0000000000160920
AUTHOR
Arild Hoff
Heuristics for the capacitated modular hub location problem
Abstract In this paper we study the hub location problem, where the goal is to identify an optimal subset of facilities (hubs) to minimize the transportation cost while satisfying certain capacity constraints. In particular, we target the single assignment version, in which each node in the transportation network is assigned to only one hub to route its traffic. We consider here a realistic variant introduced previously, in which the capacity of edges between hubs is increased in a modular way. This reflects the practical situation in air traffic where the number of flights between two locations implies a capacity in terms of number of passengers. Then, the capacity can be increased in a mo…
Heuristics for the min–max arc crossing problem in graphs
Abstract In this paper, we study the visualization of complex structures in the context of automatic graph drawing. Constructing geometric representations of combinatorial structures, such as networks or graphs, is a difficult task that requires an expert system. The automatic generation of drawings of graphs finds many applications from software engineering to social media. The objective of graph drawing expert systems is to generate layouts that are easy to read and understand. This main objective is achieved by solving several optimization problems. In this paper we focus on the most important one: reducing the number of arc crossings in the graph. This hard optimization problem has been…
Analysis of hinterland transport strategies when exporting perishable products
Since a good hinterland connection is considered an important factor in port competitiveness, the objective of this paper is to analyse the impact of the development of hinterland transport strategies on the competitiveness of the port by taking the Port of Cape Town, the Republic of South Africa as an example. The development of transport strategies is reflected in terms of a lower cost and higher frequency of inland transport. To investigate the interplay among export products, transport, and access to a port for exporters, we use a linear programming model. The model considers both the choice of transport modes and the impacts of improved inland transport strategies. The model could easi…