In this paper we propose an ACO approach, where two colonies of ants aim to optimize total costs in a transportation network. This main objective consists of two sub goals, namely fleet size minimization and minimization of the vehicle movement costs, which are conflicting for some regions of...

In this paper we propose an ACO algorithm to optimize the total costs associated with the pickup and delivery of full truckloads under time window constraints in a hub network.(...)

While in the past decades research on multi-objective evolutionaryalgorithms (MOEA) has aimed at finding the wholeset of Pareto optimal solutions, current approaches focus ononly those parts of the Pareto front which satisfy the preferencesof the decision maker (DM). Therefore, they integratethe...

The edge-set encoding is a direct encoding for trees which directly representstrees as sets of edges. In contrast to indirect representations, whereusually standard operators are applied to a list of strings and the resultingphenotype is constructed by an appropriate genotype-phenotypemapping,...

OptiNet ist ein objektorientiertes Optimierungswerkzeug für die Lösung von baumförmigen Netzwerkproblemen mit Hilfe von naturanalogen Optimierungsverfahren. In OptiNet können verschiedene naturanaloge Optimierungsverfahren mit unterschiedlichen Problemrepräsentatio-nen (charakteristische...

Evolution strategies (ES) are efficient optimization methods for continuous problems. However, many combinatorial optimization methods can not be represented by using continuous representations. The development of the network random key representation (Rothlauf et al., 2001) which represents...