We study graphs with spectral radius at most $\frac{3}{2}\sqrt{2}$ and refine results by Woo and Neumaier [On graphs whose spectral radius is bounded by $\frac{3}{2}\sqrt{2}$, Graphs Combinatorics 23 (2007), 713-726]. We study the limit points of the spectral radii of certain families of graphs,...

Latin hypercube designs (LHDs) play an important role when approximating computer simulation models.To obtain good space-filling properties, the maximin criterion is frequently used. Unfortunately, constructing maximin LHDs can be quite time-consuming when the number of dimensions and design...

Express service carriers provide time-guaranteed deliveries of parcels via a network consisting of nodes and hubs. In this, nodes take care of the collection and delivery of parcels, and hubs have the function to consolidate parcels in between the nodes. The tactical network design problem...

In the field of design of computer experiments (DoCE), Latin hypercube designs are frequently used for the approximation and optimization of black-boxes. In certain situations, we need a special type of designs consisting of two separate designs, one being a subset of the other. These nested...

We investigate minimax Latin hypercube designs in two dimensions for several distance measures. For the l-distance we are able to construct minimax Latin hypercube designs of n points, and to determine the minimal covering radius, for all n. For the l1-distance we have a lower bound for the...

In black box evaluation and optimization, Latin hypercube designs play an important role. When dealing with multiple black box functions, the need often arises to construct designs for all black boxes jointly, instead of individually. These so-called nested designs consist of two different...

This paper introduces methods to coordinate black box simulations in the construction of metamodels for situations in which we have to deal with coupled black boxes. We define three coordination methods: parallel simulation, sequential simulation and sequential modeling. To compare these three...

In many fields, we come across problems where we want to optimize several conflicting objectives simultaneously. To find a good solution for such multi-objective optimization problems, an approximation of the Pareto set is often generated. In this paper, we consider the approximation of Pareto...