中文摘要：

在非结构化P2P网络中，如何对用户所需资源进行快速、准确定位是当前研究的热点问题，也是P2P应用领域面临的核心问题之一．才目关的非结构化P2P资源定位算法在查准率、查全率和查询成本上难以同时被优化，这会造成严重的网络带宽负担以及巨大的索引维护开销．为此，提出一种面向用户需求的非结构化P2P资源定位策略（user requirements resource location strategy,简称U2RLS）．该策略的创新点是：在原有非结构化P2P网络资源定位泛洪算法的基础上，融入用户需求、用户偏好、用户兴趣度等因素，首先进行用户资源子网划分；采用带有用户需求信息的泛洪和查询索引机制，对用户所需资源进行精确定位．该策略有效避免了因海量信息引起的网络风暴、信息重叠和资源搜索偏覆盖等问题，从而解决了查询节点盲目使用中继节点的现象．实验结果表明：面向用户需求的非结构化P2P资源定位策略U2RLS以其高搜索成功率、有限网络资源消耗和短查询时间响应等优势，能够显著地提高用户资源定位效率．

英文摘要：

In unstructured P2P networks, how to rapidly and precisely locate user required resources is currently a hot issue, and is also one of core problems faced by P2P application fields. Related unstructured P2P resources location algorithms can not be optimized at the same time in respect to precision ratio, recall ration and query costs, which can cause serious network bandwidth burden and huge index maintenance costs. To address the problem, this paper proposes a query strategy called user requirement resource location strategy （U2RLS）. The innovation of this strategy is to integrate user requirements, user preferences and user interest based on the original unstructured P2P network resources location flooding algorithm. The strategy subnets the user resources, and adopts the flooding mechanism and query index mechanism with user required information to locate the resources accurately. This strategy effectively avoids the netstorm caused by mass information, data overlapping, and resource search partial coverage phenomenon, so as to solve the problem that query nodes use relay nodes blindly. The experimental results show that U2RLS has high search success rate, limited network resources consumption and short response time in query process, and therefore can significantly improve the efficiency for user resource location.