中文摘要：

为了提高不确定XML数据管理和查询处理效率，基于不确定XML的可能世界语义的概率XML模型，采用具有独立分布和互斥分布的两种不确定文档节点类型，研究了概率XML文档可能世界实例生成问题，提出了具有线性时间复杂性的概率XML文档实例生成算法，该算法通过随机选择分布节点的孩子节点子集，根据该节点子集生成随机XML文档实例，该实例可用于处理不确定XML数据查询、索引等XML数据管理问题。实验分析验证了该算法具有良好的实用性和高效性。

英文摘要：

Based on the semantic of possible worlds and pmbabilistic XML models with independent distribution and mutual ex- clusive distributional nodes, the problem of how to generate instances from a probabilistic XML is studied. This work will improve highly the efficiency ofuncertain XML data management and query answering. Moreover, an algorithm for generating XML docu- ments from a probabilistic is also proposed, which has linear time complexity. The main idea of this algorithm is selecting randomly the children subsets of distributional nodes, and generating random XML document instance according to these children subsets. These instances are necessary for processing uncertain XML data query, index and data management. Finally, experiment results are made to show up the correct and efficiency of the algorithm.