http://repub.eur.nl/res/aut/5908/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/32996/ 2012-05-17T00:00:00Z In this paper we describe how rolling stock and passenger connections in a cyclic railway timetable can be modeled in a flexible way within the model for the Periodic Event Scheduling Problem (PESP). The PESP model was introduced by Serani and Ukovich (1989). Usually, PESP-models assume that the constraints for rolling stock or passenger connections specify in detail which trains should connect with each other. However, the flexibility described in this paper allows the model to choose which trains should connect with each other in a rolling stock or passenger connection. We express the required number of train compositions in terms of the integer cycle variables of the constraint graph. We also describe an abstract framework, demonstrating that, under certain conditions, the extra flexibility can be modeled purely in terms of PESP constraints. The concept of flexible rolling stock and passenger connections is illustrated by an example based on three intercity lines of Netherlands Railways. http://repub.eur.nl/res/pub/429/ 2003-06-06T00:00:00Z Cyclic Railway Timetable Optimization describes mathematical models and solution methods for constructing high quality cyclic railway timetables. In a cyclic timetable, a train for a certain destination leaves a certain station at the same time every cycle time, say every half an hour, every hour, or every two hours. Cyclic timetables are widely used in European railways. They offer a clear and transparant product to the railway customers, who only need to memorize the minutes of the hour at which their regular trains depart. Because of the important role of timetable planning for railway operators and railway infrastructure managers, models and methods for optimizing cyclic railway timetables provide a valuable tool for these organizations. The thesis presents a mathematical model for optimizing cyclic railway timetables, and studies the theoretical aspects behind the model. The investigated aspects include cyclic sequencing, periodic tensions, cycles in graphs, cycle bases of graphs, algorithms for constructing cycle bases, and cutting planes for the model. The developed theoretical ideas are tested on some real-life cyclic railway timetabling instances. The thesis further develops several extensions of the basic model. http://repub.eur.nl/res/pub/6689/ 2003-05-01T00:00:00Z In this paper we describe how variable trip times can be included into an existing cyclic railway timetabling model based on the well-known periodic event scheduling problem (PESP). Thereby we provide an extension of the existing model because in the existing model it is assumed that the trip times of all trains on all tracks of the railway network are known a priori. However, the latter may be too restrictive in practice. The solution space of the extended model that we present is larger because small deviations from the fixed trip times are allowed. This is especially useful when a feasible solution to the fixed trip time model does not exist. The solutions obtained from the extended model are proven to be correct under certain necessary and sufficient conditions. Furthermore, the extended model has the same general structure as the original model. Therefore, solution methods developed for the original fixed trip time model can be applied to the extended model as well. [ABSTRACT FROM AUTHOR] http://repub.eur.nl/res/pub/11856/ 2001-01-01T00:00:00Z This paper describes the development of a minimum flow algorithm to determine the number of automated guided vehicles (AGVs) required at a semi-automated container terminal. At such a terminal the containers are transported by AGVs from the quay cranes to the automated stacking cranes and vice versa. A model and a strongly poly~lomial time algorithm are developed to solve the case in which containers are available for transport at known time instants.