one of the most important measures needed to be done in times of crisis is to optimize the allocation and distribution of resources among individuals. time is a critical factor effective to increase the number of people rescued by the relief activities.in this paper, we present a relief vehicle routing model in the affected area which uses covering tour approach to reduce total response time. a...

this paper deals with a multi-period fixed charge production-distribution problem associated with backorder and inventories. the objective is to determine the size of the shipments from each supplier and backorder and inventories at each period, so that the total cost incurred during the entire period towards production, transportation, backorder and inventories is minimised. a 0-1 mixed intege...

This paper deals with the determination of machine numbers and production schedules in manufacturing environments. In this line, a two-stage fuzzy stochastic programming model is discussed with fuzzy processing times where both deterioration and learning effects are evaluated simultaneously. The first stage focuses on the type and number of machines in order to minimize the total costs associat...

This paper deals with a multi-period fixed charge production-distribution problem associated with backorder and inventories. The objective is to determine the size of the shipments from each supplier and backorder and inventories at each period, so that the total cost incurred during the entire period towards production, transportation, backorder and inventories is minimised. A 0-1 mixed intege...

in this paper we consider the non-preemptive variant of a multi-mode resource constrained project scheduling problem (mrcpsp) with mode identity, in which a set of project activities is partitioned into disjoint subsets while all activities forming one subset have to be processed in the same mode. we present a depth-first branch and bound algorithm for the resource constrained project schedulin...

it is well known that in operations research‎, ‎degeneracy can cause a cycle in a network‎ ‎simplex algorithm which can be prevented by maintaining strong‎ ‎feasible bases in each pivot‎. ‎also‎, ‎in a network consists of n arcs‎ ‎and m nodes‎, ‎not considering any new conditions on the entering‎ ‎variable‎, ‎the upper bound of consecutive degenerate pivots is equal‎ $left( ‎begin{array}{c}‎ ‎n...

preemptively scheduling a set of independent jobs with release time on one processor is a historical problem. in this paper, the same problem has been considered in which objective is to minimize the mean flow time. to prepare a perfect branch-and-bound, some optimality conditions have been represented and they have been compared with the optimality conditions which have been proposed before. o...

the present study presents an algorithm that models uncertainties at the structural component level to estimate the performance reliability of rc structures. the method calculates the performance reliability using a systemic approach and incorporates the improved response surface method based on sampling blocks using the first-order reliability method and conditional reliability indices. the re...

yard crane is an important resource in container terminals. efficient utilization of the yard crane significantly improves the productivity and the profitability of the container terminal. this paper presents a mixed integer programming model for the yard crane scheduling problem with non- interference constraint that is nphard in nature. in other words, one of the most important constraints in...