Ontotext Experience

CTO Research

Our CTO group have researched such tools in May-Aug 2012, investing considerable time (25p/d)

conf page: [Ontotext:CTO Link Discovery] (you may have no access), includes presentation, relevant parts copied below
jira task: ONTOTECH-207 (you may have no access)
overview of SILK, LIMES, FEBRL.
In their opinion SILK is clearly the best
practical experiments with SILK, including:
- DBpedia/Geonames: cities, museums
- DBpedia/MuzicBrainz: music bands
- DrugBank/LinkedCT: drugs vs interventions
SILK test installation is still available

Ontotext IdRF

[IdRF:]: implemented by Milena Yankova as part of her thesis.
Used for an European Skills, Competences and Occupations classification (ESCO) mapping pilot.

Notable Tools

Research this list
Also see [DOM:CLAS#CLAS and ontology matching]

Note: Karma is not a terminology matching tool. It's a data mapping tool, see review: Data Migration and Ingestion Tools#Karma

SILK

Silk - A Link Discovery Framework for the Web of Data
"A tool for discovering relationships between data items within different Linked Data sources. Data publishers can use Silk to set RDF links from their data sources to other data sources on the Web."
Mapping framework for mapping LOD entities, terminologies etc. Includes a workbench, matching engine, server, MapReduce implementation. Excellent scalability, includes distributed processing option.

Output - alignment of entities, connected by owl:sameAs or any other defined predicate

Silk Links

homepage: http://www4.wiwiss.fu-berlin.de/bizer/silk
source: http://www.assembla.com/code/silk/git/nodes
wiki: http://www.assembla.com/spaces/silk/wiki
user manuals: http://wifo5-03.informatik.uni-mannheim.de/bizer/silk/#manual
discussion: http://groups.google.com/group/silk-discussion

Papers:

Silk Implementation

Developed by Chris Bizer with funding by Vulcan Inc and FP7 LOD2

ASL license (version 2)
Implemented in SCALA (see Yammer discussions), a scalable JVM language
Multi-threading support
Source code available and recently updated
Integration: Java API for in-process integration
Server edition allows for reconciliation service implementation - maintains an internal DB of known entities and is capable to process input stream of new data to be reconciled

Silk Rules

Data sets are interlinked via mapping rules. Powerful rules language

mappings based on similarities of property values (labels, names, dates, etc.)
fuzzy match strategies, similarity metrics, data normalisation, aggregation on similarity metrics (min, max, average)
restrictions on (ontology) classes/types

Eg a rule can be: Match cities based on

name (string comparison after lowercase transformation and with certain Levenstein distance tolerance),
population (numeric with certain tolerance) and geographic location;
combined in a certain way

Example linkage (dbpedia:City vs. geonames:P)
Unable to render embedded object: File (silkRule.png) not found.

Silk Rule Development

Manual mapping (via Linkage Rule Editor) - visual interface supports rule development (drag & drop, wizards, templates)
Linkage rule generation
- Suggests pairing candidates and the user approves/rejects suggestions
- Based on the user response the system generates linkage rules using genetic algorithms (interactive rule learning)

STITCH@CATCH

http://stitch.cs.vu.nl/: Vocabulary&Alignment Repository ("Semantic Interoperability To access Cultural Heritage")
"Web-based Repository Service for Vocabularies and Alignments in Cultural Heritage: ESWC10 paper and slides by the current Europeana scientific advisor

A vocabulary server including:

conversion to SKOS
alignment (mapping)
access by Web services, SOAP, JSON...
annotation suggestions, especially for multi-lingual mapping. "subjected a corpus of 250.000 dually indexed books of the National Library of the Netherlands (KB) to an instance-based method to derive an alignment between two KOSs, the Brinkman thesaurus and the Biblion one"
(KB is the host organization for Europeana)
numerous demos
- eg search for "pipe"

Also see CATCH, STITCH for tools from related people

Amalgame

Amalgame is a tool for semi-automatic vocabulary mapping by VU Amsterdam
Loaded with a number of vocabularies.

http://semanticweb.cs.vu.nl/europeana/datacloud: Auto-generated, but doesn't seem to include the complete list
http://semanticweb.cs.vu.nl/europeana/browse/list_graphs
- You can see the number of triples.
  E.g. http://viaf.org/viaf-persons.ttl.gz has 50M (but the file is not available at that URL)
- Many vocabularies are split between several files.
  E.g. search for "iconclass", Then you can learn about it from the various URLs
http://semanticweb.cs.vu.nl/europeana/amalgame/conceptfinder: Browse the different vocabularies

Terminology Matching Tools