支持语义匹配和QoS的组合服务选择方法研究

发布时间：2018-10-14 19:07

【摘要】：随着服务计算技术的广泛应用和深入发展，网络上的服务数量呈爆炸性增长，所以如何从大量的具有相同功能但不同非功能属性的服务中选出一组能满足用户实际需求的服务成为了Web服务领域的一个研究热点。现有的大多数组合服务选择方法不能达到理想的效果，存在的主要问题是：一方面由于服务受动态运行环境的影响，在不同的运行环境下表现出不同的服务水平，服务质量存在内在的不确定性；另一方面是在进行组合服务选择时忽视了组合服务是作为一个有机整体提供给用户，对服务间互操作性和可组合性缺乏考虑。本文的工作主要有以下几个方面：首先，利用云模型理论来衡量候选服务QoS的不确定性，根据用户对每个质量属性不同的权重对服务进行不确定性程度的综合评估，给出了一种基于QoS不确定性的服务过滤方法，为服务选择提供优化的候选服务资源，保证在服务选择过程中提供给用户的服务的QoS在一定程度上是稳定的。其次，为解决组合服务选择中存在的服务间互操作性和可组合性低的问题，本文在领域本体描述服务的基础上提出了一种基于扩展二分图的组合服务语义匹配度的计算方法，用于对组合服务进行整体量化的语义分析，以确保服务能够无缝连接和正确执行。再次，给出一种支持语义匹配和QoS的组合服务选择方法，将组合服务的语义匹配度和服务质量QoS相结合作为组合服务选择的指标，，本文将组合服务选择的问题转化为多约束多目标的优化问题并通过引入遗传算法予以实现，为用户提供适应才函数值最优的组合服务，以满足用户的需求。最后，本文设计并实现了支持语义匹配和QoS的组合服务选择仿真系统，并进行了仿真实验。仿真实验结果表明，本文提出的组合服务选择方法得到的组合服务不仅能够满足用户的需求，而且能够确保正确执行。
[Abstract]:With the wide application and deep development of service computing technology, the number of services on the network is increasing explosively. Therefore, how to select a set of services from a large number of services with the same functions but different non-functional attributes to meet the actual needs of users has become a research hotspot in the field of Web services. Most of the existing composite service selection methods can not achieve the desired results. The main problems are: on the one hand, because the service is affected by the dynamic running environment, it shows different service level in different running environment. The quality of service has inherent uncertainty, on the other hand, the composite services are provided to users as an organic whole, and the interoperability and composability among services are not considered. The main work of this paper is as follows: firstly, the uncertainty of candidate service QoS is measured by cloud model theory, and the uncertainty degree of service is evaluated according to the different weights of each quality attribute. This paper presents a service filtering method based on QoS uncertainty, which provides optimal candidate service resources for service selection, and ensures that the QoS of the service provided to the user in the process of service selection is stable to a certain extent. Secondly, in order to solve the problem of low interoperability and composability in the selection of composite services, this paper proposes a method to calculate the semantic matching degree of composite services based on extended bipartite graph based on domain ontology. It is used in the semantic analysis of composition services to ensure seamless connection and proper execution of services. Thirdly, a method for selecting composite services which supports semantic matching and QoS is presented. The semantic matching degree of composite services and quality of service (QoS) are combined as the index of composition service selection. In this paper, the problem of composition service selection is transformed into a multi-constraint and multi-objective optimization problem, which is realized by introducing genetic algorithm to provide a composition service with the optimal value of adaptive function to meet the needs of users. Finally, this paper designs and implements a composition service selection simulation system which supports semantic matching and QoS, and carries out simulation experiments. The simulation results show that the composite services can not only meet the needs of users, but also ensure the correct execution.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP393.09

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