treatment. These rates agree with those reported by Ames ( 1966), but are higher than those reported by Fisher et al. (1959). However, the cost stated by Fisher did not include labor at $2.00 per man hour. Based on the number of trees killed, basal spray is an economical method to kill small and medium size trees (Table 4). Costs ranged from 11 to 18 cents per dead tree, depending on the size a...

A cover of a hypergraph is a collection of edges whose union contains all vertices. Let H = (V, E) be a k-uniform, D-regular hypergraph on n vertices, in which no two vertices are contained in more than o(D/e log D) edges as D tends to infinity. Our results include that if k = o(log D), then there is a cover of (1 + o(1))n/k edges, extending the known result that this holds for fixed k. On the ...

About at the break of sixties and seventies of this century the first functional and publicly used information system developed from originally experimental and non commercial applications of computer technology in storing and retrieval of document records. At the beginning these were mostly parallel editions of bibliographies in both printed and magnetic format. Thus developed on one hand data...

In the economical caching problem, an online algorithm is given a sequence of prices for a certain commodity. The algorithm has to manage a buffer of fixed capacity over time. We assume that time proceeds in discrete steps. In step i, the commodity is available at price ci ∈ [α, β], where β > α ≥ 0 and ci ∈ N. One unit of the commodity is consumed per step. The algorithm can buy this unit at th...