This paper addresses the linear ordering problem, which has been solved using different metaheuristics approaches. These algorithms have the common problem of finding a proper balance of the intensification and diversification processes; in this work we propose an iterated local search in which it is incorporated a Becker heuristic strategy for constructing the initial solution, and a search st...

This paper deals with the Vehicle Routing Problem with Simultaneous Pick-up and Delivery and Time Limit (VRPSPDTL). Due to the combinatorial nature of the problem, heuristics methods are commonly used to generate good quality solutions within an acceptable computational time. Accordingly, an Iterated Local Search (ILS) procedure that uses a Variable Neighborhood Descent (VND) method to perform ...

Systematic search and local search paradigms for combinatorial problems are generally believed to have complementary strengths. Nevertheless, attempts to combine the power of the two paradigms have had limited success, due in part to the expensive information communication overhead involved. We propose a hybrid strategy based on shared memory, ideally suited for multi-core processor architectur...

This paper concerns the Split Delivery Vehicle Routing Problem (SDVRP). This problem is a relaxation of the Capacitated Vehicle Routing Problem (CVRP) since the customers’ demands are allowed to be split. We deal with the cases where the fleet is unlimited (SDVRP-UF) and limited (SDVRP-LF). In order to solve them, we implemented a multi-start Iterated Local Search (ILS) based heuristic that inc...

The multidimensional assignment problem (MAP) (abbreviated s-AP in the case of s dimensions) is an extension of the well-known assignment problem. The most studied case of MAP is 3-AP, though the problems with larger values of s have also a number of applications. In this paper we propose several local search heuristics for MAP and select the dominating ones. The results of computational experi...

We study the improvement of non-permutation over permutation schedules in flow shops when minimizing the total completion time. We solve both problems by a two-phase heuristic. The first phase uses an iterated local search to find a good permutation schedule. The second phase explores non-permutation schedules using an effective insertion neighborhood, that permits to anticipate or delay a job ...

We describe a new neighborhood structure for the capacitated minimum spanning tree problem. This neighborhood structure is used by a local search strategy, leading to good trade-offs between solution quality and computation time. We also propose a GRASP with path-relinking heuristic. It uses a randomized version of a savings heuristic in the construction phase and an extension of the above loca...

We present a new hybrid constraint solving schema which retains some systematicity of constructive search while incorporating the heuristic guidance and lack of commitment to variable assignment of local search. Our method backtracks through a space of complete but possibly inconsistent solutions while supporting the freedom to move arbitrarily under heuristic guidance. The version of the schem...

The Virtual Network Mapping Problem arises in the context of Future Internet research. Multiple virtual networks with different characteristics are defined to suit specific applications. These virtual networks, with all of the resources they require, need to be realized in one physical network in a most cost effective way. Two properties make this problem challenging: Already finding any valid ...

The Variable Neighborhood Tabu Search consists of a constructive phase and a series of local searches that use tabu tools. When the local search stops at a nontabu local minimum, a shake procedure starts a new local search. The local searches and the shake procedure are based on a series of standard moves. The local search consists of applying the best possible move until no such move exists. T...