Michael Schachtebeck

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In the past, much research has been dedicated to compute optimum railway timetables. A typical objective was the minimization of passenger waiting times. But only the planned nominal waiting times were addressed, whereas delays, as they occur in daily operations, were neglected. Delays were rather treated mainly in an online-context, and solved as a(More)
Recently, the recoverable robustness model has been introduced in the optimization area. This model allows to consider disruptions (input data changes) in a unified way, that is, during both the strategic planning phase and the operational phase. Although the model represents a significant improvement, it has the following drawback: we are typically not(More)
Delay management is an important issue in the daily operations of any railway company. The task is to update the planned timetable to a disposition timetable in such a way that the inconvenience for the passengers is as small as possible. The two main decisions that have to be made in this respect are the wait-depart decisions to decide which connections(More)
AIM Recent investigations have shown improved patient reported outcome after preservation of the inferior mesenteric artery in sigmoid resection for diverticular disease. We report on our experience with preservation of the superior rectal artery (SRA). METHODS This is an observational single center study in a high-volume, level II inner city hospital(More)
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