1.1. We denote by V a connected ^-dimensional complete Riemannian manifold, by d = d(V) the diameter of V, and by c = c(V) and c~ = c~(V), respectively, the upper and lower bounds of the sectional curvature of V. We set c = c(V) = max (| c1, | c~ |). We say that F i s ε-flat, ε > 0, if cd < ε. 1.2. Examples. a. Every compact flat manifold is ε-flat for any ε > 0. b. Every compact nil-manifold p...

we consider the queueing maximal covering location-allocation problem (qm-clap) with an m/m/1 queueing system. we propose a new solution procedure based on decomposition of the problem into smaller sub-problems. we solve the resulting sub-problems both with a branch and bound algorithm and with the meta-heuristic grasp. we also solve the entire model with grasp. computational results for these ...

Let G be a finite Abelian group and D(G) its Davenport constant, which is defined as the maximal length of a minimal zero-sum sequence in G. We show that various problems on zero-sum sequences in G may be interpreted as certain covering problems. Using this approach we study the Davenport constant of groups of the form (Z/nZ)r , with n ≥ 2 and r ∈ N. For elementary p-groups G, we derive a resul...

Abstract We study the property of spectral-tightness Riemannian manifolds, which means that bottom spectrum Laplacian separates universal covering space from any other normal a manifold. prove closed manifold is topological characterized by its fundamental group. As an application, we show non-positively curved, spectrally-tight if and only dimension Euclidean local de Rham factor zero. In thei...

Influence maximization aims at identifying a limited set of key individuals in (social) network which spreads information based on some propagation model and maximizes the number reached. We show that influence probabilistic independent cascade can be modeled as stochastic maximal covering location problem. A reformulation Benders decomposition is proposed relation between obtained optimality c...

In this paper we analyze a continuous version of the maximal covering location problem, in which facilities are required to be linked by means given graph structure (provided that two allowed if distance is not exceed). We propose mathematical programming framework for problem and different resolution strategies. First, provide Mixed Integer Non Linear Programming formulation derive some geomet...

The problem of maximal hub covering as a challenging problem in operation research. Transportation programming seeks to find an optimal location of a set of hubs to reach maximum flow in a network. Since the main structure's parameters of the problem such as origin-destination flows, costs and travel time, change periodically in the real world applications, new issues arise in handling it. In t...

In the lattice of subsets of an n-set X , every maximal Sperner family S may be partitioned into disjoint subfamilies A and B, such that the union of the upset of A with the downset of B yields the entire lattice: U(A) [ D(B) = 2 X . The result generalizes to certain posets.