The present study investigates the performance of heuristics while solving problems with routing and rostering characteristics. The target problems include scheduling and routing home care, security and maintenance personnel. In analysing the behaviour of the heuristics and determining the...

In the team orienteering problem (TOP) a set of locations is given, each with a score. The goal is to determine a fixed number of routes, limited in length, that visit some locations and maximise the sum of the collected scores. This paper describes an algorithm that combines different local...

The Traveling Umpire Problem (TUP) is a challenging combinatorial optimization problem based on scheduling umpires for Major League Baseball. The TUP aims at assigning umpire crews to the games of a fixed tournament, minimizing the travel distance of the umpires. The present paper introduces two...

In this paper we present a decomposed metaheuristic approach to solve a real-world university course timetabling problem. Essential in this problem are the overlapping time slots and the irregular weekly timetables. A first stage in the approach reduces the number of subjects through the...

Traditional route planners assist in finding the shortest or fastest route from one place to another. This paper presents a novel approach to path finding in a directed graph, namely a target distance, motivated by the problem that a recreational cyclist deals with when searching a nice route of...

Quantitative decision support on personnel planning is often restricted to either rostering or staffing. There exist some approaches in which aspects at the staffing level and the rostering level are treated in a sequential way. Obviously, such practice risks producing suboptimal solutions at...

By using expressions for the reduced matrix elements of the generators of R(5) which were obtained by considering R(5) ↓ SU(2)⊗ SU(2) reduction, a method for directly evaluating analytical expressions for the R(3) scalar shift-operator O0l eigenvalues is discussed.

In order to obtaining additional label-generating operators for the classification of octupolephonon states, a set of shift operators Pkl (k = ± 5,…, 5) in the G2 group and Okl (k = ± 3,…, 3) in the R(7) group, is constructed. Expressions connecting R(3) scalar and non-scalar products of...

O(3) shift operators O±kl (k = 0, 1, 2) constructed by means of SU(3) generators, can be combined into bilinear forms which are non-scalar with respect to the O(3) subgroup. These are shown to satisfy simple relations which are of importance in deriving eigenvalue expressions of the scalar...

The ship placement problem constitutes a daily challenge for planners in tide river harbours. In essence, it entails positioning a set of ships into as few lock chambers as possible while satisfying a number of general and specific placement constraints. These constraints make the ship placement...