Results 1 - 10 of 49

Subexponential fixed-parameter tractability of cluster editing

by Fedor V. Fomin, Stefan Kratsch, Marcin Pilipczuk, Michal Pilipczuk, Yngve Villanger , 2012
"... In the Correlation Clustering, also known as Cluster Editing, we are given an undi-rected n-vertex graph G and a positive integer k. The task is to decide if G can be transformed into a cluster graph, i.e., a disjoint union of cliques, by changing at most k adjacencies, i.e. by adding/deleting at mo ..."
Abstract - Cited by 4 (0 self) - Add to MetaCart
In the Correlation Clustering, also known as Cluster Editing, we are given an undi-rected n-vertex graph G and a positive integer k. The task is to decide if G can be transformed into a cluster graph, i.e., a disjoint union of cliques, by changing at most k adjacencies, i.e. by adding

Geometric Clustering: Fixed-Parameter Tractability and Lower Bounds with Respect to the Dimension

by Sergio Cabello, Panos Giannopoulos, Christian Knauer, Günter Rote
"... We present an algorithm for the 3-center problem in (Rd, L1), i. e., for finding the smallest side length for 3 cubes that cover a given n-point set in Rd, that runs in O(n log n) time for any fixed dimension d. This shows that the problem is fixed-parameter tractable when parameterized with d. On ..."
Abstract - Cited by 7 (6 self) - Add to MetaCart
We present an algorithm for the 3-center problem in (Rd, L1), i. e., for finding the smallest side length for 3 cubes that cover a given n-point set in Rd, that runs in O(n log n) time for any fixed dimension d. This shows that the problem is fixed-parameter tractable when parameterized with d

Fixed-Parameter Enumerability of Cluster Editing and Related Problems

by Peter Damaschke - Theory Comp. Systems
"... Cluster Editing is transforming a graph by at most k edge insertions or deletions into a disjoint union of cliques. This problem is fixed-parameter tractable (FPT). Here we compute concise enumerations of all minimal solutions in O(2.27 k + k 2 n + m) time. Such enumerations support efficient infere ..."
Abstract - Cited by 6 (2 self) - Add to MetaCart
Cluster Editing is transforming a graph by at most k edge insertions or deletions into a disjoint union of cliques. This problem is fixed-parameter tractable (FPT). Here we compute concise enumerations of all minimal solutions in O(2.27 k + k 2 n + m) time. Such enumerations support efficient

Constructing minimal phylogenetic networks from softwired clusters is fixed parameter tractable

by Steven Kelk, Celine Scornavacca , 2011
"... ..."
Abstract - Cited by 8 (6 self) - Add to MetaCart
Abstract not found

On Tractable Cases of Target Set Selection

by André Nichterlein, Rolf Niedermeier, Johannes Uhlmann, Mathias Weller
"... We study the NP-complete TARGET SET SELECTION (TSS) problem occurring in social network analysis. Complementing results on its approximability and extending results for its restriction to trees and bounded treewidth graphs, we classify the influence of the parameters “diameter”, “cluster edge delet ..."
Abstract - Cited by 7 (3 self) - Add to MetaCart
fixed-parameter algorithms for the parameter cluster edge deletion number, yielding tractability for certain dense networks.

Parameterized Complexity of k-Anonymity: Hardness and Tractability

by Stefano Beretta, Paola Bonizzoni, Gianluca Della, Vedova Riccardo Dondi, Yuri Pirola , 2010
"... The problem of publishing personal data without giving up privacy is becoming increasingly important. A clean formalization that has been recently proposed is the k-anonymity, where the rows of a table are partitioned in clusters of size at least k and all rows in a cluster become the same tuple, af ..."
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the complexity of the problem is influenced by different parameters. First we show that the problem is W[1]-hard when parameterized by the value of the solution (and k). Then we exhibit a fixed-parameter algorithm when the problem is parameterized by the number of columns and the maximum number of different

The Cluster Editing Problem: Implementations And Experiments

by Frank Dehne, Michael A. Langston, Xuemei Luo, Sylvain Pitre, Peter Shaw, Yun Zhang - IN PROC. 2ND IWPEC , 2006
"... In this paper, we study the cluster editing problem which is fixed parameter tractable. We present ..."
Abstract - Cited by 29 (3 self) - Add to MetaCart
In this paper, we study the cluster editing problem which is fixed parameter tractable. We present

Approximation algorithms for the capacitated domination problem

by Mong-jen Kao, Han-lin Chen - in FAW 2010, 2010
"... We consider the Capacitated Domination problem, which models a service-requirement as-signment scenario and is also a generalization of the well-known Dominating Set problem. In this problem, given a graph with three parameters defined on each vertex, namely cost, capacity, and demand, we want to fi ..."
Abstract - Cited by 2 (2 self) - Add to MetaCart
. On the other hand, from the per-spective of parameterization, we prove that this problem is W[1]-hard when parameterized by a structure of the graph called treewidth. Based on this hardness result, we present exact fixed-parameter tractable algorithms when parameterized by treewidth and maximum capacity

Whom You Know Matters: Venture Capital Networks and Investment Performance,

by Yael Hochberg , Alexander Ljungqvist , Yang Lu , Steve Drucker , Jan Eberly , Eric Green , Yaniv Grinstein , Josh Lerner , Laura Lindsey , Max Maksimovic , Roni Michaely , Maureen O'hara , Ludo Phalippou Mitch Petersen , Jesper Sorensen , Per Strömberg Morten Sorensen , Yael Hochberg , Johnson - Journal of Finance , 2007
"... Abstract Many financial markets are characterized by strong relationships and networks, rather than arm's-length, spot-market transactions. We examine the performance consequences of this organizational choice in the context of relationships established when VCs syndicate portfolio company inv ..."
Abstract - Cited by 138 (8 self) - Add to MetaCart
might be described as "dense" (if many actors are tied to one another via reciprocated relationships) or "sparse" (if actors tend to be more autarkic). It might have one dense area surrounded by a periphery of sparsely connected actors, or it might have several clusters of dense

Capacitated domination and covering: A parameterized perspective

by Michael Dom, Daniel Lokshtanov, Saket Saurabh, Yngve Villanger - Proceedings 3rd International Workshop on Parameterized and Exact Computation, IWPEC 2008
"... Capacitated versions of Dominating Set and Vertex Cover have been studied intensively in terms of polynomial time approximation algorithms. Although the problems Dominating Set and Vertex Cover have been subjected to considerable scrutiny in the parameterized complexity world, this is not true for t ..."
Abstract - Cited by 16 (9 self) - Add to MetaCart
for the capacitated versions. Here we make an attempt to understand the behavior of the problems Capacitated Dominating Set and Capacitated Vertex Cover from the perspective of parameterized complexity. The original versions of these problems, Vertex Cover and Dominating Set, are known to be fixed parameter tractable
Results 1 - 10 of 49