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Relief materials are transported to the disaster areas after natural disasters. This paper describes the substitution and collocation relationships among relief materials, and finds the maximum of the number of victims could be supplied by them. On this basis, this paper optimizes the loading density of relief materials by establishing and solving corresponding quadratic programming problems. The...
The green traveling purchaser problem (GTPP) is a generalization of the Traveling Purchaser Problem which consists of selecting suppliers, allocating orders and choosing the best routes, while minimizing the purchasing and traveling costs and CO2 emissions. The two objective functions pertaining to minimization of CO2 emissions and purchasing costs are in some cases conflicting and are thus considered...
The world food system is a globalized and inter-connected network, and prior research has shown the US is one of the most important countries within this global network. Considering this, any affects on the US food network might have far reaching implications. The objective of this paper is to show how the efficiency of the US food network can be optimized and to examine the tradeoffs between sustainability,...
Preplanned link restoration pre-allocates protection resources during the configuration phase of the networks. The technique involves over-provisioning of the network resources to provide enough spare capacity in order to route the traffic on backup paths in case of failure in the primary network. As a consequence, this induces extra-costs for the operators. Minimizing the toll incurred by the protection...
Solar-powered wireless mesh nodes must be provisioned with a solar panel and battery combination that is sufficient to prevent node outage. This is normally done using historical solar insolation data for the desired deployment location and based on a temporal bandwidth usage profile (BUP) for each deployed node. Unfortunately, conventional methodologies do not take into account the use of energy-aware...
In this paper, the vehicle routing problem with time windows (VRPTW) was considered, and a mixed integer programming mathematic model of VRPTW was proposed in detail. Meantime, an improved ant colony algorithm (IACA) was proposed to overcome the shortcomings of premature convergence and slow convergence of conventional ant colony algorithm (ACA). The experiment results showed that the IACA can solve...
Wireless mesh nodes must often be upgraded so that the network can accommodate evolving user demands. When some of the nodes are operated using a sustainable solar energy source, these upgrades must take into account the cost of updating the node energy resource configurations. This is required so that the new network configuration can properly accommodate the updated energy workloads of the re-provisioned...
The paper describes an optimization model which aims at minimizing the maximum link utilization of IP telecommunication networks under the joint use of the traditional IGP protocols and the more sophisticated MPLS-TE technology. The survivability of the network is taken into account in the optimization process implementing the path restoration scheme. This scheme benefits of the Fast Re-Route (FRR)...
p-Cycle protection is an efficient pre-configured and pre-cross-connected protection scheme which can achieve ring-like recovery speed while retaining the capacity efficiency of mesh-based schemes. Thereafter, we study the stability and the efficient reconfiguration of p-cycles in the context of dynamic asymmetric traffic, a protection problem that is acknowledged to be difficult to solve, but with...
A ship routing and fleet planning model is developed which takes maximum total profit as objective to improve practicability of study on optimal deployment for ship resource. The short-term scheduling and long-term planning of fleet are combined in the model. A simplex algorithm was designed to solve the linear programming model and numerical tests were provided to illustrate the validity of the model...
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