In wireless sensor networks, coverage is a fundamental issue affecting the quality of service. A coverage hole may appear anywhere in the area being monitored at any time because of many reasons. Thus, hole detection and healing have become major challenges towards achieving perfect coverage. This study provides a novel algorithm using trees and graph theory to detect and describe the existing ...

Given a tree and a set P of non-trivial simple paths on it, Vpt(P) is the VPT graph (i.e. the vertex intersection graph) of the paths P of the tree T , and Ept(P) is the EPT graph (i.e. the edge intersection graph) of P. These graphs have been extensively studied in the literature. Given two (edge) intersecting paths in a graph, their split vertices is the set of vertices having degree at least...

Wireless networks are present everywhere but their management can be tricky since their coverage may contain holes even if the network is fully connected. In this paper we propose an algorithm that can build a communication tree between nodes of a wireless network with guarantee that there is no coverage hole in the tree. We use simplicial homology to compute mathematically the coverage, and Pr...

Treeshelters are widely used to protect tree seedlings against animal browsing or rubbing. They reduce the tree transpiration as a result of the low ventilation rate of the shelter. Photosynthesis is impeded by low levels of available CO2 due to poor gas exchange with the outside. We assess the impact of ventilating a treeshelter on the microclimate, on the transpiration and on the photosynthes...

Forest ecosystems have a distinct vertical dimension, but the structuring of communities in this three-dimensional space is not well understood. Water-filled tree holes are natural microcosms structured metacommunities. Here, we used these as model systems to analyze how insect and occurrence abundance individual species influenced by biotic abiotic microhabitat characteristics, position hole, ...

Secondary cavity nesting (SCN) birds breed in holes that they do not excavate themselves. This is possible where there are large trees whose size and age permit the digging of holes by primary excavators and only rarely happens in forest plantations, where we expected a deficit of both breeding holes and SCN species. We assessed whether the availability of tree cavities influenced the number of...

Macro forest transducers (mfts) extend macro tree transducers (mtts) from ranked to unranked trees. Mfts are more powerful than mtts (operating on binary tree encodings) because they support sequence concatenation of output trees as build-in operation. Surprisingly, inverse type inference for mfts, for a fixed output type, can be done within the same complexity as for mtts. Inverse type inferen...

Using full-game databases and optimized tree-search algorithms, the game of Kalah is solved for several starting configurations up to 6 holes and 5 counters per hole. The main search algorithm used was iterative-deepening MTD(f). Major search enhancements were move ordering, transposition tables, futility pruning, enhanced transposition cut-off, and endgame databases.

It is argued that the quantum correction to the mass of some very massive, nonsupersymmetric states vanishes in inverse proportion to their tree-level mass to all orders in string loops. This approximate nonrenormalization can explain the agreement between the perturbative degeneracy of these states and the Sen entropy of the associated black holes.