In the Directed Steiner Tree (DST) problem we are given an n-vertex directed edge-
weighted graph, a root r, and a collection of k terminal nodes. Our goal is to find a minimum …

In the Directed Steiner Tree (DST) problem, we are given a directed graph on vertices with
edge-costs, a root vertex, and a set of terminals. The goal is to find a minimum-cost …

We consider the following general network design problem. The input is an asymmetric
metric (V, c), root r∈ V, monotone submodular function f: 2 V→ R+, and budget B. The goal …

We consider the classic problem of scheduling jobs with precedence constraints on identical
machines to minimize makespan, in the presence of communication delays. In this setting …

We consider the problem of scheduling jobs with precedence constraints on related
machines to minimize the weighted sum of completion times, in the presence of …

In the Directed Steiner Tree (DST) problem the input is a directed edge-weighted graph $
G=(V, E) $, a root vertex $ r $ and a set $ S\subseteq V $ of $ k $ terminals. The goal is to …

Abstract Guha et al.[STOC, 1999] and Moss and Rabani [SIAM J. Comput., 2007] introduced
two variants of the Steiner problem in undirected graphs in which the nodes are associated …

We give the first constant-factor approximation algorithm for quasi-bipartite instances of
Directed Steiner Tree on graphs that exclude fixed minors. In particular, for $ K_r $-minor …

We consider lift-and-project methods for combinatorial optimization problems and focus
mostly on those lift-and-project methods which generate polyhedral relaxations of the …

This paper is devoted to the study of the MaxMinDegree Arborescence (MMDA) problem in
layered directed graphs of depth ℓ≤ O (log n/log log n), which is an important special case …