Fixed charge solid transportation problem (FCSTP) is one of the main and most important problems in transportation and network research areas. To tackle such an NP-hard problem, An Electromagnetism-like algorithm (EM) is employed. To the best of our knowledge, EM has been considered for any kind of transportation problems. Due to the significant role of parameters on the algorithm’s performance...

This paper presents an iterated local search for the fixed-charge uncapacitated network design problem with user-optimal flow (FCNDP-UOF), which concerns routing multiple commodities from its origin to its destination by designing a network through selecting arcs, with an objective of minimizing the sum of the fixed costs of the selected arcs plus the sum of variable costs associated to the flo...

in the recent decade, special attention is paid to reverse logistic due to economic benefits of recovery and recycling of used products as well as environmental legislation and social concerns. on the other hand، many researches claim that separately and sequential planning of forward and reverse logistic causes sub-optimality. effective transport activities are also one of the most important c...

We consider the stochastic variant of the fixed-charge capacitated multicommodity network design (CMND) problem in which demands are stochastic. We propose a two-stage stochastic programming formulation where design decisions make up the first stage, while a series of recourse decisions are made in the second stage to distribute the commodities according to observed demands. The overall objecti...

When solving hard multicommodity network flow problems using an LP-based approach, the number of commodities is a driving factor in speed at which LP can be solved, as it linear constraints and variables. The conventional approach to improve solve time relaxation Mixed Integer Programming (MIP) model that encodes such instance aggregate all have same origin or destination. However, bound result...

This paper discusses a paradox in fixed charge capacitated transportation problem where the objective function is the sum of two linear fractional functions consisting of variables costs and fixed charges respectively. A paradox arises when the transportation problem admits of an objective function value which is lower than the optimal objective function value, by transporting larger quantities...

In order to keep a green planet, in particular its important to limiting the pollution with gas emissions. In a specific capacitated fixed-charge transportation problem with fixed capacities for distribution centers and customers with particular demands, the objective is to keep the pollution factor in a given range while the total cost of the transportation is as low as possible. In order to s...

The present study introduced a novel hierarchical hub set covering problem with capacity constraints. This study showed the significance of fixed charge costs for locating facilities, assigning hub links and designing a productivity network. The proposed model employs mixed integer programming to locate facilities and establish links between nodes according to the travel time between an origin-...