One of the factors which affects the gas lift performance is specific gravity of a lift gas (or the Molecular weight), which can influence the gas solubility in oil and has a direct effect on the gas lift performance. There are some previous researches which have included the lift gas specific gravity in their modeling, but in none of them, a comprehensive research about the effect of lift gas ...

Hub location problems, with the hub-and-spoke network structure, involve locating hub facilities, allocating the non-hubs (spokes) to the hubs, and determining the path for each origin-destination pair. In a pure hub-and-spoke network, all hubs, which act as intermediate switching or transshipment points for internodal flows, are fully interconnected and none of the non-hubs are directly connec...

This paper considers the single machine scheduling problem with uniform parallel machines in which the objective is to minimize the makespan. Four different GA based heuristics are designed by taking different combinations of crossover methods, viz. single point crossover method and two point crossover method, and job allocation methods while generating initial population, viz. equal number of ...

The paper studies the fair allocation of a finite set of indivisible goods among a finite set of agents. We focus on multiple assignment problems without free disposal so that, at least one agent receives more than one object. No monetary transfers are involved. The criteria include: (i) Pareto-efficiency; (ii) no-envy and derived notions namely single object no-envy which requires that all age...

in this study, a hierarchical hub location problem by considering different modes of transportation and maximum allowed delay is investigated. this study is done on iran’s express postal service with 2 days maximum delay in delivery considering ground and airport hubs. the problem is of the type of location and single allocation for collection, transfer and distribution of the shipments. all th...

In this paper, we evaluate the performance of multicast OFDM systems with single and multiple transmit antennas. We have shown that it is possible to increase the data rate of multicast OFDM systems by selecting the users with good channel for each subcarrier. For the single transmit antenna case, the resource allocation has been applied using the two-step algorithm where subcarrier allocation ...

Recent research has shown the benefits of using K -means clustering in task allocation to robots. However, there is little evaluation of other clustering techniques. In this paper we compare K -means clustering to single-linkage clustering and consider the effects of straight line and true path distance metrics in cluster formation. Our empirical results show single-linkage clustering with a tr...

UNLABELLED Numerous authors report that people with aphasia have greater difficulty allocating attention than people without neurological disorders. Studying how attention deficits contribute to language deficits is important. However, existing methods for indexing attention allocation in people with aphasia pose serious methodological challenges. Eye-tracking methods have great potential to ad...

0377-2217/$ see front matter 2011 Elsevier B.V. A doi:10.1016/j.ejor.2011.01.014 ⇑ Tel.: +90 312 290 27 68; fax: +90 312 266 40 54. E-mail address: [email protected] In this paper, we study allocation strategies and their effects on total routing costs in hub networks. Given a set of nodes with pairwise traffic demands, the p-hub median problem is the problem of choosing p nodes as hub loca...