Department of Computer Science | Institute of Theoretical Computer Science | CADMO

Theory of Combinatorial Algorithms

Prof. Emo Welzl and Prof. Bernd Gärtner

Mittagsseminar (in cooperation with A. Steger, D. Steurer and B. Sudakov)

Mittagsseminar Talk Information

Date and Time: Tuesday, February 17, 2004, 12:15 pm

Duration: This information is not available in the database

Location: This information is not available in the database

Speaker: Alexander Hall

Flows over Time

Flow variation over time is an important feature in network flow problems arising in various applications such as road or air traffic control, production systems, communication networks (e.g., the Internet), and financial flows. The common characteristic are networks with capacities and transit times on the edges which specify the amount of time it takes for flow to travel through a particular edge. Moreover, in contrast to static flow problems, flow values on edges may change with time in these networks.
I will give a short introduction to the flows over time problem and mention new complexity and inapproximability results for the case where the transit times are assumed to be constant.
In many real-world applications transit times are not constant but depend on the current flow situation in the network. For the model where the transit time of an edge is given as a nondecreasing function of the rate of inflow into the edge I will present the ideas underlying an FPTAS for the `quickest multicommodity flow problem with bounded cost'. It can be shown that this problem is NP-hard even in the single commodity case.

This is joint work with Steffen Hippler, Katharina Langkau, and Martin Skutella.

Upcoming talks     |     All previous talks     |     Talks by speaker     |     Upcoming talks in iCal format (beta version!)

Previous talks by year:   2024  2023  2022  2021  2020  2019  2018  2017  2016  2015  2014  2013  2012  2011  2010  2009  2008  2007  2006  2005  2004  2003  2002  2001  2000  1999  1998  1997  1996  

Information for students and suggested topics for student talks

Automatic MiSe System Software Version 1.4803M   |   admin login