Keywords: Semantic Annotation, Classification, Web Service Discovery, Ontology, Semantic Similarity, WSDL.
The main objective of this work is to design an effective web service discovery engine that retrieves the best matching results based on the measure of syntactic cum semantic similarity between the user query and the web service to be fetched. The idea is to draw bridges across the broad spectrum of lexical entities based on their relativeness. The essence of this work could be extended to support a wide range of applications from ‘being inculcated in search engines to fetch user-relevant data’ to ‘being used for training robots and AI based devices to respond/adhere appropriately to the different phrases of human commands’.With the accelerated revolution of internet, enterprises and organizations highly rely on Service oriented computing. Web services support inter-operation of distributed applications. Humongous amount of web services present on the internet the user is searching for. The paper focuses ondesigninga practical means of fast and relevant retrieval of web services.The phrase used for searching any given web service differs from one person to another. This work deals with the syntactic cum semantic mechanism proposed for retrieving web services based on the measure of similarity between the name of the web service and the search query entered by the user to discover that service. A list of the Web Service Description Language (WSDL) files is taken as the dataset. Protégé is the tool used for semantic annotation of WSDL files for converting them to Semantically Annotated Web Service Description Language (SAWSDL) files. ‘Wordnet’ is used as the lexical dictionary and Java language has been used to build the rest of the package for implementing the search discovery mechanism.Netbeans is used as IDE.Wamp server with PHPMyAdmin was used for managing the database of SAWSDL files. The degree of similarity is measured by evaluating performance of the engine using metrics such as ‘Precision’, ‘Recall’, ‘Accuracy’ and ‘F-measure’.While the syntactic approach is easier to implement, it suffers from keyword polysemy issues. The proposed search discovery mechanism is based on semantically annotating WSDL files and retrieving the files based on a novel syntactic cum semantic discovery algorithm which usesLeocockChordorow function for computing the similarity. The effectiveness of the proposed algorithm is tested experimentally by building a desktop application using Java.The WSDL files from various domains were semantically annotated by tagging related concepts using ontology. Themachine learning algorithm that best classifies the web services on the basis of their performance metrics is identified. The related services are retrieved by the application of the proposed LCH based Syntactic cum Semantic discovery algorithm (LCH based SSDA).A ranking system is proposed to rank the results by evaluating various QoS attributes. The results of the experiment showed that the proposed system yielded high precision and recall value.The solution has been found to be effective in minimizing the execution time and in improving the degree of relevancy. With an impending need for constructing a semantic context based secure structure,the proposed solution will- help in refining the search results and in minimizing users’ cognitive load during search formulation and execution.