Owl is an ontology language designed for the semantic. Raja mohan associate professor department of computer science. They allow the encoding of knowledge about specific domains and often include reasoning rules that support the processing of that knowledge. We propose a schema using the web ontology language owl to represent course ontologies in a standard and sharable way. Ontology is the core technology for the semantic web and this mechanism for representing formal and shared domain descriptions. It uses uris to identify web resources and to describe the relations between these resources, using a graph model. Owl web ontology language guide world wide web consortium. Web ontology language owl introduction to ontologies and. One use for owl may be the to be able to hold the concept of owl, youll need to understand terms such as. Design and analytical information extraction from educational resources. Constructing railway ontology using web ontology language. Nonvegetarianpizza is exactly pizza that is not vegetarianpizza. Owl 2 language is a new version, it is a w3c recommendation since october 2009.
A comparative study of ontology building tools in semantic. The web ontology language owl extends rdf and rdfs. A novel approach for selectively processing relevant parts of the ontology is given. Owl web ontology language owl is an ontology language standard for web applications of ontologies the semantic web. Webbased ontology languages and its description logics 1. Unfortunately, not everything from rdf can be expressed in dl. Using web tools for constructing an ontology of different. A slot corresponds to a role in a description logic, and a slot. Owl 5 the disadv an tage of owl f ull is the language has b ecome so p ow erful as to b e undecidable, dashing an y hope of complete let alone e. Pdf introduction to web ontology language owl requirements for ontology languages three species of owl syntactic forms of owl. The rdf subset of owl is the language for sharing just the data elements.
W3c web ontology working group has recently developed owl as an ontology language for the semantic web. Although many factors come into deciding the appropriate sublanguage to use, there are some simple rules of thumb. The ontology web language owl is a set of markup languages which are designed for use by applications that need to process the content of information instead of just presenting information to humans the owl ontology describe the hierarchical organization of ideas in a domain, in a way that can be parsed and understood by software. Ontologies and the semantic web school of informatics. Other vocabulary definition technologies, like owl or skos, build on rdfs and provide language for defining structured, webbased ontologies which enable richer integration and interoperability of data among descriptive communities. A vocabulary used to describe a particular view of some domain an explicit specification of the intended meaning of the vocabulary. Hierarchical course knowledge representation using. Representing information using the web ontology language. The term owl is generally used to refer particularly to the semantic markup used to annotate such rdf data. We then describe the threelayered architecture of the owl language, and we describe all of the language constructs of owl in some detail. Owl 10 is a new ontology language for the semantic web, developed by the world wide web consortium w3c web ontology working group. One of the main tools for this is owl, an ontology computer language. Thus, the proliferation of ontologies factors largely in the semantic webs success. A practical guide to building owl ontologies using the.
Semantic web representation and reasoning of data using. Owl was primarily designed to represent information about categories of objects and how objects are interrelatedthe sort of information that is often called an ontology. Phd thesis, university of karlsruhe, karlsruhe, germany, january 2006. Pdf on sep 1, 2007, goutam kumar saha and others published web. However, because owl does not have the fullfledged semantics for temporal information, it cannot perform reasoning about temporal knowledge. The w3c owl 2 web ontology language owl is a semantic web language designed to represent rich and complex knowledge about things, groups of things, and relations between things. Web ontology language owl is an ontology language designed for the semantic web it provides a rich collection of operators for forming concept descriptions it is a w3c standard, promoting interoperation and sharing between applications it has been designed to be compatible with existing web standards. Representing knowledge there are a number of options as objects, using the wellaccepted techniques of objectoriented analysis and design to capture a model as clauses, going back to the early days of ai and lisp as xml, using the industrystandard structured markup language as graphs, making use of the things we know about graph theory. Owl 1 language is a w3c recommendation since february 2004. Owls is based on ontologies of objects and concepts defined using the ontology web languageowl. One use of formal semantics is to allow humans to reason about the knowl edge. It has been designed to be compatible with existing web standards. Rdf, which is recommended by the w3c, uses uris to identify resources or things the root of.
They are used in agent systems, knowledge management systems, and ecommerce platforms. Web ontology language owl world wide web consortium. Among many ontology languages, the web ontology language owl is the widely accepted as standard for representing and sharing knowledge in the semantic web context. A common claim for all of these approaches is the need for languages to represent the semantic information that this web requiressolving heterogeneous data. In this paper, we proposed ontology based meaningful search using semantic web and natural language processing nlp techniques in the educational domain. For a more detailed synopsis of the three owl sublanguages see the owl web ontology language overview4. It is now possible to refer to the classes we defined in other owl. To construct an ontology one must have an ontology specification language, of which there are several to choose.
Definition an extension of the current web that provides an easier way to find, share, reuse and combine information. Owl has in uences from quite a number of sources, but its main representational facilities are di. An extended uml class, representing an owl datatype property definition. Knowledge representation and reasoning on the semantic. The crux of the semantic web representation and reasoning of data using ontologies. The chapter concludes with two extensive examples of owl ontologies. The ontology web language for services owls is a core set of markup language constructs for describing the properties and capabilities of web services in unambiguous, computerinterpretable form. An ontology is an engineering artefact consisting of.
This is especially important in regards to the web because it offers the hope of organizing the web by meanings, not just by matching strings of characters. Constraints capturing background knowledge about the domain. Rdf is a framework for using and representing metadata and describing the semantics of information about resources on the web in a machineaccessible way. Owl was primarily designed to represent information about categories of objects and how. Introduction to implementing ontologies in the web ontology language owl may 26, 2014 by nico matentzoglu the school of computer science at the university of manchester are pleased to invite you to participate in their internationally renowned owl ontology tutorials. Using web tools for constructing an ontology of different natural languages a ph. In this sense the yellow pages in a phone book is an instantiation of an ontology. Representing knowledge there are a number of options as objects, using the wellaccepted techniques of objectoriented analysis and design to capture a model as clauses, going back to the early days of ai and lisp as xml, using the industrystandard structured markup language. The concept of the semantic web is that information should be given.
Constructing railway ontology using web ontology language and semantic web rule language a. This document is also available in these nonnormative formats. Entities are identified using uris to work in a web setting axioms. Description framework rdf for information representation on the web, to darpa agent. Owl representing information using the web ontology language pdf book download hosted by zachary baker on october 21 2018. Ontology languages are usually declarative languages, are almost always generalizations of frame languages, and are.
Using an ontology for representing the knowledge on. One recent unifying effort in creating the ontology language for the web is the web ontology language owl by the world wide web consortium 21, which together with rdf, forms. Representing information using the web ontology language pdf. Saying that owl is about sharing data using ontologies instead of just sharing ontologies strikes me as misleading. Web, and specialpurposed ontology, such as ebxml that aims to enable enterprises of any size, in any global region, to conduct business using the internet 3. The choice between owllite and owldl may be based upon whether the simple constructs of owllite are su. An ontology defines the terms used to describe and represent an area of knowledge. The semantic web ontology learning for the semantic web alexander maedche and steffen staab, university of karlsruhe the semantic web relies heavily on formal ontologies to structure data for comprehensive and transportable machine understanding. Ontology are formal languages used to construct ontologies. Chapter 2 an introduction to t he owl web ontology language jeff heflin lehigh university abstract. This document demonstrates the use of the owl language to. Rdfs is a generalpurpose language for representing simple rdf vocabularies on the web.
Temporal ontology language for representing and reasoning. Ontologies are critical for applications that need to search across or merge information from diverse communities. Ontologies, semantic web, description logics, frames, rdf. Following this approach, a semantic network of dantes works and of references to primary sources of these works was created. Web ontology languages will be the main carriers of the information that we will want to share and integrate. Owl is a computational logicbased language such that knowledge expressed in owl can be exploited by computer programs, e. Owl example with rdf graph introduction to ontologies. In computer science and artificial intelligence, ontology languages are formal languages used to construct ontologies. Ontologies are used in artificial intelligence, semantic web, software engineering, biomedical information, library science and information architecture as a form of knowledge representation about the world or some part of it.
Description logics as ontology languages for the semantic. Thus, we will delve into different aspects of ontology representation, creation, design, reasoning, programming and applications. However, owl is used in webindependent applications as well. Semantic web aims to make web content more accessible to automated processes adds semantic annotations to web resources ontologies provide vocabulary for annotations terms have well defined meaning owl ontology language based on description logic exploits results of basic research on complexity, reasoning, etc.
Semantic web, and to discuss the formal foundations of these languages. The web ontology language owl is a family of knowledge representation languages for authoring ontologies. Reasoning in description logics using resolution and deductive databases. Its primary aim is to bring the expressive and reasoning power of description logic to the semantic web. Ontologies are a formal way to describe taxonomies and classification networks, essentially defining the structure of knowledge for various domains. The book has no discussion on inferencing or how to actually make an ontology with owl. Web ontology language owl semantics an owl ontology comprises. Owl 62,30 is an ontology language designed for use in the semantic web and is the language recommended by the w3c for this use. Web schema languages existing web languages extended to facilitate content description xml xml schema xmls rdf rdf schema rdfs xmls not an ontology language changes format of dtds document schemas to be xml adds an extensible type hierarchy integers, strings, etc. Owl example with rdf graph let us illustrate the use of owl vocabulary on an example ontology inspired by owl pizzas.
Tools for data annotation effectively annotating data with ontology terms is an open research problem primary consideration is between coverage and precision, i. An ontology language is a formal language used to encode the ontology. After these general considerations, we now engage in the details of modeling with owl 2. In this chapter we analyse the limitations of rdf schema and derive requirements for a richer web ontology language. The one example is simply a representation of the hours that a. Introduction the owl web ontology language is an international standard for encoding and exchanging ontologies and is designed to support the semantic web. The w3c web ontology language owl is a semantic web language designed to represent rich and complex knowledge about things, groups of things, and relations between things. For example, the classes of classes are not permitted in the chosen dl, and some of the triple expressions would have no. Journal of computing, volume 2, issue 6, june 2010, issn. Owl 2 web ontology language primer world wide web consortium. Technical report, university of manchester, uk pdf 561 kb acknowledgements. Rdf and rdfs allow the representation of some ontological knowledge. This book introduces the subject of ontology, owl, and shows how it can revolutionize the way we use computers.
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