Person

Thomas Rothvoss

This person is no longer with EPFL

Bin Packing via Discrepancy of Permutations

Friedrich Eisenbrand, Thomas Rothvoss, Doemoetoer Palvoelgyi

A well-studied special case of bin packing is the 3-partition problem, where n items of size > 1/4 have to be packed in a minimum number of bins of capacity one. The famous Karmarkar-Karp algorithm transforms a fractional solution of a suitable LP relaxati ...

Association for Computing Machinery2013

Bin Packing via Discrepancy of Permutations

Friedrich Eisenbrand, Thomas Rothvoss, Doemoetoer Palvoelgyi

A well studied special case of bin packing is the 3-partition problem, where n items of size > 1/4 have to be packed in a minimum number of bins of capacity one. The famous Karmarkar-Karp algorithm transforms a fractional solution of a suitable LP relaxati ...

Siam, 3600 Univ City Science Center, Philadelphia, Pa 19104-2688 Usa2011

Pricing on Paths: A PTAS for the Highway Problem

Thomas Rothvoss

In the highway problem, we are given an n-edge line graph (the highway), and a set of paths (the drivers), each one with its own budget. For a given assignment of edge weights (the tolls), the highway owner collects from each driver the weight of the assoc ...

2011

A 3/2-Approximation Algorithm for Rate-Monotonic Multiprocessor Scheduling of Implicit-Deadline Tasks

Thomas Rothvoss

We present a new approximation algorithm for rate-monotonic multiprocessor scheduling of periodic tasks with implicit deadlines. We prove that for an arbitrary parameter k it yields solutions with at most (3/2 + 1/k)*OPT+9k many processors, thus it gives a ...

Springer2011

From Uncertainty to Nonlinearity: Solving Virtual Private Network via Single-Sink Buy-at-Bulk

Thomas Rothvoss, Laura Sanità

The virtual private network problem (VPN) models scenarios in which traffic is uncertain or rapidly changing. The goal is supporting at minimum cost a given family of traffic matrices, which are implicitly given by upper bounds on the ingoing and outgoing ...

2011

EDF-schedulability of synchronous periodic task systems is coNP-hard

Friedrich Eisenbrand, Thomas Rothvoss

In the synchronous periodic task model, a set \tau_1,...,\tau_n of tasks is given, each releasing jobs of running time c_i with relative deadline d_i, at each integer multiple of the period p_i. It is a classical result that Earliest Deadline First (EDF) i ...

2010

Optimal Selection of Customers for a Last-Minute Offer

Thomas Rothvoss

We analyze a short-term revenue optimization problem involving the targeting of customers for a promotion in which a finite number of perishable items are sold on a last-minute offer. The goal is to select the subset of customers to whom the offer will be ...

2010

An Improved LP-based Approximation for Steiner Tree

Thomas Rothvoss, Laura Sanità

The Steiner tree problem is one of the most fundamental

\mathbf{NP}

-hard problems: given a weighted undirected graph and a subset of terminal nodes, find a minimum-cost tree spanning the terminals. In a sequence of papers, the approximation ratio for thi ...

Acm Order Department, P O Box 64145, Baltimore, Md 21264 Usa2010

Connected facility location via random facility sampling and core detouring

Friedrich Eisenbrand, Thomas Rothvoss

We present a simple randomized algorithmic framework for connected facility location problems. The basic idea is as follows: We run a black-box approximation algorithm for the unconnected facility location problem, randomly sample the clients, and open the ...

2010

Network Design via Core Detouring for Problems Without a Core

Thomas Rothvoss

Some of the currently best-known approximation algorithms for network design are based on random sampling. One of the key steps of such algorithms is connecting a set of source nodes to a random subset of them. In a recent work [Eisenbrand,Grandoni,Rothvo\ ...

Springer2010

An Improved LP-based Approximation for Steiner Tree

Thomas Rothvoss, Laura Sanità

The Steiner tree problem is one of the most fundamental

\mathbf{NP}

-hard problems: given a weighted undirected graph and a subset of terminal nodes, find a minimum-cost tree spanning the terminals. In a sequence of papers, the approximation ratio for thi ...

Acm Order Department, P O Box 64145, Baltimore, Md 21264 Usa2010