基于动态描述逻辑的服务组合及质量模型

Dynamic Description Logic Based Web Service Composition and QoS Model

本文提出一个基于动态描述逻辑的Web服务自动组合框架.在该框架中,Web服务自动组合被划分为逻辑层和实现层两部分,于是服务的自动组合问题在逻辑上归结为一个动作规划问题,在实现上归结为一个根据动作选择具体服务的服务选择问题.基于该框架,本文给出了一个支持非线性QoS聚合和显式数据流声明的QoS模型.得益于合理的服务组合框架和QoS模型,本文提出的服务选择方法可以将复杂服务分解为较小的服务,然后分别用递归的剪枝算法求解.实验显示该方法是有效的,不但可适应候选Web服务数量较大的情况,且相对于现有方法能更好地处理服务组合中的复杂结构.

This paper proposes a semantic model for web service based on Dynamic Description Logic（DDL）.In this paper,service composition is divided into two stages：logic plan stage and grounding stage.Therefore,a service composition problem is reduced to an action planning problem at the planning stage and a QoS-aware service selection problem at the grounding stage.This paper mainly focuses on the QoS model and service selection.A composite service is divided to several smaller services,which are then solved separately by a recursive branchand-bound algorithm.Experiments show that the proposed approach is efficient and scalable for runtime service selection,and better handles complicated structure of service composition than existing approaches.