The paper addresses a multi-item, multi-plant lot-sizing problem with transfer costs and capacity constraints. The problem is reformulated according to a multi-commodity flow formalism, and decomposed, through Lagrangean relaxation, into a master facility location problem and a slave minimal cost multi-commodity flow problem. The decomposition framework gives rise in a natural way to the design...

An approach for searching unsupported integer solutions of the bicriteria network flow problem is suggested. Some of the integer points in the triangles, defined by two neighbouring extreme nondominated points, are investigated by appropriately defined problems for a flow with one side constraint and for minimal cost flow.

Abstract The robust minimum cost flow problem under consistent constraints (RobMCF $$\equiv $$ ? ) is a new extension of the (MCF) problem. In RobMCF problem, we consider demand and supply that are subject to uncertainty. For all realizations, however, require value on an arc needs be equal if it included in ...

the immiscible displacement of oil by water through a porous and permeable reservoir rock can be described by the use of a fractional flow curves (fw versus sw). water flooding project parameters can be obtained from the fractional flow curve. however, developing a representative fractional flow curve for a specific reservoir can be quite challenging when fluid and special core analysis data is...

objective the standard of hygiene in daily life and hospitals can be increased by the use of new antimicrobial fibers, which diminish the danger of pathogenic bacteria. in this study, the antimicrobial effect of special fibers on some staphylococcus isolates was investigated. materials and methods the antimicrobial effect of special type of fibers produced in isfahan poly acryl plant on three s...

We consider Newton's method for the linear fractional combinatorial optimization. First we show a strongly polynomial bound on the number of iterations for the general case. Then we consider the transshipment problem when the maximum arc cost is being minimized. This problem can be reduced to the maximum mean-weight cut problem, which is a special case of the linear fractional combinatorial opt...

With the mushrooming of distributed renewable generation, energy storage unit (ESU) is becoming increasingly important in residential systems. This letter proposes a fractional programming model to determine optimal power, and capacities ESUs. The objective function maximizes ratio between reduced electricity tariff, investment cost ESU, ensuring minimal payback time. A decomposition algorithm ...

It is well-known how to use maximum flow to decide when a flow problem with demands, lower bounds, and upper bounds is infeasible. Less well-known is how to compute a flow that is least infeasible. This paper considers many possible ways to define “least infeasible” and shows how to compute optimal flows for each definition. For each definition it also gives a dual characterization in terms of ...

This paper addresses the Vehicle Routing Problem with Delivery Time Cost. This problem aims to find a set of routes of minimal total costs including the travelling cost and delivery time cost, starting and ending at the depot, in such a way that each customer is visited by one vehicle given the capacity of the vehicle to satisfy a specific demand. In this research, a hybrid metaheuristic approa...