Title: Imprecise query processing in wireless sensor networks: a fuzzy-based approach

Authors: Parand Akhlaghi; Mehdi Dehghan; Mohammad Mehdi Ebadzadeh

Addresses: Department of Computer Engineering, Science and Research Branch, Islamic Azad University, P.O. Box 775/14515, Tehran 1477893855, Iran ' Computer Engineering Department, Amirkabir University of Technology, No. 424, Hafez Ave, P.O. Box: 15875-4413, Tehran, Iran ' Computer Engineering Department, Amirkabir University of Technology, No. 424, Hafez Ave, P.O. Box: 15875-4413, Tehran, Iran

Abstract: Traditional query processing systems in sensor networks require precise and explicit definition of predicative thresholds to extract data. The acquired data can be imprecise and uncertain due to different reasons like measurement errors or environmental noise. In this paper, we take on a fuzzy-based approach to design a flexible query structure with linguistic and semantic predicates in sensor networks. In addition, we introduce a fuzzy-based query correlation index (FQCI), which quantifies the correlation between a sensor node and a query, based on a priori defined fuzzy membership functions, which are individual to each node. Also, our proposed fuzzy query structure can support queries with multiple predicates. This approach can reduce the rigidity in the declarative structure of query and minimise energy consumption, while providing a flexible service for event monitoring applications. Simulation results demonstrate that our method can achieve high fidelity with reasonable energy efficiency.

Keywords: fuzzy query processing; wireless sensor networks; WSNs; data acquisition; correlation; imprecise queries; in-network interpretation; query correlation index; flexible query structures; linguistic predicates; semantic predicates; fuzzy logic; fuzzy membership functions; energy consumption; event monitoring; simulation; energy efficiency.

DOI: 10.1504/IJAHUC.2016.076590

International Journal of Ad Hoc and Ubiquitous Computing, 2016 Vol.22 No.1, pp.14 - 34

Received: 16 Nov 2013
Accepted: 23 Apr 2014
Published online: 17 May 2016 *

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