Results 1 - 10 of 926

Connected coloring completion for general graphs: algorithms and complexity

by Benny Chor, Michael Fellows, Mark A. Ragan, Igor Razgon, Frances Rosamond, Sagi Snir - IN: PROCEEDINGS COCOON 2007, LECTURE NOTES IN COMPUTER SCIENCE , 2007
"... An r-component connected coloring of a graph is a coloring of the vertices so that each color class induces a subgraph having at most r connected components. The concept has been well-studied for r = 1, in the case of trees, under the rubric of convex coloring, used in modeling perfect phylogenies. ..."
Abstract - Cited by 11 (7 self) - Add to MetaCart
. Sev-eral applications in bioinformatics of connected coloring problems on general graphs are discussed, including analysis of protein-protein interaction networks and protein structure graphs, and of phylogenetic relationships modeled by splits trees. We investigate the r-COMPONENT CONNECTED COLORING

Loopy belief propagation for approximate inference: An empirical study. In:

by Kevin P Murphy , Yair Weiss , Michael I Jordan - Proceedings of Uncertainty in AI, , 1999
"... Abstract Recently, researchers have demonstrated that "loopy belief propagation" -the use of Pearl's polytree algorithm in a Bayesian network with loops -can perform well in the context of error-correcting codes. The most dramatic instance of this is the near Shannon-limit performanc ..."
Abstract - Cited by 676 (15 self) - Add to MetaCart
with loops (undirected cycles). The algorithm is an exact inference algorithm for singly connected networks -the beliefs converge to the cor rect marginals in a number of iterations equal to the diameter of the graph.1 However, as Pearl noted, the same algorithm will not give the correct beliefs for mul

A general approximation technique for constrained forest problems

by Michel X. Goemans, David P. Williamson - SIAM J. COMPUT. , 1995
"... We present a general approximation technique for a large class of graph problems. Our technique mostly applies to problems of covering, at minimum cost, the vertices of a graph with trees, cycles, or paths satisfying certain requirements. In particular, many basic combinatorial optimization proble ..."
Abstract - Cited by 414 (21 self) - Add to MetaCart
is obtained for the 2-matching problem and its variants. We also derive the first approximation algorithms for many NP-complete problems, including the nonfixed point-to-point connection problem, the exact path partitioning problem, and complex location-design problems. Moreover, for the prize

Complexity of finding embeddings in a k-tree

by Stefan Arnborg, Derek G. Corneil , Andrzej Proskurowski - SIAM JOURNAL OF DISCRETE MATHEMATICS , 1987
"... A k-tree is a graph that can be reduced to the k-complete graph by a sequence of removals of a degree k vertex with completely connected neighbors. We address the problem of determining whether a graph is a partial graph of a k-tree. This problem is motivated by the existence of polynomial time al ..."
Abstract - Cited by 386 (1 self) - Add to MetaCart
A k-tree is a graph that can be reduced to the k-complete graph by a sequence of removals of a degree k vertex with completely connected neighbors. We address the problem of determining whether a graph is a partial graph of a k-tree. This problem is motivated by the existence of polynomial time

Performance-Effective and Low-Complexity Task Scheduling for Heterogeneous Computing

by Haluk Topcuoglu, Min-you Wu, et al. - IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS , 2002
"... Efficient application scheduling is critical for achieving high performance in heterogeneous computing environments. The application scheduling problem has been shown to be NP-complete in general cases as well as in several restricted cases. Because of its key importance, this problem has been exte ..."
Abstract - Cited by 255 (0 self) - Add to MetaCart
Efficient application scheduling is critical for achieving high performance in heterogeneous computing environments. The application scheduling problem has been shown to be NP-complete in general cases as well as in several restricted cases. Because of its key importance, this problem has been

Which Problems Have Strongly Exponential Complexity?

by Russell Impagliazzo, Ramamohan Paturi, Francis Zane - Journal of Computer and System Sciences , 1998
"... For several NP-complete problems, there have been a progression of better but still exponential algorithms. In this paper, we address the relative likelihood of sub-exponential algorithms for these problems. We introduce a generalized reduction which we call Sub-Exponential Reduction Family (SERF) t ..."
Abstract - Cited by 242 (11 self) - Add to MetaCart
For several NP-complete problems, there have been a progression of better but still exponential algorithms. In this paper, we address the relative likelihood of sub-exponential algorithms for these problems. We introduce a generalized reduction which we call Sub-Exponential Reduction Family (SERF

Undirected ST-Connectivity in Log-Space

by Omer Reingold , 2004
"... We present a deterministic, log-space algorithm that solves st-connectivity in undirected graphs. The previous bound on the space complexity of undirected st-connectivity was log 4/3 (·) obtained by Armoni, Ta-Shma, Wigderson and Zhou [ATSWZ00]. As undirected st-connectivity is complete for the clas ..."
Abstract - Cited by 162 (3 self) - Add to MetaCart
We present a deterministic, log-space algorithm that solves st-connectivity in undirected graphs. The previous bound on the space complexity of undirected st-connectivity was log 4/3 (·) obtained by Armoni, Ta-Shma, Wigderson and Zhou [ATSWZ00]. As undirected st-connectivity is complete

Generalized coloring for tree-like graphs

by Klaus Jansen, Petra Scheffler , 1997
"... We discuss the PRECOLORING EXTENSION(PREXT) and the LIST COLORING(LICOL) problems for trees, partial k-trees and cographs in the decision and the construction versions. Both problems for partial k-trees are solved in linear time when the number of colors is bounded by a constant and in polynomial ti ..."
Abstract - Cited by 31 (2 self) - Add to MetaCart
time for an unbounded number of colors. For trees, we improve this to linear time. In contrast to that, the two problems differ in complexity for cographs. While PREXT has a linear-time decision algorithm, LICOL is shown to be NP-complete. We give polynomial-time algorithms for the corresponding

GRAPH SUBCOLORINGS: COMPLEXITY AND ALGORITHMS

by Jirí Fiala, Klaus Jansen, Van Bang Le, Eike Seidel - VOL. 16, NO. 4, PP. 635–650 C ○ 2003 SOCIETY FOR INDUSTRIAL AND APPLIED MATHEMATICS , 2003
"... In a graph coloring, each color class induces a disjoint union of isolated vertices. A graph subcoloring generalizes this concept, since here each color class induces a disjoint union of complete graphs. Erdős and, independently, Albertson et al., proved that every graph of maximum degree at most 3 ..."
Abstract - Cited by 17 (3 self) - Add to MetaCart
In a graph coloring, each color class induces a disjoint union of isolated vertices. A graph subcoloring generalizes this concept, since here each color class induces a disjoint union of complete graphs. Erdős and, independently, Albertson et al., proved that every graph of maximum degree at most

DSC: Scheduling Parallel Tasks on an Unbounded Number of Processors

by Tao Yang, Apostolos Gerasoulis - IEEE Transactions on Parallel and Distributed Systems
"... We present a low complexity heuristic named the Dominant Sequence Clustering algorithm (DSC) for scheduling parallel tasks on an unbounded number of completely connected processors. The performance of DSC is comparable or even better on average than many other higher complexity algorithms. We assume ..."
Abstract - Cited by 209 (11 self) - Add to MetaCart
We present a low complexity heuristic named the Dominant Sequence Clustering algorithm (DSC) for scheduling parallel tasks on an unbounded number of completely connected processors. The performance of DSC is comparable or even better on average than many other higher complexity algorithms. We
Results 1 - 10 of 926