Learn More
Wireless sensor networks (WSN) have recently received an increasing interest. They are now expected to be deployed for long periods of time, thus requiring software updates. Updating the software code automatically on a huge number of sensors is a challenging task, especially when all participating sensors are embedded on mobile entities. In this paper, we(More)
Sensor networks have recently received an increasing interest both in industry and academia and are applicable to a wide range of distributed applications. In such networks, sensors organize themselves to collect or disseminate information in the network, routing messages to specific sensors, etc. Given the limited resources of those devices, energy(More)
In this paper, we consider the problem of estimating the distance between any two large data streams in small-space constraint. This problem is of utmost importance in data intensive monitoring applications where input streams are generated rapidly. These streams need to be processed on the fly and accurately to quickly determine any deviance from nominal(More)
Peer-to-peer (P2P) file sharing systems are now at the origin of most of Internet traffic. Improving the performance of the query mechanism of such systems has generated a lot of interest both in industry and academia. In a P2P system, peers are connected to a subset of other peers with which they can communicate. Each peer maintains a cache and makes(More)
Gossip protocols are simple, robust and scalable and have been consistently applied to many (mostly wired) distributed systems. Nevertheless, most validation in this area has been empirical so far and there is a lack of a theoretical counterpart to characterize what can and cannot be computed with gossip protocols. Population protocols, on the other hand,(More)
We consider the problem of uniform sampling in large scale open systems. Uniform sampling is a fundamental primitive that guarantees that any individual in a population has the same probability to be selected as sample. An important issue that seriously hampers the feasibility of uniform sampling in open and large scale systems is the unavoidable presence(More)
In this paper, we consider sensor database systems. Sensors are attached to objects and queries on the objects are operated at the sensor network level. Although queries to such a system might be extremely complex, ensuring efficiently basic functionalities such as broadcast or anycast without any central element is not trivial. In this paper, we provide a(More)
Key grouping is a technique used by stream processing frameworks to simplify the development of parallel stateful operators. Through key grouping a stream of tuples is partitioned in several disjoint sub-streams depending on the values contained in the tuples themselves. Each operator instance target of one sub-stream is guaranteed to receive all the tuples(More)
Let consider a set of anonymous moving objects to be tracked in a binary sensor network. This article studies the problem of associating deterministically a track revealed by the sensor network with the trajectory of an unique anonymous object, namely the <i>multiple object tracking and identification</i> (MOTI) problem. In our model, the network is(More)
Everyday, people use more and more digital resources (data, application systems, Internet, etc.) for all aspects of their life, like financial management, private exchanges, collaborative work, etc. This leads to non-negligible dependences on the digital distributed resources that reveal strong reliance at the social level. Users are often not aware of(More)