Event‐Driven Top‐ k Queries in Sensor Networks with Multi Microenvironments
Yinglong Li, Mingqi Lv, Liang Huai Yang · Chinese Journal of Electronics · 2015
In the emerging area of sensor-based systems,a significant challenge is to develop reliable, energyefficient methods to extract useful information from thedistributed sensory data. Existing top-k query algorithmsof sensor networks are only applicable to the sensor networkswith single Microenvironment (ME). Besides, theseapproaches rely on using raw sensor readings, which handlingthese raw sensory data requires large amount of datatransmission and is memory-consuming. In this paper wehighlight the multiple MEs in sensor networks and proposea novel event-driven approximate top-k query frameworkbased on fuzzy method. Firstly, membership functionof fuzzy method is introduced to describe the global potentialevent confidence. Subsequently, non-uniform membershipdegree subranges based linguistic variables insteadof numeric sensor readings are used for in-network top-kevent fusion. Also two distributed event-driven approximatetop-k query algorithms are devised. Theoretical analysisas well as extensive simulations based on synthetic andreal data sets show that our framework reduces the datatransmission significantly and the query results are moreinterpretable with quality guarantees.