【摘要】 语义缓存在移动计算环境中有着非常广阔的应用前景.查询处理是语义缓存的一个关键问题,但是现有的查询处理算法在时空效率和裁剪结果的复杂度两个方面存在很大的局限性,这在一定程度上限制了语义缓存的实用性.为了克服这些缺陷,作者首先给出并证明了用于优化查询裁剪的逻辑规则;基于这些规则,给出了剩余查询的裁剪算法;最终给出了只需进行剩余查询裁剪的优化查询处理算法.算法分析从理论上证明了该优化机制的有效性,同时,仿真实验的性能比较也表明该优化方法在提高查询裁剪时空效率和降低剩余查询复杂度等方面都要明显优于没有优化的方法.更多还原

【Abstract】 Semantic caching is very attractive for use in mobile computing environments. Query processing is a key problem in semantic caching. However, the existent query processing algorithms have limitations in the two parts of the efficiency of time and space as well as the complexity of the trimming result. This restricts in a great extent the practicability of semantic caching. For overcoming the limitations, firstly some simplification rules, which can be used to optimize the query trimming, are given and proven. Based on these rules, the trimming algorithm to evaluate the probe query and the remainder query is given. Finally, the query-processing algorithm that only evaluates the remainder query is described. At the same time, the performance analysis of simulation experiment also indicates that the optimization technology is excellent more than the non-optimization query trimming in the two parts of improving the efficiency of time and space as well as reducing the complexity of trimming result.更多还原