Download or read book Efficient Parallel Algorithms on Chordal Graphs with a Sparse Tree Representation written by Elias Dahlhaus and published by . This book was released on 1993 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "Chordal graphs are nothing else than intersection graphs of subtrees of a tree. We present nearly optimal algorithms for certain graph problems if the input graph is given by a collection of subtrees of a tree and the subtrees are given by their leaves. This generalizes results of Olariu, Schwing, and Zhang [12] concerning the parallel complexity of problems on interval graphs provided the interval structure is given."
Download or read book STACS 97 written by Rüdiger Reischuk and published by Springer Science & Business Media. This book was released on 1997-02-21 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 14th Annual Symposium on Theoretical Aspects of Computer Science, STACS 97, held in Lübeck, Germany, in February/March 1997. The 46 revised full papers included were carefully selected from a total of 139 submissions; also included are three invited full papers. The papers presented span the whole scope of theoretical computer science. Among the topics covered are, in particular, algorithms and data structures, computational complexity, automata and formal languages, structural complexity, parallel and distributed systems, parallel algorithms, semantics, specification and verification, logic, computational geometry, cryptography, learning and inductive inference.
Download or read book Graph Theoretic Concepts in Computer Science written by Rolf H. Möhring and published by Springer Science & Business Media. This book was released on 1997-10-29 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the carefully refereed post-proceedings of the 22nd International Workshop on Graph-Theoretic Concepts in Computer Science, WG '96, held in Cadenabbia, Italy, in June 1996. The 30 revised full papers presented in the volume were selected from a total of 65 submissions. This collection documents the state of the art in the area. Among the topics addressed are graph algorithms, graph rewriting, hypergraphs, graph drawing, networking, approximation and optimization, trees, graph computation, and others.
Download or read book A Simple Efficient Parallel Algorithms to Recognize Chordal Graphs as Interval Graphs written by Elias Dahlhaus and published by . This book was released on 1993 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fast Parallel Algorithms for Graph Matching Problems written by Marek Karpiński and published by Oxford University Press. This book was released on 1998 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: The matching problem is central to graph theory and the theory of algorithms. This book provides a comprehensive and straightforward introduction to the basic methods for designing efficient parallel algorithms for graph matching problems. Written for students at the beginning graduate level, the exposition is largely self-contained and example-driven; prerequisites have been kept to a minimum by including relevant background material. The book contains full details of several new techniques and will be of interest to researchers in computer science, operations research, discrete mathematics, and electrical engineering. The main theoretical tools are presented in three independent chapters, devoted to combinatorial tools, probabilistic tools, and algebraic tools. One of the goals of the book is to show how these three approaches can be combined to develop efficient parallel algorithms. The book represents a meeting point of interesting algorithmic techniques and opens up new algebraic and geometric areas.
Download or read book Parallel Algorithms for Chordal Graphs written by Philip Nathan Klein and published by . This book was released on 1991 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: The key to these efficient sequential and parallel solutions is finding a perfect elimination ordering. In the latter part of this chapter, we define a framework for finding an elimination ordering by successive refinement. Working within this framework, we explain the sequential algorithm due to Rose, Tarjan, and Lueker. Then we describe the parallel algorithm due to Klein."
Download or read book Graph theoretic Concepts in Computer Science written by and published by . This book was released on 1997 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Performance Computing HiPC 2002 written by Sartaj Sahni and published by Springer. This book was released on 2003-07-01 with total page 717 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 9th International Conference on High Performance Computing, HiPC 2002, held in Bangalore, India in December 2002. The 57 revised full contributed papers and 9 invited papers presented together with various keynote abstracts were carefully reviewed and selected from 145 submissions. The papers are organized in topical sections on algorithms, architecture, systems software, networks, mobile computing and databases, applications, scientific computation, embedded systems, and biocomputing.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Efficient Parallel Algorithms for Planar Chordal and Interval Graphs written by P. N. Klein and published by . This book was released on 1988 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Attacks on Difficult Instances of Graph Isomorphism written by Greg Daniel Tener and published by . This book was released on 2009 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: The graph isomorphism problem has received a great deal of attention on both theoretical and practical fronts. However, a polynomial algorithm for the problem has yet to be found. Even so, the best of the existing algorithms perform well in practice; so well that it is challenging to find hard instances for them. The most efficient algorithms, for determining if a pair of graphs are isomorphic, are based on the individualization-refinement paradigm, pioneered by Brendan McKay in 1981 with his algorithm nauty. Nauty and various improved descendants of nauty, such as bliss and saucy, solve the graph isomorphism problem by determining a canonical representative for each of the graphs. The graphs are isomorphic if and only if their canonical representatives are identical. These algorithms also detect the symmetries in a graph which are used to speed up the search for the canonical representative--an approach that performs well in practice. Yet, several families of graphs have been shown to exist which are hard for nauty-like algorithms. This dissertation investigates why these graph families pose difficulty for individualization-refinement algorithms and proposes several techniques for circumventing these limitations. The first technique we propose addresses a fundamental problem pointed out by Miyazaki in 1993. He constructed a family of colored graphs which require exponential time for nauty (and nauty's improved descendants). We analyze Miyazaki's construction to determine the source of difficulty and identify a solution. We modify the base individualization-refinement algorithm by exploiting the symmetries discovered in a graph to guide the search for its canonical representative. This is accomplished with the help of a novel data structure called a guide tree. As a consequence, colored Miyazaki graphs are processed in polynomial time--thus obviating the only known exponential upper-bound on individualization-refinement algorithms (which has stood for the last 16 years). The preceding technique can only help if a graph has enough symmetry to exploit. It cannot be used for another family of hard graphs that have a high degree of regularity, but possess few actual symmetries. To handle these instances, we introduce an adaptive refinement method which utilizes the guide-tree data structure of the preceding technique to use a stronger vertex-invariant, but only when needed. We show that adaptive refinement is very effective, and it can result in dramatic speedups. We then present a third technique ideally suited for large graphs with a preponderance of sparse symmetries. A method was devised by Darga et al. for dealing with these large and highly symmetric graphs, which can reduce runtime by an order of magnitude. We explain the method and show how to incorporate it into our algorithm. Finally, we develop and implement a parallel algorithm for detecting the symmetries in, and finding a canonical representative of a graph. Our novel parallel algorithm divides the search for the symmetries and canonical representative among each processor, allowing for a high degree of scalability. The parallel algorithm is benchmarked on the hardest problem instances, and shown to be effective in subdividing the search space.
Download or read book Parallel algorithm for cograph recognition with applications written by Xin He and published by . This book was released on 1991 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: "We present a parallel algorithm for recognizing cographs and constructing their cotrees. The algorithm takes O(log2n) time with O(n2) processors on a PRAM. The best previously known algorithm for this problem takes O(log2n) time with O(nm) processors where n and m are the number of vertices and edges of the graph. Using cotree representation, we also obtain efficient parallel algorithms for solving the maximum matching, permutation representation and depth-first spanning tree problems for cographs. The depth-first spanning tree algorithm also works for the broader class of permutation graphs."
Download or read book Chordal Graphs and Semidefinite Optimization written by Lieven Vandenberghe and published by Foundations and Trends (R) in Optimization. This book was released on 2015-04-30 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covers the theory and applications of chordal graphs, with an emphasis on algorithms developed in the literature on sparse Cholesky factorization. It shows how these techniques can be applied in algorithms for sparse semidefinite optimization, and points out the connections with related topics outside semidefinite optimization.
Download or read book SIAM Journal on Scientific and Statistical Computing written by Society for Industrial and Applied Mathematics and published by . This book was released on 1989 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the existence of an efficient parallel algorithm for a graph theoretic problem written by Janez Žerovnik and published by . This book was released on 1991 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The problem of computing the relation $\Theta$ among edges of graph is an important step in algorithms for several graph theoretic problems. By an efficient parallel algorithm we mean one that takes polylogarithmic time usig a polynomial number of processors. In this paper we show that there are efficient parallel algorithms for computing the relation $\Theta$, for computing the equivqlence classes of its transitive closure $\hat{\Theta}$ and for deciding whether a graph is binary Hamming graph.
Download or read book Fast Parallel Algorithms for Chordal Graphs written by Joseph Naor and published by . This book was released on 1987 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Parallel Algorithms for Irregular Problems State of the Art written by Alfonso Ferreira and published by Springer. This book was released on 1995-10-31 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Efficient parallel solutions have been found to many problems. Some of them can be obtained automatically from sequential programs, using compilers. However, there is a large class of problems - irregular problems - that lack efficient solutions. IRREGULAR 94 - a workshop and summer school organized in Geneva - addressed the problems associated with the derivation of efficient solutions to irregular problems. This book, which is based on the workshop, draws on the contributions of outstanding scientists to present the state of the art in irregular problems, covering aspects ranging from scientific computing, discrete optimization, and automatic extraction of parallelism. Audience: This first book on parallel algorithms for irregular problems is of interest to advanced graduate students and researchers in parallel computer science.
