Tourists have the difficult task to schedule their holiday activities in such a way that they enjoy their holiday as much as possible, while keeping the opening times and exact locations of attractions in mind. This task can be formulated as the team orienteering problem with time windows (TOPTW). The TOPTW uses a list of locations as input, together with their opening times and appreciation sc...

Distribution planning is crucial for most companies since goods are rarely produced and consumed at the same place. Distribution costs, in addition, can be an important component of the final cost of the products. In this paper, we study a VRP variant inspired on a real case of a large distribution company. In particular, we consider a VRP with a heterogeneous fleet of vehicles that are allowed...

In this paper, we address the approximate nearest neighbor (ANN) search problem over large scale visual descriptors. We investigate a simple but very effective approach, neighborhood graph (NG) search, which conducts the local search by expanding neighborhoods with a best-first manner. Expanding neighborhood makes it efficient to locate the descriptors with high probability being true NNs. Howe...

The flow shop scheduling problem consists in the assignment of a set of jobs J = {J1, . . . , Jn}, each of which consists of a set of operations Jj = {Oj1, . . . , Ojoj} onto a set of machines M = {M1, . . . ,Mm} [5, 18]. Each operation Ojk is processed by at most one machine at a time, involving a non-negative processing time pjk. The result of the problem resolution is a schedule x, defining ...

Course timetabling is an important and recurring administrative activity in most educational institutions. This article combines a general modeling methodology with effective learning hyper-heuristics to solve this problem. The proposed hyper-heuristics are based on an iterated local search procedure that autonomously combines a set of move operators. Two types of learning for operator selectio...

The Heterogeneous Fleet Capacitated Vehicle Routing Problem with Time Windows and ThreeDimensional Loading Constraints (3L-HFCVRPTW) combines the aspects of 3D loading, heterogeneous transport with capacity constraints and time windows for deliveries. It is the first formulation that comprises all these aspects and takes its inspiration from a practical problem of distributing daily fibre board...

In this paper, we propose the first heuristic approach for the vertex separator problem (VSP), based on Breakout Local Search (BLS). BLS is a recent meta-heuristic that follows the general framework of the popular Iterated Local Search (ILS) with a particular focus on the perturbation strategy. Based on some relevant information on search history, it tries to introduce the most suitable degree ...

The main principle of a look-ahead strategy is to inspect a few steps ahead before taking a decision on the direction to choose. We propose two original look-ahead strategies that differ in the object of inspection. The first method introduces a look-ahead mechanism at a superior level for selecting local-search operators. The second method uses a look-ahead strategy on a lower level in order t...

Structure optimization is one of the two key components of score-and-search based Bayesian network learning. Extending previous work on ordering-based search (OBS), we present new local search methods for structure optimization which scale to upwards of a thousand variables. We analyze different aspects of local search with respect to OBS that guided us in the construction of our methods. Our i...

Abstract. In this paper, the experiments with local search heuristic algorithms for the traveling salesman problem (TSP) are described. Since the ordinary local search heuristics very seldom yield solutions of high quality, we investigate the enhanced local search algorithms using the extended neighbourhood structures. We also examine the performance of the local search heuristics in an iterate...