Web Ontology Language
The Web Ontology Language ( OWL short ) is a specification of the World Wide Web Consortium (W3C ) to create, publish and distribute ontologies based on a formal description language. The point is to formally describe terms of a domain and their relationships so that even software (eg, agents) to process the meaning ( "understand" ) can. OWL is thus an integral part of the Semantic Web initiative by Tim Berners- Lee. OWL is technically based on the RDF syntax and DAML OIL historically and goes far beyond the expressive power of RDF Schema addition. In addition to the RDF and RDF Schema additional language constructs are introduced which make it possible to formulate similar to predicate calculus expressions.
- 3.1 classes concerning
- 3.2 Properties concerning
- 3.3 instances concerning
- 5.1 General Tools
- 5.2 frameworks
- 5.3 validation
- 5.4 inference
- 5.5 Other
Abbreviation
The acronym for Web Ontology Language would actually WOL, need not be OWL. On the origin of letter Enver rotator answer can be found in the archives of the W3C. The name of OWL has been obviously suggested by Tim Finin on a mailing list. The originally named by him reasons are as follows:
- It is clear how to pronounce OWL (namely, like the English word for owl).
- The acronym is ideal for creating logos.
- Owls are associated with wisdom.
- There is an interesting back story.
The above-mentioned background story concerns a project of William A. Martin at MIT in the 1970s with the name One World Language, an early attempt at developing a universal language for knowledge representation. The Letter Reversals, however, is no allusion to the literary figure of the owl from Milne's Winnie the Pooh, which can be written as a single animal in the forest its name - but with a transposed letters, in the English original WOL instead of OWL.
Language levels: Lite, DL and Full
There are OWL in three different versions. For this, the levels of language OWL Lite, OWL DL and OWL Full have been defined. For the use of OWL Lite / DL restrictions have been defined, which are intended to facilitate or enable the development of complete inference tools.
OWL Lite
The "Light " version was created with the goal of creating an easy- to-implement subset of the language. It is used primarily for creating simple taxonomies and ontologies easily axiomatisierter. Different language constructs of OWL DL are not available.
OWL DL
This is the level, their semantics most likely come up to DAML OIL. DL stands for the description logic ( description logic), which is equivalent to a decidable subset of first-order predicate logic. To ensure the imageability on this logic, various restrictions on the use of RDFS constructs were inserted, for example, must not be a class instance of another class.
OWL Full
OWL Full is made of the same language constructs such as OWL DL, but dispenses with the existing restrictions there. Thus, the ontologies are undecidable, but it can predicate logic expressions allow for a higher degree.
Language constructs
The specification extends the meaning of RDF and RDF Schema to other constructs in order to increase the expressive power ( or partially restrict to achieve decidability ).
OWL distinguishes classes, properties (properties ) and instances. Classes are available for terms (including concepts, concepts engl. ). You can own properties. Instances are individuals of one or more classes.
Classes concerning
- ...
Properties concerning
- ...
Instances concerning
Example
The example describes the terms
< 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: owl = " # http://www.w3.org/2002/07/owl "
xmlns = " # http://localhost:8080/OWLBuergerInformation.owl "
xml: base = " http://localhost:8080/OWLBuergerInformation.owl " >
General tools
- Eclipse Plugin with Editor, Validator, ... Swede Eclipse Plugin
- Semantic Works from Altova
- Protégé ontology editor with OWL Plugin by Stanford University
- SWOOP formerly developed by mindswap, now at Google Code
Frameworks
- Jena Framework of HP Labs HP Labs Semantic Web Research
- Java API: OWL API
Validation
- OWL Ontology Validator http://owl.cs.manchester.ac.uk/validator/
Inference
- RACER OWL Reasoner
- FaCT
- FaCT Open Source OWL Reasoner
- Pellet OWL Reasoner Open Source
- KAON2 OWL Reasoner with strengths in large instance
Other
- KAON2 OWL tools
- DERI Ontology Management Environment ( DOME )
- UML2OWL Tool - modeling of OWL DL ontologies with UML / transformation of UML class diagrams into valid OWL DL documents
- yEd Graph Editor - Diagram Editor can be clearly visualized with the OWL ontologies