I ndo W ord N et Conversion to Web Ontology Language ( OWL ) (2016)

Abstract: WordNet plays a significant role in Linked Open Data (LOD) cloud. It has numerous application ranging from ontology annotation to ontology mapping. IndoWordNet is a linked WordNet connecting 18 Indian language WordNets with Hindi as a source WordNet. The Hindi WordNet was initially developed by linking it to English WordNet. In this paper, we present a data representation of IndoWordNet in Web Ontology Language (OWL). The schema of Princeton WordNet has been enhanced to support the representation of IndoWordNet. This IndoWordNet representation in OWL format is now available to link other web resources. This representation is implemented for eight Indian languages.

## introduction the world wide web (www) has formed a revolution in the data availability there is no other place in the world where we can find so much of the information, but the current web structure fails to make best out of it. the user can access limitless data from the web yet, it becomes a tedious task to retrieve relevant information. data available on the web covers diverse structures, formats and content. it also lacks a uniform organization of scheme that would allow easy access of data and information @xcite . many frameworks have been proposed to support the search engine and information access. resource description framework 1 (rdf), web ontology language 2 (owl) is one of the framework which provides a platform for standardization and organization of data from the web. it has been wordnet @xcite , a lexical knowledge base system that has been adopted by the semantic web research community. the current essential need is to link wordnet with different resources in order to assist natural language processing applications. indowordnet (bhattacharyya, 2010) is an indian community which builds wordnets for indian languages. it is a multilingual wordnet which links wordnets of different indian languages on a common identification number called as synset id given to each concept @xcite . it is constructed using the expansion model where hindi wordnet synsets are taken as a source. the concepts provided along with the hindi synsets are first conceived and appropriate concepts in target language are manually provided by the language experts. figure 1 shows the statistics of indradhanush consortium which consist seven indian languages belonging to indo-aryan family and is part of indowordnet consortium. to use wordnet in semantic web the data model for wordnet should be extensible, interoperable and flexible. it was created as a semantic network of word meanings which at the conceptual level is a directed graph with labeled nodes and arcs @xcite . hence, owl can be used to model wordnet since, it facilitates data manipulations and queries over the graph structure. the main objective of this paper is to represent indowordnet to owl representation. the rest of the paper is organized as follows section 2 describes the related work. section 3 introduces to semantic web layer cake model. section 4 presents the architecture of indowordnet owl; section 5 gives the implementation details, followed by conclusion and future work. ## related work wordnets other than indian languages are already available in rdf form. the work on princeton wordnet @xcite conversion to rdf/owl was carried out by wordnet task force 3 . the main goal of this conversion was to represent a language in use of semantic web community and to provide application developers a resource. also, the representation was done in such a way that it maintained the wordnets conceptual model. there are other projects focusing on lexical meta-models. lexical markup framework (lmf) @xcite . indowordnet is already available in this format by indonet @xcite which proposes modification to lmf to integrate universal word dictionary (uchida et al., 1999) and suggested upper merged ontology (sumo) @xcite . ## semantic web layer cake model the semantic web is not a separate web but a vision for the future of the web where information is given explicit meaning which makes easier for machine to automatically process and integrate the information available on the web. owl is a part of the growing stack of w3c recommendations related to the semantic web @xcite . figure 1 . is the semantic web layer cake model @xcite . this model is divided into three section: rdf schema can be viewed as an extensible, object oriented type system based on rdf @xcite . owl is an envelope to the rdf schema and enriches the expressibility of the rdf schema by expressing more properties like transitivity, symmetry, cardinality, etc. ## owl for indowordnet the architecture of the indowordnet owl representation is adopted from wordnet task force @xcite . the architecture of in-dowordnet owl contains three main classes i.e. synset foot_0 , wordsense and word foot_1 . the schema for representing indowordnet foot_2 using owl is shown in figure 2 below. figure 2 : indowordnet owl schema the schema includes three layers, namely concept layer, wordsense layer and word layer which are previously described in @xcite . every synset has a unique concept and can have several words associated with it sharing the same concept. wordsense represents a unique sense of a word. it is also possible to represent a word with many wordsenses. indoword-net owl schema handles the relations by dividing them into properties, i.e. semantic property and lexical property. semantic property represents the semantic relations which are handled in concept layer, whereas lexical property represents lexical relations which are handled in wordsense layer. all the remaining types of semantic relations and lexical relations become the sub property of semantic and lexcial property. the above schema uses several predicates foot_3 i.e. properties. indowordnet owl schema elaborates the semantic relationship like meronymy and holonymy by classifying them into the sub properties based on their attributes foot_4 whereas in princeton wordnet there is no such division. in indowordnet owl, the rdf files are organized in such a way that the management is done systematically. unlike @xcite all the rdf files are placed in one directory. following is the formatting of uris for in-dowordnet: ## implementation details the indowordnet owl is currently available in seven indian languages. it is developed using java platform, using apache jena foot_5 and indowordnet application programming interface(api). the above architecture can be used by other indian langauges to represent their respective wordnets in owl format. the repository of indowordnet owl is available on http: //nlp.unigoa.ac.in/indonet/owl/ . ## conclusion and future work the heart of semantic web is linked data that provides integration and reasoning of the data on web. the representation of indowordnet to owl will facilitate the semantic web community as the wordnet is strong lexical resource that has strengthened, enlarged and build up the other resources because of its taxonomy. in this paper we have presented the framework to represent the indian wordnets in the owl format. currently, we have represented eight indian language wordnets in owl format. in future, we will like to represent the wordnets from other indian languages in owl format. following are some future work to this problem. interlinking of wordnets: as the indoword-net is developed using ili. the advantage of this approach is that it preserves the semantic structure, but it also has some disadvantages. the drawbacks of this approach are lexical gap and semantic gap @xcite . as a result, an effort must be made to interlink the wordnet using common concept hierarchy @xcite as a backbone to link lexicons of different languages. need of approach to link dbpedia: the work on linking the indowordnet to dbpedia should be carried out as, dbpedia is the nucleus for the web of data and most of the resources are already linked to dbpedia. link it to other resources: we expect that use of the owl representation of indowordnet will be used as an infrastructure to enrich and link other web resources in india.