Björn Steffen

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In the disjoint path allocation problem, we consider a path of L + 1 vertices, representing the nodes in a communication network. Requests for an unbounded-time communication between pairs of vertices arrive in an online fashion and some central authority has to decide which of these calls to admit. The constraint is that each edge in the path can serve(More)
In this paper, we deal with several reoptimization variants of the Steiner tree problem in graphs obeying a sharpened β-triangle inequality. A reoptimization algorithm exploits the knowledge of an optimal solution to a problem instance for finding good solutions for a locally modified instance. We show that, in graphs satisfying a sharpened triangle(More)
These days, public-key cryptography is indispensable to ensure both confidentiality and authenticity in numerous applications which comprise securely communicating via mobile phone or email or digitally signing documents. For all public-key systems, such as RSA, mathematically challenging and technically involved methods are employed which are often above(More)
In this paper, we aim to do more than arguing that infor-matics is a fascinating scientific discipline with interesting applications in almost all areas of everyday life. We pose the following questions: What are the educational requirements demanded from school subjects? Can we answer this question as satisfactory as we can do it, for instance, for(More)
  • Utz Krug, Anja Koschmieder, Daniela Schwammbach, Joachim Gerss, Nicola Tidow, Björn Steffen +14 others
  • 2012
INTRODUCTION Older patients with acute myeloid leukemia (AML) experience short survival despite intensive chemotherapy. Azacitidine has promising activity in patients with low proliferating AML. The aim of this dose-finding part of this trial was to evaluate feasibility and safety of azacitidine combined with a cytarabine- and daunorubicin-based(More)