Social networks and discovery in the enterprise (SaND)
Inbal Ronen, Elad Shahar, et al.
SIGIR 2009
In this paper, we initiate the study of designing approximation algorithms for Fault-Tolerant Group-Steiner (FTGS) problems. The motivation is to protect the well-studied group-Steiner networks from edge or vertex failures. In Fault-Tolerant Group-Steiner problems, we are given a graph with edge- (or vertex-) costs, a root vertex, and a collection of subsets of vertices called groups. The objective is to find a minimum-cost subgraph that has two edge- (or vertex-) disjoint paths from each group to the root. We present approximation algorithms and hardness results for several variants of this basic problem, e.g., edge-costs vs. vertex-costs, edge-connectivity vs. vertex-connectivity, and 2-connecting a single vertex vs. two distinct vertices from each group. The main contributions of our paper include the introduction of general structural lemmas on connectivity and a charging scheme that may find more applications in the future. Our algorithmic results are supplemented by inapproximability results, which are tight in some cases. © 2011 Elsevier B.V. All rights reserved.
Inbal Ronen, Elad Shahar, et al.
SIGIR 2009
Chi-Leung Wong, Zehra Sura, et al.
I-SPAN 2002
Sabine Deligne, Ellen Eide, et al.
INTERSPEECH - Eurospeech 2001
Ohad Shamir, Sivan Sabato, et al.
Theoretical Computer Science