Research on HWSN Node Covering Algorithm

This paper first introduces the types and characteristics of HWSN, expounds its typical architecture, through comparing with homogeneous wireless sensor network, the performance of HWSN is quantitative calculated, analysis results show that HWSN can improve the reliability of data transmission, reduce the energy consumption of data transmission, reduce the delay of data transmission, and with the increase of network scale, highlight the advantages of heterogeneous networks. HWSN covering algorithm performance evaluation indexes are given finally.

Path node-covering constants for certain families of trees

1. introduction. A set P of disjoint paths in a graph G is a node-covering of G if every node of G is in a path in P. (For definitions not given here see (5) or (11).) The path (node-covering) number of G is the smallest possible number p(G) of paths in such a node-covering of G. The problem of determining the path number of a graph was considered in (1) and (4) for undirected graphs and in (2) for directed graphs. In particular, an algorithm for determining the path number of a tree was given in (1) and (4). If ℱ denotes some family of trees, let μ(n) = μℱ(n) denote the average value of p(T) over all trees T in ℱ with n nodes. Our object here is to show the existence and to determine the value of the path (node-covering) constantfor certain families ℱ of trees. The arguments are similar to those used in (7), (8), and (9), where some other parameters, associated with families of trees, were investigated.