Key Technology Of Semantic Web Service Composition And Its Application In IoT

As the combination of Web service with semantic Web, semantic Web service is makingWeb service more readable to machine with its rich capacity of description and great strengthof reasoning, and thereby offering great help to service discovery, composition, monitoringand invocation. But due to the limited function, there may not exist a single service to meet acustomer’s requirement. At this situation, how to composite the single ones to a powerfulcomposite-service is becoming a hot spot in both industry and academic. Researchers haveproposed a variety of service composition methods, but there still exist the followingproblems:①An available and small-scale service chain can’t be obtained from a huge numberof services and some service’s behavior may led to the failure of service composition;②Complex connecting relationship among sub-services can’t be represented and dealt, andfailed to organize the dynamical processes of sub-services;③matching degree betweencomposition result and user request can’t be measured;④the existing system framework can’tsupport and integrate variety methods of service discovery and composition.Focusing on the above problems, key technologies of semantic Web service compostionwill be launched with this dissertation, with the objection of dynamic composition. The maincontent and contributions are listed as follows:(1) A method of getting candidate service chains for composition in chain is proposed,based on the hyper-edge graph modelIn order to get an available and small-scale service chain and avoid the condition thatsome service’s behavior leds to the failure of service compsotion, methods of getting SingleExecution Process and candidate semantic Web service chains based on hyper-edge graph areproposed in this dissertation, providing candidate service chain sets for compostion methodsto dymantically organize the execution process.①choose the execution-behavior-basedSingle Execution Process to be the basic service set, avoiding the condition that leds to thefailure of compositon;②a hyper-edge-graph model for candidate service chain is proposed,describeb by formal, accurate and comprehensive description, which has very strongcommonability with clear and intuitive structure; in the model, making Single ExecutionProcess be the node can control the node granularity and the scale of hyper-edge model.③common algorithms of building hyper-edge graph and analyzing hyper-edge graph areproposed to achieve the candidate service chain based on node-edge path. Finally, theeffectiveness and affectiveness are verified by the prototype system and experiments. (2) Extend the basic Petri net model and An algorithm for service composition based onextended Petri-net is proposedTo address the complex conntecting relationship among subservices and to realizedynamic organization of subservices, the basic Petri net model is extended, and based onwhich, a semantic Web service compostion method is proposed:①Places of basic Petri netfor Input and Output are extended to some subtypes for multi-source input place and multiuseoutput place;②ε Place and ε transition with combine-select and copy-split mechanisms areintroduced for complex connecting relationship such as1:n and n:1;③a service compositonmethod based on the exended Petri net is proposed to dynamically organize the executionprocesses of subservices. The experiments show our methods’ affectiveness and effeciveness.(3) A method for measuring the composite matching degeree with user request isproposed, based on subservice weigth and connecting similarityFor measuring the matching degree between the results of composition and user request,a measure method for composite similarity degree is proposed, which is based on subserviceweight and connecting similarity.①Place Importance Factor Measure algorithm formeasuring the importance of different subtypes of outplaces is proposed based on analyzingtheir different usages.②the subservice weight is measured by the distribution of outputplaces and their importance factor;③a method for measuring the connecting similarityamong subservices is proposed, based on subservice weight and fuzzy ontology similarity ofI/O to transfer the information of similarity from one subservice to another.④the compositesimilarity is based on both the connecting similarity and the amount of subservices, propsosedto measure its matching degree of user request and convenient for service selection. Theexperiment shows their affectiveness.(4) A system framework based on semantic Web service router is poposedA semantic-Web-service-router-based system framework is proposed to provide systemsupport for service compositon, with domain ontology tree fusion, routing location algorithmand unified interfaces of service discovery and composition methosds:①In the framework,domain ontology tree fusion algorithm and routing location algorithm to achieve the locationof the suitable role, making the framework better suited to the distributing environment withmulti-domain registry;②through unified interfaces of service discovery and compostion, theframework is able to support and integrate a variety of service discovery and compositionmethods. Finally, an integration platform of the proposed framework is realized and the keyalgorithms and mechanisms is proved effective. (5) Applications of composition technique in Internet of ThingsApplication of key technologies reflects their practical value. The application oflogisitics suplly chain IoT combined with semantic Web service is proposed and described inthis dissertation. In vehicle scheduling scenario selected for application of key technologise inthis dissertation, the ontology and services are described using the key technology of fuzzydescription logic with custom Datatype, and then apply the key technologies proposed in thisdissertation to verify their practical values.Above all, the research achievement includes: method for getting candidate servicechains, models and methods for service composition, composite similarity measure, thesystem framework and platform, which are key technologies of semantic Web servicecomposition and their applications.