Louisa Harutyunyan

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A primary task in wireless sensor networks (WSNs) is for sensors to communicate collected data to a sink for analysis and processing. A single sink in the network can lead to high energy consumption and hence, a reduction of the network lifetime. Thus, to achieve a degree of fault tolerance we consider the problem, where the hop distance from every sensor(More)
In wireless sensor networks connected dominating sets are often used to form a virtual backbone. However, a connected dominating set is often vulnerable due to frequent node failures in sensor networks. Hence, to provide a degree of fault-tolerance, we consider a 2-connected distance-k p-dominating set, denoted D<sub>2;k;p</sub>, as a virtual backbone for(More)
In this paper we consider the 1-movable dominating set problem in wireless sensor networks (WSNs), motivated by applications of WSNs such as detection of environmental activity, surveillance, area monitoring and attaining small degree of fault tolerance in such applications. To find a minimum 1-movable dominating set is shown to be NP-complete. Hence, in(More)
Broadcasting has been used in mobile ad hoc networks to send a piece of data to every node throughout the network. Using a simple flooding scheme for such purpose causes redundant rebroadcasting at some nodes. Most approaches developed in the literature assume nodes are aware of the topological changes of the network via beacon messages, which cause an(More)
This section is based [1]. Up until now in the course we have looked at log-linear models. We were interested in finding the probability given by P (y|x) = exp k k=1 λ k f k (x, y) y' exp k k=1 λ k f k (x, y ′). (10.1) Now, we would like to know what happens when y itself is a sequence? (i.e want P (y|x)). Traditionally, graphical models were used to(More)
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