Research On Algorithms For Combined Services Selection Based On Fuzzy QOS

With the rapid development of the network, the number of web services is increasing rapidly, as well as the web services that with the same or similar functions.Facing these huge similar services that meet functional requirements, the users will naturally consider from the Quality of Services to get a best satisfied web service, that with the function requirements and the best quality of service, on the help of the search engine. So it has been an important research subject on the web services selection at present, about how to get the most satisfied web service on QoS from the numbers of similar services which meet the functional requirement according kinds of users'requirements. However, the research on combined web services selection based on QoS is just beginning. It usually just considers the data matching without the semantic matching of the parameters, which results the lower recall ratio and precision ratio. Service reputation, an important element of QoS, is usually obtained from users'evaluation, which can not guarantee the authenticity of the evaluation data.This paper proposed an algorithm of combined web services selection called CSSA-FQoS, which based on Fuzzy QoS parameters optimization, through learning the semantic web services selection tecnology.The research mainly about these:Firstly, in order to guarantee the authenticity of the QoS parameters'values, to the problem of evaluation data untruthfull and unreasonable that the users provide about the reputation of the web services, the paper suggests joining the experts group fuzzy multi-attribute decision-making method to enhance the authenticity and effectiveness of the evaluation data, correct the users'untruthfull evaluation information, and guarantee the authenticity of the reputation evaluation of the service.Secondly, in order to perform accurately matching of the QoS parameters, improve the recall ratio and precision ratio based on QoS parameters, the paper gives a double layer QoS ontology model based on the pioneers'achievements, for the semantic matching of QoS parameters when selecting the combined services, which avoid the numerical calculation of the parameters that not comply with the requirements.Finally, based on the above work, this paper proposed an improved combined web services selection algorithm based on fuzzy QoS, called CSSA-FQoS. According the different feature of different parameters, it uses different data type to descrip parameters. Then, it optimize the calculation through kinds of ways. Finally, it uses the multi-attribute decision making to get the best satisfied service that satisfys user's function requirement as well as the quality requirement.