José Verschae
Technical University of Berlin
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Publication
Featured researches published by José Verschae.
international colloquium on automata languages and programming | 2013
Nicole Megow; José Verschae
We study scheduling problems on a machine of varying speed. Assuming a known speed function (given through an oracle) we ask for a cost-efficient scheduling solution. Our main result is a PTAS for minimizing the total weighted completion time on a machine of varying speed. This implies also a PTAS for the closely related problem of scheduling to minimize generalized global cost functions. The key to our results is a re-interpretation of the problem within the well-known two-dimensional Gantt chart: instead of the standard approach of scheduling in the time-dimension, we construct scheduling solutions in the weight-dimension. We also consider a dynamic problem variant in which deciding upon the speed is part of the scheduling problem and we are interested in the tradeoff between scheduling cost and speed-scaling cost, which is typically the energy consumption. We obtain two insightful results: (1) the optimal scheduling order is independent of the energy consumption and (2) the problem can be reduced to the setting where the speed of the machine is fixed, and thus admits a PTAS.
international colloquium on automata languages and programming | 2010
Friedrich Eisenbrand; Nicolai Hähnle; Martin Niemeier; Martin Skutella; José Verschae; Andreas Wiese
We consider a real-time scheduling problem that occurs in the design of software-based aircraft control. The goal is to distribute tasks
european symposium on algorithms | 2010
Friedrich Eisenbrand; Karthikeyan Kesavan; Raju S. Mattikalli; Martin Niemeier; Arnold Nordsieck; Martin Skutella; José Verschae; Andreas Wiese
au_i=(c_i,p_i)
international colloquium on automata languages and programming | 2012
Nicole Megow; Martin Skutella; José Verschae; Andreas Wiese
on a minimum number of identical machines and to compute offsets
european symposium on algorithms | 2010
Martin Skutella; José Verschae
a_i
SIAM Journal on Computing | 2016
Nicole Megow; Martin Skutella; José Verschae; Andreas Wiese
for the tasks such that no collision occurs. A task
international colloquium on automata languages and programming | 2016
Klaus Jansen; Kim-Manuel Klein; José Verschae
au_i
european symposium on algorithms | 2011
José Verschae; Andreas Wiese
releases a job of running time
mathematical foundations of computer science | 2013
Antonios Antoniadis; Chien-Chung Huang; Sebastian Ott; José Verschae
c_i
Mathematical Programming | 2015
Alberto Marchetti-Spaccamela; Jannik Matuschke; Leen Stougie; Ola Svensson; Victor Verdugo; José Verschae
at each time