We extend the primal-dual approximation technique of Goemans and Williamson to the Steiner connectivity problem, a kind of Steiner tree problem in hypergraphs. This yields a (k+1)-approximation algorithm for the case that k is the minimum of the maximal number of nodes in a hyperedge minus 1 and the maximal number of terminal nodes in a hyperedge. These results require the proof of a degree pro...

Percolation in an information-theoretically secure graph is considered where both the legitimate and the eavesdropper nodes are distributed as Poisson point processes. For both the path-loss and the path-loss plus fading model, upper and lower bounds on the minimum density of the legitimate nodes (as a function of the density of the eavesdropper nodes) required for non-zero probability of havin...

Wireless sensor networks (WSNs) are suitable for the continuous monitoring of crop information in large-scale farmland. The information obtained is great for regulation of crop growth and achieving high yields in precision agriculture (PA). In order to realize full coverage and k-connectivity WSN deployment for monitoring crop growth information of farmland on a large scale and to ensure the ac...

in this article we present an algorithm for converting a network problem with several sources and several sinks including several transfer nodes and condition of supplying the demand of any sink from a particular source to the transportation problem.  towards this end, and considering the very special structure of transportation algorithm, after implementing the shortest path algorithm or solvi...

Mobile Ad hoc Networks are consisting of mobile nodes having limited radio range and bandwidth without having any fixed infrastructure. Thus to deliver the message from source to destination does not only require to establish the shortest route for message delivery to the destination. But also to establish such a route that can deliver the message with minimum delay so that the message can be s...

Cooperative routing in Wireless Sensor Networks can improve performance in these types of networks. In our work, we propose a routing algorithm called Location-based Cooperative Routing with Sensor Power-upper-limit for Wireless Sensor Networks. The algorithm is based on the principle of minimum link power and aims to take advantage of nodes cooperation to make the link work well in Wireless Se...

The problem of multilevel diversity coding with secure regeneration is revisited. Under the assumption that the eavesdropper can access the repair data for all compromised storage nodes, Shao el al. provided a precise characterization of the minimum-bandwidth-regeneration (MBR) point of the achievable normalized storage-capacity repair-bandwidth tradeoff region. In this paper, it is shown that ...

In hybrid wireless sensor networks composed of both static and mobile sensor nodes, the random deployment of stationary nodes may cause coverage holes in the sensing field. Hence, mobile sensor nodes are added after the initial deployment to overcome the coverage holes problem. To achieve optimal coverage, an efficient algorithm should be employed to find the best positions of the additional mo...

In this paper, the author proposes an algorithm to determine a stable Connected Dominating Set (CDS) for Mobile Ad hoc Networks (MANETs) based on the notion of a metric called the Node Stability Index (NSI) of a node, defined as the sum of the predicted expiration times of the links (LETs) with the neighbor nodes that are not yet covered by a CDS node. The proposed algorithm prefers, to include...