the set covering problem (scp) is a well-known combinatorial optimization problem. this paper investigates development of a local branching approach for the scp. this solution strategy is exact in nature, though it is designed to improve the heuristic behavior of the mixed integer programming solver. the algorithm parameters are tuned by design of experiments approach. the proposed method is te...

The impetus for this research was examining a flow shop problem in which tasks were expected to be successively carried out with no time interval (i.e., no wait time) between them. For this reason, they should be completed by specific dates or deadlines. In this regard, the efficiency of the models was evaluated based on makespan. To solve the NP-Hard problem, we developed two mathematical mode...

A three-level relief chain including a number of suppliers in fixed locations, candidate distribution centers and affected areas at certain points are considered. A mixed integer nonlinear programming model is proposed for open transportation location routing problem by considering split delivery of demand. To solve a realistic problem, foregoing parameters are considered as fuzzy in our propos...

The paper studies a robust mixed integer program with single unrestricted continuous variable. purpose of the is polyhedral study solution set using submodularity. A submodular function diminishing returns property, and little work has been studied on utilization submodularity in optimization problems considering data uncertainty. In this paper, we propose valid inequalities Valid for are defin...

This paper aims to compare a two-echelon and a single-echelon distribution system. A mathematical model for the Single-Echelon Capacitated Vehicle Routing Problem (SE-CVRP) is proposed. This SE-CVRP is the counterpart of Two-Echelon Capacitated Vehicle Routing Problem (2E-CVRP) introduced in the authors’ previous work. The proposed mathematical model is Mixed-Integer Non-Linear Programming (MIN...