Michael Zoumboulakis

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We present a new approach for the detection of complex events in Wireless Sensor Networks. Complex events are sets of data points that correspond to interesting or unusual patterns in the underlying phenomenon that the network monitors. Our approach is inspired from time-series data mining techniques and transforms a stream of realvalued sensor readings(More)
The last few years have witnessed a flurry of research in the field of query processing for networks of sensors and actuators. It is widely accepted that query processing is the method of choice for acquiring data from a sensor field. Although query processing offers a very good computational model for a variety of applications such as environmental(More)
We present a novel approach for the on-line detection of Complex Events in Wireless Sensor Networks. Complex Events are sets of data points that correspond to unusual patterns that can not be detected using threshold-based techniques. Our method uses an efficient implementation of SAX, a mature data mining algorithm, that transforms a stream of readings(More)
Complex Events are sequences of sensor measurements indicating interesting or unusual activity in the monitored process. Such events are ubiquitous in a wide range of Wireless Sensor Network (WSN) applications, yet there does not exist a common mechanism that addresses both the considerable constraints of WSNs and the specific properties of Complex Events.(More)
In this paper we argue that the fundamental constrains of WSNs impose the need to re-discover programming optimisation techniques that were widely used a few decades ago but are less common today, at least in the conventional computing arena. Integer techniques, code tuning and profiling are absolutely essential in the world of the very small devices. We(More)
The process of transforming and integrating XML data involves resolving the syntactic, semantic and schematic heterogeneities that the data sources present. Moreover, there are a number of different application settings in which such a process could take place, such as centralised or peer-to-peer settings, each of which needs to be considered separately. In(More)
Robust, dependable and concise coordination between members of a robot team is a critical ingredient of any such collective activity. Depending on the availability and the characteristics of the particular communication infrastructure, coordination mechanisms can take varied forms, leading to distinct system behaviors. In this paper, we consider the case of(More)
We present an algorithm that makes an appropriate use of a Kalman filter combined with a geometric computation with respect to the localisation of a pollutant-emitting point source. Assuming resourceconstrained inexpensive nodes and no specific placement distance to the source, our approach has been shown to perform well in estimating the coordinates and(More)