A semantic web services discovery approach based on a mobile agent using metadata

Purpose-The success of web services involved the adoption of this technology by different service providers through the web,which increased the number of web services,as a result making their discovery a tedious task.The UDDI standard has been proposed for web service publication and discovery.However,it lacks sufficient semantic description in the content of web services,which makes it difficult to find and compose suitable web services during the analysis,search,and matching processes.In addition,few works on semantic web services discovery take into account the user’s profile.The purpose of this paper is to optimize the web services discovery by reducing the search space and increasing the number of relevant services.Design/methodology/approach-The authors propose a new approach for the semantic web services discovery based on the mobile agent,user profile and metadata catalog.In the approach,each user can be described by a profile which is represented in two dimensions:personal dimension and preferences dimension.The description of web service is based on two levels:metadata catalog and WSDL.Findings-First,the semantic web services discovery reduces the number of relevant services through the application of matching algorithm“semantic match”.The result of this first matching restricts the search space at the level of UDDI registry,which allows the users to have good results for the“functional match”.Second,the use of mobile agents as a communication entity reduces the traffic on the network and the quantity of exchanged information.Finally,the integration of user profile in the service discovery process facilitates the expression of the user needs and makes intelligible the selected service.Originality/value-To the best knowledge of the authors,this is the first attempt at implementing the mobile agent technology with the semantic web service technology.

The research of traffic density extraction method under vehicular ad hoc network environment

Purpose–Traffic density is one of the most important parameters to consider in the traffic operationfield.Owing to limited data sources,traditional methods cannot extract traffic density directly.In the vehicular ad hoc network(VANET)environment,the vehicle-to-vehicle(V2V)and vehicle-to-infrastructure(V2I)interaction technologies create better conditions for collecting the whole time-space and refined traffic data,which provides a new approach to solving this problem.Design/methodology/approach–On that basis,a real-time traffic density extraction method has been proposed,including lane density,segment density and network density.Meanwhile,using SUMO and OMNet11 as traffic simulator and network simulator,respectively,the Veins framework as middleware and the two-way coupling VANET simulation platform was constructed.Findings–Based on the simulation platform,a simulated intersection in Shanghai was developed to investigate the adaptability of the model.Originality/value–Most research studies use separate simulation methods,importing trace data obtained by using from the simulation software to the communication simulation software.In this paper,the tight coupling simulation method is applied.Using real-time data and history data,the research focuses on the establishment and validation of the traffic density extraction model.