In this paper we consider the problem of sending data in real time from information sources to sets of receivers, using peer-to-peer communications. We consider several models of communication resources, and for each model we identify schemes that achieve successful diffusion of information at optimal rates. For edge-capacitated networks, we show optimality of the so-called “random-useful” pack...

Precision farming in viticulture raises challenging combinatorial issues such as the Differential Harvest Problem . This problem might appear at first similar to a simple Capacitated Vehicle Routing but it exhibits problem-specific constraints that make this much harder solve and which are discussed article. Our objective was develop efficient exact methods using column generation VRPSolver™ ba...

The network loading problem (NLP) is a specialized capacitated network design problem in which prescribed point-to-point demand between various pairs of nodes of a network must be met by installing (loading) a capacitated facility. We can load any number of units of the facility on each of the arcs at a specified arc dependent cost. The problem is to determine the number of facilities to be loa...

Min-k-cut is the problem of partitioning vertices of a given graph or hypergraph into k subsets such that the total weight of edges or hyperedges crossing different subsets is minimized. For the capacitated min-k-cut problem, each edge has a nonnegative weight, and each subset has a possibly different capacity that imposes an upper bound on its size. The objective is to find a partition that mi...

In this paper we study the maximum two-flow problem in vertexand edge-capacitated undirected STI-planar graphs, that is, planar graphs where the vertices of each terminal pair arc on the same face. For such graphs we provide an O(n) algorithm for finding a minimum two-cut and an O(n log n) algorithm for determining a maximum two-flow and show that the value of a maximum two-flow equals the valu...

The hierarchical hub covering facility location problems are applied to distribution systems, transportation, waste disposal, treatment services, emergency services and remote communication. The problems attempt to determine the location of service providers' facilities at different levels and specify their linking directions in order to reduce costs and to establish an appropriate condition in...

We give an efficient polynomial-time approximation scheme (EPTAS) for the Joint Replenishment Problem (JRP) with stationary demand. Moreover, using a similar technique, we give a PTAS for the capacitated JRP with non-stationary demand but constant size capaci-

background: the glycoconjugate content of sperms indicates their physiological and fertility properties. lectin reactivity is indicative of intact, capacitated, and acrosome-reacted sperms. in the epididymis, sperms experience maturation, glycoconjugate modification, and simultaneously, higher l-carnitine (lc) concentrations. the aim of this project was to evaluate the effects of lc and pentoxi...