfs: http://www.w3.org/2000/01/rdf-schema# . @prefix lgd: http://linkedgeodata.org/triplify/ . lgd:node1 rdfs:label Universitaet Leipzig . lgd:node1 rdfs:label University of Leipzig@en . Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 24 / 55
  25. 25. SML - Mapping Example II: Source Data (2/8) OSM Table id 1 1 1 1 1 node_tags k name name:en amenity addr:street addr:city v Universitaet Leipzig University of Leipzig university Augustusplatz Leipzig Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 25 / 55
  26. 26. SML - Mapping Example II: Mapping Table (3/8) OSM Table id 1 1 1 1 1 node_tags k name name:en amenity addr:street addr:city RDF Mapping Table v Universitaet Leipzig University of Leipzig university Augustusplatz Leipzig Stadler, Lehmann (Univ. Leipzig) k lgd_map_literal name name:en alt_label note ... LinkedGeoData and GeoKnow property rdfs:label rdfs:label skos:altLabel rdfs:comment ... lang en ... 2013-09-19 26 / 55
  27. 27. SML - Mapping Example II: Helper View (4/8) OSM Table id node_tags 1 1 1 1 1 k name name:en amenity addr:street addr:city RDF Mapping Table v Universitaet Leipzig University of Leipzig university Augustusplatz Leipzig k lgd_map_literal name name:en alt_label note ... property rdfs:label rdfs:label skos:altLabel rdfs:comment ... lang en ... Helper View lgd_node_tags_literal id 1 1 ... property rdfs:label rdfs:label ... v Universitaet Leipzig University of Leipzig ... lang en ... SELECT id, property, v, lang FROM node_tags, lgd_map_literal WHERE node_tags.k = lgd_map_literal.k Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 27 / 55
  28. 28. SML - Mapping Example II: SML View (5/8) Logical Table id 1 1 ... SML View lgd_node_tags_literal property rdfs:label rdfs:label ... v Univ. L. Univ. of L. ... Stadler, Lehmann (Univ. Leipzig) lang en ... Create View lgd_node_tags_text As Construct { LinkedGeoData and GeoKnow 2013-09-19 28 / 55
  29. 29. SML - Mapping Example II: SML View (6/8) Logical Table id 1 1 ... SML View lgd_node_tags_literal property rdfs:label rdfs:label ... v Univ. L. Univ. of L. ... Stadler, Lehmann (Univ. Leipzig) lang en ... Create View lgd_node_tags_text As Construct { ?s ?p ?o . } With ... From lgd_node_tags_literal LinkedGeoData and GeoKnow 2013-09-19 29 / 55
  30. 30. SML - Mapping Example II: SML View (7/8) Logical Table id 1 1 ... SML View lgd_node_tags_literal property rdfs:label rdfs:label ... v Univ. L. Univ. of L. ... Stadler, Lehmann (Univ. Leipzig) lang en ... Create View lgd_node_tags_text As Construct { ?s ?p ?o . } With ?s = uri(lgd:node, ?id) ?p = uri(?property) ?o = plainLiteral(?v, ?lang) From lgd_node_tags_literal LinkedGeoData and GeoKnow 2013-09-19 30 / 55
  31. 31. SML - Mapping Example II: SML View (8/8) Logical Table SML View + Create View lgd_node_tags_text As Construct { ?s ?p ?o . } With ?s = uri(lgd:node, ?id) ?p = uri(?property) ?o = plainLiteral(?v, ?lang) From lgd_node_tags_literal id 1 1 ... lgd_node_tags_literal property rdfs:label rdfs:label ... v Univ. L. Univ. of L. ... lang en ... Resulting RDF @prefix rdfs: http://www.w3.org/2000/01/rdf-schema# . @prefix lgd: http://linkedgeodata.org/triplify/ . lgd:node1 rdfs:label Universitaet Leipzig . lgd:node1 rdfs:label University of Leipzig@en . Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 31 / 55
  32. 32. Further Tag Mappings decide datatype based on key: lgd_map_dataype k seats unisex datatype integer boolean decide property: based on key: lgd_map_property k website property foaf:homepage decide predicate and object based on key (e.g. class assertion): lgd_map_resource_k k highway property rdf:type object lgdo:HighwayThing decide predicate and object based on key and value: lgd_map_resource_kv k waterway v river property rdf:type Stadler, Lehmann (Univ. Leipzig) object lgdo:River LinkedGeoData and GeoKnow 2013-09-19 32 / 55
  33. 33. LGD Edit Tool Automatic heuristics for mappings + Multi user tag mapping web application for manual renements Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 33 / 55
  34. 34. Ontology Lightweight: taxonomy + domain/range axioms 1200+ classes Enriched classes and properties with multilingual labels from TranslateWiki http://translatewiki.net Imported icons for 90 classes from the freely available icon collection from the SJJB Management http://www.sjjb.co.uk/mapicons/ Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 34 / 55
  35. 35. Outline 1 Motivation for LinkedGeoData 2 OpenStreetMap 3 LinkedGeoData Architecture 4 Sparqlify and Tag Mappings 5 Access and Statistics 6 Use Cases 7 GeoKnow Project Overview 8 GeoKnow Achievements Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 35 / 55
  36. 36. Resources Sparqlify http://sparqlify.org LinkedGeoData http://linkedgeodata.org Tag Mappings https://github.com/GeoKnow/LinkedGeoData/blob/master/linkedgeodata-core/src/main/resources/ org/aksw/linkedgeodata/sql/Mappings.sql SML View Denitions https://github.com/GeoKnow/LinkedGeoData/blob/master/linkedgeodata-core/src/main/resources/ org/aksw/linkedgeodata/sml/LinkedGeoData-Triplify-IndividualViews.sml Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 36 / 55
  37. 37. Statistics (15 August 2013) Complete OSM planet le corresponds to ∼ 20.000.000.000 triples Virtual access via Sparqlify Full download: ca. 120 GB bz2 compressed (ca. 2.5 TB uncompressed) 2.7 MB ontology Downloads for important fragments available (no roads etc.): 292.780.188 Triples 153.613.243 triples of Nodes 139.166.945 triples of Ways Relations not yet available for download Among them 532.812 PlaceOfWorship 82.788 RailwayStation 72.091 Toilets 71.613 Town 19.937 City Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 37 / 55
  38. 38. Access Materialized Sparql Endpoint (based on Virtuoso DB, download datasets loaded) http://linkedgeodata.org/sparql http://linkedgeodata.org/snorql Virtual Sparql Endpoint (based on Sparqlify, access to 20B triples, limited SPARQL 1.0 support) http://linkedgeodata.org/vsparql http://linkedgeodata.org/vsnorql Rest Interface (based on the Virtual Sparql Endpoint) Supports limited queries (e.g. circular/rectangular area, ltering by labels) Downloads http://downloads.linkedgeodata.org Monthly updates on the above datasets envisioned Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 38 / 55
  39. 39. Outline 1 Motivation for LinkedGeoData 2 OpenStreetMap 3 LinkedGeoData Architecture 4 Sparqlify and Tag Mappings 5 Access and Statistics 6 Use Cases 7 GeoKnow Project Overview 8 GeoKnow Achievements Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 39 / 55
  40. 40. Use Cases Augmented Reality Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 40 / 55
  41. 41. Use Cases Generic Browsing Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 41 / 55
  42. 42. Use Cases Generic Browsing Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 42 / 55
  43. 43. App Generation Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 43 / 55
  44. 44. Event Management Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 44 / 55
  45. 45. Outline 1 Motivation for LinkedGeoData 2 OpenStreetMap 3 LinkedGeoData Architecture 4 Sparqlify and Tag Mappings 5 Access and Statistics 6 Use Cases 7 GeoKnow Project Overview 8 GeoKnow Achievements Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 45 / 55
  46. 46. Project Overview Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 46 / 55
  47. 47. Outline 1 Motivation for LinkedGeoData 2 OpenStreetMap 3 LinkedGeoData Architecture 4 Sparqlify and Tag Mappings 5 Access and Statistics 6 Use Cases 7 GeoKnow Project Overview 8 GeoKnow Achievements Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 47 / 55
  48. 48. Achievements - Linked Data Stack Many SW tools support one or more life-cycle stages Linked Data Stack (http: Interlinking / Fusing //stack.linkeddata.org) Manual revision/ Authoring provides a consolidated repository of such tools Each tool is a Debian package Classification/ Enrichment Linked Data Lifecycle Storage/ Querying Lightweight integration between Quality Analysis tools via common vocabularies and SPARQL Evolution / Repair Extraction Demonstrator interfaces for Search/ Browsing/ Exploration showing tools in combination Developed by LOD2 and GeoKnow Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 48 / 55
  49. 49. Achievements - Benchmarking Intensive work on benchmarking geospatial systems Slippy map benchmark for standard web map applications and other benchmarks to follow State of the Art Analysis for Triple Stores performed (Virtuoso, uSeekM, Parliament, AllegroGraph, OWLIM-SE, Strabon + Oracle Spatial 11g, PostGIS as reference) using fragments of OSM and Ordnance Survey data High deviation in performance and supported functionality between geospatial triple stores GeoSPARQL compliance not achieved yet More specic results to be published throughout the project . . . Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 49 / 55
  50. 50. Achievements - Sparqlify SPARQL-SQL rewriter Rewrites a SPARQL query to a single SQL query allowing the underlying database to perform optimizations Improved extensibility of Sparqlify's model of the underlying database: Custom SQL functions can now be programatically declared. Web interface with syntax highlighting and live data generation for easy mapping creation Many bug xes, new optimizations (SQL, LEFT JOIN, ORDER BY) Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 50 / 55
  51. 51. Achievements - LinkedGeoData LinkedGeoData conversion simplied to a set of SQL les and Sparqlify Mapping Denitions Monthy dumps now working and automatically scheduled 1 2 LinkedGeoData and Sparqlify are available as Debian Packages! 1 2 https://github.com/AKSW/Sparqlify https://github.com/GeoKnow/LinkedGeoData Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 51 / 55
  52. 52. Achievements - TripleGeo Converts shapeles /spatial DBMS output to RDF Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 52 / 55
  53. 53. Achievements - Linking Orthodromic distance only supported by LIMES and SILK Linking algorithm ORCHID for geospatial data Reduces number of comparisons For DBpedia (threshold in kilometres): Runtime (ms) 107 106 ORCHID SILK 105 104 0.1 0.2 0.5 1 Threshold Linking papers at ESWC'13 (linking + cloud, best paper award) and ISWC'13 (ORCHID algorithm) Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 53 / 55
  54. 54. Achievements - Facete Generic faceted browser for HTTP SPARQL endpoints Nested facets and client side pagination without pre-processing Tested with up 10K spatial objects → Goal is to work with DBpedia/LGD Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 54 / 55
  55. 55. The End Claus Stadler cstadler@informatik.uni-leipzig.de AKSW/Uni Leipzig Jens Lehmann lehmann@informatik.uni-leipzig.de AKSW/Uni Leipzig Geo Know http://geoknow.eu Stadler, Lehmann (Univ. Leipzig) LinkedGeoData and GeoKnow 2013-09-19 55 / 55

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