This paper presents an innovative approach to the tactical planning of aircraft remote and contact-stands allocation at airports. We use the concept of recoverable robustness to obtain a recoverable robust solution to the stand allocation problem, a solution that can be recovered by limited means for the included scenarios. Four objective functions are discussed and tested to assess the efficiency of a stand allocation plan. Namely, the minimization of passengers' walking distance, the minimization of tows, the maximization of the number of passengers allocated to contact-stands, and the maximization of the potential airport commercial revenue. The inclusion of an airport commercial revenue metric in the stand allocation optimization model and the comparison of its performance to the pre-mentioned other objectives is another novelty of this work. The research was developed in collaboration with the Guarulhos International Airport of São Paulo for which the recoverable robust approach was tested for 6 days of operations at the airport. We demonstrate that the solutions obtained with the proposed approach outperform the solutions of a traditional robust approach. In addition, a discussion of the trade-off between the different objectives is provided.

Medium height breakwaters are subjected to a considerable amount of overtopping. This implies the armour on the inner slope has to stable against overtopping waves. Existing equations do lack some basic understanding of the process of starting up movement of rock on the inner slopes.In order to get more insight into this phenomenon a special device has been constructed in the laboratory. In this device it is possible to generate one single, overtopping wave. So with this piece of equipment overtopping of single waves can be repeated several times and a relation can be looked for between the individual plunge and the stability of the individual blocks. In an other research program the relation between the random waves and the individual plunges is investigated. As a follow up the results of damage by individual waves will be combined with the distribution of overtopping water over a breakwater. This combination will result in a damage distribution due to random overtopping.It has been found from the first test series that stability of the blocks can be described as a function of the maximum water velocity on the crest, combined with some geometrical parameters of the inner slope. From this research followed that the crest height and inner slope also had an effect on stability.