Maarten Lipmann

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A solitary choroidal mass with an overlying neurosensory retinal detachment was seen in an otherwise healthy 25-year-old Caucasian female. Ocular and general physical examinations, serum chemistry, and pathological examination of a lymph node biopsy confirmed sarcoidosis as the cause for the choroidal mass. Treatment with systemic steroids resulted in(More)
In on-line dial-a-ride problems servers are traveling in some metric space to serve requests for rides which are presented over time. Each ride is characterized by two points in the metric space, a source, the starting point of the ride, and a destination, the endpoint of the ride. Usually it is assumed that at the release of a request, complete information(More)
In the online dial-a-ride problem (OlDarp), objects must be transported by a server between points in a metric space. Transportation requests (“rides”) arrive online, specifying the objects to be transported and the corresponding source and destination. We investigate the OlDarp for the objective of minimizing the maximum flow time. It has been well known(More)
In the cake cutting problem, <i>n</i> &#8805; 2 players want to cut a cake into <i>n</i> pieces so that every player gets a "fair" share of the cake by his own measure. We describe a protocol with <i>n</i> - 1 cuts in which each player can enforce to get a share of at least 1/(2<i>n</i> - 2) of the cake. Moreover we show that no protocol with <i>n</i> - 1(More)
We consider the online traveling salesperson problem (TSP), where requests appear online over time on the real line and need to be visited by a server initially located at the origin. We distinguish between closed and open online TSP, depending on whether the server eventually needs to return to the origin or not. While online TSP on the line is a very(More)
In the online traveling salesman problem (OlTsp) requests for visits to cities arrive online while the salesman is traveling. The Fmax-OlTsp has as objective to minimize the maximum flow time, which is particularly interesting for applications. Unfortunately, there can be no competitive algorithm, neither deterministic nor randomized. Hence, competitive(More)
Acknowledgments I thank Leen Stougie who has been an enormous help during my PhD research. His enthusiasm motivated me and people around me which created a great atmosphere for research. He advised me in many ways and most of this research was done with him. It am very happy to have Leen as advisor and supervisor. I thank Jan Karel Lenstra for his advise,(More)
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