Tim studied mathematics
at the universities of Stuttgart
and Uppsala from 2000
to 2005. After some time in the IT-industry, he made his
PhD at Albert
Ludwigs University of Freiburg
from 2007 to 2010. Then he started
working at IBM
Research - Zurich in July 2010. His research interests
are scheduling and inventory planning problems, both
from a theoretical and practical perspective. Moreover,
he enjoys thinking about approximation algorithms for
hard combinatorial optimization problems in general,
especially problems with a rich geometric structure that
are "almost" polynomially solvable by approximation
schemes.
Publications
PTAS for
Densest k-Subgraph in Interval Graphs
In
Proceedings of the 12th Workshop on Algorithms and
Data Structures (WADS'11)
Clique
Clustering yields a PTAS for max-Coloring Interval Graphs
In Proceeding of the 38th International
Conference on Automata, Languages and Programming
(ICALP'11)
Capacitated
Max-Batching with Interval Graph Compatibilities
In Proceedings of the 12th
Scandinavian Symposium and Workshops on Algorithm Theory
(SWAT'10)
SRPT is
1.86-Competitive for Completion Time Scheduling
(with Christine Chung and Alexander Souza)
In Proceedings of the 21st ACM-SIAM Symposium on Discrete
Algorithms (SODA'10)
The Bell
is Ringing in Speed-Scaled Multiprocessor Scheduling
(with Gero Greiner and Alexander
Souza) In Proceedings of the 21st ACM Symposium on
Parallelism in Algorithms and Architectures (SPAA'09)
Approximating
the Joint Replenishment Problem with Deadlines
(with Alexander Souza) Discrete
Mathematics, Algorithms and Applications (DMAA), World
Scientific, Volume 1, Issue 2 (June 2009)
Latency
Constrained Data Aggregation in Chain Networks Admits a
PTAS
(with Alexander Souza)
In Proceedings of the 5th International Conference on
Algorithmic Aspects in Information and Management
(AAIM'09)
A
5/3-Approximation Algorithm for Joint Replenishment with
Deadlines
(with Alexander
Souza) In Proceedings of the 3rd Annual Conference on
Combinatorial Optimization and Applications (COCOA'09)
Distributed
Approximation Algorithms for Finding 2-Edge-Connected
Subgraphs
(with Sven
Krumke, Peter Merz, and Katharina Gerhardt) In Proceedings
of the 12th International Conference On Principles Of
Distributed Systems (OPODIS'07)
Theses
Approximation
in Batch and Multiprocessor Scheduling
PhD thesis, Albert Ludwigs University of
Freiburg, 2010
Subwordproblems
in compressed words
Diploma
thesis (in german), University of Stuttgart, 2005,
advisor: Markus Lohrey
Selected
Talks
Polynomial-Time Approximation Schemes for Shortest Path with Alternatives
DIMAP Seminar at University of Warwick, Coventry,
UK, April 16th 2012
Introduction to IBM Research
DPG Fruehjahrstagung, Berlin,
Germany, March 28th 2012
PTAS for
Densest k-Subgraph in Interval Graphs
IP for Lunch Seminar, IBM T.J. Watson,
United States, August 23rd 2011
PTAS
for Densest k-Subgraph in Interval Graphs
WADS'11,
New York City, United States, August 7th 2011
Clique
Clustering yields a PTAS for Max-Coloring Interval Graphs
MAPSP'11, Nymburg, Czech Republic, June
22nd 2011
Approximation
in Batch and Multiprocessor Scheduling
my defense talk at Albert Ludwigs
University of Freiburg, December 3rd 2010
Geometric
Max-Partitioning Problems
8th
Swiss Joint OR Days, Fribourg, Switzerland, September
10th 2010
Capacitated
max-Batching with Interval Graph Compatibilities
SWAT'10, Bergen, Norway, June 22nd
2010
Batch
Scheduling with Interval Compatibilities
Research Seminar, IBM Research Zurich,
Switzerland, April 27th 2010
SRPT is
1.86-Competitive for Completion Time Scheduling
SODA'10, Austin, United States,
January 19th 2010
SRPT and
Completion Time Scheduling
IP
for Lunch Seminar, IBM T.J. Watson, United States,
September 14th 2009
The Bell
is Ringing in Speed-Scaled Multiprocessor Scheduling
SPAA'09, Calgary, Canada, August
11th 2009
The Bell
is Ringing in Speed-Scaled Multiprocessor Scheduling
MAPSP'09, Rolduc, Netherlands, June
30th 2009
Latency
Constrained Aggregation in Chain Networks Admits a PTAS
AAIM'09, San Francisco, United
States, June 15th 2009
A
5/3-Approximation Algorithm for Joint Replenishment with
Deadlines
COCOA'09,
Huangshan, China, June 10th 2009
Distributed
Algorithms for Finding 2-Edge-Connected Subgraphs
OPODIS'07, Guadeloupe, France,
December 7th 2007
More
Matching Problems on Compressed Strings
Oberseminar Universität Stuttgart, June
1st 2005, the seminar talk about my diploma thesis, back
in the days
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