We study the two-level uncapacitated facility location (TUFL) problem. Given two types of facilities, which we call y-facilities and z-facilities, the problem is to decide which facilities of both types to open, and to which pair of yand z-facilities each client should be assigned, in order to satisfy the demand at maximum profit. We first present two multi-commodity How formulations of TUFL an...

In logistics management, selecting the carriers to deliver freight is a critical process for global enterprises. This paper determines the optimal carrier selection based on a multi-commodity reliability criterion for a logistics network subject to budget. Traditionally, a logistics network includes nodes and routes connecting the supplier and customer. Along each route, several carriers are av...

The traditional multi-commodity flow problem assumes a given flow network in which multiple commodities are to be maximally routed in response to given demands. This paper considers the multi-commodity flow network-desigu problem: given a set of multi-commodity flow demands, find a network subject to certain constraints such that the commodities can be maximally routed. This paper focuses on th...

In this paper, we study the approximability of the capacitated network design problem (Cap-NDP) on undirected graphs: GivenG = (V,E) with non-negative costs c and capacities u on its edges, sourcesink pairs (si, ti) with demand ri, the goal is to find the minimum cost subgraph where the minimum (si, ti) cut with u-capacities is at least ri. When u ≡ 1, we get usual SNDP for which Jain gave a 2-...

We consider a capacity expansion problem arising in the design of telecommunication networks. The problem is to install capacity on links of the network so as to meet customer demand while minimizing total costs incurred. When studying this and related problems it is customary to assume that point to point demands are given. This will not be the case in practice, however, since future demand is...

This paper presents an evolutionary algorithm for the network design problem in the liner shipping industry with focus on the fitness calculation. The main contribution of this work are several new business constraints, such as committed partner capacities using a maximum flow algorithm and the transit times using a shortest path evaluation. Beside the cargo flows, the transit times are importa...

the environmental rules of reverse logistic networks have caused important economic growth in the past decades. to integrate forward logistic networks with reverse logistics networks a helpful method is to design both networks simultaneously. considering more retrieval choices in modeling reverse logistic systems can be very critical. this article contains a mixed integer linear programming mod...