作　　者： ; ; ; ;

机构地区： 华南农业大学信息学院

出　　处： 《传感器与微系统》 2010年第12期124-127,共4页

摘　　要： 无线传感器网络(WSNs)是一种能量受限的网络,WSNs采样查询执行中首先要考虑到如何节省能量的问题。针对查询参数复杂、参量变化细微的传感器网络应用背景,提出了一种基于谓词的WSNs查询优化(PQOA-WSNs)算法。从用户输入的谓词查询表达式着手,把查询表达式转换为等价的析取范式,再根据概率学的原理对采样谓词作最优排序,以减少整个查询上传的数据量,从而延长传感器网络生命期。PQOA-WSNs包括了词法与语法分析、表达式转换、概率算法3个子算法模块。对PQOA-WSNs仿真测试显示:采样谓词越多,本算法的优化率也越明显,在2,3,4,5,7个查询谓词的条件下,测试优化率分别为48%,65%,74%,78%和85%左右。 Wireless sensor networks（WSNs） is a kind of energy-constrained networks. Any search algorithm based on wireless sensor networks must be taken into account the issue of how to save energy. Because of the characteristics of many parameters and small change in parameters, a predicate-based query optimization algorithms（PQOA-WSNs） has been designed. Starting from the user＇s predicate query expression, the query type is converted to equivalent disjunctive paradigm, and then query optimization algorithm makes the best sort order in order to reduce the amount of data and extend the sensor network lifetime according to studies based on the principle of probability. In this paper, PQOA-WSNs algorithm includes the lexical and grammatical analysis, the conversion formulas and the probability of algorithm modules. Simulation tests show that the more sampling parameters ,that is, the more sampling predicate, the more obvious optimization algorithm is. In case of 2,3,4,5,7 predicates in the query conditions,optimize the rate of the test were 48 % ,65 % ,74 % ,78 % and 85 %.

关 键 词： 无线传感器网络 查询优化 采样 谓词

领　　域： [自动化与计算机技术] [自动化与计算机技术]