Methodological Guidelines for Publishing Government Linked Data

Transcription

1 Methodological Guidelines for Publishing Government Linked Data Boris Villazón-Terrazas, Luis M. Vilches, Oscar Corcho, and Asunción Gómez-Pérez Facultad de Informática, Universidad Politécnica de Madrid Campus de Montegancedo sn, Boadilla del Monte, Madrid {bvillazon, lmvilches, ocorcho, Phone: , Fax: Slides available at: Credits to the OEG members involved in LD Initiatives Universidad Rey Juan Carlos September, 2011

2 ToC Introduction to Linked Data Guidelines for Publishing Government Linked Data Demo 2

3 ToC Introduction to Linked Data Guidelines for Publishing Government Linked Data Demo 3

4 Classic Web MovieDB Data exposed to the Web via HTML, pdf, etc. CIA World FactBook Slide adapted from 5min Introduction to Linked Data - Olaf Hartig 4

5 Classic Web Information from Complex single pages queries can over be multiple found via search pages engines / data sources? Slide adapted from 5min Introduction to Linked Data - Olaf Hartig 5

6 What do we actually want? Use the Web like a single global database CIA World FactBook MovieDB Slide adapted from 5min Introduction to Linked Data - Olaf Hartig 6

7 Linked Data enables such Web of Data Global Identifier: URI (Uniform Resource Identifier), which is a string of characters used to identify a name or a resource on the Internet. Data Model: RDF (Resource Description Framework), which is a standard model for data interchange on the Web Access Mechanism: HTTP Connection: Typed Links Even the Rain CIA World FactBook MovieDB Slide adapted from 5min Introduction to Linked Data - Olaf Hartig 7

8 An extension of the current Web where information data and services are given well-defined and explicitly represented meaning, so that it can be shared and used by humans and machines, better enabling them to work in cooperation In a nutshell How? Promoting information exchange by tagging web content with machine processable descriptions of its meaning. And technologies and infrastructure to do this And clear principles on how to publish data 8

9 The four principles (Tim Berners Lee, 2006) 1. Use URIs as names for things 2. Use HTTP URIs so that people can look up those names. 3. When someone looks up a URI, provide useful information, using the standards (RDF*, SPARQL) 4. Include links to other URIs, so that they can discover more things. esignissues/linked Data.html 9

10 So does that mean I have to publish my data as Linked Data, now? But, why? What was your incentive to publish an HTML page in 1990? Share data in documents and because your neighbor was doing it So, why should we publish Linked Data in 2011? Share data as data and because your neighbor is doing it Slide adapted from Introduction to Linked Data - Juan Sequeda 13

11 And guess who is starting to publish Linked Data now? UK Government US Government BBC Open Calais Freebase NY Times CNET Dbpedia. 14

12 Linked Open Data evolution

13 2011 Linked Open Data Linking Open Data cloud diagram, by Richard Cyganiak and Anja Jentzsch. 16

14 ToC Introduction to Linked Data Guidelines for Publishing Government Linked Data Demo 18

15 Guidelines for Publishing Government Linked Data The process of publishing Government Linked Data has an iterative incremental life cycle model. Based on our experience in the production of Linked Data in several Governmental Contexts, have been applied in real case government scenarios. 19

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18 Specification Identification and analysis of the government data sources URI design Definition of the license 22

19 Identification and analysis of the government data sources We have to distinguish Specification Open and publish data that government agencies have not yet opened up and published Task that may require contacting to specific government data owners to get access to their legacy data Reuse and leverage on data already opened up and published by government agencies Task to look for these data in public government catalogs Open Government Data datacatalogs.org Open Government Catalog 23

20 Specification Identification and analysis of the government data sources After we have identified and selected the government data sources Search and compile all the available data and documentation about those resources Identify the schema of those resources including conceptual components and their relationships Identify the items in the domain, i.e., things whose properties and relations are described in the data sources 24

21 Specification GeoLinkedData Identification of the data sources IGN National Geographic Institute of Spain Agreement with the IGN Oracle & MySQL INE National Statistic Institute of Spain Data sources available in a public data catalog 25

22 Specification GeoLinkedData Analysis of the data sources Year Province Industry Production Index 26

23 Specification URI Design Use meaningful URIs, instead of opaque URIs, when possible Separate TBox (ontology model) from ABox (instances) URIs. Base URI TBox URIs property} ABox URIs

24 Specification GeoLinkedData - URI design Base URI TBox URIs property} ABox URIs type}/{r. name} 28

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26 Modelling Ontology An ontology is an engineering artifact, which provides: A set of terms A set of explicit assumptions regarding the intended meaning of the terms. Almost always including concepts and their classification Almost always including properties between concepts Shared understanding of a domain of interest Ontologies expressed in OWL or RDF(S), both based on RDF 32

27 2. Vocabulary development

28 Modelling Reuse available vocabularies Search for suitable vocabularies Linked Open Vocabularies are there suitable vocabularies? Yes Build the vocabulary by reusing available vocabularies No 34

29 Vocabulary Modelling Reuse available non-ontological resources Highly reliable Web Sites Search for suitable non-ontological resources Domain-related sites Government Catalogs are there suitable resources? Yes Build the vocabulary by transforming available resources No Build the vocabulary from scratch 35

30 Modelling GeoLinkedData hydrographical phenomena (rivers, lakes, etc.) haslat/long W3C Vocabulary WGS84 4 WGS84 Geo Positioning: an RDF vocabulary haslat/long hasstatisticaldata O. Statistics SCOVO scv:dimension scv:item scv:dataset UNESCO EGM / ERM GeoNames hydrontology 4 Ontology for OGC Geography Markup Language hasgeometry haslocation/islocated GML 4 GML Specification hasgeometry FAO FAO Geopolitical ontology on Names and international code systems for territories and groups O. Time W3C Time Ontology Legend Specification Vocabulary for instants, intervals, durations, etc. 4 Classes Object Properties Data Properties Thesaurus 36

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32 Transformation Generation Data cleansing Linking 39

33 Generation Transformation Take the data sources selected in the specification activity and transform them to RDF according to the vocabulary created in the modelling activity Some tools CSV and spreadsheets RDF extension of Google Refine, XLWrap, RDF123, NOR 2 O RDB D2R Server, ODEMapster, W3C RDB2RDF WG R2RML XML GRDDL, ReDeFer 40

34 Generation GeoLinkedData - Transformation NOR 2 O INE ODEMapster IGN Geospatial column Geometry2RDF IGN 41

35 NOR 2 O INE Asunción Gómez Pérez 42

36 Introduction NOR 2 O is a software library for transforming nonontological resources to ontologies. 43

37 NOR data models Non-Ontological Resources Classification Schemes Path Enumeration Adjacency List Snowflake Flattened Thesauri Record based Relation based Lexicons Record based Relation based 44

38 Description The software library needs three configuration files: 1. nor.xml that contains the description of the nonontological resource and includes: - The schema entities of the resource and the relationships among the entities are described in the Schema section. - The descriptions of the resource s internal data model are included in the DataModel section. - The information needed to physically access the resource is defined in the Implementation section. 45

39 Description 2. prnor.xml for describing the transformation between the NOR elements and the ontology elements. It has only one section - PRNOR section, that includes the description of the transformations from the NOR schema components (e.g., schema entities, atributes and relations) into ontology elements (e.g., classes, object properties, datatype properties, and individuals). Additionally it indicates the transformation approach, e.g., TBox, ABox, or Population. 46

40 Description 3. or.xml for describing the ontology to be generated. - OR section, which includes the name, URI, file and implementation language of the ontology. Additionally, this section indicates if the ontology already exists, in the case we want to populate an existing ontology. 47

41 Download You can find the lastest version at: 48

42 How to use the software library? There are 3 configuartion files: nor.xml, for describing the non-ontological resource. prnor.xml, for describing the pattern for re-engineering. or.xml, for describing the ontology generated. There is a batch file nor2o.bat, for performing the transformation Requirements Java runtime environment (tested in 1.5) You should set tha JAVA_HOME to the location of the installation directory.

43 Example 1: Transforming the ASFA thesaurus non-ontological resource: asfa Type: term-based thesaurus Datamodel: record-based Implementation: XML

44 Example 1: Transforming the ASFA thesaurus nor.xml, description of the non-ontological resource

45 Example 1: Transforming the ASFA thesaurus prnor.xml, description of the pattern Transformation approach: TBox Term -> Class or.xml, description of the ontology generated

46 Example 1: Transforming the ASFA thesaurus Run the transformation Execute the nor2o.bat Wait until it finishes, and check the ontology.

47 Industry Production Index Example 2: Industry Production Index, Spreadsheet Year Province NOR 2 O

48 Additional information All the resources, examples, readme file: Questions to bvillazon at fi dot upm dot es 55

49 ODEMapster IGN Asunción Gómez Pérez 56

50 R20: Vista semántica sobre un modelo relacional Ontología O 1 Estación Centro Comunicaciones Ontología O 2 Punto Europeo PuntoGPS Aeropuerto PuntoEspañol PuntoAsiatico Aeropuerto = f (Aeropuertos) PuntoEuropeo = f (Aeropuertos) RC(O 1,M 1 ) RC(O 2,M 1 ) Aeropuertos Modelo Relacional M 1

51 Upgrading Database content to the semantic Web Integrating information from different DB sources Reuse of legacy DBs and legacy ontologies R 2 O: Declarative Mapping description language ODEMapster: Generic query processor. asking queries to a relational database using ontology terms On demand query answering Batch ontology population A well defined method for upgrading and integrating content from heterogeneous sources.

52 Migración de datos a la Web de los Datos - Enfoques, técnicas y herramientas Luis Manuel Vilches Blázquez R 2 O es un lenguaje declarativo que describe mappings entre los esquemas de bases de datos relaciones y ontologías. RDB Relational Model Organization Persons <xml> R 2 O Mapping </xml> Professor Ontology University Student

53 Generation GeoLinkedData - Transformation R 2 O is an extensible, fully declarative language to describe mappings between relational database schemas and ontologies. The ODEMapster processor generates RDF instances from relational instances based on the mapping description expressed in the R 2 O document 60

54 Generation GeoLinkedData - Transformation Creation of the R 2 O Mappings 61

55 Generation Linking Identify suitable data sets as linking targets LIMES Discover relationships between data items Silk Framework Validate the relationships discovered sameas Validator 68

56 Generation GeoLinkedData - Linking GeoLinked Data DBPedia GeoNames. source/madrid s.org/ /. 69

57 Silk Download: Configuration file (xml), main sections Prefixes Datasources Interlinks Interlink LinkType LinkCondition Filter Outputs 70

58 Silk Example : airports (geolinkeddata dbpedia) 71

59 Silk Example : airports (geolinkeddata dbpedia) 72

60 Silk Example : airports (geolinkeddata dbpedia) Accepted links, nt file Links to verify, xml file 73

61 Limes 74

62 Generation GeoLinkedData - Linking 75

63 6. Linking of the RDF Data 76

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65 Dataset publication Publication Metadata publication Dataset discovery 78

66 Publication Dataset Publication Tools for storing RDF Virtuoso Universal Server, Jena, Sesame, 4Store, YARS, OWLIM SPARQL endpoint and Linked Data frontend Pubby, Talis Platform, Fuseki 79

67 Publication Metadata Publication VoID allows to express metadata about RDF datasets Open Provenance Model 80

68 Publication Dataset discovery Register the dataset into CKAN Registry Generate sitemap files for your dataset, by using sitemap4rdf Submit the sitemap location to Google and Sindice

69 82 ckan.net entry example

70 Publication GeoLinkedData HTML Linked Data SPARQL Including Provenance Support Pubby Pubby 0.3 Virtuoso

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72 Exploitation Streaming resources 85

73 Exploitation GeoLinkedData map4rdf: Google maps viewer of RDF resources Resources with spatial information Extensible with google plugins Used in other applications like Aemet, Goodrelations map4rdf SPARQL Triplestore 86

74 DEMO 87

75 88 Provinces

76 89 Capital of Province

77 Provinces Industry Production Index 90

78 91 Beaches

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80 Methodological Guidelines for Publishing Government Linked Data Boris Villazón-Terrazas, Luis M. Vilches, Oscar Corcho, and Asunción Gómez-Pérez Facultad de Informática, Universidad Politécnica de Madrid Campus de Montegancedo sn, Boadilla del Monte, Madrid {bvillazon, lmvilches, ocorcho, Phone: , Fax: Slides available at: Credits to the OEG members involved in LD Initiatives Universidad Rey Juan Carlos September, 2011