Lali Barrière

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Consider a team of mobile software agents deployed to capture a (possibly hostile) intruder in a network. All agents, including the intruder move along the network links; the intruder could be arbitrarily fast, and aware of the positions of all the agents. The problem is to design the agents' strategy for capturing the intruder. The main efficiency(More)
Several papers showed how to perform routing in <i>ad hoc</i> wireless networks based on the positions of the mobile hosts. However, all these protocols are likely to fail if the transmission ranges of the mobile hosts vary due to natural or man-made obstacles or weather conditions. These protocols may fail because in routing either some connections are not(More)
Bluetooth is a promising recent radio technology for <i>ad hoc</i> networking. Bluetooth networks are based on connecting together <i>piconets</i>, to form a <i>scatternet</i>. The structure of the scatternet, and the way the scatternet is built and maintained, are not part of the Bluetooth specifications, but have a tremendous impact on the performance of(More)
The aim of this paper is to study the computational power of the qualitative model, where entities are given distinct labels which are however mutually incomparable; this model is opposed to the quantitative model, where labels are integers. The qualitative model captures, for example,the case when the labels are written in different alphabets (e.g.,(More)
Consider a collection of r identical asynchronous mobile agents dispersed on an arbitrary anonymous network of size n. The agents all execute the same protocol and move from node to neighboring node. At each node there is a whiteboard where the agents can write and read from. The topology of the network is unknown to the agents. We examine the problems of(More)
This paper is concerned with the graph searching game. The search number s(G) of a graph G is the smallest number of searchers required to “clear” G. A search strategy is monotone (m) if no recontamination ever occurs. It is connected (c) if the set of clear edges always forms a connected subgraph. It is internal (i) if the removal of searchers is not(More)
A new operation on graphs is introduced and some of its properties are studied. We call it hierarchical product, because of the strong (connectedness) hierarchy of the vertices in the resulting graphs. In fact, the obtained graphs turn out to be subgraphs of the cartesian product of the corresponding factors. Some well-known properties of the cartesian(More)