university-logo Graph Expansions
St Andrews, University of
university-logo Graph Expansions Green's Relations Closing Remarks Semigroup Graph Expansions January 2009 Rebecca Noonan Heale Semigroup Graph Expansions: #12;university-logo Graph Expansions Green;university-logo Graph Expansions Green's Relations Closing Remarks History Definitions Graph Expansions
VISSOFT'07 Submission Kagdi, Maletic Onion Graphs for Focus+Context Views of UML Class Diagrams
Maletic, Jonathan I.
VISSOFT'07 Submission Kagdi, Maletic Onion Graphs for Focus+Context Views of UML Class Diagrams+context technique for visualizing large UML class models. The focus area, which can be manually or automatically source project. 1. Introduction Developers find UML class models1 useful for designing systems along
Drawing symmetric planar graphs
Meric, Burak Necati
1998-01-01T23:59:59.000Z
16 17 19 20 21 22 23 24 25 26 A drawing generated by repeating graphs. Generation of the drawing with the unit cell. Calculation of the converted lines. Rectangular unit cell for hexagonal groups. Construction ofhexagonal cells by using... of pixels requires much computer memories and much powerful processors. Figure 1. A drawing generated by repeating graphs. Drawing uses an object-oriented point of view. In drawing, patterns are created as a collection of objects such as points, lines...
Bertrand, Nathalie; 10.4204/EPTCS.39.6
2010-01-01T23:59:59.000Z
Deterministic graph grammars generate regular graphs, that form a structural extension of configuration graphs of pushdown systems. In this paper, we study a probabilistic extension of regular graphs obtained by labelling the terminal arcs of the graph grammars by probabilities. Stochastic properties of these graphs are expressed using PCTL, a probabilistic extension of computation tree logic. We present here an algorithm to perform approximate verification of PCTL formulae. Moreover, we prove that the exact model-checking problem for PCTL on probabilistic regular graphs is undecidable, unless restricting to qualitative properties. Our results generalise those of EKM06, on probabilistic pushdown automata, using similar methods combined with graph grammars techniques.
A heuristic algorithm for graph isomorphism
Torres Navarro, Luz
1999-01-01T23:59:59.000Z
polynomial time algorithm O(n?), ISO-MT, that seems' to solve the graph isomorphism decision problem correctly for all classes of graphs. Our algorithm is extremely useful from the practical point of view since counter examples (pairs of graphs for which our...
A heuristic algorithm for graph isomorphism
Torres Navarro, Luz
1999-01-01T23:59:59.000Z
polynomial time algorithm O(n?), ISO-MT, that seems' to solve the graph isomorphism decision problem correctly for all classes of graphs. Our algorithm is extremely useful from the practical point of view since counter examples (pairs of graphs for which our...
Wong, Pak C. (Richland, WA); Mackey, Patrick S. (Kennewick, WA); Perrine, Kenneth A. (Richland, WA); Foote, Harlan P. (Richland, WA); Thomas, James J. (Richland, WA)
2008-12-23T23:59:59.000Z
Methods for visualizing a graph by automatically drawing elements of the graph as labels are disclosed. In one embodiment, the method comprises receiving node information and edge information from an input device and/or communication interface, constructing a graph layout based at least in part on that information, wherein the edges are automatically drawn as labels, and displaying the graph on a display device according to the graph layout. In some embodiments, the nodes are automatically drawn as labels instead of, or in addition to, the label-edges.
Extending graph homomorphism and simulation for real life graph matching
Wu, Yinghui
2011-06-30T23:59:59.000Z
Among the vital problems in a variety of emerging applications is the graph matching problem, which is to determine whether two graphs are similar, and if so, find all the valid matches in one graph for the other, based ...
Graphs, matrices, and the GraphBLAS: Seven good reasons
Kepner, Jeremy [Massachusetts Inst. of Technology., Cambridge, MA (United States); Bader, David [Georgia Inst. of Technology, Atlanta, GA (United States); Buluç, Ayd?n [Lawrence Berkeley National Lab., CA (United States); Gilbert, John [Univ. of California, Santa Barbara, CA (United States); Mattson, Timothy [Intel Corporation, Portland, OR (United States); Meyerhenke, Henning [Karlsruhe Inst. of Technology, Karlsruhe (Germany)
2015-01-01T23:59:59.000Z
The analysis of graphs has become increasingly important to a wide range of applications. Graph analysis presents a number of unique challenges in the areas of (1) software complexity, (2) data complexity, (3) security, (4) mathematical complexity, (5) theoretical analysis, (6) serial performance, and (7) parallel performance. Implementing graph algorithms using matrix-based approaches provides a number of promising solutions to these challenges. The GraphBLAS standard (istcbigdata.org/GraphBlas) is being developed to bring the potential of matrix based graph algorithms to the broadest possible audience. The GraphBLAS mathematically defines a core set of matrix-based graph operations that can be used to implement a wide class of graph algorithms in a wide range of programming environments. This paper provides an introduction to the GraphBLAS and describes how the GraphBLAS can be used to address many of the challenges associated with analysis of graphs.
Graphs, matrices, and the GraphBLAS: Seven good reasons
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Kepner, Jeremy; Bader, David; Buluç, Ayd?n; Gilbert, John; Mattson, Timothy; Meyerhenke, Henning
2015-01-01T23:59:59.000Z
The analysis of graphs has become increasingly important to a wide range of applications. Graph analysis presents a number of unique challenges in the areas of (1) software complexity, (2) data complexity, (3) security, (4) mathematical complexity, (5) theoretical analysis, (6) serial performance, and (7) parallel performance. Implementing graph algorithms using matrix-based approaches provides a number of promising solutions to these challenges. The GraphBLAS standard (istcbigdata.org/GraphBlas) is being developed to bring the potential of matrix based graph algorithms to the broadest possible audience. The GraphBLAS mathematically defines a core set of matrix-based graph operations that can be used to implementmore »a wide class of graph algorithms in a wide range of programming environments. This paper provides an introduction to the GraphBLAS and describes how the GraphBLAS can be used to address many of the challenges associated with analysis of graphs.« less
Dismantling sparse random graphs
Janson, Svante
2007-01-01T23:59:59.000Z
We consider the number of vertices that must be removed from a graph G in order that the remaining subgraph has no component with more than k vertices. Our principal observation is that, if G is a sparse random graph or a random regular graph on n vertices with n tending to infinity, then the number in question is essentially the same for all values of k such that k tends to infinity but k=o(n).
Lothian, Josh [ORNL; Powers, Sarah S [ORNL; Sullivan, Blair D [ORNL; Baker, Matthew B [ORNL; Schrock, Jonathan [ORNL; Poole, Stephen W [ORNL
2013-12-01T23:59:59.000Z
The benchmarking effort within the Extreme Scale Systems Center at Oak Ridge National Laboratory seeks to provide High Performance Computing benchmarks and test suites of interest to the DoD sponsor. The work described in this report is a part of the effort focusing on graph generation. A previously developed benchmark, SystemBurn, allowed the emulation of dierent application behavior profiles within a single framework. To complement this effort, similar capabilities are desired for graph-centric problems. This report examines existing synthetic graph generator implementations in preparation for further study on the properties of their generated synthetic graphs.
*D. J. Kelleher
2011-09-30T23:59:59.000Z
Spectral Graph Theory. *D. J. Kelleher2. 2Department of Mathematics. University of Connecticut. UConn— SIGMA Seminar — Fall 2011. D. J. Kelleher. Spectral ...
Graph concatenation for quantum codes
Beigi, Salman
Graphs are closely related to quantum error-correcting codes: every stabilizer code is locally equivalent to a graph code and every codeword stabilized code can be described by a graph and a classical code. For the ...
Vacuum Energy in Quantum Graphs
Wilson, Justin
2007-07-14T23:59:59.000Z
We calculate the vacuum energy in quantum graphs. Vacuum energy arose in quantum physics but has an independent mathematical interest as a functional carrying information about the eigenvalue spectrum of a system. A quantum graph is a metric graph...
Vacuum Energy in Quantum Graphs
Wilson, Justin
2007-07-14T23:59:59.000Z
We calculate the vacuum energy in quantum graphs. Vacuum energy arose in quantum physics but has an independent mathematical interest as a functional carrying information about the eigenvalue spectrum of a system. A quantum graph is a metric graph...
Egerstedt, Magnus
Distribution of Agents with Multiple Capabilities in Heterogeneous Multiagent Networks A Graph networks. I. INTRODUCTION One of the challenges in heterogeneous networks is to optimally distribute agents more fundamental concern is if such a distribution is possible at all for a given network topology. We
Graph Automatic Semigroups Rachael Carey
St Andrews, University of
Graph Automatic Semigroups Rachael Carey NBSAN St Andrews 22/04/2015 Rachael Carey NBSAN St Andrews Graph Automatic Semigroups #12;Regular languages An alphabet is a set of symbols.The elements are accepted by finite state automata. Rachael Carey NBSAN St Andrews Graph Automatic Semigroups #12;Graph
Efficiently Controllable Graphs
Can Gokler; Kevin Thompson; Peter Shor; Seth Lloyd
2015-03-18T23:59:59.000Z
We show that universal quantum computation can be performed efficiently on quantum networks while the fraction of controlled subsystems vanishes as the network grows larger. We provide examples of quantum spin network families admitting polynomial quantum gate complexity with a vanishing fraction of controlled spins. We define a new family of graphs, the efficiently controllable family, which admits efficient computation with vanishing fraction of controls. We explore generalizations to percolation clusters, fractals and random graphs. We show that the classical computational complexity of estimating the ground state of Hamiltonians described by controllable graphs is polynomial in the number of subsystems/qubits.
Chebotarev, Pavel
2008-01-01T23:59:59.000Z
For a weighted multidigraph, let $f_{ij}$ be the total weight of spanning converging forests that have vertex $i$ in a tree converging to $j$. We prove that $f_{ij}f_{jk}=f_{ik}f_{jj}$ if and only if every directed path from $i$ to $k$ contains $j$ (a graph bottleneck equality). Otherwise, $f_{ij}f_{jk}inequality). In a companion paper, this inequality provides the foundation for the construction of a new family of graph distances by ensuring the fulfillment of the triangle inequality. This stems from the fact that the graph bottleneck inequality is a multiplicative analogue of the triangle inequality for proximities.
Graphs associated with semigroups
Baber, Stephen Asa
1976-01-01T23:59:59.000Z
to the graph of this system as well. We first consider the question of when G(g ) is a com- 3 19 piete graph. The more general question of connectedness will be considered later' In order to state the next few results we need a definitions A minimal right... tM2. In [2], Clifford and Preston show that any two idempotent elements in an inverse semigroup commute. Thus, complete graph. ele2=e2el e MI()M2. As above, G(4 ) is a In order to show that the four conditions in corollary 4. 3...
Zager, Laura (Laura A.)
2005-01-01T23:59:59.000Z
Measures of graph similarity have a broad array of applications, including comparing chemical structures, navigating complex networks like the World Wide Web, and more recently, analyzing different kinds of biological data. ...
Martin, Jeremy L.
2003-01-01T23:59:59.000Z
(G)isasetofedges, or unordered pairs of distinct verticesfv;wg.Wefrequently abbreviatefv;wgby vw when no confusion can arise (for instance, when the vertices are one-digit positive integers). The vertices v;w are called the endpoints of the edge vw.Asubgraph of G is a graph G 0... =(V 0 ;E 0 )withV 0 V and E 0 E.We de ne K(V 0 )=fvw j v;w2V 0 ;v6= wg and E(V 0 )=E\\K(V 0 ): The complete graph on V is the graph (V;K(V)). We write K n for the complete graph onf1;:::;ng.ForE 0 E and v2V,thevalence of v with respect to E 0 is val...
Graph Grammars Matilde Marcolli
Marcolli, Matilde
to computer science, Lecture Notes in Computer Science, Vol. 532, Springer, 1990. G. Rozenberg, Handbook Grammars H. Ehrig, K. Ehrig, U. Prange, G. Taentzer, Fundamentals of algebraic graph transformation. New
Open Graphs and Computational Reasoning
Dixon, Lucas; Ross, Duncan; Aleks, Kissinger
2010-01-01T23:59:59.000Z
We present a form of algebraic reasoning for computational objects which are expressed as graphs. Edges describe the flow of data between primitive operations which are represented by vertices. These graphs have an interface ...
Matthew McKague
2010-10-11T23:59:59.000Z
We give a construction for a self-test for any connected graph state. In other words, for each connected graph state we give a set of non-local correlations that can only be achieved (quantumly) by that particular graph state and certain local measurements. The number of correlations considered is small, being linear in the number of vertices in the graph. We also prove robustness for the test.
Temporal Representation in Semantic Graphs
Levandoski, J J; Abdulla, G M
2007-08-07T23:59:59.000Z
A wide range of knowledge discovery and analysis applications, ranging from business to biological, make use of semantic graphs when modeling relationships and concepts. Most of the semantic graphs used in these applications are assumed to be static pieces of information, meaning temporal evolution of concepts and relationships are not taken into account. Guided by the need for more advanced semantic graph queries involving temporal concepts, this paper surveys the existing work involving temporal representations in semantic graphs.
Densities in graphs and matroids
Kannan, Lavanya
2009-05-15T23:59:59.000Z
Certain graphs can be described by the distribution of the edges in its subgraphs. For example, a cycle C is a graph that satisfies |E(H)| |V (H)| < |E(C)| |V (C)| = 1 for all non-trivial subgraphs of C. Similarly, a tree T is a graph that satisfies...
Quantum chaos on discrete graphs
Uzy Smilansky
2007-04-26T23:59:59.000Z
Adapting a method developed for the study of quantum chaos on {\\it quantum (metric)} graphs \\cite {KS}, spectral $\\zeta$ functions and trace formulae for {\\it discrete} Laplacians on graphs are derived. This is achieved by expressing the spectral secular equation in terms of the periodic orbits of the graph, and obtaining functions which belongs to the class of $\\zeta$ functions proposed originally by Ihara \\cite {Ihara}, and expanded by subsequent authors \\cite {Stark,Sunada}. Finally, a model of "classical dynamics" on the discrete graph is proposed. It is analogous to the corresponding classical dynamics derived for quantum graphs \\cite {KS}.
Spectral fluctuations of quantum graphs
Pluha?, Z. [Faculty of Mathematics and Physics, Charles University, 180 00 Praha 8 (Czech Republic); Weidenmüller, H. A. [Max-Planck-Institut für Kernphysik, 69029 Heidelberg (Germany)
2014-10-15T23:59:59.000Z
We prove the Bohigas-Giannoni-Schmit conjecture in its most general form for completely connected simple graphs with incommensurate bond lengths. We show that for graphs that are classically mixing (i.e., graphs for which the spectrum of the classical Perron-Frobenius operator possesses a finite gap), the generating functions for all (P,Q) correlation functions for both closed and open graphs coincide (in the limit of infinite graph size) with the corresponding expressions of random-matrix theory, both for orthogonal and for unitary symmetry.
Chebotarev, Pavel
2010-01-01T23:59:59.000Z
A matrix $S=(s_{ij})_{n\\times n}$ is said to determine a \\emph{transitional measure} for a digraph $\\Gamma$ on $n$ vertices if for all $i,j,k\\in\\{1,...,n\\},$ the \\emph{transition inequality} $s_{ij}s_{jk}\\le s_{ik}s_{jj}$ holds and reduces to the equality (called the \\emph{graph bottleneck identity}) if and only if every path in $\\Gamma$ from $i$ to $k$ contains $j$. We show that every positive transitional measure produces a distance by means of a logarithmic transformation. Moreover, the resulting distance $d(\\cdot,\\cdot)$ is \\emph{graph-geodetic}, that is, $d(i,j)+d(j,k)=d(i,k)$ holds if and only if every path from $i$ to $k$ contains $j$. Five types of matrices that determine transitional measures for a strong digraph are considered, namely, the matrices of path weights, connection reliabilities, route weights, and the weights of in-forests and out-forests. The results obtained have undirected counterparts. In [P. Chebotarev, A family of graph distances generalizing both the shortest-path and the resistan...
Wang, Suijie
2010-01-01T23:59:59.000Z
In this paper, we give a Laplacian characterization of the product of the complete graphs $K_m$ with trees, unicyclic graphs, and bicyclic graphs. More precisely, let $G$ be a connected graph with at most two independent cycles. If $G$ is neither $C_{6}$ nor $\\Theta_{3,2,5}$ and determined by its Laplacain spectrum, then the product $G\\times K_{m}$ is also a graph determined by its Laplacian spectrum. In addition, we find the cosepctral graphs of $C_{6}\\times K_{m}$ and $\\Theta_{3,2,5}\\times K_{m}$, where the case $m=1$ is shown in Figure \\ref{F1} and \\ref{F2}.
Graph Algorithms in the Internet Age
Stanton, Isabelle Lesley
2012-01-01T23:59:59.000Z
5.2 Classic Matching Algorithms . . . . . . . . . . . . .4.3 Analysis of Algorithms on Random Graphs . . . . . . . .Graph Problems 5 An Introduction to Matching Algorithms 5.1
Chromatic scheduling of dynamic data-graph computations
Kaler, Tim (Tim F. S.)
2013-01-01T23:59:59.000Z
Data-graph computations are a parallel-programming model popularized by programming systems such as Pregel, GraphLab, PowerGraph, and GraphChi. A fundamental issue in parallelizing data-graph computations is the avoidance ...
Estrada, Ernesto
2015-01-01T23:59:59.000Z
A generalization of the random geometric graph (RGG) model is proposed by considering a set of points uniformly and independently distributed on a rectangle of unit area instead of on a unit square \\left[0,1\\right]^{2}. The topological properties, such as connectivity, average degree, average path length and clustering, of the random rectangular graphs (RRGs) generated by this model are then studied as a function of the rectangle sides lengths a and b=1/a, and the radius r used to connect the nodes. When a=1 we recover the RGG, and when a\\rightarrow\\infty the very elongated rectangle generated resembles a one-dimensional RGG. We provided computational and analytical evidence that the topological properties of the RRG differ significantly from those of the RGG. The connectivity of the RRG depends not only on the number of nodes as in the case of the RGG, but also on the side length of the rectangle. As the rectangle is more elongated the critical radius for connectivity increases following first a power-law an...
GRAPH III: a digitizing and graph plotting program
Selleck, C.B.
1986-03-01T23:59:59.000Z
GRAPH is an interactive program that allows the user to perform two functions. The first is to plot two dimensional graphs and the second is to digitize graphs or plots to create data files of points. The program is designed to allow the user to get results quickly and easily. It is written in RATIV (a FORTRAN preprocessor) and is currently in use at Sandia under VMS on a VAX computer and CTSS on a Cray supercomputer. The program provides graphical output through all of the Sandia Virtual Device Interface (VDI) graphics devices. 2 refs., 3 figs., 3 tabs.
Tools for Large Graph Mining Deepayan Chakrabarti
Tools for Large Graph Mining by Deepayan Chakrabarti Submitted to the Center for Automated Learning computer networks to sociology, biology, ecology and many more. How do such "normal" graphs look like? How-graph, which can be both weighted or unweighted. · Ecology: Food webs are self-graphs with each node
Contagious Sets in Random Graphs Uriel Feige
Contagious Sets in Random Graphs Uriel Feige Michael Krivelevich Daniel Reichman August 10, 2014. A contagious set is a set whose activation results with the entire graph being active. Given a graph G, let m(G, 2) be the minimal size of a contagious set. We consider the binomial random graph G := G(n, p
GRAPH THEORY STUDY GUIDE 1. Definitions
Cooper, Joshua N.
GRAPH THEORY STUDY GUIDE 1. Definitions Definition 1 (Partition of A). A set A = A1, ..., Ak. Definition 2 (Vertex set). The set of vertices in a graph denoted by V (G). Definition 3 (Edge set). The set of edges in a graph denoted by E(G). Definition 4 (Order). the number of vertices of a graph G written |G
Johan Kok; K. P. Chithra; N. K. Sudev; C. Susanth
2015-04-09T23:59:59.000Z
A \\textit{primitive hole} of a graph $G$ is a cycle of length $3$ in $G$. The number of primitive holes in a given graph $G$ is called the primitive hole number of that graph $G$. The primitive degree of a vertex $v$ of a given graph $G$ is the number of primitive holes incident on the vertex $v$. In this paper, we introduce the notion of set-graphs and study the properties and characteristics of set-graphs. We also check the primitive hole number and primitive degree of set-graphs. Interesting introductory results on the nature of order of set-graphs, degree of the vertices corresponding to subsets of equal cardinality, the number of largest complete subgraphs in a set-graph etc. are discussed in this study. A recursive formula to determine the primitive hole number of a set-graph is also derived in this paper.
Rainbow Connection Number of Graph Power and Graph Products
Basavaraju, Manu; Rajendraprasad, Deepak; Ramaswamy, Arunselvan
2011-01-01T23:59:59.000Z
Rainbow connection number, $rc(G)$, of a connected graph G is the minimum number of colors needed to color its edges, so that every pair of vertices is connected by at least one path in which no two edges are colored the same. In this paper we study the rainbow connection number with respect to three important graph product operations (cartesian product, lexicographic product and strong product) and the operation of graph powering. More specifically we show the following: (Here, $r(G)$ denotes the radius of $G$, an obvious lower bound for $rc(G)$) (1.) For a connected graph $G$, let $G^{k}$ be the k-th power of $G$. We show that for $k \\ge 2$, $r(G^{k}) \\le rc(G^{k}) \\le 2r(G^{k}) + 1$. The upper bound is tight up to an additive constant of 1. (2.) For two-connected, non-trivial graphs $G$ and $H$, let $G \\Box H$ be the Cartesian Product of $G$ and $H$. We show that $r(G \\Box H) \\le rc(G \\Box H)$ $\\le$ $2r(G \\Box H)$. The bound is tight. (3.) For two graphs $G$ and $H$ such that $G$ is a connected, non-trivia...
Approximate Graph Products Marc Hellmutha
Stadler, Peter F.
Approximate Graph Products Marc Hellmutha , Wilfried Imrichb , Werner Kl¨ocklb , Peter F. Stadlera or fingers) can vary independently of other traits, or Email addresses: marc@bioinf.uni-leipzig.de (Marc
Summing tree graphs at threshold
Brown, L.S. (Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))
1992-11-15T23:59:59.000Z
The solution of the classical field equation generates the sum of all tree graphs. We show that the classical equation reduces to an easily solved ordinary differential equation for certain multiparticle threshold amplitudes and compute these amplitudes.
Doing time : inducing temporal graphs
Bramsen, Philip James
2006-01-01T23:59:59.000Z
We consider the problem of constructing a directed acyclic graph that encodes temporal relations found in a text. The unit of our analysis is a temporal segment, a fragment of text that maintains temporal coherence. The ...
An Experimental Comparison of Pregel-like Graph Processing Systems
Daudjee, Khuzaima
Attribution- NonCommercial-NoDerivs 3.0 Unported License. To view a copy of this li- cense, visit http://creativecommons.org/licenses/by-nc Apache Hama [2], Apache Giraph [1], Catch the Wind (CatchW) [34], GPS [32], GraphLab [28] (which now incorporates PowerGraph [18]), and Mizan [23]. The relative performance characteristics of such systems
Some algorithmic results in graph imbeddings
Joshi, Sanjay
1990-01-01T23:59:59.000Z
, is constructed by: 1. joining vertez us in graph G to vertez vr in H by an edge b, and 8. joining vertez uq in graph G to vertez vq in H by an edge V. The figure 2. 2 on the following page shows the double bar amalgamation of graphs Gq and Gq. We select a... vertex pair (un u2) in the graph Gq which are connected by an edge and similar vertex pair (vr, vq) on the graph Gz. The connecting bars b and b' join these two graphs at the selected vertices. 93 From the previous lemmas we can now prove, the mair...
Exploring the Graph of Graphs: Network Evolution and Centrality Distances
Pignolet, Yvonne Anne; Schmid, Stefan; Tredan, Gilles
2015-01-01T23:59:59.000Z
The topological structure of complex networks has fascinated researchers for several decades, and today we have a fairly good understanding of the types and reoccurring characteristics of many different complex networks. However, surprisingly little is known today about models to compare complex graphs, and quantitatively measure their similarity and dynamics. In the past a variety of node centralities, i.e., functions which assign values to nodes to represent their importance in the graph. Based on such centralities we propose a natural similarity measure for complex networks: the centrality distance $d_C$, the difference between two graphs with respect to a given node centrality $C$. Centrality distances can take the specific roles of the different nodes in the network into account, and have many interesting applications. As a case study, we investigate the evolution of networks with respect to centrality distances and their approximations based on closeness, betweenness, pagerank, clustering and degree cen...
On the Recognition of Four-Directional Orthogonal Ray Graphs
Felsner, Stefan
class of graphs is also known as grid intersection graphs (GIG), see [9]. The recognition of GIGs is NP
Polynomials associated with graph coloring and orientations
Humpert, Brandon Eugene
2011-04-26T23:59:59.000Z
We study colorings and orientations of graphs in two related contexts. Firstly, we generalize Stanley's chromatic symmetric function using the k-balanced colorings of Pretzel to create a new graph invariant. We show that ...
Minimal Spanning Trees with Conflict Graphs
symmetric conflict relations by means of an undirected conflict graph, where ..... International Symposium on Mathematical Foundations of Computer. Science ...
On semidefinite programming bounds for graph bandwidth
Etienne De Klerk
2011-06-06T23:59:59.000Z
Jun 6, 2011 ... Keywords: Graph bandwidth, cyclic bandwidth, semidefinite programming, quadratic assignment problem. Category 1: Linear, Cone and ...
ALGORITHMS FOR EMBEDDING GRAPHS IN BOOKS
North Carolina at Chapel Hill, University of
investigate the problem ol embedding graphs in boob. A book is some number or half- planes (the page
Effecting Parallel Graph Eigensolvers Through Library Composition
Lumsdaine, Andrew
is not possible in general. Conventional linear algebra libraries cannot operate on graph data types. Likewise exploitation of this duality. Graph libraries and matrix libraries use different data types, and despiteEffecting Parallel Graph Eigensolvers Through Library Composition Alex Breuer, Peter Gottschling
Graph Decompositions and Secret Sharing Schemes 1
Stinson, Douglas
Graph Decompositions and Secret Sharing Schemes 1 C. Blundo and A. De Santis Dipartimento di In this paper, we continue a study of secret sharing schemes for access structures based on graphs. Given a graph G, we require that a subset of participants can compute a secret key if they contain an edge of G
The Joys of Graph Transformation Arend Rensink
Rensink, Arend
The Joys of Graph Transformation Arend Rensink Department of Computer Science, University of Twente, the things being changed are graphs. A fundamental assumption in studying such changes, the handbook [21] is a 1 #12;Figure 1: Two graphs with a matching good source); rather, we want to illustrate
Constrained Graph Optimization: Interdiction and Preservation Problems
Schild, Aaron V [Los Alamos National Laboratory
2012-07-30T23:59:59.000Z
The maximum flow, shortest path, and maximum matching problems are a set of basic graph problems that are critical in theoretical computer science and applications. Constrained graph optimization, a variation of these basic graph problems involving modification of the underlying graph, is equally important but sometimes significantly harder. In particular, one can explore these optimization problems with additional cost constraints. In the preservation case, the optimizer has a budget to preserve vertices or edges of a graph, preventing them from being deleted. The optimizer wants to find the best set of preserved edges/vertices in which the cost constraints are satisfied and the basic graph problems are optimized. For example, in shortest path preservation, the optimizer wants to find a set of edges/vertices within which the shortest path between two predetermined points is smallest. In interdiction problems, one deletes vertices or edges from the graph with a particular cost in order to impede the basic graph problems as much as possible (for example, delete edges/vertices to maximize the shortest path between two predetermined vertices). Applications of preservation problems include optimal road maintenance, power grid maintenance, and job scheduling, while interdiction problems are related to drug trafficking prevention, network stability assessment, and counterterrorism. Computational hardness results are presented, along with heuristic methods for approximating solutions to the matching interdiction problem. Also, efficient algorithms are presented for special cases of graphs, including on planar graphs. The graphs in many of the listed applications are planar, so these algorithms have important practical implications.
Lamplighter groups, de Bruijn graphs, spider-web graphs and their spectra
Rostislav Grigorchuk; Paul-Henry Leemann; Tatiana Nagnibeda
2015-05-05T23:59:59.000Z
We describe the infinite family of spider-web graphs $S_{k,M,N }$, $k \\geq 2$, $M \\geq 1$ and $N \\geq 0$, studied in physical literature as tensor products of well-known de Brujin graphs $B_{k,N}$ and cyclic graphs $C_M$ and show that these graphs are Schreier graphs of the lamplighter groups $L_k = Z/kZ \\wr Z$. This allows us to compute their spectra and to identify the infinite limit of $S_{k,M,N}$, as $N, M \\to\\infty$, with the Cayley graph of the lamplighter group $L_k$.
Models of random graph hierarchies
Paluch, Robert; Holyst, Janusz
2015-01-01T23:59:59.000Z
We introduce two models of inclusion hierarchies: Random Graph Hierarchy (RGH) and Limited Random Graph Hierarchy (LRGH). In both models a set of nodes at a given hierarchy level is connected randomly, as in the Erd\\H{o}s-R\\'{e}nyi random graph, with a fixed average degree equal to a system parameter $c$. Clusters of the resulting network are treated as nodes at the next hierarchy level and they are connected again at this level and so on, until the process cannot continue. In the RGH model we use all clusters, including those of size $1$, when building the next hierarchy level, while in the LRGH model clusters of size $1$ stop participating in further steps. We find that in both models the number of nodes at a given hierarchy level $h$ decreases approximately exponentially with $h$. The height of the hierarchy $H$, i.e. the number of all hierarchy levels, increases logarithmically with the system size $N$, i.e. with the number of nodes at the first level. The height $H$ decreases monotonically with the conne...
On graphs whose Laplacian matrix's multipartite separability is invariant under graph isomorphism
Chai Wah Wu
2009-06-04T23:59:59.000Z
Normalized Laplacian matrices of graphs have recently been studied in the context of quantum mechanics as density matrices of quantum systems. Of particular interest is the relationship between quantum physical properties of the density matrix and the graph theoretical properties of the underlying graph. One important aspect of density matrices is their entanglement properties, which are responsible for many nonintuitive physical phenomena. The entanglement property of normalized Laplacian matrices is in general not invariant under graph isomorphism. In recent papers, graphs were identified whose entanglement and separability properties are invariant under isomorphism. The purpose of this note is to characterize the set of graphs whose separability is invariant under graph isomorphism. In particular, we show that this set consists of $K_{2,2}$, $\\overline{K_{2,2}}$ and all complete graphs.
A Feasible Graph Partition Framework for Random Walks Implemented by Parallel Computing in Big Graph
Liu, Xiaoming; Guan, Xiaohong
2015-01-01T23:59:59.000Z
Graph partition is a fundamental problem of parallel computing for big graph data. Many graph partition algorithms have been proposed to solve the problem in various applications, such as matrix computations and PageRank, etc., but none has pay attention to random walks. Random walks is a widely used method to explore graph structure in lots of fields. The challenges of graph partition for random walks include the large number of times of communication between partitions, lots of replications of the vertices, unbalanced partition, etc. In this paper, we propose a feasible graph partition framework for random walks implemented by parallel computing in big graph. The framework is based on two optimization functions to reduce the bandwidth, memory and storage cost in the condition that the load balance is guaranteed. In this framework, several greedy graph partition algorithms are proposed. We also propose five metrics from different perspectives to evaluate the performance of these algorithms. By running the al...
Multipartite separability of Laplacian matrices of graphs
Chai Wah Wu
2008-09-04T23:59:59.000Z
Recently, Braunstein et al. [1] introduced normalized Laplacian matrices of graphs as density matrices in quantum mechanics and studied the relationships between quantum physical properties and graph theoretical properties of the underlying graphs. We provide further results on the multipartite separability of Laplacian matrices of graphs. In particular, we identify complete bipartite graphs whose normalized Laplacian matrix is multipartite entangled under any vertex labeling. Furthermore, we give conditions on the vertex degrees such that there is a vertex labeling under which the normalized Laplacian matrix is entangled. These results address an open question raised in [1]. Finally, we extend some of the results in [1,2] to the multipartite case and show that the Laplacian matrix of any product of graphs (strong, Cartesian, tensor, categorical, etc.) is multipartite separable.
Fast generation of sparse random kernel graphs
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Hagberg, Aric; Lemons, Nathan; Du, Wen -Bo
2015-09-10T23:59:59.000Z
The development of kernel-based inhomogeneous random graphs has provided models that are flexible enough to capture many observed characteristics of real networks, and that are also mathematically tractable. We specify a class of inhomogeneous random graph models, called random kernel graphs, that produces sparse graphs with tunable graph properties, and we develop an efficient generation algorithm to sample random instances from this model. As real-world networks are usually large, it is essential that the run-time of generation algorithms scales better than quadratically in the number of vertices n. We show that for many practical kernels our algorithm runs in timemore »at most ?(n(logn)²). As an example, we show how to generate samples of power-law degree distribution graphs with tunable assortativity.« less
Counting matchings in irregular bipartite graphs
Marc Lelarge
2015-07-16T23:59:59.000Z
We give a sharp lower bound on the number of matchings of a given size in a bipartite graph. When specialized to regular bipartite graphs, our results imply Friedland's Lower Matching Conjecture and Schrijver's theorem. It extends the recent work of Csikv\\'ari done for regular and bi-regular bipartite graphs. Moreover, our lower bounds are order optimal as they are attained for a sequence of $2$-lifts of the original graph. We then extend our results to permaments and subpermanents sums. For permanents, we are able to recover the lower bound of Schrijver recently proved by Gurvits using stable polynomials. We provide new lower bounds for subpermanents sums. Our proof borrows ideas from the theory of local weak convergence of graphs, statistical physics and covers of graphs.
Graphs in machine learning: an introduction
Latouche, Pierre
2015-01-01T23:59:59.000Z
Graphs are commonly used to characterise interactions between objects of interest. Because they are based on a straightforward formalism, they are used in many scientific fields from computer science to historical sciences. In this paper, we give an introduction to some methods relying on graphs for learning. This includes both unsupervised and supervised methods. Unsupervised learning algorithms usually aim at visualising graphs in latent spaces and/or clustering the nodes. Both focus on extracting knowledge from graph topologies. While most existing techniques are only applicable to static graphs, where edges do not evolve through time, recent developments have shown that they could be extended to deal with evolving networks. In a supervised context, one generally aims at inferring labels or numerical values attached to nodes using both the graph and, when they are available, node characteristics. Balancing the two sources of information can be challenging, especially as they can disagree locally or globall...
Maximum Estrada Index of Bicyclic Graphs
Wang, Long; Wang, Yi
2012-01-01T23:59:59.000Z
Let $G$ be a simple graph of order $n$, let $\\lambda_1(G),\\lambda_2(G),...,\\lambda_n(G)$ be the eigenvalues of the adjacency matrix of $G$. The Esrada index of $G$ is defined as $EE(G)=\\sum_{i=1}^{n}e^{\\lambda_i(G)}$. In this paper we determine the unique graph with maximum Estrada index among bicyclic graphs with fixed order.
Discussiones Mathematicae Graph Theory 34 (2014) 287307
Al Hanbali, Ahmad
2014-01-01T23:59:59.000Z
FOR TRACEABILITY OF BLOCK-CHAINS Binlong Lia,b1, Hajo Broersmab and Shenggui Zhanga2 a Department of Applied at least n-1 in G. A block-chain is a graph whose block graph is a path, i.e., it is either a P1, P2, every traceable graph is a block-chain, but the reverse does not hold. In this paper we characterize all
Nuclear reactor multiphysics via bond graph formalism
Sosnovsky, Eugeny
2014-01-01T23:59:59.000Z
This work proposes a simple and effective approach to modeling nuclear reactor multiphysics problems using bond graphs. Conventional multiphysics simulation paradigms normally use operator splitting, which treats the ...
Generation of graph-state streams
Daniel Ballester; Jaeyoon Cho; M. S. Kim
2010-12-08T23:59:59.000Z
We propose a protocol to generate a stream of mobile qubits in a graph state through a single stationary parent qubit and discuss two types of its physical implementation, namely, the generation of photonic graph states through an atom-like qubit and those of flying atoms through a cavity-mode photonic qubit. The generated graph states fall into an important class that can hugely reduce the resource requirement of fault-tolerant linear optics quantum computation, which was previously known to be far from realistic. In regard to the flying atoms, we also propose a heralded generation scheme, which allows for high-fidelity graph states even under the photon loss.
Spectral statistics of nearly unidirectional quantum graphs
Maram Akila; Boris Gutkin
2015-03-04T23:59:59.000Z
The energy levels of a quantum graph with time reversal symmetry and unidirectional classical dynamics are doubly degenerate and obey the spectral statistics of the Gaussian Unitary Ensemble. These degeneracies, however, are lifted when the unidirectionality is broken in one of the graph's vertices by a singular perturbation. Based on a Random Matrix model we derive an analytic expression for the nearest neighbour distribution between energy levels of such systems. As we demonstrate the result agrees excellently with the actual statistics for graphs with a uniform distribution of eigenfunctions. Yet, it exhibits quite substantial deviations for classes of graphs which show strong scarring.
Graph algorithms in the titan toolkit.
McLendon, William Clarence, III; Wylie, Brian Neil
2009-10-01T23:59:59.000Z
Graph algorithms are a key component in a wide variety of intelligence analysis activities. The Graph-Based Informatics for Non-Proliferation and Counter-Terrorism project addresses the critical need of making these graph algorithms accessible to Sandia analysts in a manner that is both intuitive and effective. Specifically we describe the design and implementation of an open source toolkit for doing graph analysis, informatics, and visualization that provides Sandia with novel analysis capability for non-proliferation and counter-terrorism.
Spectral statistics of nearly unidirectional quantum graphs
Maram Akila; Boris Gutkin
2015-08-19T23:59:59.000Z
The energy levels of a quantum graph with time reversal symmetry and unidirectional classical dynamics are doubly degenerate and obey the spectral statistics of the Gaussian Unitary Ensemble. These degeneracies, however, are lifted when the unidirectionality is broken in one of the graph's vertices by a singular perturbation. Based on a Random Matrix model we derive an analytic expression for the nearest neighbour distribution between energy levels of such systems. As we demonstrate the result agrees excellently with the actual statistics for graphs with a uniform distribution of eigenfunctions. Yet, it exhibits quite substantial deviations for classes of graphs which show strong scarring.
3D Graph Visualization with the Oculus Rift Virtual Graph Reality
Wismath, Stephen
reality environment such as a CAVE, or · printed as a physical model with a 3D printer. Early studies3D Graph Visualization with the Oculus Rift Virtual Graph Reality Farshad Barahimi, Stephen Wismath regarding three- dimensional (3D) representations of graphs. However, the actual usefulness of such 3D
Graph-Theoretic Generation of Assembly Plans Part I: Correct Generation of Precedence Graphs
Wu, David
1 Graph-Theoretic Generation of Assembly Plans Part I: Correct Generation of Precedence Graphs Lehigh University Bethlehem, Pennsylvania Abstract Automatic generation and selection of assembly plans a graph-theoretic scheme for the generation of assembly plans. Our scheme involves decomposing the CSP
Star graphs and Seba billiards
G. Berkolaiko; E. B. Bogomolny; J. P. Keating
2000-10-26T23:59:59.000Z
We derive an exact expression for the two-point correlation function for quantum star graphs in the limit as the number of bonds tends to infinity. This turns out to be identical to the corresponding result for certain Seba billiards in the semiclassical limit. Reasons for this are discussed. The formula we derive is also shown to be equivalent to a series expansion for the form factor - the Fourier transform of the two-point correlation function - previously calculated using periodic orbit theory.
A Count of Classical Field Theory Graphs
Gordon Chalmers
2005-07-28T23:59:59.000Z
A generating function is derived that counts the number of diagrams in an arbitrary scalar field theory. The number of graphs containing any number $n_j$ of $j$-point vertices is given. The count is also used to obtain the number of classical graphs in gauge theory and gravity.
A COLUMN GENERATION APPROACH FOR GRAPH COLORING
Grossmann, Ignacio E.
set in the graph). We use a column generation method for implicit optimization of the linear program based on an integer programming formulation of the graph coloring problem. This formulation, called is an assignment of labels to each vertex such that the endpoints of any edge have different labels. A minimum
Operational Equivalence of Graph Transformation Systems
Sarna-Starosta, Beata
Operational Equivalence of Graph Transformation Systems Frank Raiser and Thom FrÂ¨uhwirth Faculty. With the growing number of GTS- based applications the comparison of operational equivalence of two GTS becomes an important area of research. This work introduces a notion of operational equivalence for graph
On the spectra of simplicial rook graphs
Martin, Jeremy L.; Wagner, Jennifer D.
2014-05-05T23:59:59.000Z
The \\emph{simplicial rook graph} $\\SR(d,n)$ is the graph whose vertices are the lattice points in the $n$th dilate of the standard simplex in $\\mathbb{R}^d$, with two vertices adjacent if they differ in exactly two coordinates. We prove...
Small Alliances in Graphs Rodolfo Carvajal1
Fondements et Applications, Université Paris 7
Small Alliances in Graphs Rodolfo Carvajal1 , Mart´in Matamala1,2 , Ivan Rapaport1,2 , and Nicolas is a (strong defensive) alliance of G if every node in S has at least as many neighbors in S than in V \\S typically belong to small alliances. Despite the fact that finding the smallest alliance in a graph is NP
On terminal deltawye reducibility of planar graphs
Sagols, Feliú
On terminal deltawye reducibility of planar graphs Isidoro Gitler1 Feli´u Sagols2 Departamento de´exico City, D.F. igitler@math.cinvestav.mx fsagols@math.cinvestav.mx Abstract A graph is terminal - Y -reducible if it can be reduced to a set of terminal vertices by a sequence of series-parallel reductions
Graph Mining Meets the Semantic Web
Lee, Sangkeun (Matt) [ORNL; Sukumar, Sreenivas R [ORNL; Lim, Seung-Hwan [ORNL
2015-01-01T23:59:59.000Z
The Resource Description Framework (RDF) and SPARQL Protocol and RDF Query Language (SPARQL) were introduced about a decade ago to enable flexible schema-free data interchange on the Semantic Web. Today, data scientists use the framework as a scalable graph representation for integrating, querying, exploring and analyzing data sets hosted at different sources. With increasing adoption, the need for graph mining capabilities for the Semantic Web has emerged. We address that need through implementation of three popular iterative Graph Mining algorithms (Triangle count, Connected component analysis, and PageRank). We implement these algorithms as SPARQL queries, wrapped within Python scripts. We evaluate the performance of our implementation on 6 real world data sets and show graph mining algorithms (that have a linear-algebra formulation) can indeed be unleashed on data represented as RDF graphs using the SPARQL query interface.
Clustering attributed graphs: models, measures and methods
Bothorel, Cecile; Magnani, Matteo; Micenkova, Barbora
2015-01-01T23:59:59.000Z
Clustering a graph, i.e., assigning its nodes to groups, is an important operation whose best known application is the discovery of communities in social networks. Graph clustering and community detection have traditionally focused on graphs without attributes, with the notable exception of edge weights. However, these models only provide a partial representation of real social systems, that are thus often described using node attributes, representing features of the actors, and edge attributes, representing different kinds of relationships among them. We refer to these models as attributed graphs. Consequently, existing graph clustering methods have been recently extended to deal with node and edge attributes. This article is a literature survey on this topic, organizing and presenting recent research results in a uniform way, characterizing the main existing clustering methods and highlighting their conceptual differences. We also cover the important topic of clustering evaluation and identify current open ...
Vienna Graph Template Library Version 1.0
Neumaier, Arnold
.1 Vienna Graph Template Library Modules Here is a list of all modules: Classes and types for external useVienna Graph Template Library Version 1.0 Reference Manual Hermann Schichl University of Vienna.2.14 #12;CONTENTS 1 Contents 1 Introduction 1 2 Vienna Graph Template Library Module Index 2 3 Vienna Graph
Minimal comparability completions of arbitrary graphs Pinar Heggernes
Heggernes, Pinar
Minimal comparability completions of arbitrary graphs Pinar Heggernes Federico Mancini Charis for which completion of arbitrary graphs can be achieved through such a vertex incremental approach. 1 to an arbitrary graph is called a comparability completion of the input graph. Unfortunately, computing
What Energy Functions Can Be Minimized via Graph Cuts?
Field, David
What Energy Functions Can Be Minimized via Graph Cuts? Vladimir Kolmogorov, Member, IEEE, and Ramin been developed to solve energy minimization problems in computer vision. Each of these techniques constructs a graph such that the minimum cut on the graph also minimizes the energy. Yet, because these graph
A role for matrices in graph theory
McLean, John Patrick
1971-01-01T23:59:59.000Z
Theory are well established areas in mathematics, much remains to be done in the standardization of notation and conventions. Thus we begin by defining terms to be used in this Thesis. 1. ) ~Gh 1'h By the directed graph G(X, r), or simply G, we mean... directed graph is said to be stronglb connected if for each pair of vertices x and x. , there is a path from xi to x ~ If Z is a subset of X and TZ is the subfunction of I' from Z into Z, then G'(Z, "Z) is a subgz'aph of G. The bi-partite graph G(X, Y...
Information inequalities and Generalized Graph Entropies
Sivakumar, Lavanya
2012-01-01T23:59:59.000Z
In this article, we discuss the problem of establishing relations between information measures assessed for network structures. Two types of entropy based measures namely, the Shannon entropy and its generalization, the R\\'{e}nyi entropy have been considered for this study. Our main results involve establishing formal relationship, in the form of implicit inequalities, between these two kinds of measures when defined for graphs. Further, we also state and prove inequalities connecting the classical partition-based graph entropies and the functional-based entropy measures. In addition, several explicit inequalities are derived for special classes of graphs.
Werner Trobin, May 26, 2004 The Boost Graph Library -p. 1/48 The Boost Graph Library
Werner Trobin, May 26, 2004 The Boost Graph Library - p. 1/48 The Boost Graph Library Generic Library Design Werner Trobin #12;Introduction The Boost Graph Library Demo References Werner Trobin, May 26, 2004 The Boost Graph Library - p. 2/48 Outline I Introduction to Boost I The Boost
Fault-tolerant dynamic task graph scheduling
Kurt, Mehmet C.; Krishnamoorthy, Sriram; Agrawal, Kunal; Agrawal, Gagan
2014-11-16T23:59:59.000Z
In this paper, we present an approach to fault tolerant execution of dynamic task graphs scheduled using work stealing. In particular, we focus on selective and localized recovery of tasks in the presence of soft faults. We elicit from the user the basic task graph structure in terms of successor and predecessor relationships. The work stealing-based algorithm to schedule such a task graph is augmented to enable recovery when the data and meta-data associated with a task get corrupted. We use this redundancy, and the knowledge of the task graph structure, to selectively recover from faults with low space and time overheads. We show that the fault tolerant design retains the essential properties of the underlying work stealing-based task scheduling algorithm, and that the fault tolerant execution is asymptotically optimal when task re-execution is taken into account. Experimental evaluation demonstrates the low cost of recovery under various fault scenarios.
On semidefinite programming bounds for graph bandwidth
2011-05-24T23:59:59.000Z
May 24, 2011 ... the rectangular grid graph Pn × Pm (i.e. the Cartesian product of the paths Pn and Pm) is min{n, m} [6] ...... Ars Combinatoria, 47:147-152, 1997.
Projective representations from quantum enhanced graph symmetries
2015-03-11T23:59:59.000Z
Presently, we will label the edges of a graph by elements of a group ...... (a) Read off the matrix ? by putting the G label of a vertex onto the diagonal in the place.
Constant time algorithms in sparse graph model
Nguyen, Huy Ngoc, Ph. D. Massachusetts Institute of Technology
2010-01-01T23:59:59.000Z
We focus on constant-time algorithms for graph problems in bounded degree model. We introduce several techniques to design constant-time approximation algorithms for problems such as Vertex Cover, Maximum Matching, Maximum ...
Support graph preconditioners for sparse linear systems
Gupta, Radhika
2005-02-17T23:59:59.000Z
. In this thesis, we develop support graph preconditioners for symmetric positive de?nite matrices that arise from the ?nite element discretization of elliptic partial di?erential equations. An object oriented code is developed for the construction, integration...
Continuous Time Group Discovery in Dynamic Graphs
Miller, K; Eliassi-Rad, T
2010-11-04T23:59:59.000Z
With the rise in availability and importance of graphs and networks, it has become increasingly important to have good models to describe their behavior. While much work has focused on modeling static graphs, we focus on group discovery in dynamic graphs. We adapt a dynamic extension of Latent Dirichlet Allocation to this task and demonstrate good performance on two datasets. Modeling relational data has become increasingly important in recent years. Much work has focused on static graphs - that is fixed graphs at a single point in time. Here we focus on the problem of modeling dynamic (i.e. time-evolving) graphs. We propose a scalable Bayesian approach for community discovery in dynamic graphs. Our approach is based on extensions of Latent Dirichlet Allocation (LDA). LDA is a latent variable model for topic modeling in text corpora. It was extended to deal with topic changes in discrete time and later in continuous time. These models were referred to as the discrete Dynamic Topic Model (dDTM) and the continuous Dynamic Topic Model (cDTM), respectively. When adapting these models to graphs, we take our inspiration from LDA-G and SSN-LDA, applications of LDA to static graphs that have been shown to effectively factor out community structure to explain link patterns in graphs. In this paper, we demonstrate how to adapt and apply the cDTM to the task of finding communities in dynamic networks. We use link prediction to measure the quality of the discovered community structure and apply it to two different relational datasets - DBLP author-keyword and CAIDA autonomous systems relationships. We also discuss a parallel implementation of this approach using Hadoop. In Section 2, we review LDA and LDA-G. In Section 3, we review the cDTM and introduce cDTMG, its adaptation to modeling dynamic graphs. We discuss inference for the cDTM-G and details of our parallel implementation in Section 4 and present its performance on two datasets in Section 5 before concluding in Section 6.
Graphs of subgroups of free groups
Louder, Larsen
2009-01-01T23:59:59.000Z
We construct an efficient model for graphs of finitely generated subgroups of free groups. Using this we give a very short proof of Dicks's reformulation of the strengthened Hanna Neumann Conjecture as the Amalgamated Graph Conjecture. In addition, we answer a question of Culler and Shalen on ranks of intersections in free groups. The latter has also been done independently by R. P. Kent IV.
Accelerating semantic graph databases on commodity clusters
Morari, Alessandro; Castellana, Vito G.; Haglin, David J.; Feo, John T.; Weaver, Jesse R.; Tumeo, Antonino; Villa, Oreste
2013-10-06T23:59:59.000Z
We are developing a full software system for accelerating semantic graph databases on commodity cluster that scales to hundreds of nodes while maintaining constant query throughput. Our framework comprises a SPARQL to C++ compiler, a library of parallel graph methods and a custom multithreaded runtime layer, which provides a Partitioned Global Address Space (PGAS) programming model with fork/join parallelism and automatic load balancing over a commodity clusters. We present preliminary results for the compiler and for the runtime.
Graph representation of protein free energy landscape
Li, Minghai; Duan, Mojie; Fan, Jue; Huo, Shuanghong, E-mail: shuo@clarku.edu [Gustaf H. Carlson School of Chemistry and Biochemistry, Clark University, 950 Main Street, Worcester, Massachusetts 01610 (United States)] [Gustaf H. Carlson School of Chemistry and Biochemistry, Clark University, 950 Main Street, Worcester, Massachusetts 01610 (United States); Han, Li [Department of Mathematics and Computer Science, Clark University, 950 Main Street, Worcester, Massachusetts 01610 (United States)] [Department of Mathematics and Computer Science, Clark University, 950 Main Street, Worcester, Massachusetts 01610 (United States)
2013-11-14T23:59:59.000Z
The thermodynamics and kinetics of protein folding and protein conformational changes are governed by the underlying free energy landscape. However, the multidimensional nature of the free energy landscape makes it difficult to describe. We propose to use a weighted-graph approach to depict the free energy landscape with the nodes on the graph representing the conformational states and the edge weights reflecting the free energy barriers between the states. Our graph is constructed from a molecular dynamics trajectory and does not involve projecting the multi-dimensional free energy landscape onto a low-dimensional space defined by a few order parameters. The calculation of free energy barriers was based on transition-path theory using the MSMBuilder2 package. We compare our graph with the widely used transition disconnectivity graph (TRDG) which is constructed from the same trajectory and show that our approach gives more accurate description of the free energy landscape than the TRDG approach even though the latter can be organized into a simple tree representation. The weighted-graph is a general approach and can be used on any complex system.
Intro Algo ring Arbitrary graphs Conclusion PING PONG IN DANGEROUS GRAPHS
Fondements et Applications, Université Paris 7
Intro Algo ring Arbitrary graphs Conclusion PING PONG IN DANGEROUS GRAPHS Optimal Black Hole Search blocking and destroying any mobile agent entering it. Motivations : Site which is destroyed or dangerous blocking and destroying any mobile agent entering it. Motivations : Site which is destroyed or dangerous
Random key graphs can have many more triangles than Erdos-Renyi graphs
Yagan, Osman
, and in the First Workshop on Applications of Graph Theory in Wireless Ad hoc Networks and Sensor Networks (GRAPH-HOC 2009), Chennai (India), December 2009. O. Yagan was with the Department of Electrical and Computer is now with Department of Electrical and Computer Engineering and CyLab, Carnegie Mellon University
Outline of the talk Statistics on Graphs, Exponential Formula and
Poinsot, Laurent
Outline of the talk Statistics on Graphs, Exponential Formula and Combinatorial Physics G and Complexity" Laurent Poinsot Statistics on Graphs, Exponential Formula and Combinatorial Physics #12;Exponential Formula : Informal Version Ingredients for the exponential formula Partial commutative monoids
Scalable Parallel Algorithms for Massive Scale-free Graphs
Pearce, Roger Allan
2013-12-05T23:59:59.000Z
, distributed, and external memory. This dissertation develops new techniques to parallelize the storage, computation, and communication for scale-free graphs with high-degree vertices. Our work facilitates the processing of large real-world graph datasets...
On perfect codes in Cartesian product of graphs Michel Mollard
Boyer, Edmond
] and others. The existence of perfect codes have also been proved in Towers of Hanoi graphs [6] and Sierpinski on the symmetric group Sn+1 thus are of order (n + 1)!. These families include star graphs, for which the existence
A New Combinatorial Approach for Sparse Graph Problems
Blelloch, Guy E.
A New Combinatorial Approach for Sparse Graph Problems Guy E. Blelloch, Virginia Vassilevska- totic improvement over O(mn) for all pairs least common ancestors on directed acyclic graphs. 1
Scalable Parallel Algorithms for Massive Scale-free Graphs
Pearce, Roger Allan
2013-12-05T23:59:59.000Z
, distributed, and external memory. This dissertation develops new techniques to parallelize the storage, computation, and communication for scale-free graphs with high-degree vertices. Our work facilitates the processing of large real-world graph datasets...
On the topology of graph picture spaces
Martin, Jeremy L.
2005-03-01T23:59:59.000Z
V and edges E. The d-dimensional picture space Xd(G) is de ned as the projective algebraic set whose points are pictures of G in complex projective d-space Pd = PdC. A picture P consists of a point P(v) 2 Pd for each vertex v of G and a line P...(e) for each edge e, subject to the conditions P(v) 2 P(e) whenever v is an endpoint of e. Two fundamental operations of graph theory are deletion and contraction: given a graph G and an edge e, we may delete e to form a graph G e, or identify the end- points...
Johan Alwall; Michel Herquet; Fabio Maltoni; Olivier Mattelaer; Tim Stelzer
2011-06-02T23:59:59.000Z
MadGraph 5 is the new version of the MadGraph matrix element generator, written in the Python programming language. It implements a number of new, efficient algorithms that provide improved performance and functionality in all aspects of the program. It features a new user interface, several new output formats including C++ process libraries for Pythia 8, and full compatibility with FeynRules for new physics models implementation, allowing for event generation for any model that can be written in the form of a Lagrangian. MadGraph 5 builds on the same philosophy as the previous versions, and its design allows it to be used as a collaborative platform where theoretical, phenomenological and simulation projects can be developed and then distributed to the high-energy community. We describe the ideas and the most important developments of the code and illustrate its capabilities through a few simple phenomenological examples.
Discrete Lagrangian Systems on Graphs. Symplecto-Topological Properties
S. P. Novikov; A. S. Schwarz
2000-04-11T23:59:59.000Z
Discrete Lagrangian Systems on graphs are considered. Vector-valued closed differential 2-form on the space of solutions is constructed. This form takes values in the first homology group of the graph. This construction generalizes the Symplectic Wronskian for the linear self-adjoint operators on graphs found in 1997 by the first author and used for the needs of the Scattering Theory for graphs with tails
Evaluating Graph Coloring on Pascal Grosset, Peihong Zhu, Shusen Liu,
Hall, Mary W.
any relevant related works for graph coloring on GPUs · Main inspiration: o Gebremedhin and Manne o (G
Mining Closed Relational Graphs with Connectivity Constraints X. Jasmine Zhou
Zhou, Xianghong Jasmine
Mining Closed Relational Graphs with Connectivity Constraints Xifeng Yan X. Jasmine Zhou Jiawei Han relational graphs, how to mine frequent highly connected subgraphs from it? ... G1 G2 Gn pattern Figure 1. Mining Massive Relational Graphs This new problem setting has three major characteristics different from
Bicycles and Left-Right Tours in Locally Finite Graphs
Diestel, Reinhard
Bicycles and Left-Right Tours in Locally Finite Graphs von Melanie Win Myint, M. S. Dem Department-Right Tours 29 6 LRTs Generate the Bicycle Space 43 7 The ABL Planarity Criterion 53 8 Pedestrian Graphs 69 bicycles and some other concepts they relate to, such as left- right tours and pedestrian graphs
On Sum--Connectivity Index of Bicyclic Graphs
Du, Zhibin
2009-01-01T23:59:59.000Z
We determine the minimum sum--connectivity index of bicyclic graphs with $n$ vertices and matching number $m$, where $2\\le m\\le \\lfloor\\frac{n}{2}\\rfloor$, the minimum and the second minimum, as well as the maximum and the second maximum sum--connectivity indices of bicyclic graphs with $n\\ge 5$ vertices. The extremal graphs are characterized.
A Visualization System for Correctness Proofs of Graph Algorithms
Metaxas, Takis
A Visualization System for Correctness Proofs of Graph Algorithms P.A. Gloor1, D.B. Johnson2, F. Makedon2, P. Metaxas3 Feb. 28, 1993 Running head: Proof Visualization of Graph Algorithms Correspondence proofs of graph algorithms. The system has been demonstrated for a greedy algorithm, Prim's algorithm
The power graph of a group Peter J. Cameron
Burton, Geoffrey R.
; graphs are much looser. For example, there are only five different groups with eight elementsThe power graph of a group Peter J. Cameron Queen Mary, University of London LTCC Open Day, 8 January 2010 Groups and graphs A group is an algebraic structure: a set with a bi- nary operation
VGTL (Vienna Graph Template Library) Version 1.1
Schichl, Hermann
.1 Vienna Graph Template Library Modules Here is a list of all modules: Classes and types for external useVGTL (Vienna Graph Template Library) Version 1.1 Reference Manual Hermann Schichl University June 2003 #12;CONTENTS 1 Contents 1 Introduction 1 2 Vienna Graph Template Library Module Index 2 3
Multivariate Graphs in Software Engineering and A. Telea2
Telea, Alexandru C.
Multivariate Graphs in Software Engineering S. Diehl1 and A. Telea2 1 Department of Computer, the Netherlands Abstract. Multivariate networks, or graphs, are an essential element of various activities. In this chapter, we present the specific context in which multivariate graphs occur in software engineering
Making arbitrary graphs transitively orientable: Minimal comparability completions
Papadopoulos, Charis
Making arbitrary graphs transitively orientable: Minimal comparability completions Pinar Heggernes to an arbitrary graph is called a comparability completion of the input graph. Unfortunately, computing a comparability completion with the minimum number of added edges (called a minimum completion) is an NP
A Static Analysis Technique for Graph Transformation Systems
Baldan, Paolo
A Static Analysis Technique for Graph Transformation Systems Paolo Baldan, Andrea Corradini,andrea,koenigb}@di.unipi.it Abstract. In this paper we introduce a static analysis technique for graph transformation systems. We in a direct and intuitive way. Graph Transformation Systems (GTSs) [18] add to the static description given
*The graph shown at the top right is the complement of line graph of the complete graph on 8 the existence of 28 equiangular lines in R7. References [1] D. DE CAEN, Large equiangular sets of lines the Minimize command in MAPLE to find such a vector with high precision. One of the challenges was to deal
SQLGraph: An Efficient Relational-Based Property Graph , Achille Fokoue
Cortes, Corinna
[Database Management]: Systems General Terms Property graphs; Gremlin Keywords Property graphs; Relational Storage; Gremlin 1. INTRODUCTION There is increased interest in graph data management re- cently, fueled literature has been on RDF data management (e.g., [39, 18, 27, 24, 6, 25, 16]). Much of this work targets
VACUUM ENERGY IN QUANTUM GRAPHS A Senior Honors Thesis
VACUUM ENERGY IN QUANTUM GRAPHS A Senior Honors Thesis by JUSTIN HOWARD WILSON Submitted ABSTRACT Vacuum Energy in Quantum Graphs. (April 2007) Justin Howard Wilson Department of Physics the vacuum energy in quantum graphs. Vacuum energy arose in quantum physics but has an independent
Cellular Algebras and Graph Invariants Based on Quantum Walks
Jamie Smith
2011-03-01T23:59:59.000Z
We consider two graph invariants inspired by quantum walks- one in continuous time and one in discrete time. We will associate a matrix algebra called a cellular algebra with every graph. We show that, if the cellular algebras of two graphs have a similar structure, then they are not distinguished by either of the proposed invariants.
Periodic schedules for Unitary Timed Weighted Event Graphs
Paris-Sud XI, Université de
Event Graph model (TEG also called marked graphs [5]) and dataflow graphs, oftenly used in the computer questions are polynomially solved for ordinary TEG [1], [5], [6], [8]. In particular, it has been shown that if a TEG is live, there always exists a periodic schedule with the optimal throughput (i.e. with the same
Problems of Distance-Regular Graphs Hiroshi Suzuki
Xi, Changchang
Â328. [14] H. Suzuki, The Terwilliger algebra associated with a set of vertices in a distance-regular graph, J. Alg. Combin. 22 (2005), 5-38. [15] P. Terwilliger, Distance-regular graphs and (s, c, a, k)-graphs, J. Combin. Th. (B) 34 (1983), 151Â164. [16] P. Terwilliger, A new inequality for distance
CPM: A Graph Pattern Matching Kernel with Diffusion for Accurate Graph Classification
Kansas, University of
(the Molecular Library Initiative project) that aims to determine and publicize the biological activ chemical structure data sets and have compared our methods to all major graph kernel functions that we know
Solving the Graph Isomorphism Problem with a Quantum Annealer
Itay Hen; A. P. Young
2012-08-08T23:59:59.000Z
We propose a novel method using a quantum annealer -- an analog quantum computer based on the principles of quantum adiabatic evolution -- to solve the Graph Isomorphism problem, in which one has to determine whether two graphs are isomorphic (i.e., can be transformed into each other simply by a relabeling of the vertices). We demonstrate the capabilities of the method by analyzing several types of graph families, focusing on graphs with particularly high symmetry called strongly regular graphs (SRG's). We also show that our method is applicable, within certain limitations, to currently available quantum hardware such as "D-Wave One".
Expander Graph Arguments for Message Passing Algorithms
Burshtein, David
Expander Graph Arguments for Message Passing Algorithms David Burshtein and Gadi Miller Dept arguments may be used to prove that message passing algorithms can correct a linear number of erroneous a message passing algorithm has corrected a sufficiently large fraction of the errors, it will eventually
Graph Coloring with Quantum Heuristics Alex Fabrikant
Fabrikant, Alex
empirically with small graphs near a phase transition in search performance. It im- proves on two prior and physical phase transitions [4, 23, 19], which has led to new heuristics for conventional machines [12, 8 a conventional machine eval- uates just one. Hence one might expect high performance for problems having a rapid
Spectral statistics for scaling quantum graphs
Yu. Dabaghian
2006-08-09T23:59:59.000Z
The explicit solution to the spectral problem of quantum graphs is used to obtain the exact distributions of several spectral statistics, such as the oscillations of the quantum momentum eigenvalues around the average, $\\delta k_{n}=k_{n}-\\bar k_{n}$, and the nearest neighbor separations, $s_{n}=k_{n}-k_{n-1}$.
Quantum secret sharing with qudit graph states
Keet, Adrian; Fortescue, Ben; Sanders, Barry C. [Institute for Quantum Information Science, University of Calgary, Alberta, T2N 1N4 (Canada); Markham, Damian [LTCI-CNRS, Telecom ParisTech, 37/39 rue Dareau, F-75014 Paris (France)
2010-12-15T23:59:59.000Z
We present a unified formalism for threshold quantum secret sharing using graph states of systems with prime dimension. We construct protocols for three varieties of secret sharing: with classical and quantum secrets shared between parties over both classical and quantum channels.
Atomic Representations of Rank 2 Graph Algebras
Davidson, Ken
Atomic Representations of Rank 2 Graph Algebras Kenneth R. Davidson a , Stephen C. Power b , Dilian University, Lancaster LA1 4YF, U.K. Abstract We provide a detailed analysis of atomic -representations- posed into a direct sum or direct integral of irreducible atomic representations. The building blocks
Graph-Theoretic Connectivity Control of Mobile
Pappas, George J.
]Â[23]. This research has given rise to connectivity or topology control algorithms that regulate the transmission powerINVITED P A P E R Graph-Theoretic Connectivity Control of Mobile Robot Networks This paper develops an analysis for groups of vehicles connected by a communication network; control laws are formulated
Three Theorems Regarding Testing Graph Properties*
Trevisan, Luca
Three Theorems Regarding Testing Graph Properties* Oded Goldreich,1, Luca Trevisan2 1 Department-mail: luca@eecs.berkeley.edu Received 9 December 2001; accepted 18 September 2002 DOI 10.1002/rsa.10078 ABSTRACT: Property testing is a relaxation of decision problems in which it is required to distinguish YES
Parsimonious Flooding in Dynamic Graphs Herv Baumann
Fondements et Applications, Université Paris 7
Parsimonious Flooding in Dynamic Graphs Hervé Baumann University Paris Diderot herve bounds on their flooding time -- flooding is the basic mechanism in which every node becoming aware. In this paper, we establish tight bounds on the complexity of flooding for all possible birth rates and death
Frequent Subgraph Discovery in Large Attributed Streaming Graphs
Ray, Abhik; Holder, Larry; Choudhury, Sutanay
2014-08-13T23:59:59.000Z
The problem of finding frequent subgraphs in large dynamic graphs has so far only consid- ered a dynamic graph as being represented by a series of static snapshots taken at various points in time. This representation of a dynamic graph does not lend itself well to real time processing of real world graphs like social networks or internet traffic which consist of a stream of nodes and edges. In this paper we propose an algorithm that discovers the frequent subgraphs present in a graph represented by a stream of labeled nodes and edges. Our algorithm is efficient and consists of tunable parameters that can be tuned by the user to get interesting patterns from various kinds of graph data. In our model updates to the graph arrive in the form of batches which contain new nodes and edges. Our algorithm con- tinuously reports the frequent subgraphs that are estimated to be found in the entire graph as each batch arrives. We evaluate our system using 5 large dynamic graph datasets: the Hetrec 2011 challenge data, Twitter, DBLP and two synthetic. We evaluate our approach against two popular large graph miners, i.e., SUBDUE and GERM. Our experimental re- sults show that we can find the same frequent subgraphs as a non-incremental approach applied to snapshot graphs, and in less time.
Graph processing platforms at scale: practices and experiences
Lim, Seung-Hwan [ORNL; Lee, Sangkeun (Matt) [ORNL; Brown, Tyler C [ORNL; Sukumar, Sreenivas R [ORNL; Ganesh, Gautam [ORNL
2015-01-01T23:59:59.000Z
Graph analysis unveils hidden associations of data in many phenomena and artifacts, such as road network, social networks, genomic information, and scientific collaboration. Unfortunately, a wide diversity in the characteristics of graphs and graph operations make it challenging to find a right combination of tools and implementation of algorithms to discover desired knowledge from the target data set. This study presents an extensive empirical study of three representative graph processing platforms: Pegasus, GraphX, and Urika. Each system represents a combination of options in data model, processing paradigm, and infrastructure. We benchmarked each platform using three popular graph operations, degree distribution, connected components, and PageRank over a variety of real-world graphs. Our experiments show that each graph processing platform shows different strength, depending the type of graph operations. While Urika performs the best in non-iterative operations like degree distribution, GraphX outputforms iterative operations like connected components and PageRank. In addition, we discuss challenges to optimize the performance of each platform over large scale real world graphs.
Line graphs e contrazioni: un approccio rigoroso alla space syntax
D'Autilia, Roberto
2015-01-01T23:59:59.000Z
The methods of the space syntax have been the subject of extensive discussion, and several techniques to identify the axis lines have been proposed. The space syntax can be represented in terms of line graph, a graphs defined on the edge of a given primary graph. By means of the line graph algorithms, a system of labels defined on the edges of the primary graph is transformed into a system of labels on the vertices of the line graph. The contraction of adjacent edges with the same label allows to build a more general graph than those generated with the methods of the space syntax. By means of the functions implemented in Mathematica is therefore possible to redefine the space syntax on any system of urban quantities (labels) and reproduce the results of the axial lines as a special case. As an example is discussed a possible application of the method to the urban noise analysis.
Crunching Large Graphs with Commodity Processors
Nelson, Jacob E.; Myers, Brandon D.; Hunter, Andrew H.; Briggs, Preston; Ceze, Luis; Ebeling, William C.; Grossman, Dan; Kahan, Simon H.; Oskin, Mark
2011-05-26T23:59:59.000Z
Crunching large graphs is the basis of many emerging appli- cations, such as social network analysis and bioinformatics. Graph analytics algorithms exhibit little locality and therefore present signi?cant performance challenges. Hardware multi- threading systems (e.g, Cray XMT) show that with enough concurrency, we can tolerate long latencies. Unfortunately, this solution is not available with commodity parts. Our goal is to develop a latency-tolerant system built out of commodity parts and mostly in software. The proposed system includes a runtime that supports a large number of lightweight contexts, full-bit synchronization and a memory manager that provides a high-latency but high-bandwidth global shared memory. This paper lays out the vision for our system, and justi?es its feasibility with a performance analysis of the run- time for latency tolerance.
Local semicircle law for random regular graphs
Roland Bauerschmidt; Antti Knowles; Horng-Tzer Yau
2015-05-26T23:59:59.000Z
We consider random $d$-regular graphs on $N$ vertices, with degree $d$ at least $(\\log N)^4$. We prove that the Green's function of the adjacency matrix and the Stieltjes transform of its empirical spectral measure are well approximated by Wigner's semicircle law, down to the optimal scale given by the typical eigenvalue spacing (up to a logarithmic correction). Aside from well-known consequences for the local eigenvalue distribution, this result implies the complete delocalization of all eigenvectors.
Parameters of Integral Circulant Graphs and Periodic Quantum Dynamics
Nitin Saxena; Simone Severini; Igor Shparlinski
2007-03-26T23:59:59.000Z
The intention of the paper is to move a step towards a classification of network topologies that exhibit periodic quantum dynamics. We show that the evolution of a quantum system, whose hamiltonian is identical to the adjacency matrix of a circulant graph, is periodic if and only if all eigenvalues of the graph are integers (that is, the graph is integral). Motivated by this observation, we focus on relevant properties of integral circulant graphs. Specifically, we bound the number of vertices of integral circulant graphs in terms of their degree, characterize bipartiteness and give exact bounds for their diameter. Additionally, we prove that circulant graphs with odd order do not allow perfect state transfer.
Dynamics of entanglement of bosonic modes on symmetric graphs
F. Ghahhari; V. Karimipour; R. Shahrokhshahi
2006-11-23T23:59:59.000Z
We investigate the dynamics of an initially disentangled Gaussian state on a general finite symmetric graph. As concrete examples we obtain properties of this dynamics on mean field graphs of arbitrary sizes. In the same way that chains can be used for transmitting entanglement by their natural dynamics, these graphs can be used to store entanglement. We also consider two kinds of regular polyhedron which show interesting features of entanglement sharing.
Nodal Parity Invariants of Knotted Rigid Vertex Graphs
Kauffman, Louis H
2012-01-01T23:59:59.000Z
This paper introduces new invariants of rigid vertex graph embeddings by using non-local combinatorial information that is available at each graphical node. The new non-local information that we use in this paper involves parity in the Gauss code of the underlying graph. We apply these methods to graphs in classical and virtual knot theory, and we give formulations for applications to the topology of protein folding.
k-Boson Quantum Walks Do Not Distinguish Arbitrary Graphs
Jamie Smith
2010-04-01T23:59:59.000Z
In this paper, we define k-equivalence, a relation on graphs that relies on their associated cellular algebras. We show that a k-Boson quantum walk cannot distinguish pairs of graphs that are k- equivalent. The existence of pairs of k-equivalent graphs has been shown by Ponomarenko et al. [2, 6]. This gives a negative answer to a question posed by Gamble et al. [7].
Large induced forests in sparse graphs , Dhruv Mubayi
Shamir, Ron
(G) of G. Given a graph G, let NG(v) or simply N(v) denote the set of neighbors of vertex v. For sets
An efficient semidefinite programming relaxation for the graph ...
2012-08-28T23:59:59.000Z
can be computed efficiently for larger graphs that have suitable algebraic symmetry. For a comparison of the SDP bounds for the GEP, see [45]. While the GEP is ...
On the Adequacy of Program Dependence Graphs for Representing Programs
Reps, Thomas W.
introduced by Kuck as an intermediate program representation well suited for performing optimizations are strongly equivalent. 1. Introduction Program dependence graphs were introduced by Kuck as an intermediate
Quasiperiodic graphs: structural design, scaling and entropic properties
Bartolo Luque; Fernando J. Ballesteros; Ángel M. Núñez; Alberto Robledo
2012-03-16T23:59:59.000Z
A novel class of graphs, here named quasiperiodic, are constructed via application of the Horizontal Visibility algorithm to the time series generated along the quasiperiodic route to chaos. We show how the hierarchy of mode-locked regions represented by the Farey tree is inherited by their associated graphs. We are able to establish, via Renormalization Group (RG) theory, the architecture of the quasiperiodic graphs produced by irrational winding numbers with pure periodic continued fraction. And finally, we demonstrate that the RG fixed-point degree distributions are recovered via optimization of a suitably defined graph entropy.
Computing the Stretch of an Embedded Graph Sergio Cabello
Cabello, Sergio
. GIG/11/E023. 1 #12;Here, len() denotes the number of edges in and a cycle is a closed walk in a graph
course web site Note: For all homework assignments, when graphs and plots are
Palmeri, Thomas
PSY318! Week 4 #12;course web site #12;Note: For all homework assignments, when graphs and plots web site is a simple example of some Matlab code for creating line and bar graphs: Graph
Graph searching and a generalized parking function
Kostic, Dimitrije Nenad
2009-05-15T23:59:59.000Z
sequence (a1,a2,...,an) of non-negative integers for which there exists a permutation pi ?Sn such that 0 ?api(i) ?i?1 for all indexes i. In other words, if we choose a permutation pi such that api(1) ?api(2) ? ...? api(n) then we have (api(1),api(2),...,api... if at the end of this process we have removed all vertices from consideration. More formally, Proposition 7. A vertex function is a G-parking function if and only if there exists an ordering pi(1),pi(2),...,pi(n) of the vertices of a graph G such that for every...
Spectral properties of magnetic chain graphs
Pavel Exner; Stepan Manko
2015-07-02T23:59:59.000Z
We discuss spectral properties of a charged quantum particle confined to a chain graph consisting of an infinite array of rings under influence of a magnetic field assuming a $\\delta$-coupling at the points where the rings touch. We start with the situation when the system has a translational symmetry and analyze spectral consequences of perturbations of various kind, such as a local change of the magnetic field, of the coupling constant, or of a ring circumference. A particular attention is paid to weak perturbations, both local and periodic; for the latter we prove a version of Saxon-Hutner conjecture.
Graph Transformation and Intuitionistic Linear Logic
Ulidowski, Irek
; } } CISA Â p. #12;L1 L2 x y pt t L3 pt pt nx L1 L2 x y pt t L3 pt pt nx pt nx pt nx l[0] NULLx x y L1 L3L1y x L2 pt pt nx L3 L2 y nxpt pt pointer cell nx pt INITIAL STATE TYPE GRAPH RULE 1 RULE 2 CISA Â p. #12;ILL representation Definitions ptlist(x, l) pt(x, Hd(l)) list(l) list(h#l) nx(h, Hd(l)) list
Scalability Analysis of Partitioning Strategies for Finite Element Graphs. \\Lambda
Kumar, Vipin
Scalability Analysis of Partitioning Strategies for Finite Element Graphs. \\Lambda Grama Y. Ananth Y. Grama ananth@cs:umn:edu Abstract Issues of partitioning Finite Element Graphs are central for implementing the Finite Element Method (FEM). Parallel formulations of finite element techniques require
The Generic Graph Component Library Dr. Dobb's Journal September 2000
Lumsdaine, Andrew
by Jeremy G. Siek and Andrew Lumsdaine). The most important aspect of designing the library was to defineThe Generic Graph Component Library Dr. Dobb's Journal September 2000 Generic programming for graph.nd.edu, and lumsg@lsc.nd.edu, respectively. The Standard Template Library has established a solid foundation
Bicyclic graphs with exactly two main signless Laplacian eigenvalues
Huang, He
2012-01-01T23:59:59.000Z
A signless Laplacian eigenvalue of a graph $G$ is called a main signless Laplacian eigenvalue if it has an eigenvector the sum of whose entries is not equal to zero. In this paper, all connected bicyclic graphs with exactly two main eigenvalues are determined.
Priority Algorithms for Graph Optimization Problems Allan Borodin
Larsen, Kim Skak
Priority Algorithms for Graph Optimization Problems Allan Borodin University of Toronto bor of priority or "greedy-like" algorithms as initiated in [10] and as extended to graph theoretic problems, there are several natural input formulations for a given problem and we show that priority algorithm bounds
The Parallel BGL: A Generic Library for Distributed Graph Computations
Lumsdaine, Andrew
] and written in a style similar to the C++ Standard Template Library (STL) [38, 46], 1 #12;data types providedThe Parallel BGL: A Generic Library for Distributed Graph Computations Douglas Gregor and Andrew,lums}@osl.iu.edu Abstract This paper presents the Parallel BGL, a generic C++ library for distributed graph computation
GRAPH THEORETIC APPROACHES TO INJECTIVITY IN CHEMICAL REACTION SYSTEMS
Craciun, Gheorghe
GRAPH THEORETIC APPROACHES TO INJECTIVITY IN CHEMICAL REACTION SYSTEMS MURAD BANAJI AND GHEORGHE algebraic and graph theoretic conditions for injectivity of chemical reaction systems. After developing the possibility of multiple equilibria in the systems in question. Key words. Chemical reactions; Injectivity; SR
Semidefinite programming and eigenvalue bounds for the graph ...
2013-11-26T23:59:59.000Z
Page 1 ... Using what we call the Laplacian algebra of a graph, we ..... Let us now consider graphs with symmetry, and assume that the data matrices of .... constraints (16) and (17) (respectively) don't occur precisely because of the vanishing of.
Albert R Meyer April 1, 2013 sexgraph.1 Graph Theory
Meyer, Albert R.
1 Albert R Meyer April 1, 2013 sexgraph.1 Graph Theory & Sex Albert R Meyer April 1, 2013 sexgraph women partners Albert R Meyer April 1, 2013 sexgraph.3 Sex in America: Men more Promiscuous? Studies this is nonsense Albert R Meyer April 1, 2013 sexgraph.4 M partners F Sex Partner Graph #12;2 Albert R Meyer April
Statistical Selection of Congruent Subspaces for Mining Attributed Graphs
Antwerpen, Universiteit
Statistical Selection of Congruent Subspaces for Mining Attributed Graphs Patricia Iglesias S (KIT), Germany University of Antwerp, Belgium {patricia.iglesias, emmanuel.mueller, fabian.laforet, fabian.keller, klemens.boehm}@kit.edu Abstract--Current mining algorithms for attributed graphs exploit
An Introduction to Game Trees Ross Casebolt --Graph Theory
Laison, Josh
Ross Casebolt -- Graph Theory Lobsters vs Caterpillars! #12;What is a game? Definition (Game) A game G Theory Lobsters vs Caterpillars! #12;What is a game? Definition (Game) A game G must satisfy Ross Casebolt -- Graph Theory Lobsters vs Caterpillars! #12;What is a game? Definition (Game) A game G
Querying RDF Data from a Graph Database Perspective
Baeza-Yates, Ricardo
}@dcc.uchile.cl Agenda · Motivations, Problem and Proposal · Database Models · Graph Database Models · RDF as data model of data model with inherent graph structure. · Database models and query languages should support its that a query language for RDF should provide. Database Models Data structures Operators and Query Language
Grid Intersection Graphs and Order Dimension Steven Chaplick
Felsner, Stefan
in Figure 2. A grid intersection graph (GIG) is an intersection graph of horizontal and vertical segments intersects, some authors prefer to call this class pure-GIG. If G admits a grid Supported by ESF Euro Structures' (GRK 1408) 1 #12;bipartite permutation Stick 3-DORG UGIGStabGIG GIG 4-DORG SegRay 2-DORG Bip
Critical behavior in inhomogeneous random graphs Remco van der Hofstad
Hofstad, Remco van der
Critical behavior in inhomogeneous random graphs Remco van der Hofstad June 10, 2010 Abstract We study the critical behavior of inhomogeneous random graphs where edges are present independently but with unequal edge occupation probabilities. The edge probabilities are moderated by vertex weights
On global offensive k-alliances in graphs
Bermudo, Sergio; Sigarreta, Jose M; Yero, Ismael G
2008-01-01T23:59:59.000Z
We investigate the relationship between global offensive $k$-alliances and some characteristic sets of a graph including $r$-dependent sets and $\\tau$-dominating sets. As a consequence of the study, we obtain bounds on the global offensive $k$-alliance number in terms of several parameters of the graph.
Generalized Graph Products for Network Design and Analysis
Roughan, Matthew
Generalized Graph Products for Network Design and Analysis Eric Parsonage, Hung X. Nguyen, Rhys--Network design, as it is currently practiced, involves putting devices together to create a network. However as a whole object. In this paper we develop generalized graph products that allow the mathematical design
Hierarchical Remote Sensing Image Analysis via Graph Laplacian Energy
Zhou, Jun
1 Hierarchical Remote Sensing Image Analysis via Graph Laplacian Energy Zhang Huigang, Bai Xiao for an efficient image description, which may cause increased computational complexity. In this paper, we propose a new hierarchical segmentation method that applies graph Laplacian energy as a generic measure
Bond graph models of electromechanical systems. The AC generator case
Batlle, Carles
to an AC generator, and the case of permanent magnets is also considered. The corresponding bond graphs in Section III, and Section IV discusses the permanent magnet case. Finally, Section V, statesBond graph models of electromechanical systems. The AC generator case Carles Batlle Department
SPATIAL POINT PROCESSES AND GRAPH BASED STATISTICAL FEATURES
Jyväskylä, University of
2010 2000 Mathematics Subject Classification. 60G55, 62-07, 62M30. ISSN 1457-9235 #12;SPATIAL POINT Classification. 60G55, 62-07, 62M30. 1 #12;Spatial point processes and graph based statistical features Tuomas library has been developed for the computation of the graph-based summaries. Keywords: Spatial point
Scaling Semantic Graph Databases in Size and Performance
Morari, Alessandro; Castellana, Vito G.; Villa, Oreste; Tumeo, Antonino; Weaver, Jesse R.; Haglin, David J.; Choudhury, Sutanay; Feo, John T.
2014-08-06T23:59:59.000Z
In this paper we present SGEM, a full software system for accelerating large-scale semantic graph databases on commodity clusters. Unlike current approaches, SGEM addresses semantic graph databases by only employing graph methods at all the levels of the stack. On one hand, this allows exploiting the space efficiency of graph data structures and the inherent parallelism of graph algorithms. These features adapt well to the increasing system memory and core counts of modern commodity clusters. On the other hand, however, these systems are optimized for regular computation and batched data transfers, while graph methods usually are irregular and generate fine-grained data accesses with poor spatial and temporal locality. Our framework comprises a SPARQL to data parallel C compiler, a library of parallel graph methods and a custom, multithreaded runtime system. We introduce our stack, motivate its advantages with respect to other solutions and show how we solved the challenges posed by irregular behaviors. We present the result of our software stack on the Berlin SPARQL benchmarks with datasets up to 10 billion triples (a triple corresponds to a graph edge), demonstrating scaling in dataset size and in performance as more nodes are added to the cluster.
Rapidly mixing Markov chains for dismantleable constraint graphs
Dyer, Martin
Rapidly mixing Markov chains for dismantleable constraint graphs Martin Dyer Mark Jerrum Eric adjacency. Brightwell and Winkler introduced the notion of dismantleable constraint graph to characterize proportional to vVG ((v)). We prove, for each dismantleable H, that there exist positive constant fugacities
Math 304 Handout: Linear algebra, graphs, and networks.
Anshelevich, Michael
and adjacency matrices. 1 2. Word search 3 3. Ranking the web pages. 4 1. GRAPHS AND ADJACENCY MATRICES. Â· The World Wide Web is a directed graph, with web pages as vertices and links as edges. Â· Towns connected column corresponds to a web page, each row to a word, and each entry is 1 if a particular word occurs
Analogical Representation and Graph Comprehension Aidan Feeney and Lara Webber
comprehension make the assumption that viewers build up a wholly propositional description of the graph a scale of two different levels of a variable, one may extract information about the value of each level with the information presented in the graph. A is high on the scale B is low on the scale A is higher on the scale than
On the concurrent semantics of Algebraic Graph Grammars #
Baldan, Paolo
â??a di Pisa, Italy baldan@dsi.unive.it andrea@di.unipi.it Abstract. Graph grammars are a powerful model. These semantics have served as basis for the development of a variety of modelling and verification techniques graph transformation systems as an alternative model of concurrency, extending Petri nets. The basic
Power Domination in Cylinders, Tori, and Generalized Petersen Graphs
Ferrero, Daniela - Department of Mathematics, Texas State University
of graphs by Haynes et al. in 2002 [7]. Indeed, an electrical power network can be modeled by a graph where for power system monitoring. The minimum cardi- nality of a PDS of G is its power domination number. INTRODUCTION Electric power companies need to monitor the state of their networks continually. The state
Unicyclic graphs with large energy Eric Ould Dadah Andriantiana 1
Wagner, Stephan
Unicyclic graphs with large energy Eric Ould Dadah Andriantiana 1 and Stephan Wagner 2 Department Abstract We study the energy (i.e., the sum of the absolute values of all eigenvalues) of so- called on the largest and second-largest energy of a unicyclic graph due to Caporossi, Cvetkovi´c, Gutman and Hansen
An Experiment on Graph Analysis Methodologies for Scenarios
Brothers, Alan J.; Whitney, Paul D.; Wolf, Katherine E.; Kuchar, Olga A.; Chin, George
2005-09-30T23:59:59.000Z
Visual graph representations are increasingly used to represent, display, and explore scenarios and the structure of organizations. The graph representations of scenarios are readily understood, and commercial software is available to create and manage these representations. The purpose of the research presented in this paper is to explore whether these graph representations support quantitative assessments of the underlying scenarios. The underlying structure of the scenarios is the information that is being targeted in the experiment and the extent to which the scenarios are similar in content. An experiment was designed that incorporated both the contents of the scenarios and analysts’ graph representations of the scenarios. The scenarios’ content was represented graphically by analysts, and both the structure and the semantics of the graph representation were attempted to be used to understand the content. The structure information was not found to be discriminating for the content of the scenarios in this experiment; but, the semantic information was discriminating.
International energy indicators. [Statistical tables and graphs
Bauer, E.K. (ed.)
1980-05-01T23:59:59.000Z
International statistical tables and graphs are given for the following: (1) Iran - Crude Oil Capacity, Production and Shut-in, June 1974-April 1980; (2) Saudi Arabia - Crude Oil Capacity, Production, and Shut-in, March 1974-Apr 1980; (3) OPEC (Ex-Iran and Saudi Arabia) - Capacity, Production and Shut-in, June 1974-March 1980; (4) Non-OPEC Free World and US Production of Crude Oil, January 1973-February 1980; (5) Oil Stocks - Free World, US, Japan, and Europe (Landed, 1973-1st Quarter, 1980); (6) Petroleum Consumption by Industrial Countries, January 1973-December 1979; (7) USSR Crude Oil Production and Exports, January 1974-April 1980; and (8) Free World and US Nuclear Generation Capacity, January 1973-March 1980. Similar statistical tables and graphs included for the United States include: (1) Imports of Crude Oil and Products, January 1973-April 1980; (2) Landed Cost of Saudi Oil in Current and 1974 Dollars, April 1974-January 1980; (3) US Trade in Coal, January 1973-March 1980; (4) Summary of US Merchandise Trade, 1976-March 1980; and (5) US Energy/GNP Ratio, 1947 to 1979.
Component evolution in general random intersection graphs
Bradonjic, Milan [Los Alamos National Laboratory; Hagberg, Aric [Los Alamos National Laboratory; Hengartner, Nick [Los Alamos National Laboratory; Percus, Allon G [CLAREMONT GRADUATE UNIV.
2010-01-01T23:59:59.000Z
We analyze component evolution in general random intersection graphs (RIGs) and give conditions on existence and uniqueness of the giant component. Our techniques generalize the existing methods for analysis on component evolution in RIGs. That is, we analyze survival and extinction properties of a dependent, inhomogeneous Galton-Watson branching process on general RIGs. Our analysis relies on bounding the branching processes and inherits the fundamental concepts from the study on component evolution in Erdos-Renyi graphs. The main challenge becomes from the underlying structure of RIGs, when the number of offsprings follows a binomial distribution with a different number of nodes and different rate at each step during the evolution. RIGs can be interpreted as a model for large randomly formed non-metric data sets. Besides the mathematical analysis on component evolution, which we provide in this work, we perceive RIGs as an important random structure which has already found applications in social networks, epidemic networks, blog readership, or wireless sensor networks.
Noisy entanglement evolution for graph states
L. Aolita; D. Cavalcanti; R. Chaves; C. Dhara; L. Davidovich; A. Acin
2011-03-29T23:59:59.000Z
A general method for the study of the entanglement evolution of graph states under the action of Pauli was recently proposed in [Cavalcanti, et al., Phys. Rev. Lett. 103, 030502 (2009)]. This method is based on lower and upper bounds on the entanglement of the entire state as a function only of the state of a considerably-smaller subsystem, which undergoes an effective noise process. This provides a huge simplification on the size of the matrices involved in the calculation of entanglement in these systems. In the present paper we elaborate on this method in details and generalize it to other natural situations not described by Pauli maps. Specifically, for Pauli maps we introduce an explicit formula for the characterization of the resulting effective noise. Beyond Pauli maps, we show that the same ideas can be applied to the case of thermal reservoirs at arbitrary temperature. In the latter case, we discuss how to optimize the bounds as a function of the noise strength. We illustrate our ideas with explicit exemplary results for several different graphs and particular decoherence processes. The limitations of the method are also discussed.
The Generic Graph Component Library LieQuan Lee Jeremy G. Siek Andrew Lumsdaine
Lumsdaine, Andrew
The Generic Graph Component Library LieQuan Lee Jeremy G. Siek Andrew Lumsdaine Laboratory In this paper we present the Generic Graph Component Library (GGCL), a generic programming framework for graph data struc tures and graph algorithms. Following the theme of the Standard Template Library (STL
A Graph-Based Data Model and its Ramifications Mark Levene and George Loizou
Levene, Mark
A Graph-Based Data Model and its Ramifications Mark Levene and George Loizou Abstract- Currently candidate for for- malising hypertext. We then compare it with other graph-based data models and with set-based as a paradigm for graph-based data modelling, we show how to bridge the gap between graph-based and set-based
Energy Models for Drawing Signed Graphs Anne-Marie Kermarrec and Afshin Moin
Paris-Sud XI, Université de
by proposing a dual energy model for graphs containing uniquely negative edges, and combining it linearly
A characterization of K2,4-minor-free graphs M. N. Ellingham1
Ellingham, Mark
A characterization of K2,4-minor-free graphs M. N. Ellingham1 Emily A. Marshall1,2 Department structural characterization of K2,4-minor-free graphs. The 3-connected K2,4- minor-free graphs consist many forbidden minors. So characterizations of graphs without one or two specific minors form natural
Interactive Visualization of Genealogical Graphs Michael J. McGuffin Ravin Balakrishnan
McGuffin, Michael J.
Interactive Visualization of Genealogical Graphs Michael J. McGuffin Ravin Balakrishnan Department of visualizing "family trees", or genealogi- cal graphs, in 2D, is considered. A graph theoretic analysis is given, which identifies why genealogical graphs can be difficult to draw. This motivates some novel
The elliptic dilogarithm for the sunset graph
Spencer Bloch; Pierre Vanhove
2014-10-24T23:59:59.000Z
We study the sunset graph defined as the scalar two-point self-energy at two-loop order. We evaluate the sunset integral for all identical internal masses in two dimensions. We give two calculations for the sunset amplitude; one based on an interpretation of the amplitude as an inhomogeneous solution of a classical Picard-Fuchs differential equation, and the other using arithmetic algebraic geometry, motivic cohomology, and Eisenstein series. Both methods use the rather special fact that the amplitude in this case is a family of periods associated to the universal family of elliptic curves over the modular curve X_1(6). We show that the integral is given by an elliptic dilogarithm evaluated at a sixth root of unity modulo periods. We explain as well how this elliptic dilogarithm value is related to the regulator of a class in the motivic cohomology of the universal elliptic family.
Bicyclic graphs with maximal revised Szeged index
Li, Xueliang
2011-01-01T23:59:59.000Z
The revised Szeged index $Sz^*(G)$ is defined as $Sz^*(G)=\\sum_{e=uv \\in E}(n_u(e)+ n_0(e)/2)(n_v(e)+ n_0(e)/2),$ where $n_u(e)$ and $n_v(e)$ are, respectively, the number of vertices of $G$ lying closer to vertex $u$ than to vertex $v$ and the number of vertices of $G$ lying closer to vertex $v$ than to vertex $u$, and $n_0(e)$ is the number of vertices equidistant to $u$ and $v$. Hansen used the AutoGraphiX and made the following conjecture about the revised Szeged index for a connected bicyclic graph $G$ of order $n \\geq 6$:
The Incidence Hopf Algebra of Graphs
Humpert, Brandon; Martin, Jeremy L.
2012-05-03T23:59:59.000Z
), unit u(1) = K 0 , comultiplication ?(G) = ? T?V (G) G|T ?G|T , and counit #3;(G) = { 1 if n(G) = 0, 0 if n(G) > 0. The graph algebra is commutative and cocommutative; in particular, its character group X(G) is abelian. As proved by Schmitt [Sch94, (12.1...) counts the number of k-colorings of G such that every color-induced subgraph is H-free. As an extreme example, if G = H , then P?G(G; k) = k n(G) ? k, because the non-G-free colorings are precisely those using only one color. If H = Km,1, then Pm(G; k...
The Graph Laplacian and the Dynamics of Complex Networks
Thulasidasan, Sunil [Los Alamos National Laboratory
2012-06-11T23:59:59.000Z
In this talk, we explore the structure of networks from a spectral graph-theoretic perspective by analyzing the properties of the Laplacian matrix associated with the graph induced by a network. We will see how the eigenvalues of the graph Laplacian relate to the underlying network structure and dynamics and provides insight into a phenomenon frequently observed in real world networks - the emergence of collective behavior from purely local interactions seen in the coordinated motion of animals and phase transitions in biological networks, to name a few.
Local computation algorithms for graphs of non-constant degrees
Yodpinyanee, Anak
2014-01-01T23:59:59.000Z
In the model of local computation algorithms (LCAs), we aim to compute the queried part of the output by examining only a small (sublinear) portion of the input. Many recently developed LCAs on graph problems achieve time ...
Efficient graphlet kernels for large graph comparison Nino Shervashidze
Mehlhorn, Kurt
Efficient graphlet kernels for large graph comparison Nino Shervashidze MPI for Biological such as gSpan (Yan & Han, 2003) have been developed for this task, which use el- egant data structures
The competition number of a graph with exactly two holes
] as a means of deter- mining the smallest dimension of ecological phase space. Since then, various variations to ecology, the concept of competition graph can be applied to a variety of fields, as summarized in [11
The competition number of a graph with exactly two holes
] as a means of deter mining the smallest dimension of ecological phase space. Since then, various variations to ecology, the concept of competition graph can be applied to a variety of fields, as summarized in [11
Quantum Graphs: Applications to Quantum Chaos and Universal Spectral Statistics
Sven Gnutzmann; Uzy Smilansky
2006-12-15T23:59:59.000Z
During the last years quantum graphs have become a paradigm of quantum chaos with applications from spectral statistics to chaotic scattering and wave function statistics. In the first part of this review we give a detailed introduction to the spectral theory of quantum graphs and discuss exact trace formulae for the spectrum and the quantum-to-classical correspondence. The second part of this review is devoted to the spectral statistics of quantum graphs as an application to quantum chaos. Especially, we summarise recent developments on the spectral statistics of generic large quantum graphs based on two approaches: the periodic-orbit approach and the supersymmetry approach. The latter provides a condition and a proof for universal spectral statistics as predicted by random-matrix theory.
Automated Inclusive Design Heuristics Generation with Graph Mining
Sangelkar, Shraddha Chandrakant
2013-08-01T23:59:59.000Z
relations, and graph data mining to extract the design heuristics. The goal of this research is to formalize and automate the inclusive-design heuristics generation process. The rule generation allows statistical mining of the design guidelines...
Computing the stability number of a graph via semidefinite and ...
2006-04-27T23:59:59.000Z
then the vertices of G can be numbered so that E(G8) ? E(G ). Thus G8 is the smallest graph G such that ?(1)(G) > ?(G) = 3. We can extend the above reasoning ...
SEMANTICS OF PROGRAM REPRESENTATION GRAPHS G. RAMALINGAM and THOMAS REPS
Reps, Thomas W.
dependence graphs (PDGs) [Kuck81, Ferr87, Horw89]. They have also been used in a new algorithm for merging representation in various appli cations such as vectorization, parallelization [Kuck81], and merging program
Graph Coloring on a Coarse Grained Multiprocessor (extended abstract)
Gebremedhin, Assefaw Hadish
Graph Coloring on a Coarse Grained Multiprocessor (extended abstract) Assefaw Hadish Gebremedhin1 Allwright et al. (1995). However, in a recent result, Gebremedhin and Manne (1999a, 1999b) present
Speeding up Parallel Graph Coloring Assefaw H. Gebremedhin1,
Manne, Fredrik
Speeding up Parallel Graph Coloring Assefaw H. Gebremedhin1, , Fredrik Manne2 , and Tom Woods2 1. Gebremedhin, Fredrik Manne, and Tom Woods However, in practice greedy sequential coloring heuristics have been
Technology Portfolio Planning by Weighted Graph Analysis of System Architectures
de Weck, Olivier L.
Technology Portfolio Planning by Weighted Graph Analysis of System Architectures Peter Davison and Bruce Cameron Massachusetts Institute of Technology, Cambridge, MA 02139 Edward F. Crawley Skolkovo Institute of Science and Technology, Skolkovo 143025, Russia Abstract5 Many systems undergo significant
Poster: -Graphs: Flexible Topology Control in Wireless Ad Hoc Networks
Williamson, Carey
Poster: -Graphs: Flexible Topology Control in Wireless Ad Hoc Networks Ashikur Rahman Department networks. Most algorithms strive to reduce energy consumption by cre- ating a sparse topology with few long of topologies and provides the flexibility to network
Stirling numbers of graphs, and the normal ordering
Mayfield, John
Stirling numbers of graphs, and the normal ordering problem Galvin earned his PhD in mathematics correlations in discrete random structures. The Stirling number of the second kind ${n \\brace k}$ counts
Graph Rotation Systems for Physical Construction of Large Structures
Xing, Qing
2012-02-14T23:59:59.000Z
In this dissertation, I present an approach for physical construction of large structures. The approach is based on the graph rotation system framework. I propose two kinds of physical structures to represent the shape of design models. I have...
Ranking Outlier Nodes in Subspaces of Attributed Graphs
Antwerpen, Universiteit
. Our graph outlier ranking (GOutRank) introduces scoring functions based on these selected subgraphs by looking at the most promising objects first. They 1http://www.ipd.kit.edu/~muellere/GOutRank/ allow users
Temporally Scalable Visual SLAM using a Reduced Pose Graph
Johannsson, Hordur
2012-05-25T23:59:59.000Z
In this paper, we demonstrate a system for temporally scalable visual SLAM using a reduced pose graph representation. Unlike previous visual SLAM approaches that use keyframes, our approach continually uses new measurements ...
Temporally scalable visual SLAM using a reduced pose graph
Johannsson, Hordur
In this paper, we demonstrate a system for temporally scalable visual SLAM using a reduced pose graph representation. Unlike previous visual SLAM approaches that maintain static keyframes, our approach uses new measurements ...
Generalized Domination in Graphs with Applications in Wireless Networks
Sung, Je Sang
2013-12-10T23:59:59.000Z
The objective of this research is to study practical generalization of domination in graphs and explore the theoretical and computational aspects of models arising in the design of wireless networks. For the construction of a virtual backbone of a...
Checking and Comparison of WB-Graphs Peter B. Ladkin
Ladkin, Peter B.
as a running comparison. These graphs were produced by beginners at WBA, namely students in the first semester. It also caused the trauma death of the co-pilot, as well as the loss of consciousness of a passenger, who
Automated Inclusive Design Heuristics Generation with Graph Mining
Sangelkar, Shraddha Chandrakant
2013-08-01T23:59:59.000Z
relations, and graph data mining to extract the design heuristics. The goal of this research is to formalize and automate the inclusive-design heuristics generation process. The rule generation allows statistical mining of the design guidelines...
Probabilistic Flooding for Efficient Information Dissemination in Random Graph
Stavrakakis, Ioannis
Probabilistic Flooding for Efficient Information Dissemination in Random Graph Topologies 1 & Telecommunications, Athens, Greece Abstract Probabilistic flooding has been frequently considered as a suitable) flooding approaches that are used to disseminate globally information in unstructured peer
Finding structural anomalies in graphs by means of quantum walks
Feldman, Edgar [Department of Mathematics, Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016 (United States); Hillery, Mark; Zheng, Hongjun [Department of Physics, Hunter College of the City University of New York, 695 Park Avenue, New York, New York 10021 (United States); Lee, Hai-Woong [Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); Reitzner, Daniel; Buzek, Vladimir [Research Center for Quantum Information, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava (Slovakia)
2010-10-15T23:59:59.000Z
We explore the possibility of using quantum walks on graphs to find structural anomalies, such as extra edges or loops, on a graph. We focus our attention on star graphs, whose edges are like spokes coming out of a central hub. If there are N spokes, we show that a quantum walk can find an extra edge connecting two of the spokes or a spoke with a loop on it in O({radical}(N)) steps. We initially find that if all except one of the spokes have loops, the walk will not find the spoke without a loop, but this can be fixed if we choose the phase with which the particle is reflected from the vertex without the loop. Consequently, quantum walks can, under some circumstances, be used to find structural anomalies in graphs.
A note on light geometric graphs Eyal Ackerman
Fox, Jacob
A note on light geometric graphs Eyal Ackerman Jacob Fox Rom Pinchasi March 19, 2012 Abstract Let G be a geometric graph on n vertices in general position in the plane. We say that G is k-light if no edge e of G than k edges of G. We extend the previous result in [1] and with a shorter argument show that every k-light
Alliance free sets in Cartesian product graphs
Yero, Ismael G; Bermudo, Sergio
2011-01-01T23:59:59.000Z
Let $G=(V,E)$ be a graph. For a non-empty subset of vertices $S\\subseteq V$, and vertex $v\\in V$, let $\\delta_S(v)=|\\{u\\in S:uv\\in E\\}|$ denote the cardinality of the set of neighbors of $v$ in $S$, and let $\\bar{S}=V-S$. Consider the following condition: {equation}\\label{alliancecondition} \\delta_S(v)\\ge \\delta_{\\bar{S}}(v)+k, \\{equation} which states that a vertex $v$ has at least $k$ more neighbors in $S$ than it has in $\\bar{S}$. A set $S\\subseteq V$ that satisfies Condition (\\ref{alliancecondition}) for every vertex $v \\in S$ is called a \\emph{defensive} $k$-\\emph{alliance}; for every vertex $v$ in the neighborhood of $S$ is called an \\emph{offensive} $k$-\\emph{alliance}. A subset of vertices $S\\subseteq V$, is a \\emph{powerful} $k$-\\emph{alliance} if it is both a defensive $k$-alliance and an offensive $(k +2)$-alliance. Moreover, a subset $X\\subset V$ is a defensive (an offensive or a powerful) $k$-alliance free set if $X$ does not contain any defensive (offensive or powerful, respectively) $k$-allianc...
Quantum Vacuum Energy in Graphs and Billiards
L. Kaplan
2011-01-03T23:59:59.000Z
The vacuum (Casimir) energy in quantum field theory is a problem relevant both to new nanotechnology devices and to dark energy in cosmology. The crucial question is the dependence of the energy on the system geometry under study. Despite much progress since the first prediction of the Casimir effect in 1948 and its subsequent experimental verification in simple geometries, even the sign of the force in nontrivial situations is still a matter of controversy. Mathematically, vacuum energy fits squarely into the spectral theory of second-order self-adjoint elliptic linear differential operators. Specifically, one promising approach is based on the small-t asymptotics of the cylinder kernel e^(-t sqrt(H)), where H is the self-adjoint operator under study. In contrast with the well-studied heat kernel e^(-tH), the cylinder kernel depends in a non-local way on the geometry of the problem. We discuss some results by the Louisiana-Oklahoma-Texas collaboration on vacuum energy in model systems, including quantum graphs and two-dimensional cavities. The results may shed light on general questions, including the relationship between vacuum energy and periodic or closed classical orbits, and the contribution to vacuum energy of boundaries, edges, and corners.
Noisy entanglement evolution for graph states
Aolita, L; Chaves, R; Dhara, C; Davidovich, L; Acin, A
2010-01-01T23:59:59.000Z
A general method for the study of the entanglement evolution of graph states under the action of Pauli was recently proposed in [Cavalcanti, et al., Phys. Rev. Lett. 103, 030502 (2009)]. This method is based on lower and upper bounds on the entanglement of the entire state as a function only of the state of a considerably-smaller subsystem, which undergoes an effective noise process. This provides a huge simplification on the size of the matrices involved in the calculation of entanglement in these systems. In the present paper we elaborate on this method in details and generalize it to other natural situations not described by Pauli maps. Specifically, for Pauli maps we introduce an explicit formula for the characterization of the resulting effective noise. Beyond Pauli maps, we show that the same ideas can be applied to the case of thermal reservoirs at arbitrary temperature. In the latter case, we discuss how to optimize the bounds as a function of the noise strength. We illustrate our ideas with explicit ...
Experimental entanglement of six photons in graph states
Chao-Yang Lu; Xiao-Qi Zhou; Otfried Gühne; Wei-Bo Gao; Jin Zhang; Zhen-Sheng Yuan; Alexander Goebel; Tao Yang; Jian-Wei Pan
2006-09-18T23:59:59.000Z
Graph states are special kinds of multipartite entangled states that correspond to mathematical graphs where the vertices take the role of quantum spin systems and the edges represent interactions. They not only provide an efficient model to study multiparticle entanglement, but also find wide applications in quantum error correction, multi-party quantum communication and most prominently, serve as the central resource in one-way quantum computation. Here we report the creation of two special instances of graph states, the six-photon Greenberger-Horne-Zeilinger states -- the largest photonic Schr\\"{o}dinger cat, and the six-photon cluster states-- a state-of-the-art one-way quantum computer. Flexibly, slight modifications of our method allow creation of many other graph states. Thus we have demonstrated the ability of entangling six photons and engineering multiqubit graph states, and created a test-bed for investigations of one-way quantum computation and studies of multiparticle entanglement as well as foundational issues such as nonlocality and decoherence.
Zhao, Jun; Gligor, Virgil
2015-01-01T23:59:59.000Z
Random intersection graphs have received much interest and been used in diverse applications. They are naturally induced in modeling secure sensor networks under random key predistribution schemes, as well as in modeling the topologies of social networks including common-interest networks, collaboration networks, and actor networks. Simply put, a random intersection graph is constructed by assigning each node a set of items in some random manner and then putting an edge between any two nodes that share a certain number of items. Broadly speaking, our work is about analyzing random intersection graphs, and models generated by composing it with other random graph models including random geometric graphs and Erd\\H{o}s-R\\'enyi graphs. These compositional models are introduced to capture the characteristics of various complex natural or man-made networks more accurately than the existing models in the literature. For random intersection graphs and their compositions with other random graphs, we study properties su...
An improved spectral graph partitioning algorithm for mapping parallel computations
Hendrickson, B.; Leland, R.
1992-09-01T23:59:59.000Z
Efficient use of a distributed memory parallel computer requires that the computational load be balanced across processors in a way that minimizes interprocessor communication. We present a new domain mapping algorithm that extends recent work in which ideas from spectral graph theory have been applied to this problem. Our generalization of spectral graph bisection involves a novel use of multiple eigenvectors to allow for division of a computation into four or eight parts at each stage of a recursive decomposition. The resulting method is suitable for scientific computations like irregular finite elements or differences performed on hypercube or mesh architecture machines. Experimental results confirm that the new method provides better decompositions arrived at more economically and robustly than with previous spectral methods. We have also improved upon the known spectral lower bound for graph bisection.
Asymptotic structure and singularities in constrained directed graphs
David Aristoff; Lingjiong Zhu
2015-02-17T23:59:59.000Z
We study the asymptotics of large directed graphs, constrained to have certain densities of edges and/or outward $p$-stars. Our models are close cousins of exponential random graph models (ERGMs), in which edges and certain other subgraph densities are controlled by parameters. The idea of directly constraining edge and other subgraph densities comes from Radin and Sadun. Such modeling circumvents a phenomenon first made precise by Chatterjee and Diaconis: that in ERGMs it is often impossible to independently constrain edge and other subgraph densities. In all our models, we find that large graphs have either uniform or bipodal structure. When edge density (resp. $p$-star density) is fixed and $p$-star density (resp. edge density) is controlled by a parameter, we find phase transitions corresponding to a change from uniform to bipodal structure. When both edge and $p$-star density are fixed, we find only bipodal structures and no phase transition.
Metric intersection problems in Cayley graphs and the Stirling recursion
Phongpattanacharoen, Teeraphong
2012-01-01T23:59:59.000Z
In the symmetric group Sym(n) with n at least 5 let H be a conjugacy class of elements of order 2 and let \\Gamma be the Cayley graph whose vertex set is the group G generated by H (so G is Sym(n) or Alt(n)) and whose edge set is determined by H. We are interested in the metric structure of this graph. In particular, for g\\in G let B_{r}(g) be the metric ball in \\Gamma of radius r and centre g. We show that the intersection numbers \\Phi(\\Gamma; r, g):=|\\,B_{r}(e)\\,\\cap\\,B_{r}(g)\\,| are generalized Stirling functions in n and r. The results are motivated by the study of error graphs and related reconstruction problems.
Regular graphs maximize the variability of random neural networks
Gilles Wainrib; Mathieu Galtier
2014-12-17T23:59:59.000Z
In this work we study the dynamics of systems composed of numerous interacting elements interconnected through a random weighted directed graph, such as models of random neural networks. We develop an original theoretical approach based on a combination of a classical mean-field theory originally developed in the context of dynamical spin-glass models, and the heterogeneous mean-field theory developed to study epidemic propagation on graphs. Our main result is that, surprisingly, increasing the variance of the in-degree distribution does not result in a more variable dynamical behavior, but on the contrary that the most variable behaviors are obtained in the regular graph setting. We further study how the dynamical complexity of the attractors is influenced by the statistical properties of the in-degree distribution.
Graph Applications To know the Seven Bridges of Knigsberg problem and
Liang, Y. Daniel
the shortest distance between two cities can be modeled using a graph, where the vertices represent cities
A Structure Theory of the Sandpile Monoid for Directed Graphs Laszlo Babai
Babai, LÃ¡szlÃ³
A Structure Theory of the Sandpile Monoid for Directed Graphs LÂ´aszlÂ´o Babai Evelin Toumpakari June
Sudan z Abstract We consider the problem of coloring kÂcolorable graphs with the fewest possible colors
Exercise 1: part 1 p Consider the simple web graph shown in slide 72
Ricci, Francesco
the file and brose the content of the class directory p Transform the input graphs tiny.txt and medium
Handling Context-Sensitivity in Protein Structures Using Graph Theory: Bona Fide Prediction
Samudrala, Ram
structure(s).5 METHODS General Description of the Graph-Theoretic Clique-Finding Approach Each possible
Independent set problems and odd-hole-preserving graph reductions
Warren, Jeffrey Scott
2009-05-15T23:59:59.000Z
. Independent Set Problems For a graph G = (V;E), S V is an independent set if no vertices in S are adjacent. The maximum independent set (MIS) problem is to find an independent set of largest cardinality in a given graph. The maximum weight independent set... for determining the optimality of a best known solution of the master problem. Many have worked to solve both the MIS and MWIS problems exactly. Tech- niques include explicit enumeration of maximal independent sets [4], combinato- rial branch-and-bound [5, 6, 7, 8...
Leaf-to-leaf distances in Catalan tree graphs
Andrew M. Goldsborough; Jonathan M. Fellows; Matthew Bates; S. Alex Rautu; George Rowlands; Rudolf A. Römer
2015-03-02T23:59:59.000Z
We study the average leaf-to-leaf path lengths on ordered Catalan tree graphs with $n$ nodes and show that these are equivalent to the average length of paths starting from the root node. We give an explicit analytic formula for the average leaf-to-leaf path length as a function of separation of the leaves and study its asymptotic properties. At the heart of our method is a strategy based on an abstract graph representation of generating functions which we hope can be useful also in other contexts.
Vacuum Energy and Repulsive Casimir Forces in Quantum Star Graphs
S. A. Fulling; L. Kaplan; J. H. Wilson
2007-03-27T23:59:59.000Z
Casimir pistons are models in which finite Casimir forces can be calculated without any suspect renormalizations. It has been suggested that such forces are always attractive, but we present several counterexamples, notably a simple type of quantum graph in which the sign of the force depends upon the number of edges. We also show that Casimir forces in quantum graphs can be reliably computed by summing over the classical orbits, and study the rate of convergence of the periodic orbit expansion. In generic situations where no analytic expression is available, the sign and approximate magnitude of Casimir forces can often be obtained using only the shortest classical orbits.
The smallest k-regular h-edge-connected graphs without , Douglas B. West
West, Douglas B.
-regular graph with no cut-edge has a 1-factor. This has many generalizations. Showing that every kThe smallest k-regular h-edge-connected graphs without 1-factors John Ganci , Douglas B. West March-regular (k - 1)-edge-connected graph of even order has a 1-factor is a standard elementary exercise (#3
Diameter of the NEPS of Bipartite Graphs Richard A. Brualdi and Jian Shen y
Brualdi, Richard A.
Diameter of the NEPS of Bipartite Graphs Richard A. Brualdi #3; and Jian Shen y Department 4, 2000 Abstract We prove that, if connected, the NEPS of connected, bipartite graphs has diameter-complete, extended p-sum, abbreviated NEPS, of G 1 ; G 2 ; : : : ; G n with basis B is the graph (see e.g. [1]) G
Directed acyclic graphs, su cient causes and the properties of conditioning on a
Directed acyclic graphs, su¢ cient causes and the properties of conditioning on a common e #12;Abstract Su¢ cient-component causes are incorporated into the directed acyclic graph (DAG) causal su¢ cient causes on a graph, it is possible to detect conditional independencies within strata
Loops in Reeb Graphs of 2-Manifolds Kree Cole-McLaughlin
Pascucci, Valerio
-resolution versions of the Reeb graph have lead to data-base search methods for topologically similar geo- metric and scientific data. Specifically, we study Reeb graphs, which express the connectivity of level sets. These graphs have been used in the past to con- struct data structures and user-interfaces for modeling
Message-passing for Inference and Optimization of Real Variables on Sparse Graphs
Wong, Michael K Y
Message-passing for Inference and Optimization of Real Variables on Sparse Graphs K. Y. Michael with extensive inter-dependencies among the variables, the graph-based models can be solved by passing messages between neighbouring variables on the graphs. This message-passing approach has gained recent success
Rapid Multipole Graph Drawing on the GPU Apeksha Godiyal*, Jared Hoberock*, Michael Garland
Garland, Michael
Rapid Multipole Graph Drawing on the GPU Apeksha Godiyal*, Jared Hoberock*, Michael Garland task of drawing large graphs. This paper describes a new parallel anal- ysis of the multipole method of graph drawing to support its efficient GPU implementation. We use a variation of the Fast Multipole
Light Edges in Degree-Constrained Graphs Prosenjit Bose Michiel Smid David R. Wood
Wismath, Stephen
Light Edges in Degree-Constrained Graphs #3; Prosenjit Bose Michiel Smid David R. Wood School of a graph with bounded degree end-points is said to be light. The primary result of this paper is that ev- ery degree-constrained graph has a light edge, where the degree bound depends on the minimum and aver
Universality for distances in power-law random graphs Remco van der Hofstad1,a
Hofstad, Remco van der
classical random graphs such as the ErdsRényi random graph. It is often suggested that the behavior with similar degree sequences share similar behavior. We survey the available results on graph distances of the occupation status of the other ed
Graph-theoretic design and analysis of key predistribution schemes Michelle Kendall Keith M. Martin
International Association for Cryptologic Research (IACR)
Graph-theoretic design and analysis of key predistribution schemes Michelle Kendall Keith M. Martin, a general understanding of the design prin- ciples on which to base such constructions is somewhat lacking as a sound design principle. Second, we propose the use of incidence graphs and concurrence graphs as tools
Effective Graph Classification Based on Topological and Label Attributes , Murat Semerci2
Zaki, Mohammed Javeed
online 12 June 2012 in Wiley Online Library (wileyonlinelibrary.com). Abstract: Graph classificationEffective Graph Classification Based on Topological and Label Attributes Geng Li1 , Murat Semerci2 propose an alternative approach to graph classification that is based on feature vectors constructed from
Intermediate statistics for a system with symplectic symmetry: the Dirac rose graph
statistics formed of a gas of energy levels interacting with a logarithmic potential. Spectral statisticsIntermediate statistics for a system with symplectic symmetry: the Dirac rose graph J.M. Harrison1 Abstract We study the spectral statistics of the Dirac operator on a rose-shaped graph-- a graph
Between automation and exploration: SAS graphing techniques for visualization of survey data
Yu, Alex
Between automation and exploration: SAS graphing techniques for visualization of survey data Chong of survey data. There is always a tension between automation and exploration. Automation is a common to automate the graphing processes via SAS/Macros and SAS/Graph. However, hidden patterns of the data may
On the edgeconnectivity of Cartesian product graphs # Sandi Klavzar
Klavzar, Sandi
edge cut of G#H, then either S is induced by a minimum edge cut of a factor, or S is a set of edges is given and the structure of minimum edge cuts is described. It is also proved that the connectivity product of graphs; edgeÂconnectivity; minimum edge cuts; AMS subject classification (2000): 05C40 1
A spectral graph based approach to analyze hyperspectral data
Bertozzi, Andrea L.
A spectral graph based approach to analyze hyperspectral data Blake Hunter Department of Mathematics, UCLA 520 Portola Plaza Los Angeles, CA 90095 Email: blakehunter@math.ucla.edu Yifei Lou Department of Mathematics, UCLA 520 Portola Plaza Los Angeles, CA 90095 Email: bertozzi
Brain Mapping Using Topology Graphs Obtained by Surface Segmentation
Linsen, Lars
Brain Mapping Using Topology Graphs Obtained by Surface Segmentation Fabien Vivodtzev1 , Lars@ucdavis.edu Summary. Brain mapping is a technique used to alleviate the tedious and time- consuming process of annotating brains by mapping existing annotations from brain atlases to individual brains. We introduce
Asymmetric Structure-Preserving Subgraph Queries for Large Graphs
Choi, Byron "Koon Kau"
Asymmetric Structure-Preserving Subgraph Queries for Large Graphs Zhe Fan1 Byron Choi1 Jianliang Xu the novel cyclic group based encryption so that query processing is transformed into a series of private are effective. I. INTRODUCTION Subgraph queries (via subgraph isomorphism) are a fun- damental and powerful
Terminological Logics and Conceptual Graphs: An Historical Perspective?
Schmidt, Renate A.
expressive ones, like KL of [6]. The history of these algebras can be traced back to the work of Boole, De be traced, as far back, as the nineteenth century, to the beginnings of algebraic logic and quantification on the existential graphs of Peirce. It is less well-known tha* *t, in essence, Peirce also developed the algebraic
Exploring Blog Graphs Patterns and a Model for Information
1 Exploring Blog Graphs Patterns and a Model for Information Propagation Mary Mc characterize individual blogs? #12;3 Why blogs? Blogs are a widely used medium of information for many topics and have become an important mode of communication. Blogs cite one another, creating a record of how
Tighter Bounds for Graph Steiner Tree Approximation Gabriel Robins
Zelikovsky, Alexander
of Computer Science, University of Virginia, Charlottesville, VA 22904 robins@cs.virginia.edu, www.cs.virginia of 1.28 within time O(mn2) (m and n are the numbers of terminals and non-terminals in the graph
(Co)Algebraic Characterizations of Signal Flow Graphs
Rutten, Jan
Signal flow graphs are a graphical representation for the analysis, modeling and evaluation of linear as a linear combination of the input and the registers. That is, the dynamics of a circuit can be expressed as a system of linear of equations, one for each register. Since we consider open circuits, the corresponding
THE GROUP OF SYMMETRIES OF THE TOWER OF HANOI GRAPH
Behrstock, Jason
THE GROUP OF SYMMETRIES OF THE TOWER OF HANOI GRAPH SO EUN PARK The classical Tower of Hanoi puzzle the tower of disks to another peg, moving one topmost disk at a time while never stacking a disk referred to as the Tower of Hanoi problem. Figure 1. Convention for labeling k pegs and n disks
Fast-Mixed Searching and Related Problems on Graphs
Bonato, Anthony
Fast-Mixed Searching and Related Problems on Graphs Boting Yang Department of Computer Science University of Regina May 27, 2012 1GRASCan 2012, Ryerson University #12;Outline Fast searching and mixed searching Induced-path cover Fast-mixed searching vs fast searching Fast-mixed searching vs mixed
A Numerical Optimization Approach to General Graph Drawing
Paul Heckbert Bruce Maggs Omar Ghattas, Civil and Environmental Engineering Mark Wegman, IBM T . J Maggs, and Mark Wegman. I am especially grateful that they allowed me to pursue a dissertation. I owe my interest in graph drawing to Mark Wegman, who introduced me to the area when I was an MIT
Synchronization Helps Robots to Detect Black Holes in Directed Graphs
Pinotti, Maria Cristina
nodes are the so called black hole nodes, and once a robot enters in one of them, it is destroyed supported by the Italian CNR Short-Term Mobility Program. #12;1 Introduction The subject of exploring that destroy any entering entity. Such nodes are called black holes, and the exploration of a graph
The TROPOS Analysis Process as Graph Transformation System Paolo Bresciani
Trento-Povo, Italy Abstract Tropos is an agent-oriented methodology that covers soft- ware developmentThe TROPOS Analysis Process as Graph Transformation System Paolo Bresciani ITC-irst via Sommarive of the operational environment of the new software system. In earlier work we have characterized the process of early
k-Connectivity in Random Key Graphs with Unreliable Links
Yagan, Osman
of Eschenauer and Gligor for securing wireless sensor network (WSN) communications. Random key graphs have real-world networks; e.g., with secure WSN application in mind, link unreliability can be attributed for securing WSN communications is the random predistribution of cryptographic keys to sensor nodes
Spectra of graphs and semi-conducting polymers
Philipp Schapotschnikow; Sven Gnutzmann
2008-02-04T23:59:59.000Z
We study the band gap in some semi-conducting polymers with two models: H\\"uckel molecular orbital theory and the so-called free electron model. The two models are directly related to spectral theory on combinatorial and metric graphs.
Secret sharing schemes on graphs L aszl o Csirmaz
Csirmaz, László
Secret sharing schemes on graphs L#19;aszl#19;o Csirmaz Mathematical Institute of the Hungarian secret sharing scheme based on G is a method to distribute a secret data among the vertices of G, the participants, so that a subset of participants can recover the secret if they contain an edge of G, otherwise
On Linear Secret Sharing for Connectivity in Directed Graphs
Beimel, Amos
On Linear Secret Sharing for Connectivity in Directed Graphs Amos Beimel 1 and Anat Paskin 2 1 Dept, Israel. Abstract. In this work we study linear secret sharing schemes for sÂt connectivity in directed.e., edges) can reconstruct the secret if it contains a path from node s to node t. We prove that in every
On Linear Secret Sharing for Connectivity in Directed Graphs
Beimel, Amos
On Linear Secret Sharing for Connectivity in Directed Graphs Amos Beimel1 and Anat Paskin2 1 Dept, Israel. Abstract. In this work we study linear secret sharing schemes for s-t connectivity in directed.e., edges) can reconstruct the secret if it contains a path from node s to node t. We prove that in every
Graph-based Navigation Strategies for Heterogeneous Spatial Data Sets
Rodríguez-Tastets, Maria Andrea
Graph-based Navigation Strategies for Heterogeneous Spatial Data Sets Andrea Rodr´iguez1 the information contribution of data sets based on correspondence relations outperform a strategy that considers- base representation, this work describes strategies that optimize the navigation of data sets
Selectivity Estimation for SPARQL Graph Pattern Faculty of ICT
Liu, Chengfei
, for an arbitrary composite SPARQL graph pattern, we maximally combines the results of the star and chain patterns with different properties sharing the same subject (an example is shown in Figure 1). For estimating' Income 'Prof.' Position 'Advance d course' (Adc) TeacherOf ?Z, Income, '
Table of Contents Part 1: Climate Graphs Activity
. Quantity. How much precipitation falls? What is the general trend east to west in Texas concerningTable of Contents Part 1: Climate Graphs Activity Part 2: Texas Climate Handout Maps for transparencies: a. Texas Average Annual Temperature b. Texas Average Annual Precipitation c. Texas Climate
Offensive Alliances in Graphs Odile Favaron, Universite Paris-Sud
Goddard, Wayne
Offensive Alliances in Graphs Odile Favaron, Universit´e Paris-Sud Gerd Fricke, Morehead State Duane Skaggs, Morehead State University Abstract A set S is an offensive alliance if for every vertex v. The offensive alliance number is the minimum cardi- nality of an offensive alliance. In this paper we explore
Computing global offensive alliances in Cartesian product graphs
Yero, Ismael G
2012-01-01T23:59:59.000Z
A global offensive alliance in a graph $G$ is a set $S$ of vertices with the property that every vertex not belonging to $S$ has at least one more neighbor in $S$ than it has outside of $S$. The global offensive alliance number of $G$, $\\gamma_o(G)$, is the minimum cardinality of a global offensive alliance in $G$. A set $S$ of vertices of a graph $G$ is a dominating set for $G$ if every vertex not belonging to $S$ has at least one neighbor in $S$. The domination number of $G$, $\\gamma(G)$, is the minimum cardinality of a dominating set of $G$. In this work we obtain closed formulas for the global offensive alliance number of several families of Cartesian product graphs, we also prove that $\\gamma_o(G\\square H)\\ge \\frac{\\gamma(G)\\gamma_o(H)}{2}$ for any graphs $G$ and $H$ and we show that if $G$ has an efficient dominating set, then $\\gamma_o(G\\square H)\\ge \\gamma(G)\\gamma_o(H).$ Moreover, we present a Vizing-like conjecture for the global offensive alliance number and we prove it for several families of grap...
Partitioning a graph into defensive k-alliances
Yero, Ismael G; Rodriguez-Velazquez, Juan A; Sigarreta, Jose M
2009-01-01T23:59:59.000Z
A defensive $k$-alliance in a graph is a set $S$ of vertices with the property that every vertex in $S$ has at least $k$ more neighbors in $S$ than it has outside of $S$. A defensive $k$-alliance $S$ is called global if it forms a dominating set. In this paper we study the problem of partitioning the vertex set of a graph into (global) defensive $k$-alliances. The (global) defensive $k$-alliance partition number of a graph $\\Gamma=(V,E)$, ($\\psi_{k}^{gd}(\\Gamma)$) $\\psi_k^{d}(\\Gamma)$, is defined to be the maximum number of sets in a partition of $V$ such that each set is a (global) defensive $k$-alliance. We obtain tight bounds on $\\psi_k^{d}(\\Gamma)$ and $\\psi_{k}^{gd}(\\Gamma)$ in terms of several parameters of the graph including the order, size, maximum and minimum degree, the algebraic connectivity and the isoperimetric number. Moreover, we study the close relationships that exist among partitions of $\\Gamma_1\\times \\Gamma_2$ into (global) defensive $(k_1+k_2)$-alliances and partitions of $\\Gamma_i$ into...
An Approach to Security Policy Configuration Using Semantic Threat Graphs
Foley, Simon
An Approach to Security Policy Configuration Using Semantic Threat Graphs Simon N. Foley, in turn, unnecessarily expose the enterprise to known threats. This paper pro- poses a threat management- nomic configuration of security mechanisms. This knowledge is mod- eled in terms of Semantic Threat
Insider Threat Detection using Stream Mining and Graph Mining
Hamlen, Kevin W.
Insider Threat Detection using Stream Mining and Graph Mining Pallabi Parveen, Jonathan Evans threats who attempt to conceal their activities by varying their behaviors over time. This paper applies of insider threat detection, demonstrating that the ensemble-based approach is significantly more effective
Decentralized Semantic Threat Graphs Simon N. Foley1
Foley, Simon
Decentralized Semantic Threat Graphs Simon N. Foley1 William M. Fitzgerald1 Cork Constraint.foley@cs.ucc.ie wfitzgerald@4c.ucc.ie Abstract. Threat knowledge-bases such as those maintained by MITRE and NIST provide a basis with which to mitigate known threats to an enterprise. These centralised knowledge-bases assume
Towards Efficient Query Processing on Massive Time-Evolving Graphs
Miller, John A.
Email: {ar, ara, laks, jam}@cs.uga.edu Abstract--Time evolving graph (TEG) is increasingly being used on massive TEGs is central to building powerful analytic applications for these domains. Unfortunately effective for processing massive TEGs. Towards designing scalable mechanisms for answering TEG queries
Distanceregular graphs having an eigenvalue of small multiplicity
Martin, Bill
, results of Godsil [12] and Terwilliger [19], to allow computer generation of all feasible intesection of Godsil and Terwilliger and on results in this paper, we now have the diameter bound d Å¸ 3m \\Gamma 8 for m of graph representaÂ tions is outlined, theorems of Godsil and Terwilliger are stated and several
Mining Large Graphs And Streams Using Matrix And Tensor Tools
Kolda, Tamara G.
RESULTS The graphs at right show overall variability distribution estimated for the Pentium D 800 where a core no longer works properly. In the Sun T1 Niagara cores this is done with a built-in- self processors we record the temperature at which the failure occurred and adjust to the frequencies
Math 304 Handout: Linear algebra, graphs, and networks.
Anshelevich, Michael
. Â· The World Wide Web is a directed graph, with web pages as vertices and links as edges. Â· Towns connected on the web, all the words that they contain. Again, an efficient way to do this is using a (very, very large) matrix. Each column corresponds to a web page, each row to a word, and each entry is 1 if a particular
A SPATIAL WEB GRAPH MODEL WITH LOCAL INFLUENCE REGIONS
Pralat, Pawel
mining technique, web pages are often represented as vectors in a word-document space. Using LatentA SPATIAL WEB GRAPH MODEL WITH LOCAL INFLUENCE REGIONS W. AIELLO, A. BONATO, C. COOPER, J. JANSSEN-degree distribution, with exponent in [2, ) depending on the parameters, and with concentration for a wide range of in
Lesson Summary Students graph and analyze raw data for
Mojzsis, Stephen J.
energy balance equation? What ultimate effect will this have on the energy balance of the Earth? 8 Setting The Earth The Mathematical World Symbolic Relationships Common Themes Constancy and Change NSES://www.strategies.org/index.aspx #12;Earth's Energy Budget or Can You Spare a Sun? Activity 8: Greenhouse Gases Objective: To graph
Level of Repair Analysis and Minimum Cost Homomorphisms of Graphs
Gutin, Gregory
of Lillian Barros Abstract. Level of Repair Analysis (LORA) is a prescribed procedure for defence logistics, LORA seeks to determine an optimal provision of repair and maintenance facilities to minimize overall on bipartite graphs is polynomial time solvable. Keywords: Computational Logistics; Level of Repair Analysis
Determining Vision Graphs for Distributed Camera Networks Using Feature Digests
Radke, Rich
1 Determining Vision Graphs for Distributed Camera Networks Using Feature Digests Zhaolin Cheng and the length of each feature descriptor are substantially reduced to form a fixed-length "feature digest" that is broadcast to the rest of the network. Each receiver camera decompresses the feature digest to recover
Constructing and sampling graphs with a given joint degree distribution.
Pinar, Ali; Stanton, Isabelle (UC Berkeley)
2010-09-01T23:59:59.000Z
One of the most influential recent results in network analysis is that many natural networks exhibit a power-law or log-normal degree distribution. This has inspired numerous generative models that match this property. However, more recent work has shown that while these generative models do have the right degree distribution, they are not good models for real life networks due to their differences on other important metrics like conductance. We believe this is, in part, because many of these real-world networks have very different joint degree distributions, i.e. the probability that a randomly selected edge will be between nodes of degree k and l. Assortativity is a sufficient statistic of the joint degree distribution, and it has been previously noted that social networks tend to be assortative, while biological and technological networks tend to be disassortative. We suggest understanding the relationship between network structure and the joint degree distribution of graphs is an interesting avenue of further research. An important tool for such studies are algorithms that can generate random instances of graphs with the same joint degree distribution. This is the main topic of this paper and we study the problem from both a theoretical and practical perspective. We provide an algorithm for constructing simple graphs from a given joint degree distribution, and a Monte Carlo Markov Chain method for sampling them. We also show that the state space of simple graphs with a fixed degree distribution is connected via end point switches. We empirically evaluate the mixing time of this Markov Chain by using experiments based on the autocorrelation of each edge. These experiments show that our Markov Chain mixes quickly on real graphs, allowing for utilization of our techniques in practice.
A Simple Method for Finding the Scattering Coefficients of Quantum Graphs
Seth S. Cottrell
2015-03-01T23:59:59.000Z
Quantum walks are roughly analogous to classical random walks, and like classical walks they have been used to find new (quantum) algorithms. When studying the behavior of large graphs or combinations of graphs it is useful to find the response of a subgraph to signals of different frequencies. In so doing we can replace an entire subgraph with a single vertex with frequency dependent scattering coefficients. In this paper a simple technique for quickly finding the scattering coefficients of any quantum graph will be presented. These scattering coefficients can be expressed entirely in terms of the characteristic polynomial of the graph's time step operator. Moreover, with these in hand we can easily derive the "impulse response" which is the key to predicting the response of a graph to any signal. This gives us a powerful set of tools for rapidly understanding the behavior of graphs or for reducing a large graph into its constituent subgraphs regardless of how they are connected.
A Mathematical Analysis of the R-MAT Random Graph Generator
Groer, Christopher S [ORNL; Sullivan, Blair D [ORNL; Poole, Stephen W [ORNL
2011-01-01T23:59:59.000Z
The R-MAT graph generator introduced by Chakrabarti, Faloutsos, and Zhan offers a simple, fast method for generating very large directed graphs. These properties have made it a popular choice as a method of generating graphs for objects of study in a variety of disciplines, from social network analysis to high performance computing. We analyze the graphs generated by R-MAT and model the generator in terms of occupancy problems in order to prove results about the degree distributions of these graphs. We prove that the limiting degree distributions can be expressed as a mixture of normal distributions, contradicting the widely held belief that R-MAT degree distributions exhibit the power law or scale free distribution observed in many real world graphs. Additionally, this paper offers an efficient computational technique for computing the exact degree distribution, as well as concise expressions for a number of properties of R-MAT graphs.
LDRD final report : first application of geospatial semantic graphs to SAR image data.
Brost, Randolph C.; McLendon, William Clarence,
2013-01-01T23:59:59.000Z
Modeling geospatial information with semantic graphs enables search for sites of interest based on relationships between features, without requiring strong a priori models of feature shape or other intrinsic properties. Geospatial semantic graphs can be constructed from raw sensor data with suitable preprocessing to obtain a discretized representation. This report describes initial work toward extending geospatial semantic graphs to include temporal information, and initial results applying semantic graph techniques to SAR image data. We describe an efficient graph structure that includes geospatial and temporal information, which is designed to support simultaneous spatial and temporal search queries. We also report a preliminary implementation of feature recognition, semantic graph modeling, and graph search based on input SAR data. The report concludes with lessons learned and suggestions for future improvements.
Qubits from Adinkra Graph Theory via Colored Toric Geometry
Aadel, Y; Benslimane, Z; Sedra, M B; Segui, A
2015-01-01T23:59:59.000Z
We develop a new approach to deal with qubit information systems using toric geometry and its relation to Adinkra graph theory. More precisely, we link three different subjects namely toric geometry, Adinkras and quantum information theory. This one to one correspondence may be explored to attack qubit system problems using geometry considered as a powerful tool to understand modern physics including string theory. Concretely, we examine in some details the cases of one, two, and three qubits, and we find that they are associated with \\bf CP^1, \\bf CP^1\\times CP^1 and \\bf CP^1\\times CP^1\\times CP^1 toric varieties respectively. Using a geometric procedure referred to as colored toric geometry, we show that the qubit physics can be converted into a scenario handling toric data of such manifolds by help of Adinkra graph theory. Operations on toric information can produce universal quantum gates.
Average Interpolating Wavelets on Point Clouds and Graphs
Rustamov, Raif M
2011-01-01T23:59:59.000Z
We introduce a new wavelet transform suitable for analyzing functions on point clouds and graphs. Our construction is based on a generalization of the average interpolating refinement scheme of Donoho. The most important ingredient of the original scheme that needs to be altered is the choice of the interpolant. Here, we define the interpolant as the minimizer of a smoothness functional, namely a generalization of the Laplacian energy, subject to the averaging constraints. In the continuous setting, we derive a formula for the optimal solution in terms of the poly-harmonic Green's function. The form of this solution is used to motivate our construction in the setting of graphs and point clouds. We highlight the empirical convergence of our refinement scheme and the potential applications of the resulting wavelet transform through experiments on a number of data stets.
A Graph Analytic Metric for Mitigating Advanced Persistent Threat
Johnson, John R.; Hogan, Emilie A.
2013-06-04T23:59:59.000Z
This paper introduces a novel graph analytic metric that can be used to measure the potential vulnerability of a cyber network to specific types of attacks that use lateral movement and privilege escalation such as the well known Pass The Hash, (PTH). The metric is computed from an oriented subgraph of the underlying cyber network induced by selecting only those edges for which a given property holds between the two vertices of the edge. The metric with respect to a select node on the subgraph is defined as the likelihood that the select node is reachable from another arbitrary node in the graph. This metric can be calculated dynamically from the authorization and auditing layers during the network security authorization phase and will potentially enable predictive deterrence against attacks such as PTH.
A characterization of Q-polynomial distance-regular graphs
Jurisic, Aleksandar; Zitnik, Arjana
2009-01-01T23:59:59.000Z
We obtain the following characterization of $Q$-polynomial distance-regular graphs. Let $\\G$ denote a distance-regular graph with diameter $d\\ge 3$. Let $E$ denote a minimal idempotent of $\\G$ which is not the trivial idempotent $E_0$. Let $\\{\\theta_i^*\\}_{i=0}^d$ denote the dual eigenvalue sequence for $E$. We show that $E$ is $Q$-polynomial if and only if (i) the entry-wise product $E \\circ E$ is a linear combination of $E_0$, $E$, and at most one other minimal idempotent of $\\G$; (ii) there exists a complex scalar $\\beta$ such that $\\theta^*_{i-1}-\\beta \\theta^*_i + \\theta^*_{i+1}$ is independent of $i$ for $1 \\le i \\le d-1$; (iii) $\\theta^*_i \
Deciding Graph MSO Properties: Has it all been told already?
Gajarský, Jakub
2012-01-01T23:59:59.000Z
A famous result of Courcelle claims that on graphs of bounded tree-width extensions for the MSO1 case are presented also in [Ganian, IPEC2011]. We take a general approach, proving that the MSO model-checking problem admits an FPT algorithm with an elementary dependence on the formula on all classes of trees of bounded height. This result, via standard logic interpretation, implies that all MSO2 properties \\phi are decidable in FPT with an elemen...
Support graph preconditioning for elliptic finite element problems
Wang, Meiqiu
2009-05-15T23:59:59.000Z
OF PHILOSOPHY Approved by: Chair of Committee, Vivek Sarin Committee Members, Ricardo Gutierrez-Osuna Jianer Chen Raytcho Lazarov Head of Department, Valerie E. Taylor December 2008 Major Subject: Computer Science iii ABSTRACT Support Graph Preconditioning... insightful guidance this work wouldn?t be finished. He also has been supporting me financially during all these years, thus that I can concentrate on my work without worries. I also would like to thank my committee members: Dr. Gutierrez-Osuna, Dr. Chen...
Connection probability for random graphs with given degree sequence
Xinping Xu
2007-08-20T23:59:59.000Z
Recently, the classical configuration model for random graphs with given degree distribution has been extensively used as a null model in contraposition to real networks with the same degree distribution. In this paper, we briefly review the applications of this model and derive analytical expression for connection probability by the expanding coefficient method. We also use our expanding coefficient method to obtain the connection probability for the directed configuration model.
Principal Patterns on Graphs: Discovering Coherent Structures in Datasets
Benzi, Kirell; Vandergheynst, Pierre
2015-01-01T23:59:59.000Z
In this work, we propose a fast, robust and scalable method for retrieving and analyzing recurring patterns of activity induced by a causal process, typically modeled as time series on a graph. We introduce a particular type of multilayer graph as a model for the data. This graph is structured for emphasizing causal relations between connected nodes and their successive time series values. Within the data, the patterns of activity are assumed to be dynamic, sparse or small compared to the size of the network. For some applications they are also expected to appear in a repeated manner over time but are allowed to differ from an exact copy. The analysis of the activity within a social network and within a transportation network illustrates the power and efficiency of the method. Relevant information can be extracted, giving insights on the behavior of group of persons in social networks and on traffic congestion patterns. Moreover, in this era of big data, it is crucial to design tools able to handle large data...
Strong Integer Additive Set-valued Graphs: A Creative Review
N. K. Sudev; K. A. Germina; K. P. Chithra
2015-04-23T23:59:59.000Z
For a non-empty ground set $X$, finite or infinite, the {\\em set-valuation} or {\\em set-labeling} of a given graph $G$ is an injective function $f:V(G) \\to \\mathcal{P}(X)$, where $\\mathcal{P}(X)$ is the power set of the set $X$. A set-indexer of a graph $G$ is an injective set-valued function $f:V(G) \\to \\mathcal{P}(X)$ such that the function $f^{\\ast}:E(G)\\to \\mathcal{P}(X)-\\{\\emptyset\\}$ defined by $f^{\\ast}(uv) = f(u){\\ast} f(v)$ for every $uv{\\in} E(G)$ is also injective., where $\\ast$ is a binary operation on sets. An integer additive set-indexer is defined as an injective function $f:V(G)\\to \\mathcal{P}({\\mathbb{N}_0})$ such that the induced function $g_f:E(G) \\to \\mathcal{P}(\\mathbb{N}_0)$ defined by $g_f (uv) = f(u)+ f(v)$ is also injective, where $\\mathbb{N}_0$ is the set of all non-negative integers and $\\mathcal{P}(\\mathbb{N}_0)$ is its power set. An IASI $f$ is said to be a strong IASI if $|f^+(uv)|=|f(u)|\\,|f(v)|$ for every pair of adjacent vertices $u,v$ in $G$. In this paper, we critically and creatively review the concepts and properties of strong integer additive set-valued graphs.
Long cycles in critical graphs Noga Alon Michael Krivelevich y Paul Seymour z
Krivelevich, Michael
) Therefore, any k-critical graph on n vertices contains a path of length at least log(n 1)= log(k 2 that there are in#12;nitely many values of n for which there is a k-critical graph on n vertices with no pathLong cycles in critical graphs Noga Alon #3; Michael Krivelevich y Paul Seymour z Abstract
LIGHT SUBGRAPHS IN PLANAR GRAPHS OF MINIMUM DEGREE 4 AND EDGE-DEGREE 9
Mohar, Bojan
LIGHT SUBGRAPHS IN PLANAR GRAPHS OF MINIMUM DEGREE 4 AND EDGE-DEGREE 9 B. MOHAR , R. SKREKOVSKI vertices of degree 4 are adjacent. A graph H is light in G if there is a constant w such that every graph is w. Then we also write w(H) w. It is proved that the cycle Cs is light if and only if 3 s 6, where
A sharp lower bound for the Wiener index of a graph
Balakrishnan, R; Iyer, K V
2010-01-01T23:59:59.000Z
Given a simple connected undirected graph G, the Wiener index W(G) of G is defined as half the sum of the distances over all pairs of vertices of G. In practice, G corresponds to what is known as the molecular graph of an organic compound. We obtain a sharp lower bound for W(G) of an arbitrary graph in terms of the order, size and diameter of G.
Ding, Chris; He, Xiaofeng; Xiong, Hui; Peng, Hanchuan; Holbrook, Stephen R.
2006-01-01T23:59:59.000Z
Closure and Metric Inequality of Weighted Graphs – Detectingleads to a transitivity inequality which is equivalentto ultra-metric inequality. This can be used to de?ne
Integrative Protein Function Transfer using Factor Graphs and Heterogeneous Data Sources
Mishra, Bud
Integrative Protein Function Transfer using Factor Graphs and Heterogeneous Data Sources Antonina, translation initiation, enzymatic catalysis, and immune re- sponse. However, for a large portion of proteins
Graphs whose normalized Laplacian matrices are separable as density matrices in quantum mechanics
Chai Wah Wu
2014-07-23T23:59:59.000Z
Recently normalized Laplacian matrices of graphs are studied as density matrices in quantum mechanics. Separability and entanglement of density matrices are important properties as they determine the nonclassical behavior in quantum systems. In this note we look at the graphs whose normalized Laplacian matrices are separable or entangled. In particular, we show that the number of such graphs is related to the number of 0-1 matrices that are line sum symmetric and to the number of graphs with at least one vertex of degree 1.
Choosability of the square of planar subcubic graphs with large girth
Bermond, Jean-Claude
is at most 5. 1 Introduction Let G be a (simple) graph. The neighbourhood of a vertex v of G, denoted NG(v
THE GEOMETRY OF BRAUER GRAPH ALGEBRAS AND CLUSTER ROBERT J. MARSH AND SIBYLLE SCHROLL
Marsh, Robert J.
author. 1 #12;2 MARSH AND SCHROLL sense. We may also consider the dual graph of the m-angulation, which
Global Binary Optimization on Graphs for Classification of High-Dimensional Data
Merkurjev, E; Bae, E; Bertozzi, AL; Tai, XC
2015-01-01T23:59:59.000Z
J.H. : Convergence and energy landscape for Cheeger cutmax-flow algorithms for energy minimization in vision. IEEER. : Fast approxi- mate energy minimization via graph cuts.
Materials for Math 13900 Bring to class each day: graph paper ...
Roames, Renee S
2015-01-08T23:59:59.000Z
Materials for Math 13900. Bring to class each day: graph paper isometric dot paper unlined paper cm ruler. We will also be using: compass small scissors.
Bhattacharyya, Shuvra S.
framework for construction and manipulation of dataflow graphs for DSP system design. To facilitate design of complex systems, our framework includes a powerful integration of C-based procedural programming topologies increases, textual manipulation of graph specifications becomes increasingly important
Random Procedures for Dominating Sets in Graphs Sarah Artmann1
of a vertex u V in the graph G is the set NG(u) = {v V | uv E} and the closed neighbourhood of u in G is NG[u] = NG(u){u}. The degree of u in G is the number dG(u) = |NG(u)| of its neighbours. For a set U V let NG[U] = uU NG[U] and NG(U) = NG[U] \\ U. A set of vertices D V of G is dominating, if every vertex in V \\ D
Groups generated by bounded automata and their schreier graphs
Bondarenko, Ievgen
2009-05-15T23:59:59.000Z
by Bounded Automata and Their Schreier Graphs. (December 2007) Ievgen Bondarenko, B.S., National Taras Shevchenko University of Kyiv, Ukraine; M.S., National Taras Shevchenko University of Kyiv, Ukraine Chair of Advisory Committee: Dr. Rostislav Grigorchuk... maps In Chapter III we study spectral properties and iterations of piecewise linear maps of the form fK(v) = min A?K Av, v?RN, (1.1) where K is a finite set of nonnegative square matrices of fixed dimension and by ?min? we mean component-wise minimum...
Groups generated by bounded automata and their schreier graphs
Bondarenko, Ievgen
2008-10-10T23:59:59.000Z
by Bounded Automata and Their Schreier Graphs. (December 2007) Ievgen Bondarenko, B.S., National Taras Shevchenko University of Kyiv, Ukraine; M.S., National Taras Shevchenko University of Kyiv, Ukraine Chair of Advisory Committee: Dr. Rostislav Grigorchuk... maps In Chapter III we study spectral properties and iterations of piecewise linear maps of the form fK(v) = min A?K Av, v?RN, (1.1) where K is a finite set of nonnegative square matrices of fixed dimension and by “min” we mean component-wise minimum...
Vacuum energy and repulsive Casimir forces in quantum star graphs
Fulling, Stephen; Kaplan, L.; Wilson, J. H.
2007-01-01T23:59:59.000Z
Vacuum energy and repulsive Casimir forces in quantum star graphs S. A. Fulling,1,* L. Kaplan,2,? and J. H. Wilson1,? 1Departments of Mathematics and Physics, Texas A&M University, College Station, Texas 77843-3368, USA 2Department of Physics... vacuum en- ergy in the region outside the box, and it involves ?renormal- ization? in the sense of discarding divergent terms associated with the boundary although #1;unlike the case of parallel plates, or any calculation of forces between rigid...
Covering Cuts in Bridgeless Cubic Graphs Sylvia BOYD, Satoru IWATA, Kenjiro TAKAZAWA
are interested in algorithms for finding 2-factors that cover certain prescribed edge-cuts in bridgeless cubic graphs. We present an algorithm for finding a minimum-weight 2-factor covering all the 3-edge cuts for finding a 2-factor covering all the 3- and 4-edge cuts in bridgeless cubic graphs. Both
Graph Mining for Object Tracking in Videos Fabien Diot1,2
Graph Mining for Object Tracking in Videos Fabien Diot1,2 , Elisa Fromont1 , Baptiste Jeudy1 of graph mining for tracking objects in videos with moving cameras and without any contextual information on the objects to track. To make the mining algorithm efficient, we benefit from a video representation based
Combining Bond-Graphs with Genetic Programming for Unified/Automated Design of Mechatronic or
Fernandez, Thomas
Combining Bond-Graphs with Genetic Programming for Unified/Automated Design of Mechatronic or Multi of a mechatronic system makes it difficult to model using a single modeling technique over the whole system and polymorphic modeling and simulation technique. Bond-Graph model of the mechatronic system can be directly
System-Level Synthesis of MEMS via Genetic Programming and Bond Graphs
Hu, Jianjun
System-Level Synthesis of MEMS via Genetic Programming and Bond Graphs Zhun Fan+ , Kisung Seo for automatic synthesis of MEMS system-level lumped parameter models using genetic programming and bond graphs. This paper first dis- cusses the necessity of narrowing the problem of MEMS synthesis into a certain specific
A solid solution to a conjecture on the maximal energy of bipartite bicyclic graphs
Huo, Bofeng; Li, Xueliang; Shi, Yongtang
2011-01-01T23:59:59.000Z
The energy of a simple graph $G$, denoted by $E(G)$, is defined as the sum of the absolute values of all eigenvalues of its adjacency matrix. Let $C_n$ denote the cycle of order $n$ and $P^{6,6}_n$ the graph obtained from joining two cycles $C_6$ by a path $P_{n-12}$ with its two leaves. Let $\\mathscr{B}_n$ denote the class of all bipartite bicyclic graphs but not the graph $R_{a,b}$, which is obtained from joining two cycles $C_a$ and $C_b$ ($a, b\\geq 10$ and $a \\equiv b\\equiv 2\\, (\\,\\textmd{mod}\\, 4)$) by an edge. In [I. Gutman, D. Vidovi\\'{c}, Quest for molecular graphs with maximal energy: a computer experiment, {\\it J. Chem. Inf. Sci.} {\\bf41}(2001), 1002--1005], Gutman and Vidovi\\'{c} conjectured that the bicyclic graph with maximal energy is $P^{6,6}_n$, for $n=14$ and $n\\geq 16$. In [X. Li, J. Zhang, On bicyclic graphs with maximal energy, {\\it Linear Algebra Appl.} {\\bf427}(2007), 87--98], Li and Zhang showed that the conjecture is true for graphs in the class $\\mathscr{B}_n$. However, they could not...
The domination number of on-line social networks and random geometric graphs
Pralat, Pawel
of graphs in the Facebook 100 data set, and these bounds are well-correlated with those predicted geometric graphs. 1. Introduction On-line social networks (or OSNs) such as Facebook have emerged as a hot-demographics are closer together in the space. We give the precise definition of the GEO-P model (actually, one of its
Karahalios, Karrie G.
People Search within an Online Social Network: Large Scale Analysis of Facebook Graph Search Query and Facebook2 , Menlo Park, CA 94025 {spirin2,kkarahal}@illinois.edu and {jfh,miked,maxime}@fb.com ABSTRACT Facebook in- troduced its innovative Graph Search product with the goal to take the OSN search experience
Enterprise Social Network Analysis and Modeling: A Tale of Two Graphs
Li, Li Erran
Enterprise Social Network Analysis and Modeling: A Tale of Two Graphs Jin Cao1, Hongyu Gao2, Li to understand how people are using these social networks. Unlike the public social networks like Facebook social networks are also governed by an organization graph. Based on a six month dataset collected from
JACOBIANS OF NEARLY COMPLETE AND THRESHOLD GRAPHS SERGUEI NORINE AND PETER WHALEN
Norin, Sergey
to it as the sandpile group [7]. Seven years later, Bacher et al referred to it alternatively as the Picard group. The Jacobian of a graph, also known as the Picard Group, Sandpile Group, or Critical Group, is a discrete is odd, where k is such that the order of the group is the number of spanning trees of the graph
Termination Graphs for Java Bytecode M. Brockschmidt, C. Otto, C. von Essen, and J. Giesl
ÃbrahÃ¡m, Erika
Termination Graphs for Java Bytecode M. Brockschmidt, C. Otto, C. von Essen, and J. Giesl LuFG Informatik 2, RWTH Aachen University, Germany Abstract. To prove termination of Java Bytecode (JBC) automatically, we transform JBC to finite termination graphs which represent all pos- sible runs of the program
Fundamenta Informaticae 33(2), 1998, 201{209 1 Termination of graph rewriting is undecidable
Plump, Detlef
Fundamenta Informaticae 33(2), 1998, 201{209 1 IOS Press Termination of graph rewriting pushout approach") is terminating. The proof is by a reduction of the Post Correspondence Problem or of the termination problem for string rewriting systems to the present problem. Keywords: graph rewriting
Privacy-Preserving Query over Encrypted Graph-Structured Data in Cloud Computing
Hou, Y. Thomas
Privacy-Preserving Query over Encrypted Graph-Structured Data in Cloud Computing Ning Cao, Zhenyu, Chicago, IL 60616 Email: {cong, kren}@ece.iit.edu Abstract-- In the emerging cloud computing paradigm of privacy-preserving query over encrypted graph-structured data in cloud computing (PPGQ), and establish
Perfect Completion and Deletion in Random Graphs Assaf Natanzon \\Lambda Ron Shamir \\Lambda y
Shamir, Ron
Perfect Completion and Deletion in Random Graphs Assaf Natanzon \\Lambda Ron Shamir \\Lambda y Abstract In the Perfect Completion problem one wishes to add the fewest possible edges to a graph in order Introduction Edge Completion/Deletion problems call for making minimum changes to the edge set of an input
A Rule-Based Quasi-Static Scheduling Approach for Static Islands in Dynamic Dataflow Graphs
Teich, JÃ¼rgen
A A Rule-Based Quasi-Static Scheduling Approach for Static Islands in Dynamic Dataflow Graphs-Nuremberg In this article, an efficient rule-based clustering algorithm for static dataflow subgraphs in a dynamic dataflow graph is presented. The clustered static dataflow actors are quasi-statically scheduled, in such a way
An Updated Taxonomy of Evolutionary Computation Problems using Graph-based
Ashlock, Dan
An Updated Taxonomy of Evolutionary Computation Problems using Graph-based Evolutionary Algorithms some other groups of problems scatter across the taxonomy. This paper updates an earlier taxonomy of 23, for the self-avoiding-walk problems corrects, a taxonomy of 23 problems given in [8]. The list of graphs
Solving planning-graph by compiling it into CSP Minh Binh Do & Subbarao Kambhampati
Kambhampati, Subbarao
Solving planning-graph by compiling it into CSP Minh Binh Do & Subbarao Kambhampati Department to adapt CSP search techniques into the backward search phase of Graphplan. This paper describes GP-CSP, a system that does planning by automati- cally converting Graphplan's planning graph into a CSP encoding
Massive Scale Cyber Traffic Analysis: A Driver for Graph Database Research
Joslyn, Cliff A.; Choudhury, S.; Haglin, David J.; Howe, Bill; Nickless, William K.; Olsen, Bryan K.
2013-06-19T23:59:59.000Z
We describe the significance and prominence of network traffic analysis (TA) as a graph- and network-theoretical domain for advancing research in graph database systems. TA involves observing and analyzing the connections between clients, servers, hosts, and actors within IP networks, both at particular times and as extended over times. Towards that end, NetFlow (or more generically, IPFLOW) data are available from routers and servers which summarize coherent groups of IP packets flowing through the network. IPFLOW databases are routinely interrogated statistically and visualized for suspicious patterns. But the ability to cast IPFLOW data as a massive graph and query it interactively, in order to e.g.\\ identify connectivity patterns, is less well advanced, due to a number of factors including scaling, and their hybrid nature combining graph connectivity and quantitative attributes. In this paper, we outline requirements and opportunities for graph-structured IPFLOW analytics based on our experience with real IPFLOW databases. Specifically, we describe real use cases from the security domain, cast them as graph patterns, show how to express them in two graph-oriented query languages SPARQL and Datalog, and use these examples to motivate a new class of "hybrid" graph-relational systems.
Sand Drawings and Gaussian Graphs Erik D. Demaine Martin L. Demaine
Demaine, Erik
Sand Drawings and Gaussian Graphs Erik D. Demaine Martin L. Demaine Computer Science and AI@cs.mcgill.ca Abstract Sand drawings form a part of many cultural artistic traditions. Depending on the part of the world uncover a bridge between sand drawings and Gaussian graphs, leading to a variety of new mathematical
The power graph of a finite group, II Peter J. Cameron
Cameron, Peter
The power graph of a finite group, II Peter J. Cameron School of Mathematical Sciences Queen Mary, University of London Mile End Road London E1 4NS, U.K. Abstract The directed power graph of a group G is the digraph with vertex set G, having an arc from y to x whenever x is a power of y; the undirected power
Figure 1. Schematic of initial air pump design Design of Air Pump System Using Bond Graph
Fernandez, Thomas
Figure 1. Schematic of initial air pump design Design of Air Pump System Using Bond Graph for an air pump system using bond graphs and genetic programming to maximize outflow subject to a constraint components and can introduce additional components. The air pump system is a mixed-domain system
Contraction decomposition in h-minor-free graphs and algorithmic applications
Demaine, Erik D.
We prove that any graph excluding a fixed minor can have its edges partitioned into a desired number k of color classes such that contracting the edges in any one color class results in a graph of treewidth linear in k. ...
Construction of abstract state graphs with PVS Susanne Graf and Hassen Saidi
Grosu, Radu
Construction of abstract state graphs with PVS Susanne Graf and Hassen Saidi VERIMAG Centre at the address http:://www.imag.fr/VERIMAG/PEOPLE/Hassen.Saidi/BRP 2 #12; Construction of abstract state graphs of infinite systems with PVS Susanne Graf and Hassen Saidi VERIMAG 1 Abstract In this paper, we propose
Fault-Tolerant Exploration of an Unknown Dangerous Graph by Scattered Agents
Flocchini, Paola
Fault-Tolerant Exploration of an Unknown Dangerous Graph by Scattered Agents Paola Flocchini1 a network where there are dangerous sites (black holes) that eliminate any incoming searcher without leaving a discernible trace. Dangerous graph exploration (Dge) extends the Bhs problem to include dangerous links (black
Management of Security Policy Configuration using a Semantic Threat Graph Approach
Foley, Simon
Management of Security Policy Configuration using a Semantic Threat Graph Approach Simon N. Foley, in turn, unnec- essarily expose the enterprise to known threats. This paper proposes a threat management Threat Graphs, a variation of the tradi- tional Threat/Attack Tree, extended in order to relate semantic
NEW DATA MODEL FOR GRAPH-CUT SEGMENTATION: APPLICATION TO AUTOMATIC MELANOMA DELINEATION
Lezoray, Olivier
NEW DATA MODEL FOR GRAPH-CUT SEGMENTATION: APPLICATION TO AUTOMATIC MELANOMA DELINEATION R. K but also texture and shape information. For melanoma images, we also introduce skin chromophore features- tion to melanoma delineation compares favorably to manual delineation and related graph
Timed Event Graphs with variable resources: asymptotic behavior, representation in (min,+)
Paris-Sud XI, Université de
-1032" #12;1. Introduction Timed Event Graphs (TEG's), which constitute a subclass of timed Petri nets precisely, we define a class of timed Petri nets, called TEG's with variable resources, which can be likened to linear time-varying systems over ´Ñ Ò ·µ algebra - a particular dioid. These graphs (TEG's on which
Paris-Sud XI, Université de
.hardouin, bertrand.cottenceau]@istia.univ-angers.fr Abstract This paper deals with control of Timed Event Graphs (TEG). In a first part the disturbance decoupling problem for TEG is defined. In a second part we propose is introduced for a particular class of Discrete Event Dynamic Systems (DEDS) called Timed Event Graphs (TEG
The freezing threshold for k-colourings of a random graph Michael Molloy
Molloy, Mike
The freezing threshold for k-colourings of a random graph Michael Molloy March 9, 2012 Abstract We rigorously determine the exact freezing threshold, rf k , for k-colourings of a random graph. We prove using the non-rigorous cavity method. It has been hypothesized that the freezing threshold is the cause
THE RADIO NUMBERS OF ALL GRAPHS OF ORDER n AND DIAMETER n -2
Tomova, Maggy
THE RADIO NUMBERS OF ALL GRAPHS OF ORDER n AND DIAMETER n - 2 KATHERINE BENSON, MATTHEW PORTER, AND MAGGY TOMOVA Abstract. A radio labeling of a connected graph G is a function c : V (G) Z+ such that for every two distinct vertices u and v of G distance(u, v) + |c(u) - c(v)| 1 + diameter(G). The radio
Discrete Applied Mathematics 95 (1999) 241249 Note on a helicopter search problem on graphs
Fomin, Fedor V.
1999-01-01T23:59:59.000Z
Discrete Applied Mathematics 95 (1999) 241249 Note on a helicopter search problem on graphs Fedor 1998 Abstract We consider a search game on a graph in which one cop in a helicopter ying from vertex . In the ÿrst step, Cop occupies some vertex of G. In each of the following steps, Cop moves ( ies by helicopter
Scheduling tree-shaped task graphs to minimize memory and makespan
Paris-Sud XI, Université de
Scheduling tree-shaped task graphs to minimize memory and makespan Loris Marchal CNRS experimental evaluation using realistic trees. Keywords-scheduling; makespan-memory tradeoff; tree- shaped task.vivien@inria.fr Abstract--This paper investigates the execution of tree- shaped task graphs using multiple processors. Each
Cross-Domain Fault Localization: A Case for a Graph Digest Approach
Cross-Domain Fault Localization: A Case for a Graph Digest Approach William D. Fischer Naval an inference-graph-digest based formulation of the problem. The formulation not only explicitly models propagation can use a function to create a digest representation of their network state and dependencies
for based on Open Inventor scene graph stroke based methods ·non-photorealistic rendering (NPR) architecture· end user: looks at created renditions or · designer interaction uses applications Open Inventor
Sze, Sing-Hoi; Tarone, Aaron M
2014-07-14T23:59:59.000Z
The recent advance of high-throughput sequencing makes it feasible to study entire transcriptomes through the application of de novo sequence assembly algorithms. While a popular strategy is to first construct an intermediate de Bruijn graph...
Williams, Susan
Vertex-Colored Graphs, Bicycle Spaces and Mahler Measure Kalyn R. Lamey Daniel S. Silver Susan G to the bicycle space of the graph. For graphs G with a free Zd -action by automorphisms, C is a finitely identify the subspace C0 of based conservative vertex colorings with the bicycle space B of G. In section 3
Silver, Dan
Vertex-Colored Graphs, Bicycle Spaces and Mahler Measure Kalyn R. Lamey Daniel S. Silver Susan G to be isomorphic to the bicycle space of the graph. For graphs G with a free Zd -action by automorphisms, C C0 of based conservative vertex colorings with the bicycle space B of G. In section 3 we define
A framework for graph-based synthesis, analysis, and visualization of HPC cluster job data.
Mayo, Jackson R.; Kegelmeyer, W. Philip, Jr.; Wong, Matthew H.; Pebay, Philippe Pierre; Gentile, Ann C.; Thompson, David C.; Roe, Diana C.; De Sapio, Vincent; Brandt, James M.
2010-08-01T23:59:59.000Z
The monitoring and system analysis of high performance computing (HPC) clusters is of increasing importance to the HPC community. Analysis of HPC job data can be used to characterize system usage and diagnose and examine failure modes and their effects. This analysis is not straightforward, however, due to the complex relationships that exist between jobs. These relationships are based on a number of factors, including shared compute nodes between jobs, proximity of jobs in time, etc. Graph-based techniques represent an approach that is particularly well suited to this problem, and provide an effective technique for discovering important relationships in job queuing and execution data. The efficacy of these techniques is rooted in the use of a semantic graph as a knowledge representation tool. In a semantic graph job data, represented in a combination of numerical and textual forms, can be flexibly processed into edges, with corresponding weights, expressing relationships between jobs, nodes, users, and other relevant entities. This graph-based representation permits formal manipulation by a number of analysis algorithms. This report presents a methodology and software implementation that leverages semantic graph-based techniques for the system-level monitoring and analysis of HPC clusters based on job queuing and execution data. Ontology development and graph synthesis is discussed with respect to the domain of HPC job data. The framework developed automates the synthesis of graphs from a database of job information. It also provides a front end, enabling visualization of the synthesized graphs. Additionally, an analysis engine is incorporated that provides performance analysis, graph-based clustering, and failure prediction capabilities for HPC systems.
4F13: Machine Learning Propagation on Factor Graphs
Ghahramani, Zoubin
Graphs x3 x1 x2 x4 f1 f2 f3 initialise all messages to be 1 an example schedule of messages resulting in computing p(x4): message direction message value x1 f1 1(x1) x3 f2 1(x3) f1 x2 x1 f1(x1, x2)1(x1) f2 x2 x3 f2(x3, x2)1(x3) x2 f3 x1 f1(x1, x2) x3 f2(x3, x2) f3 x4 x2 f3(x2, x4) x1 f1(x1, x2) x3 f2(x3, x
Graph fusion algebras of WLM(p,p')
Jorgen Rasmussen
2010-01-14T23:59:59.000Z
We consider the W-extended logarithmic minimal model WLM(p,p'). As in the rational minimal models, the so-called fundamental fusion algebra of WLM(p,p') is described by a simple graph fusion algebra. The fusion matrices in the regular representation thereof are mutually commuting, but in general not diagonalizable. Nevertheless, we show that they can be brought simultaneously to block-diagonal forms whose blocks are upper-triangular matrices of dimension 1, 3, 5 or 9. The directed graphs associated with the two fundamental modules are described in detail. The corresponding adjacency matrices share a complete set of common generalized eigenvectors organized as a web constructed by interlacing the Jordan chains of the two matrices. This web is here called a Jordan web and it consists of connected subwebs with 1, 3, 5 or 9 generalized eigenvectors. The similarity matrix, formed by concatenating these vectors, simultaneously brings the two fundamental adjacency matrices to Jordan canonical form modulo permutation similarity. The ranks of the participating Jordan blocks are 1 or 3, and the corresponding eigenvalues are given by 2cos(j\\pi/n) where j=0,...,n and n=p,p'. For p>1, only some of the modules in the fundamental fusion algebra of WLM(p,p') are associated with boundary conditions within our lattice approach. The regular representation of the corresponding fusion subalgebra has features similar to the ones in the regular representation of the fundamental fusion algebra, but with dimensions of the upper-triangular blocks and connected Jordan-web components given by 1, 2, 3 or 8. Some of the key results are illustrated for W-extended critical percolation WLM(2,3).
Partitioning 2-edge-colored Ore-type graphs by monochromatic cycles
Sarkozy, Gabor
. A more elementary proof, still for large enough n, was obtained by Allen [1]. Finally, Bessy and Thomass, the above mentioned Bessy-ThomassÂ´e result [5] would hold for graphs with minimum degree larger than 3n/4
The Effect of Graph Layout on Inference from Social Network Data
Blythe, Jim
The Effect of Graph Layout on Inference from Social Network Data Jim Blythe 1 and Cathleen Mc of information to be #12; Ivo Jack Ben York Earl Rick Mel Dale Robin Nan Gerry Bob Fran Walt Ovid Gary Chris Hugh
Dynamic Distributed Multimedia: Seamless Sharing and Reconfiguration of Multimedia Flow Graphs
Lohse, Marco
Dynamic Distributed Multimedia: Seamless Sharing and Reconfiguration of Multimedia Flow Graphs Abstract Mobile devices with multimedia and networking capabilities are quickly becoming ubiquitous through the availability of small note- books, PDA, and in particular, mobile phones. However, most multimedia systems
Continuous-Time Intruder Isolation Using Unattended Ground Sensors on a General Graph
Zhang, Wei
Continuous-Time Intruder Isolation Using Unattended Ground Sensors on a General Graph Hua Chen by several Unattended Ground Sensors (UGSs). The intruder is assumed to travel on a road network
A Genetic Algorithm Applied to Graph Problems Involving Subsets of Vertices
Wainwright, Roger L.
and Computer Sciences University of Tulsa University of Tulsa 600 South College Avenue 600 South College Avenue Tulsa, OK 74104 USA Tulsa, OK 74104 USA rogerw@utulsa.edu Abstract - Many graph problems seek subsets
CyGraph: A Reconfigurable Architecture for Parallel Breadth-First Search
Zambreno, Joseph A.
--Large-scale graph structures are considered as a keystone for many emerging high-performance computing appli among themselves, which could potentially cause pipeline stalls and other implementation inefficiencies
Omega: an Overlap-graph de novo Assembler for Meta-genomics
Haider, Bahlul [ORNL; Ahn, Tae-Hyuk [ORNL; Bushnell, Brian [U.S. Department of Energy, Joint Genome Institute; Chai, JJ [ORNL; Copeland, Alex [U.S. Department of Energy, Joint Genome Institute; Pan, Chongle [ORNL
2014-01-01T23:59:59.000Z
Motivation: Metagenomic sequencing allows reconstruction of mi-crobial genomes directly from environmental samples. Omega (overlap-graph metagenome assembler) was developed here for assembling and scaffolding Illumina sequencing data of microbial communities. Results: Omega found overlaps between reads using a prefix/suffix hash table. The overlap graph of reads was simplified by removing transitive edges and trimming small branches. Unitigs were generat-ed based on minimum cost flow analysis of the overlap graph. Obtained unitigs were merged to contigs and scaffolds using mate-pair information. Omega was compared with two de Bruijn graph assemblers, SOAPdenovo and IDBA-UD, using a publically-available Illumina sequencing dataset of a 64-genome mock com-munity. The assembly results were verified by their alignment with reference genomes. The overall performances of the three assem-blers were comparable and each assembler provided best results for a subset of genomes.
How the permutation of edges of a metric graph affects the number of points moving along the edges
V. L. Chernyshev; A. A. Tolchennikov
2014-10-18T23:59:59.000Z
We consider a dynamical system on a metric graph, that corresponds to a semiclassical solution of a time-dependent Schr\\"odinger equation. We omit all details concerning mathematical physics and work with a purely discrete problem. We find a weak inequality representation for the number of points coming out of the vertex of an arbitrary tree graph. We apply this construction to an "H-junction" graph. We calculate the difference between numbers of moving points corresponding to the permutation of edges. Then we find a symmetrical difference of the number of points moving along the edges of a metric graph.
Fusion categories in terms of graphs and relations
Hendryk Pfeiffer
2011-04-20T23:59:59.000Z
Every fusion category C that is k-linear over a suitable field k, is the category of finite-dimensional comodules of a Weak Hopf Algebra H. This Weak Hopf Algebra is finite-dimensional, cosemisimple and has commutative bases. It arises as the universal coend with respect to the long canonical functor \\omega:C->Vect_k. We show that H is a quotient H=H[G]/I of a Weak Bialgebra H[G] which has a combinatorial description in terms of a finite directed graph G that depends on the choice of a generator M of C and on the fusion coefficients of C. The algebra underlying H[G] is the path algebra of the quiver GxG, and so the composability of paths in G parameterizes the truncation of the tensor product of C. The ideal I is generated by two types of relations. The first type enforces that the tensor powers of the generator M have the appropriate endomorphism algebras, thus providing a Schur-Weyl dual description of C. If C is braided, this includes relations of the form `RTT=TTR' where R contains the coefficients of the braiding on \\omega M\\otimes\\omega M, a generalization of the construction of Faddeev-Reshetikhin-Takhtajan to Weak Bialgebras. The second type of relations removes a suitable set of group-like elements in order to make the category of finite-dimensional comodules equivalent to C over all tensor powers of the generator M. As examples, we treat the modular categories associated with U_q(sl_2).
Graph Coloring Algorithms for Muti-core and Massively Multithreaded Architectures
Catalyurek, Umit; Gebremedhin, Assefaw; Halappanavar, Mahantesh; Pothen, Alex
2012-01-01T23:59:59.000Z
We explore the interplay between architectures and algorithm design in the context of shared-memory platforms and a specific graph problem of central importance in scientific and high-performance computing, distance-1 graph coloring. We introduce two different kinds of multithreaded heuristic algorithms for the stated, NP-hard, problem. The first algorithm relies on speculation and iteration, and is suitable for any shared-memory system. The second algorithm uses dataflow principles, and is targeted at the non-conventional, massively multithreaded Cray XMT system. We study the performance of the algorithms on the Cray XMT and two multi-core systems, Sun Niagara 2 and Intel Nehalem. Together, the three systems represent a spectrum of multithreading capabilities and memory structure. As testbed, we use synthetically generated large-scale graphs carefully chosen to cover a wide range of input types. The results show that the algorithms have scalable runtime performance and use nearly the same number of colors as...
Powers, Sarah S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lothian, Joshua [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2014-12-01T23:59:59.000Z
The benchmarking effort within the Extreme Scale Systems Center at Oak Ridge National Laboratory seeks to provide High Performance Computing benchmarks and test suites of interest to the DoD sponsor. The work described in this report is a part of the effort focusing on graph generation. A previously developed benchmark, SystemBurn, allows the emulation of a broad spectrum of application behavior profiles within a single framework. To complement this effort, similar capabilities are desired for graph-centric problems. This report described the in-depth analysis of the generated synthetic graphs' properties at a variety of scales using different generator implementations and examines their applicability to replicating real world datasets.
Cascading Power Outages Propagate Locally in an Influence Graph that is not the Actual Grid Topology
Hines, Paul D H; Rezaei, Pooya
2015-01-01T23:59:59.000Z
In a cascading power transmission outage, component outages propagate non-locally; after one component outages, the next failure may be very distant, both topologically and geographically. As a result, simple models of topological contagion do not accurately represent the propagation of cascades in power systems. However, cascading power outages do follow patterns, some of which are useful in understanding and reducing blackout risk. This paper describes a method by which the data from many cascading failure simulations can be transformed into a graph-based model of influences that provides actionable information about the many ways that cascades propagate in a particular system. The resulting "influence graph" model is Markovian, since component outage probabilities depend only on the outages that occurred in the prior generation. To validate the model we compare the distribution of cascade sizes resulting from n-2 contingencies in a 2896 branch test case to cascade sizes in the influence graph. The two dist...
Bhattacharyya, Shuvra S.
DYNAMIC CONFIGURATION OF DATAFLOW GRAPH TOPOLOGY FOR DSP SYSTEM DESIGN Dong-Ik Ko and Shuvra S dynamic port can keep the model bounded. However, control flow depends on FSMs. Using FSMs for minor changes of control flow with data- flow graphs can make application models unnecessarily compli- cated
Boyer, Edmond
synthesis for Timed Event Graphs (TEG) in dioid algebra. The feedback synthesis is done in order to stabilize a TEG without decreasing its original production rate, optimize the initial marking Event Graphs (TEG) stabilization. We rst recall that a TEG is a Petri net whose each place has one
Aleks Kissinger
2012-03-22T23:59:59.000Z
This work is about diagrammatic languages, how they can be represented, and what they in turn can be used to represent. More specifically, it focuses on representations and applications of string diagrams. String diagrams are used to represent a collection of processes, depicted as "boxes" with multiple (typed) inputs and outputs, depicted as "wires". If we allow plugging input and output wires together, we can intuitively represent complex compositions of processes, formalised as morphisms in a monoidal category. [...] The first major contribution of this dissertation is the introduction of a discretised version of a string diagram called a string graph. String graphs form a partial adhesive category, so they can be manipulated using double-pushout graph rewriting. Furthermore, we show how string graphs modulo a rewrite system can be used to construct free symmetric traced and compact closed categories on a monoidal signature. The second contribution is in the application of graphical languages to quantum information theory. We use a mixture of diagrammatic and algebraic techniques to prove a new classification result for strongly complementary observables. [...] We also introduce a graphical language for multipartite entanglement and illustrate a simple graphical axiom that distinguishes the two maximally-entangled tripartite qubit states: GHZ and W. [...] The third contribution is a description of two software tools developed in part by the author to implement much of the theoretical content described here. The first tool is Quantomatic, a desktop application for building string graphs and graphical theories, as well as performing automated graph rewriting visually. The second is QuantoCoSy, which performs fully automated, model-driven theory creation using a procedure called conjecture synthesis.
Buliga, Marius; Vallee, Claude
2008-01-01T23:59:59.000Z
We show a surprising connexion between a property of the inf convolutions of a family of convex lower semicontinuous functions and the fact that intersections of maximal cyclically monotone graphs are the critical set of a bipotential. We then extend the results from arXiv:math/0608424v4 to bipotentials convex covers, generalizing the notion of a bi-implicitly convex lagrangian cover. As an application we prove that the bipotential related to Coulomb's friction law is related to a specific bipotential convex cover with the property that any graph of the cover is non maximal cyclically monotone.
EZPIX: a tablet entry method for computer-generated slides, drawings, and graphs
Williams, J.M.
1984-09-01T23:59:59.000Z
This manual outlines a method for making slides, drawings, maps, graphs, etc., with the touch of a button. A minicomputer-based program, called EZPIX, connects the host computer graphics system to a tablet on which one can digitize input and specify graphics commands from a menu. A minicomputer terminal serves as editor and provides local graphics output. The magic button does practically everything else. It signs you on, starts, builds, ends, executes and saves your command file, and signs you off. It even allows you to make a composite picture from an assortment of inappropriately sized originals. The graph and pie chart modes are handy, too.
A novel configuration model for random graphs with given degree sequence
Xinping Xu; Feng Liu
2007-08-20T23:59:59.000Z
Recently, random graphs in which vertices are characterized by hidden variables controlling the establishment of edges between pairs of vertices have attracted much attention. Here, we present a specific realization of a class of random network models in which the connection probability between two vertices (i,j) is a specific function of degrees ki and kj. In the framework of the configuration model of random graphs, we find analytical expressions for the degree correlation and clustering as a function of the variance of the desired degree distribution. The expressions obtained are checked by means of numerical simulations. Possible applications of our model are discussed.
Automation of the Dipole Subtraction Method in MadGraph/MadEvent
Rikkert Frederix; Thomas Gehrmann; Nicolas Greiner
2008-08-15T23:59:59.000Z
We present the implementation of the dipole subtraction formalism for the real radiation contributions to any next-to-leading order QCD process in the MadGraph/MadEvent framework. Both massless and massive dipoles are considered. Starting from a specific (n+1)-particle process the package provides a Fortran code for all possible dipoles to all Born processes that constitute the subtraction term to the (n+1)-particle process. The output files are given in the usual "MadGraph StandAlone" style using helicity amplitudes.
Fault Diagnosis of Steam Generator Using Signed Directed Graph and Artificial Neural Networks
Aly, Mohamed N. [Nuclear Eng. Department, Fac. of Eng., Alex. Univ., Alex. (Egypt); Hegazy, Hesham N. [Nuclear Power Plants Authority, Cairo (Egypt)
2006-07-01T23:59:59.000Z
Diagnosis is a very complex and important task for finding the root cause of faults in nuclear power plants. The objective of this paper is to investigate the feasibility of using the combination of signed directed graph (SDG) and artificial neural networks for fault diagnosis in nuclear power plants especially in U-Tube steam generator. Signed directed graph has been the most widely used form of qualitative based model methods for process fault diagnosis. It is constructed to represent the cause-effect relations among the dynamic process variables. Signed directed graph consists of nodes represent the process variables and branches. The branch represents the qualitative influence of a process variable on the related variable. The main problem in fault diagnosis using the signed directed graph is the unmeasured variables. Therefore, neural networks are used to estimate the values of unmeasured nodes. In this work, different four cases of faults in the steam generator ( SG) have been diagnosed, three of them are single fault and the fourth is multiple fault. The first three faults are by pass valve leakage (Vbp(+)), main feed water valve opening increase (Vfw(+)), main feed water valve opening decrease (Vfw (-)). The fourth fault is a multiple fault where by-pass valve leakage and main feed water valve opening decrease (Vbp(+) and Vfw (-)) in the same time. The used data are collected from a basic principle simulator of pressurized water reactor 925 Mwe. The signed directed graph of the steam generator is constructed to represent the cause-effect relations among SG variables. It consists of 26 nodes represent the SG variables, and 48 branches represent the cause effect relations among this variables. For each fault the values of measured nodes are coming from sensors and the values of unmeasured nodes are coming from the trained neural networks. These values of the nodes are compared by normal values to get the sign of the nodes. The cause-effect graph for each fault is constructed from the steam generator signed directed graph by removing the invalid (normal) nodes and inconsistent branches. Then in the cause-effect graph we search about the node which does not have an input branch. This node is the fault origin node. The result of this work demonstrated that this method can be used in nuclear power plant fault diagnosis. The advantages of this method are, it enables us to diagnose a multi fault, it is not restricted by pre-defined faults, and it is fast method. (authors)
Paris-Sud XI, Université de
Quantum Secret Sharing with Graph States Sylvain Gravier1,2, J´er^ome Javelle3, Mehdi Mhalla1 study the graph-state-based quantum secret sharing protocols [24, 17] which are not only very promising on the graphical characterization of the graph-state-based secret shar- ing properties, in particular we point out
Aizenman, Michael [Departments of Physics and Mathematics, Princeton University, Princeton, New Jersey 08544 (United States); Warzel, Simone [Zentrum Mathematik, TU Munich, Boltzmannstr. 3, 85747 Garching (Germany)
2012-09-15T23:59:59.000Z
We discuss the dynamical implications of the recent proof that for a quantum particle in a random potential on a regular tree graph absolutely continuous (ac) spectrum occurs non-perturbatively through rare fluctuation-enabled resonances. The main result is spelled in the title.
Unifying Models of Churn and Resilience for Unstructured P2P Graphs
Loguinov, Dmitri
Unifying Models of Churn and Resilience for Unstructured P2P Graphs Zhongmei Yao, Student Member modeled heterogeneity of user churn (i.e., difference in online behavior) or the impact of in churn and derive the distribution of the various metrics observed in prior experimental studies. We also
Application-only Call Graph Construction Karim Ali and Ondrej Lhotak
Lhotak, Ondrej
program (i.e., both the application and the libraries that the application depends on). A popular of the library code and any calls the library makes back into the application. This results in potential un the code of the library. 1 Introduction A call graph is a necessary prerequisite for most interprocedural
Visualizing Cells and their Connectivity Graphs for CompuCell3D Randy Heiland
Indiana University
Visualizing Cells and their Connectivity Graphs for CompuCell3D Randy Heiland CREST, Pervasive models that simulate the behavior of different types of interacting biological cells can be a very time consuming and er- ror prone task. CompuCell3D is an open source application that addresses this challenge
Enumerating the edge-colourings of a regular graph Stephane Bessy and Frederic Havet
Paris-Sud XI, Université de
Enumerating the edge-colourings of a regular graph St´ephane Bessy and Fr´ed´eric Havet Assistant and Combinatorics Deparment of Applied Mathematics, National Sun Yat-sen University, Kaohsiung, Taiwan. S. Bessy. Bessy and F.Havet () Enumerating the edge-colourings WGTC, Kaohsiung, 2012 2 / 41 lirmm-00811571,version
Improving Offline Narrowing-Driven Partial Evaluation using Size-Change Graphs
Vidal, Germán
that should be generalized at partial evaluation time to ensure termination) are based on a simple syntac- ticImproving Offline Narrowing-Driven Partial Evaluation using Size-Change Graphs Gustavo Arroyo, J to narrowing-driven partial eval- uation--a partial evaluation scheme for first-order functional and func
Improving Offline Narrowing-Driven Partial Evaluation using Size-Change Graphs
Vidal, Germán
be generalised at partial evaluation time to ensure termination) are based on a simple syntac- ticImproving Offline Narrowing-Driven Partial Evaluation using Size-Change Graphs Gustavo Arroyo, J-driven partial evaluation (a partial evaluation scheme for first-order functional and functional logic programs
Improving Offline Narrowing-Driven Partial Evaluation using Size-Change Graphs
Vidal, Germán
that should be generalized at partial evaluation time to ensure termination) are based on a simple syntacticImproving Offline Narrowing-Driven Partial Evaluation using Size-Change Graphs Gustavo Arroyo, J-driven partial evaluation (a partial evaluation scheme for first-order functional and functional logic programs
Algebraic Higher-Order Nets: Graphs and Petri Nets as Tokens
Mossakowski, Till - Deutschen Forschungszentrum fÃ¼r KÃ¼nstliche Intelligenz & Fachbereich 3
Algebraic Higher-Order Nets: Graphs and Petri Nets as Tokens Kathrin Hoffmann1 and Till Mossakowski 2 BISS, Department of Computer Science University of Bremen Abstract. Petri nets and Algebraic High-Level Nets are well-known to model parallel and concurrent systems. In this paper, we introduce the concept
Algebraic HigherOrder Nets: Graphs and Petri Nets as Tokens
Mossakowski, Till - Deutschen Forschungszentrum fÃ¼r KÃ¼nstliche Intelligenz & Fachbereich 3
Algebraic HigherÂOrder Nets: Graphs and Petri Nets as Tokens Kathrin Ho#mann 1 and Till Mossakowski 2 BISS, Department of Computer Science University of Bremen Abstract. Petri nets and Algebraic HighÂLevel Nets are wellÂknown to model parallel and concurrent systems. In this paper, we introduce the concept
Improved Microarray-Based Decision Support with Graph Encoded Interactome Data
Engineering ESAT/SCD, Katholieke Universiteit Leuven, Leuven, Belgium Abstract In the past, microarray studies-Based Decision Support with Graph Encoded Interactome Data. PLoS ONE 5(4): e10225. doi:10.1371/journal (FWO-Vlaanderen). OG is supported by the Research Foundation - Flanders (FWO). JS is a professor
On the edge-connectivity of Cartesian product graphs Sandi Klavzar
Klavzar, Sandi
, then either S is induced by a minimum edge cut of a factor, or S is a set of edges incident to a vertex of G H is given and the structure of minimum edge cuts is described. It is also proved that the connectivity product of graphs; edge-connectivity; minimum edge cuts; AMS subject classification (2000): 05C40 1
Distributed Detection in Sensor Networks: Connectivity Graph and Small World Networks
Moura, José
Distributed Detection in Sensor Networks: Connectivity Graph and Small World Networks Saeed A study distributed detection in a sensor network where the sensors cooperate by exchanging information distributed decision making algorithms in the network. This is a difficult problem since it corresponds
Geosocial Graph-Based Community Detection Yves van Gennip, Huiyi Hu, Blake Hunter
Soatto, Stefano
geosocial information. The data come from the policing district Hollenbeck (see Fig. 1) in Los AngelesGeosocial Graph-Based Community Detection Yves van Gennip, Huiyi Hu, Blake Hunter Department of Mathematics University of California, Los Angeles Los Angeles, CA, USA Email: yvgennip@math.ucla.edu, huiyihu
GRAPH-BASED METHOD FOR MULTITEMPORAL SEGMENTATION OF SEA ICE FLOES FROM SATELLITE DATA
Paris-Sud XI, Université de
the Arc- tic sea ice pack in December 2007, continuously moved with the Arctic ocean currents and meltedGRAPH-BASED METHOD FOR MULTITEMPORAL SEGMENTATION OF SEA ICE FLOES FROM SATELLITE DATA Claudio, MODIS, Sea Ice Floes. ABSTRACT: Automated segmentation of the sea ice evolution would allow scientists
Automatic clustering of multispectral imagery by maximization of the graph modularity
Harkin, Anthony
Automatic clustering of multispectral imagery by maximization of the graph modularity ABSTRACT Automatic clustering of spectral image data is a common problem with a diverse set of desired and potential visually useful than previous methods. Additionally, this method outperforms many typical automatic
Automated Design Methodology for Mechatronic Systems Using Bond Graphs and Genetic Programming
Fernandez, Thomas
Automated Design Methodology for Mechatronic Systems Using Bond Graphs and Genetic Programming for synthesizing designs for multi-domain systems, such as mechatronic systems. The domain of mechatronic systems range. 1. INTRODUCTION Mechatronic system design is a type of multi-domain problem that differs from
Relations in Mathematical Morphology with applications to Graphs and Rough Sets
Stell, John
School of Computing, University of Leeds Leeds, LS2 9JT, U.K. jgs@comp.leeds.ac.uk Abstract. Rough sets of morphology for graphs. The structure of the paper is as follows. I begin in Section 2 with a brief review
Social Networks 29 (2007) 231248 Advances in exponential random graph (p*
Fienberg, Stephen E.
2007-01-01T23:59:59.000Z
Social Networks 29 (2007) 231248 Advances in exponential random graph (p* ) models applied to a large social network Steven M. Goodreau University of Washington, Department of Anthropology and Center ability to conduct inference on dependence in large social networks [Snijders, T.A.B., 2002. Markov Chain
Social Networks 29 (2007) 169172 Advances in exponential random graph (p*
Fienberg, Stephen E.
2007-01-01T23:59:59.000Z
Social Networks 29 (2007) 169172 Editorial Advances in exponential random graph (p* ) models Statistical approaches to social networks have a rather long history. Few now recall that Moreno and Jennings networks. But to specify a successful statistical model for a social network has been a more difficult
The Power of Team Exploration: Two Robots Can Learn Unlabeled Directed Graphs
Bender, Michael
The Power of Team Exploration: Two Robots Can Learn Unlabeled Directed Graphs Michael A. Bender communicate freely by radio. Radio communication is used to synchro nize actions. If we assume that the two robots move synchronously and share a polynomiallength random string, then no communication is necessary
Patterns of Cascading Behavior in Large Blog Graphs Jure Leskovec, Mary McGlohon, Christos Faloutsos
Patterns of Cascading Behavior in Large Blog Graphs Jure Leskovec, Mary McGlohon, Christos Faloutsos Natalie Glance, Matthew Hurst Abstract How do blogs cite and influence each other? How do such links evolve? Does the popularity of old blog posts drop exponentially with time? These are some
Improved Steiner Tree Approximation in Graphs Gabriel Robins \\Lambda Alexander Zelikovsky y
Zelikovsky, Alexander
). In quasibipartite graphs our heuristic achieves an approximation ratio of ß 1:28 in time O(mn 2 ), where m also show \\Lambda Department of Computer Science, University of Virginia, Thornton Hall, Charlottesville, VA, 22903, robins@cs.virginia.edu y Department of Computer Science, Georgia State University
Quasi-Termination Analysis of Logic Programs Using Size-Change Graphs
Vidal, GermÃ¡n
Quasi-Termination Analysis of Logic Programs Using Size-Change Graphs GermÂ´an Vidal DSIC, Technical program is quasi-terminating when only a finite num- ber of different calls--up to variable renaming--are deriv- able from any given goal. Ensuring the quasi-termination of programs w.r.t. a class of goals
Explicit Collision Simulation of Chemical Reactions in a Graph Based Artifical Chemistry
Stadler, Peter F.
Explicit Collision Simulation of Chemical Reactions in a Graph Based Artifical Chemistry Gil BenkË?uckel Theory method. Here we describe an extension of the model that models chemical reactions as the result, the reactions are simulated in a way that treats the formation and breakage of individual chemical bonds
Explicit Collision Simulation of Chemical Reactions in a Graph Based Artifical Chemistry
Stadler, Peter F.
Explicit Collision Simulation of Chemical Reactions in a Graph Based Artifical Chemistry Gil BenkÂ¨uckel Theory method. Here we describe an extension of the model that models chemical reactions as the result, the reactions are simulated in a way that treats the formation and breakage of individual chemical bonds
Experimental Test of Bell inequalities with Six-Qubit Graph States
Wei-Bo Gao; Xing-Can Yao; Ping Xu; Otfried Gühne; Adán Cabello; Chao-Yang Lu; Tao Yang; Zeng-Bing Chen; Jian-Wei Pan
2011-01-04T23:59:59.000Z
We report on the experimental realization of two different Bell inequality tests based on six-qubit linear-type and Y-shape graph states. For each of these states, the Bell inequalities tested are optimal in the sense that they provide the maximum violation among all Bell inequalities with stabilizing observables and possess the maximum resistance to noise.
The Economics Of Supply And Demand: An Important Challenge For Conceptual Graphs
Delugach, Harry S.
The Economics Of Supply And Demand: An Important Challenge For Conceptual Graphs Simon Polovina domains, but the domain of economics is particularly difficult because its knowledge is based as muchknown basic economic area: namely, the law of supply and demand. Employing Peirce logic negative contexts, we
Multi-robot Human Guidance using Topological Graphs Piyush Khandelwal and Peter Stone
Stone, Peter
Multi-robot Human Guidance using Topological Graphs Piyush Khandelwal and Peter Stone Department,pstone}@cs.utexas.edu Abstract Prior approaches to human guidance using robots in- side a building have typically been limited to a single robot guide that navigates a human from start to goal. However, due to their limited mobility
The AME2003 atomic mass evaluation (II). Tables, graphs and references
Boyer, Edmond
with the binding energy per nucleon, the beta-decay energy and the full atomic mass in mass units. * This work has&UPS, B^atiment 108, F-91405 Orsay Campus, France b National Institute of Nuclear Physics and High-Energy, a table of separation energies and reaction energies, and finally, a series of graphs of separation
Handbook of Graph Theory. Edited by Jonathan L. Gross and Jay Yellen. CRC Press,
Beezer, Robert A.
Handbook of Graph Theory. Edited by Jonathan L. Gross and Jay Yellen. CRC Press, Boca Raton, Florida, 2004. ISBN 1-58488-090-2, Harcover. 1167 pp., $119.95. The "CRC Handbook" is well-known to any-familiarity to greatly expand its "Handbook" series. One of the newest entries to join titles such as the Hand- book
Myers, Chris
Software systems as complex networks: Structure, function, and evolvability of software York 14853, USA Received 27 May 2003; published 20 October 2003 Software systems emerge from mere software collaboration graphs contained within several open-source soft- ware systems, and have found them
Amaral, José Nelson
University of Alberta Expression Data Flow Graph: Precise Flow-Sensitive Pointer Analysis for C Thiessen Fall 2011 Edmonton, Alberta Permission is hereby granted to the University of Alberta Libraries, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other
Erdos-Renyi random graphs + forest fires = self-organized criticality
Rath, Balazs
2008-01-01T23:59:59.000Z
We modify the usual Erdos-Renyi random graph evolution by letting connected clusters 'burn down' (i.e. fall apart to disconnected single sites) due to a Poisson flow of lightnings. In a range of the intensity of rate of lightnings the system sticks to a permanent critical state.
Reference Manual for Package "graphMC" J. Ray, A. Pinar and C. Safta
Ray, Jaideep
#12;Below we describe the "public" functions in these libraries. We provide some description This section contains description of the "public" functions in the 3 libraries distributed with this package. 2 available to the public. 3. libgraphDB: A utility library, containing a graph data base. This is used
Artificial Intelligence 135 (2002) 73123 Planning graph as the basis for deriving heuristics
Kambhampati, Subbarao
2002-01-01T23:59:59.000Z
families of heuristics, some aimed at search speed and others at optimality of solutions, and analyze many search, we describe a novel way of using the planning graph structure to derive highly effective variable explicitly search in the space of world states. Their superior performance comes from the heuristic
Non-perturbative corrections to mean-field behavior: spherical model on spider-web graph
Ajit C. Balram; Deepak Dhar
2012-02-09T23:59:59.000Z
We consider the spherical model on a spider-web graph. This graph is effectively infinite-dimensional, similar to the Bethe lattice, but has loops. We show that these lead to non-trivial corrections to the simple mean-field behavior. We first determine all normal modes of the coupled springs problem on this graph, using its large symmetry group. In the thermodynamic limit, the spectrum is a set of $\\delta$-functions, and all the modes are localized. The fractional number of modes with frequency less than $\\omega$ varies as $\\exp (-C/\\omega)$ for $\\omega$ tending to zero, where $C$ is a constant. For an unbiased random walk on the vertices of this graph, this implies that the probability of return to the origin at time $t$ varies as $\\exp(- C' t^{1/3})$, for large $t$, where $C'$ is a constant. For the spherical model, we show that while the critical exponents take the values expected from the mean-field theory, the free-energy per site at temperature $T$, near and above the critical temperature $T_c$, also has an essential singularity of the type $\\exp[ -K {(T - T_c)}^{-1/2}]$.
.1October 8, 2005Copyright Albert R. Meyer, 2005. All rights reserved. Planar Graphs
Goldwasser, Shafi
.1October 8, 2005Copyright Â© Albert R. Meyer, 2005. All rights reserved. Drawing Planar Graphs Mathematics for Computer Science MIT 6.042J/18.062J #12;.2October 8, 2005Copyright Â© Albert R. Meyer, 2005 edges crossing. #12;.3October 8, 2005Copyright Â© Albert R. Meyer, 2005. All rights reserved. Planar
Interactive Graph Cut Based Segmentation With Shape Priors Daniel Freedman and Tao Zhang
Interactive Graph Cut Based Segmentation With Shape Priors Daniel Freedman and Tao Zhang Computer segmentation can be very chal- lenging, a small amount of user input can often resolve ambiguous decisions can be very chal- lenging, a small amount of user input can often resolve am- biguous decisions
A Factor-Graph based ZP-OFDM Receiver for Deep Water Acoustic Channels
Zhou, Shengli
A Factor-Graph based ZP-OFDM Receiver for Deep Water Acoustic Channels Zhaohui Wang, Shengli Zhou-OFDM) transmissions over deep water channels with extremely long delay spreads. Due to the geometric structure of deep receiver. Index Terms-- OFDM, deep water communications, inter- block-interference, inter
Bond Graph Model of a Vertical U-Tube Steam Condenser Coupled with a Heat Exchanger
Paris-Sud XI, Université de
turbines, distillation industries using water as a solvent, etc. System-level modeling of steam condensersBond Graph Model of a Vertical U-Tube Steam Condenser Coupled with a Heat Exchanger K. Medjaher1+ A A simulation model for a vertical U-tube steam condenser in which the condensate is stored at the bottom well
Representative Subsets For Big Data Learning using k-NN Graphs
Representative Subsets For Big Data Learning using k-NN Graphs Raghvendra Mall, Vilen Jumutc, Rocco a deterministic method to obtain subsets from big data which are a good representative of the inherent structure a subset for this big data network. The FURS selection technique selects nodes from different dense regions
Predicting Protein Folds with Structural Repeats Using a Chain Graph Model
Xing, Eric P.
Predicting Protein Folds with Structural Repeats Using a Chain Graph Model Yan Liu yanliu, Carnegie Mellon University, Pittsburgh, PA 15213 USA Abstract Protein fold recognition is a key step to to accurately identify protein folds aris- ing from typical spatial arrangements of well-defined secondary
Fast Approximate Energy Minimization via Graph Cuts Yuri Boykov Olga Veksler Ramin Zabih
Field, David
Fast Approximate Energy Minimization via Graph Cuts Yuri Boykov Olga Veksler Ramin Zabih Computer of minimizing a large class of energy functions that occur in early vision. The major restriction is that the energy func- tion's smoothness term must only involve pairs of pix- els. We propose two algorithms
Identifying Affinity Classes of Inorganic Materials Binding Sequences via a Graph-based Model
Buffalo, State University of New York
material. We first generate a large set of simulated peptide sequences based on an amino acid transition peptide sequences, which are usually 7-14 amino acids long, are differentiated from other polypeptides1 Identifying Affinity Classes of Inorganic Materials Binding Sequences via a Graph-based Model Nan
Burns, Peter
required to get the simulation working. The paper is organized as follows: Section 2 introduces Modelica, a new equation-based declarative language. Some specific Modelica language constructs necessary using Modelica. Section 5 gives some preliminary definitions related to the concept of bipartite graphs
DNA fragment assembly: an application of graph theory in molecular biology
Willems, Wolfgang
DNA fragment assembly: an application of graph theory in molecular biology Martin Mascher Leibniz Technology Since the central importance of the DNA in storing biological informa- tion had been recognised limitations permit scientists only to obtain contigu- ous DNA fragments whose lengths range from a few dozen
A Discrete Chain Graph Model for 3d+t Cell Tracking with High
Heermann, Dieter W.
the exact MAP solution by integer linear programming (ILP), and when comparing to the gold standard by assignment is well suited for tracking a varying number of divisible cells, but suffers from false positive detections. We reformulate tracking by assignment as a chain grapha mixed directed- undirected probabilistic
Limits on the network sensitivity function for homogeneous multi-agent systems on a graph
Murray, Richard M.
in feedback control of interconnected multi- agent systems, focused on the network sensitivity functions. We linear dynamics and we model the interconnection topology as a graph, in which the single agents], edge agreement [5], [6], linear quadratic regulator [7], decomposition and linear matrix inequalities
Erdos-Renyi random graphs + forest fires = self-organized criticality
Balazs Rath; Balint Toth
2009-08-26T23:59:59.000Z
We modify the usual Erdos-Renyi random graph evolution by letting connected clusters 'burn down' (i.e. fall apart to disconnected single sites) due to a Poisson flow of lightnings. In a range of the intensity of rate of lightnings the system sticks to a permanent critical state.
Scheduling Parallel Task Graphs on (Almost) Homogeneous Multi-cluster Platforms
Paris-Sud XI, Université de
1 Scheduling Parallel Task Graphs on (Almost) Homogeneous Multi-cluster Platforms Pierre these applications efficiently on parallel platforms has been a long-standing challenge. In the case of a single homogeneous platform, such as a cluster, results have been obtained both in theory, i.e., guaranteed
Critical Path and Area Based Scheduling of Parallel Task Graphs on Heterogeneous Platforms
Paris-Sud XI, Université de
Critical Path and Area Based Scheduling of Parallel Task Graphs on Heterogeneous Platforms Tchimou research has been done in the context of single homogeneous clus- ters, heterogeneous platforms have become) a novel "virtual" cluster methodology for handling platform het- erogeneity; (ii) a novel task placement
SUGI 15, April, 1990 SAS/GRAPH SOFTWARE MEETS THE LOGO TURTLE
Friendly, Michael
SUGI 15, April, 1990 SAS/GRAPH® SOFTWARE MEETS THE LOGO TURTLE Michael Friendly, York University Abstract What is Logo? This talk describes a set of SAS macros which provide the ability to Logo of the Logo language, rather setting. Part of its appeal is an extremely simple yet flexible than absolute X
A NOVEL FRAMEWORK FOR ACCURATE LUNG SEGMENTATION USING GRAPH CUTS Asem M. Ali1
Louisville, University of
A NOVEL FRAMEWORK FOR ACCURATE LUNG SEGMENTATION USING GRAPH CUTS Asem M. Ali1 Ayman S. El-Baz 2 Bioengineering Department, University of Louisville ABSTRACT The closeness of the gray levels between lung tissues and the chest tissues makes lung segmentation based only on image signals dif- ficult. This work
Automatic Lung Segmentation of Volumetric Low-Dose CT Scans Using Graph Cuts
Farag, Aly A.
Automatic Lung Segmentation of Volumetric Low-Dose CT Scans Using Graph Cuts Asem M. Ali and Aly A for unsupervised segmentation of the lung region from low dose computed tomography (LDCT) images. We follow distribution model. To better spec- ify region borders between lung and chest, each empirical distribution
Kronk, Hudson V., Associate Professor, PhD, 1964, Michigan State University: Graph theory.
Suzuki, Masatsugu
227 Kronk, Hudson V., Associate Professor, PhD, 1964, Michigan State University: Graph theory. (1964) Lercher, Bruce L., Associate Professor Emeritus, PhD, 1963, Pennsylvania State University: Mathematical logic. (1962) McAuley, Louis F., Professor, PhD, 1954, University of North Carolina: Topology
Flexible Graph Layout for the Web Trevor Hansen, Kim Marriott & Bernd Meyer
Marriott, Kimbal
and is manifest in almost all web standards from the HTML/CSS [1] combination to XML/XSL [6, 23]. Recent graphics bandwidth has meant that graphics has become increasingly important on the web. Graph-based dia- grams are one of the most important types of structured graphical information. Here we demonstrate how XML can
Interactive Separation of Segmented Bones in CT Volumes Using Graph Cut
Ju, Tao
mask customized to the shape of the bone, such as the femoral head. However, creat- ing masks for bones of different methodology have been reported for bone segmen- tation (see a recent survey in [1]). DueInteractive Separation of Segmented Bones in CT Volumes Using Graph Cut Lu Liu, David Raber, David
Sentiment Sentence Extraction Using a Hierarchical Directed Acyclic Graph Structure and a Bootstrap on the Web. We obtain a huge number of review documents that include user's opinions for products. To classify the opinions is one of the hottest topics in natural language processing. In general, we need
Bond Graph Modeling of Centrifugal Compressor System Nur Uddin and Jan Tommy Gravdahl
Gravdahl, Jan Tommy
Bond Graph Modeling of Centrifugal Compressor System Nur Uddin and Jan Tommy Gravdahl Dept, Norway N-7491 nur.uddin@itk.ntnu.no, Jan.Tommy.Gravdahl@itk.ntnu.no Keywords: Compressor, compressor. A model of a compression system with recycle flow is derived in this work. 1. INTRODUCTION Compressors
Haarslev, Volker
An Enhanced Graph-Oriented Approach for Change Management in Distributed Biomedical Ontologies of the most challenging issues in ontology change management is keeping ontologies consistent when changes occur. Generally most of the existing change management approaches have been faced with the following
Gibbs Sampling for Logistic Normal Topic Models with Graph-Based Priors
McCallum, Andrew
in the T - 1 simplex (i.e., a T-dimensional logistic normal random variable) can be generated as follows: 1Gibbs Sampling for Logistic Normal Topic Models with Graph-Based Priors David Mimno, Hanna M relationships. Models for spatial and temporal data often rely on real-valued state space models such as dynamic
Fusion rule algebras and walks on graphs V.S. Sunder
Wildberger, Norman
Fusion rule algebras and walks on graphs V.S. Sunder Institute of Mathematical Sciences Madras the relation between fusion algebras and Cartan algebras in Mn(IR); as a result of our analysis, we arrive Hermitian fusion algebra', which turns out, in many cases to have non-negative structure constants
First Steps toward Automated Design of Mechatronic Systems Using Bond Graphs and Genetic Programming
Fernandez, Thomas
(GARAGe) Department of Mechanical Engineering Case Center for Computer-Aided Engineering and Manufacturing, mechanical, hydraulic, pneumatic, and thermal components, making it difficult to design a system to meet of elements, each of which performs analogous roles across energy domains. Bond graphs are "grown
Margin based Transductive Graph Cuts using Linear Programming K. Pelckmans(1)
, and is subsequently related to the classical MINCUT approach. From a practical perspective a simple and intu- itive clustering. Keywords: Graph Cuts, Transductive Inference, Statistical Learning, Clustering, Combinatorial research witnessed a renewed surge of interest in the MINCUT problem, culminating in the theoretical
Jouve, Bertrand
1 Organization of cortical areas in central and peripheral visual fields as revealed by graph theory analysis Kenneth Knoblauch, Bertrand Jouve, Arnaud Falchier, Laetitia Cirilli and Henry Kennedy patterns of connections between visual areas so as to determine the prinÂ ciples of cortical organization
Dvelopper une bibliothque de calculs sur des grands graphes lorsque la matrice
Grigoras, .Romulus
extrÃªmement favorables pour la faible complexitÃ© espace et temps des algorithmes de traitements. Dans ce les propriÃ©tÃ©s des graphes de terrain an d'optimiser le temps et l'espace des calculs (par l
Data mining in an engineering design environment: OR applications from graph matching1
Nagi, Rakesh
1 Data mining in an engineering design environment: OR applications from graph matching1 Carol J York 14623 Abstract Data mining has been making inroads into the engineering design environment an area that generates large amounts of heterogeneous data for which suitable mining methods
Modeling and Control for Balanced Timed and Weighted Event Graphs in Dioids
Paris-Sud XI, Université de
1 Modeling and Control for Balanced Timed and Weighted Event Graphs in Dioids Bertrand Cottenceau for which some model matching control problems have been solved. In the context of manufacturing applications, the controllers obtained by these approaches have the effect of regulating material flows
On the Formal Verification of Embedded Software Using Multiway Decision Graphs
Tahar, SofiÃ¨ne
. Recently attention has been given to the verification of embedded systems using formal methods and Claesen [10] suggested a methodology for modeling both the software and hardware of an embedded system1 On the Formal Verification of Embedded Software Using Multiway Decision Graphs Subhashini
Incremental Program Testing Using Program Dependence Graphs SAMUEL BATES SUSAN HORWITZ
Horwitz, Susan B.
data adequacy is a widely accepted concept for pro viding some confidence that a particular test suiteIncremental Program Testing Using Program Dependence Graphs SAMUEL BATES SUSAN HORWITZ samuel as the basis for incremental program testing when using test data adequacy criteria. Test data adequacy
Lowest Common Ancestors in Trees and Directed Acyclic Graphs1 Michael A. Bender2 3
Bender, Michael
lowest common ancestors(LCA) in trees and directed acyclic graphs (DAGs). Specifically, we extend the LCA problem to DAGs and study the LCA variants that arise in this general setting. We begin with a clear exposition of Berkman and Vishkin's simple optimal algorithm for LCA in trees. The ideas presented
On Reducing the Global State Graph for Verification of Distributed Computations
Garg, Vijay
On Reducing the Global State Graph for Verification of Distributed Computations Arindam Chakraborty and Vijay K. Garg Parallel and Distributed Systems Laboratory The University of Texas at Austin Austin, TX 78712, USA {chakrabo,garg}@ece.utexas.edu Abstract Correct distributed programs are very hard to write
Paris-Sud XI, Université de
floods. Model checking is a powerful tool for system verification because it can reveal errors that were to describe the properties checking the system model. 395 hal-00617998,version1-31Aug2011 Author manuscriptSCALESEM Evaluation of Semantic Graph based on Model Checking Mahdi Gueffaz, Sylvain Rampacek
Computing Nash Equilibria of Action-Graph Games Navin A. R. Bhat
Sipe,J. E.
Computing Nash Equilibria of Action-Graph Games Navin A. R. Bhat Department of Physics University.g., Fudenberg and Tirole [1991].) The central game-theoretic solution con- cept is the Nash equilibrium, a fixed-point in mixed strat- egy space which Nash [1950] proved exists in every finite game. It remains an important
Path Deformation Roadmaps: Compact Graphs with Useful Cycles for Motion Planning
Cortés, Juan
Path Deformation Roadmaps: Compact Graphs with Useful Cycles for Motion Planning L´eonard Jaillet quality roadmaps that encode the multiple connectedness of the configuration space inside small but yet Roadmaps (PDR) rely on a notion of path deformability indicating whether or not a given path can
Isenberg, Petra
arrow S, (b) tapered T, (c) dark-to-light DL (a.k.a intensity I), (d) light-to-dark LD, (e- net. Graphs represent a collection of elements called vertices or nodes as well as the connections
.pelckmans@esat.kuleuven.be SCD/sista - ESAT - KULeuven - Kasteelpark 10, 3001 Leuven, Belgium Abstract This short report analyses; Pelckmans Preliminary work. Under review by the International Work- shop on Mining and Learning with Graphs
Choset, Howie
Multi-Agent Deterministic Graph Mapping via Robot Rendezvous Chaohui Gong, Stephen Tully, George at Carnegie Mellon University, Pittsburgh, PA 15213, USA. C. Gong, G. Kantor, and H. Choset
Exact scattering matrix of graphs in magnetic field and quantum noise
Caudrelier, Vincent, E-mail: v.caudrelier@city.ac.uk [Department of Mathematical Science, City University London, Northampton Square, London EC1V 0HB (United Kingdom); Mintchev, Mihail, E-mail: mintchev@df.unipi.it [Istituto Nazionale di Fisica Nucleare and Dipartimento di Fisica dell’Università di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); Ragoucy, Eric, E-mail: eric.ragoucy@lapth.cnrs.fr [LAPTh, Laboratoire d’Annecy-le-Vieux de Physique Théorique, CNRS, Université de Savoie, BP 110, 74941 Annecy-le-Vieux Cedex (France)
2014-08-15T23:59:59.000Z
We consider arbitrary quantum wire networks modelled by finite, noncompact, connected quantum graphs in the presence of an external magnetic field. We find a general formula for the total scattering matrix of the network in terms of its local scattering properties and its metric structure. This is applied to a quantum ring with N external edges. Connecting the external edges of the ring to heat reservoirs, we study the quantum transport on the graph in ambient magnetic field. We consider two types of dynamics on the ring: the free Schrödinger and the free massless Dirac equations. For each case, a detailed study of the thermal noise is performed analytically. Interestingly enough, in presence of a magnetic field, the standard linear Johnson-Nyquist law for the low temperature behaviour of the thermal noise becomes nonlinear. The precise regime of validity of this effect is discussed and a typical signature of the underlying dynamics is observed.
Spin models on random graphs with controlled topologies beyond degree constraints
Coolen, ACC "Ton"
and outlook #12;1. MOTIVATION Model processes on complex real graphs by solvable processes on suitable random/J 5.944 Tc/J 4.933 Tc/J 4.51? small world model: k = 2 + c p(k2) = e-c ck-2 (k-2)! c = 0 : Tc/J 1) = N-1 i k, j cij r, jk cijcjkcki These models are solvable, calculate average of free energy per spin
Instability of Bose-Einstein condensation on quantum graphs under repulsive perturbations
Jens Bolte; Joachim Kerner
2014-11-26T23:59:59.000Z
In this Note we investigate Bose-Einstein condensation in interacting quantum many-particle systems on graphs. We extend previous results obtained for particles on an interval and show that even arbitrarily small repulsive two-particle interactions destroy a condensate in the non-interacting Bose gas. Our results also cover singular two-particle interactions, such as the well-known Lieb-Lininger model, in the thermodynamic limit.
Convex Drawings of Graphs in Two and Three Dimensions (Preliminary Version)
Goodrich, Michael T.
], Steinitz 47], and Tutte 50, 51]. Our workaimsatcharacterizing the area/volume requirement of 2D/3D convex of drawings of n-vertex 3-connectedplanar graphs: 2D convex grid drawings with (3n) (3n=2) area under the edge L1-resolution rule; 2D strictly convex grid drawings with O(n 3) O(n 3) area under the edge
Sampling graphs with a prescribed joint degree distribution using Markov Chains.
Pinar, Ali; Stanton, Isabelle (UC Berkeley)
2010-10-01T23:59:59.000Z
One of the most influential results in network analysis is that many natural networks exhibit a power-law or log-normal degree distribution. This has inspired numerous generative models that match this property. However, more recent work has shown that while these generative models do have the right degree distribution, they are not good models for real life networks due to their differences on other important metrics like conductance. We believe this is, in part, because many of these real-world networks have very different joint degree distributions, i.e. the probability that a randomly selected edge will be between nodes of degree k and l. Assortativity is a sufficient statistic of the joint degree distribution, and it has been previously noted that social networks tend to be assortative, while biological and technological networks tend to be disassortative. We suggest that the joint degree distribution of graphs is an interesting avenue of study for further research into network structure. We provide a simple greedy algorithm for constructing simple graphs from a given joint degree distribution, and a Monte Carlo Markov Chain method for sampling them. We also show that the state space of simple graphs with a fixed degree distribution is connected via endpoint switches. We empirically evaluate the mixing time of this Markov Chain by using experiments based on the autocorrelation of each edge.
Madduri, Kamesh; Bader, David A.
2009-02-15T23:59:59.000Z
Graph-theoretic abstractions are extensively used to analyze massive data sets. Temporal data streams from socioeconomic interactions, social networking web sites, communication traffic, and scientific computing can be intuitively modeled as graphs. We present the first study of novel high-performance combinatorial techniques for analyzing large-scale information networks, encapsulating dynamic interaction data in the order of billions of entities. We present new data structures to represent dynamic interaction networks, and discuss algorithms for processing parallel insertions and deletions of edges in small-world networks. With these new approaches, we achieve an average performance rate of 25 million structural updates per second and a parallel speedup of nearly28 on a 64-way Sun UltraSPARC T2 multicore processor, for insertions and deletions to a small-world network of 33.5 million vertices and 268 million edges. We also design parallel implementations of fundamental dynamic graph kernels related to connectivity and centrality queries. Our implementations are freely distributed as part of the open-source SNAP (Small-world Network Analysis and Partitioning) complex network analysis framework.
Scaling Graph Community Detection on the Tilera Many-core Architecture
Chavarría-Miranda, Daniel; Halappanavar, Mahantesh; Kalyanaraman, Anantharaman
2014-12-01T23:59:59.000Z
In an era when power constraints and data movement are proving to be significant barriers for the application of high-end computing, the Tilera many-core architecture offers a low-power platform exhibiting many important characteristics of future systems, including a large number of simple cores, a sophisticated network-on-chip, and fine-grained control over memory and caching policies. While this emerging architecture has been previously studied for structured compute-intensive kernels, benchmarking the platform for data-bound, irregular applications present significant challenges that have remained unexplored. Community detection is an advanced prototypical graph-theoretic operation with applications in numerous scientific domains including life sciences, cyber security, and power systems. In this work, we explore multiple design strategies toward developing a scalable tool for community detection on the Tilera platform. Using several memory layout and work scheduling techniques we demonstrate speedups of up to 46x on 36 cores of the Tilera TileGX36 platform over the best serial implementation, and also show results that have comparable quality and performance to mainstream x86 platforms. To the best of our knowledge this is the first work addressing graph algorithms on the Tilera platform. This study demonstrates that through careful design space exploration, low-power many-core platforms like Tilera can be effectively exploited for graph algorithms that that embody all the essential characteristics of an irregular application.
Graph Cube: On Warehousing and OLAP Multidimensional Networks
Cortes, Corinna
, United States Google Inc., Mountain View, CA, United States pzhao4@uiuc.edu xiaoleil that copies are not made or distributed for profit or commercial advantage and that copies bear this notice
P. Butera; P. Federbush; M. Pernici
2015-02-24T23:59:59.000Z
Using a relation between the virial expansion coefficients of the pressure and the entropy expansion coefficients in the case of the monomer-dimer model on infinite regular lattices, we have shown that, on hypercubic lattices of any dimension, the virial coefficients are positive through the 20th order. We have observed that all virial coefficients so far known for this system are positive also on infinite regular lattices with different structure. We are thus led to conjecture that the virial expansion coefficients $m_k $ are always positive. These considerations can be extended to the study of related bounds on finite graphs generalizing the infinite regular lattices, namely the finite grids and the regular biconnected graphs. The validity of the bounds $\\Delta^k {\\rm ln}(i! N(i)) \\le 0$ for $k \\ge 2$, where $N(i)$ is the number of configurations of $i$ dimers on the graph and $\\Delta$ is the forward difference operator, is shown to correspond to the positivity of the virial coefficients. Our tests on many finite lattice graphs indicate that on large lattices these bounds are satisfied, giving support to the conjecture on the positivity of the virial coefficients. An exhaustive survey of some classes of regular biconnected graphs with a not too large number $v$ of vertices shows only few violations of these bounds. We conjecture that the frequency of the violations vanishes as $v \\to \\infty$. We find rigorous upper bounds on $N(i)$ valid for arbitrary graphs and for regular graphs. The similarity between the Heilman-Lieb inequality and the one conjectured above suggests that one study the stricter inequality $m_k \\ge \\frac{1}{2k}$ for the virial coefficients, which is valid for all the known coefficients of the infinite regular lattice models.
Personalized Recommendation via Integrated Diffusion on User-Item-Tag Tripartite Graphs
Zhang, Zi-Ke; Zhang, Yi-Cheng
2009-01-01T23:59:59.000Z
Personalized recommender systems are confronting great challenges of accuracy, diversification and novelty, especially when the data set is sparse and lacks accessorial information, such as user profiles, item attributes and explicit ratings. Collaborative tags contain rich information about personalized preferences and item contents, and are therefore potential to help in providing better recommendations. In this paper, we propose a recommendation algorithm based on an integrated diffusion on user-item-tag tripartite graphs. We use three benchmark data sets, Del.icio.us, MovieLens and BibSonomy, to evaluate our algorithm. Experimental results demonstrate that the usage of tag information can significantly improve accuracy, diversification and novelty of recommendations.
Distance-regular graphs of $q$-Racah type and the $q$-tetrahedron algebra
Ito, Tatsuro
2007-01-01T23:59:59.000Z
In this paper we discuss a relationship between the following two algebras: (i) the subconstituent algebra $T$ of a distance-regular graph that has $q$-Racah type; (ii) the $q$-tetrahedron algebra $\\boxtimes_q$ which is a $q$-deformation of the three-point $sl_2$ loop algebra. Assuming that every irreducible $T$-module is thin, we display an algebra homomorphism from $\\boxtimes_q$ into $T$ and show that $T$ is generated by the image together with the center $Z(T)$.
Nelson Faustino; Uwe Kaehler
2015-05-31T23:59:59.000Z
Based on \\cite{DH94}, we introduce a bijective correspondence between first order differential calculi and the graph structure of the symmetric lattice that allows one to encode completely the interconnection structure of the graph in the exterior derivative. As a result, we obtain the Grassmannian character of the lattice as well as the mutual commutativity between basic vector-fields on the tangent space. This in turn gives several similarities between the Clifford setting and the algebra of endomorphisms endowed by the graph structure, such as the hermitian structure of the lattice as well as the Clifford-like algebra of operators acting on the lattice. This naturally leads to a discrete version of Clifford Analysis.
A Fast Parallel Maximum Clique Algorithm for Large Sparse Graphs and Temporal Strong Components
Rossi, Ryan A; Gebremedhin, Assefaw H; Patwary, Md Mostofa Ali
2013-01-01T23:59:59.000Z
We propose a fast, parallel, maximum clique algorithm for large, sparse graphs that is designed to exploit characteristics of social and information networks. We observe roughly linear runtime scaling over graphs between 1000 vertices and 100M vertices. In a test with a 1.8 billion-edge social network, the algorithm finds the largest clique in about 20 minutes. For social networks, in particular, we found that using the core number of a vertex in combination with a good heuristic clique finder efficiently removes the vast majority of the search space. In addition, we parallelize the exploration of the search tree. In the algorithm, processes immediately communicate changes to upper and lower bounds on the size of maximum clique, which occasionally results in a super-linear speedup because vertices with especially large search spaces can be pruned by other processes. We use this clique finder to investigate the size of the largest temporal strong components in dynamic networks, which requires finding the large...
Moura, José
DISTRIBUTED KALMAN FILTERS IN SENSOR NETWORKS: BIPARTITE FUSION GRAPHS Usman A. Khan and Jos´e M. F {ukhan, moura}@ece.cmu.edu ABSTRACT We study the distributed Kalman filter in sensor networks where into reduced coupled sensor-based models. We implement local Kalman filters on these reduced models
14.1.1Graphing Sine, Cosine and Tangent Functions To work properly, a solar panel must
energy to fall on a given square-meter of the solar panel. Slanted rays are less efficient, and deliver14.1.1Graphing Sine, Cosine and Tangent Functions To work properly, a solar panel must be placed so less energy to the solar panel, so the amount of electricity will be lower. The equation below accounts
Abolmaesumi, Purang
Finding Statistics & Data at Queen's Sept/08 STATISTICS Facts & figures in tables, charts, time series, graphs, etc. 1. Statistics Canada www.statcan.ca English use the search box... REMEMBER: Don't Pay Contact madgic@queensu.ca to get statistics for free if faced with a fee! 2. Social
Cabalar, Pedro
. An This research was partially supported by Spanish MEC project TIN2009-14562-C05-04, Xunta program INCITE 2011Under consideration for publication in Theory and Practice of Logic Programming 1 Causal Graph Justifications of Logic Programs Pedro Cabalar, Jorge Fandinno Department of Computer Science University
TauDecay: a library to simulate polarized tau decays via FeynRules and MadGraph5
Kaoru Hagiwara; Tong Li; Kentarou Mawatari; Junya Nakamura
2014-12-15T23:59:59.000Z
TauDecay is a library of helicity amplitudes to simulate polarized tau decays, constructed in the FeynRules and MadGraph5 framework. Together with the leptonic mode, the decay library includes the main hadronic modes, \\tau \\to \
Gerren, Sally Sue
2008-10-10T23:59:59.000Z
, Respectively Representative of Symbolic, Graphic, and Numeric Aspects of a Linear Function ............... 73 2 Comparison of the Mean Percentages of Time Students Received and Acted on High Levels of Cognitive Information and Graphing... LIST OF TABLES TABLE Page 1 Summary of Students’ Background Information ....................................... 22 2...
Janssen, Jeannette C.M.
technique, web pages are often represented as vectors in a word-document space. Using Latent SematicA SPATIAL WEB GRAPH MODEL WITH LOCAL INFLUENCE REGIONS W. AIELLO, A. BONATO, C. COOPER, J. JANSSEN in [2, ) depending on the parameters, and with concentration for a wide range of in-degree values. We
HOW TO PLOT SCIENCE GRAPHS WITH MATLAB A guide to using Matlab for scientific plots in Physics 359E
Landstreet, John D.
HOW TO PLOT SCIENCE GRAPHS WITH MATLAB A guide to using Matlab for scientific plots in Physics 359E functions for example, fits to the data points using the computing language Matlab. Matlab is available on the computers in the lab. You may also have bought a student edition of Matlab for a previous course in applied
Turbak, Franklyn
Chapter 8 EDGAR: Explicit Demand Graph Reduction I have demonstrated how slivers and synchronized (Edgar), a frame work that I have developed for describing how computations unfold over time. Whereas many semantic frameworks focus on the value produced by a computation, Edgar is de signed to emphasize
A Feynman-Kac-Itô Formula for magnetic Schrödinger operators on graphs
Batu Güneysu; Matthias Keller; Marcel Schmidt
2015-05-21T23:59:59.000Z
In this paper we prove a Feynman-Kac-It\\^{o} formula for magnetic Schr\\"odinger operators on arbitrary weighted graphs. To do so, we have to provide a natural and general framework both on the operator theoretic and the probabilistic side of the equation. On the operator side we identify a very general class of potentials that allows the definition of magnetic Schr\\"odinger operators. On the probabilistic side, we introduce an appropriate notion of stochastic line integrals with respect to magnetic potentials. Apart from linking the world of discrete magnetic operators with the probabilistic world through the Feynman-Kac-It\\^{o} formula, the insights from this paper gained on both sides should be of an independent interest. As applications of the Feynman-Kac-It\\^{o} formula, we prove a Kato inequality, a Golden-Thompson inequality and an explicit representation of the quadratic form domains corresponding to a large class of potentials.
Approximate inference on planar graphs using loop calculus and belief progagation
Chertkov, Michael [Los Alamos National Laboratory; Gomez, Vicenc [RADBOUD UNIV; Kappen, Hilbert [RADBOUD UNIV
2009-01-01T23:59:59.000Z
We introduce novel results for approximate inference on planar graphical models using the loop calculus framework. The loop calculus (Chertkov and Chernyak, 2006b) allows to express the exact partition function Z of a graphical model as a finite sum of terms that can be evaluated once the belief propagation (BP) solution is known. In general, full summation over all correction terms is intractable. We develop an algorithm for the approach presented in Chertkov et al. (2008) which represents an efficient truncation scheme on planar graphs and a new representation of the series in terms of Pfaffians of matrices. We analyze in detail both the loop series and the Pfaffian series for models with binary variables and pairwise interactions, and show that the first term of the Pfaffian series can provide very accurate approximations. The algorithm outperforms previous truncation schemes of the loop series and is competitive with other state-of-the-art methods for approximate inference.
Understanding resonance graphs using Easy Java Simulations (EJS) and why we use EJS
Wee, Loo Kang; Chew, Charles; Wong, Darren; Tan, Samuel
2015-01-01T23:59:59.000Z
This paper reports a computer model- simulation created using Easy Java Simulation (EJS) for learners to visualize how the steady-state amplitude of a driven oscillating system varies with the frequency of the periodic driving force. The simulation shows (N=100) identical spring-mass systems being subjected to (1) periodic driving force of equal amplitude but different driving frequencies and (2) different amount of damping. The simulation aims to create a visually intuitive way of understanding how the series of amplitude versus driving frequency graphs are obtained by showing how the displacement of the system changes over time as it transits from the transient to the steady state. A suggested how to use the model is added to help educators and students in their teaching and learning, where we explained the theoretical steady state equation, time conditions when the model starts allowing data recording of maximum amplitudes to closely match the theoretical equation and steps to collect different runs of deg...
Using Graph Theory and a Plenoptic Sensor to Recognize Phase Distortions of a Laser Beam
Wu, Chensheng; Davis, Christopher C
2015-01-01T23:59:59.000Z
Atmospheric turbulence causes fluctuations in the local refractive index of air that accumulatively disturb a wave's phase and amplitude distribution as it propagates. This impairs the effective range of laser weapons as well as the performance of free space optical (FSO) communication systems. Adaptive optics (AO) can be applied to effectively correct wavefront distortions in weak turbulence situations. However, in strong or deep turbulence, where scintillation and beam breakup are common phenomena, traditional wavefront sensing techniques such as the use of Shack-Hartmann sensors lead to incorrect results. Consequently, the performance of AO systems will be greatly compromised. We propose a new approach that can determine the major phase distortions in a beam instantaneously and guide an AO device to compensate for the phase distortion in a few iterations. In our approach, we use a plenoptic wavefront sensor to image the distorted beam into its 4D phase space. A fast reconstruction algorithm based on graph ...
Bipartite Q-polynomial distance-regular graphs and uniform posets
Miklavic, Stefko
2011-01-01T23:59:59.000Z
Let $\\G$ denote a bipartite distance-regular graph with vertex set $X$ and diameter $D \\ge 3$. Fix $x \\in X$ and let $L$ (resp. $R$) denote the corresponding lowering (resp. raising) matrix. We show that each $Q$-polynomial structure for $\\G$ yields a certain linear dependency among $RL^2$, $LRL$, $L^2R$, $L$. Define a partial order $\\le$ on $X$ as follows. For $y,z \\in X$ let $y \\le z$ whenever $\\partial(x,y)+\\partial(y,z)=\\partial(x,z)$, where $\\partial$ denotes path-length distance. We determine whether the above linear dependency gives this poset a uniform or strongly uniform structure. We show that except for one special case a uniform structure is attained, and except for three special cases a strongly uniform structure is attained.
Diego Noja; Dmitry Pelinovsky; Gaukhar Shaikhova
2014-12-28T23:59:59.000Z
We develop a detailed rigorous analysis of edge bifurcations of standing waves in the nonlinear Schr\\"odinger (NLS) equation on a tadpole graph (a ring attached to a semi-infinite line subject to the Kirchhoff boundary conditions at the junction). It is shown in the recent work [7] by using explicit Jacobi elliptic functions that the cubic NLS equation on a tadpole graph admits a rich structure of standing waves. Among these, there are different branches of localized waves bifurcating from the edge of the essential spectrum of an associated Schr\\"odinger operator. We show by using a modified Lyapunov-Schmidt reduction method that the bifur- cation of localized standing waves occurs for every positive power nonlinearity. We distinguish a primary branch of never vanishing standing waves bifurcating from the trivial solution and an infinite sequence of higher branches with oscillating behavior in the ring. The higher branches bifurcate from the branches of degenerate standing waves with vanishing tail outside the ring. Moreover, we analyze stability of bifurcating standing waves. Namely, we show that the primary branch is composed by orbitally stable standing waves for subcritical power nonlinearities, while all nontrivial higher branches are linearly unstable near the bifurcation point. The stability character of the degenerate branches remains inconclusive at the analytical level, whereas heuristic arguments based on analysis of embedded eigenvalues of negative Krein signatures support the conjecture of their linear instability at least near the bifurcation point. Numerical results for the cubic NLS equation show that this conjecture is valid and that the degenerate branches become spectrally stable far away from the bifurcation point.
Designing a graph-based approach to landscape ecological assessment of linear infrastructures
Girardet, Xavier, E-mail: xavier.girardet@univ-fcomte.fr; Foltête, Jean-Christophe, E-mail: jean-christophe.foltete@univ-fcomte.fr; Clauzel, Céline, E-mail: celine.clauzel@univ-fcomte.fr
2013-09-15T23:59:59.000Z
The development of major linear infrastructures contributes to landscape fragmentation and impacts natural habitats and biodiversity in various ways. To anticipate and minimize such impacts, landscape planning needs to be capable of effective strategic environmental assessment (SEA) and of supporting environmental impact assessment (EIA) decisions. To this end, species distribution models (SDMs) are an effective way of making predictive maps of the presence of a given species. In this paper, we propose to combine SDMs and graph-based representation of landscape networks to integrate the potential long-distance effect of infrastructures on species distribution. A diachronic approach, comparing distribution before and after the linear infrastructure is constructed, leads to the design of a species distribution assessment (SDA), taking into account population isolation. The SDA makes it possible (1) to estimate the local variation in probability of presence and (2) to characterize the impact of the infrastructure in terms of global variation in presence and of distance of disturbance. The method is illustrated by assessing the impact of the construction of a high-speed railway line on the distribution of several virtual species in Franche-Comté (France). The study shows the capacity of the SDA to characterize the impact of a linear infrastructure either as a research concern or as a spatial planning challenge. SDAs could be helpful in deciding among several scenarios for linear infrastructure routes or for the location of mitigation measures. -- Highlights: • Graph connectivity metrics were integrated into a species distribution model. • SDM was performed before and after the implementation of linear infrastructure. • The local variation of presence provides spatial indicators of the impact.
Chong, Hogun
2004-09-30T23:59:59.000Z
This research explored the causal relationships among strategies, corporate structure, and performance of the largest U.S. non-financial firms using Directed Acyclic Graphs (DAGs). Corporate strategies and structure have ...
Gandhi, Rajiv C.
Sub-coloring and Hypo-coloring Interval Graphs Rajiv Gandhi1, Bradford Greening, Jr.1, Sriram, Iowa 52242. E-mail: sriram@cs.uiowa.edu. 3 Max-Planck Institute for Informatik, SaarbrÂ¨ucken, Germany
On the critical parameters of the $q\\ge4$ random-cluster model on isoradial graphs
Vincent Beffara; Hugo Duminil-Copin; Stanislav Smirnov
2015-07-06T23:59:59.000Z
The critical surface for random-cluster model with cluster-weight $q\\ge 4$ on isoradial graphs is identified using parafermionic observables. Correlations are also shown to decay exponentially fast in the subcritical regime. While this result is restricted to random-cluster models with $q\\ge 4$, it extends the recent theorem of the two first authors to a large class of planar graphs. In particular, the anisotropic random-cluster model on the square lattice is shown to be critical if $\\frac{p_vp_h}{(1-p_v)(1-p_h)}=q$, where $p_v$ and $p_h$ denote the horizontal and vertical edge-weights respectively. We also mention consequences for Potts models.
S. A. Fulling
2009-07-20T23:59:59.000Z
Vacuum energy and other spectral functions of Laplace-type differential operators have been studied approximately by classical-path constructions and more fundamentally by boundary integral equations. As the first step in a program of elucidating the connections between these approaches and improving the resulting calculations, I show here how the known solutions for Kirchhoff quantum graphs emerge in a boundary-integral formulation.
A Quantum Annealing Approach for Fault Detection and Diagnosis of Graph-Based Systems
Alejandro Perdomo-Ortiz; Joseph Fluegemann; Sriram Narasimhan; Rupak Biswas; Vadim N. Smelyanskiy
2014-10-02T23:59:59.000Z
Diagnosing the minimal set of faults capable of explaining a set of given observations, e.g., from sensor readouts, is a hard combinatorial optimization problem usually tackled with artificial intelligence techniques. We present the mapping of this combinatorial problem to quadratic unconstrained binary optimization (QUBO), and the experimental results of instances embedded onto a quantum annealing device with 509 quantum bits. Besides being the first time a quantum approach has been proposed for problems in the advanced diagnostics community, to the best of our knowledge this work is also the first research utilizing the route Problem $\\rightarrow$ QUBO $\\rightarrow$ Direct embedding into quantum hardware, where we are able to implement and tackle problem instances with sizes that go beyond previously reported toy-model proof-of-principle quantum annealing implementations; this is a significant leap in the solution of problems via direct-embedding adiabatic quantum optimization. We discuss some of the programmability challenges in the current generation of the quantum device as well as a few possible ways to extend this work to more complex arbitrary network graphs.
PyDecay/GraphPhys: A Unified Language and Storage System for Particle Decay Process Descriptions
Dunietz, Jesse N.; /MIT /SLAC
2011-06-22T23:59:59.000Z
To ease the tasks of Monte Carlo (MC) simulation and event reconstruction (i.e. inferring particle-decay events from experimental data) for long-term BaBar data preservation and analysis, the following software components have been designed: a language ('GraphPhys') for specifying decay processes, common to both simulation and data analysis, allowing arbitrary parameters on particles, decays, and entire processes; an automated visualization tool to show graphically what decays have been specified; and a searchable database storage mechanism for decay specifications. Unlike HepML, a proposed XML standard for HEP metadata, the specification language is designed not for data interchange between computer systems, but rather for direct manipulation by human beings as well as computers. The components are interoperable: the information parsed from files in the specification language can easily be rendered as an image by the visualization package, and conversion between decay representations was implemented. Several proof-of-concept command-line tools were built based on this framework. Applications include building easier and more efficient interfaces to existing analysis tools for current projects (e.g. BaBar/BESII), providing a framework for analyses in future experimental settings (e.g. LHC/SuperB), and outreach programs that involve giving students access to BaBar data and analysis tools to give them a hands-on feel for scientific analysis.
Central limit theorems, Lee-Yang zeros, and graph-counting polynomials
J. L. Lebowitz; B. Pittel; D. Ruelle; E. R. Speer
2014-08-18T23:59:59.000Z
We consider the asymptotic normalcy of families of random variables $X$ which count the number of occupied sites in some large set. We write $Prob(X=m)=p_mz_0^m/P(z_0)$, where $P(z)$ is the generating function $P(z)=\\sum_{j=0}^{N}p_jz^j$ and $z_0>0$. We give sufficient criteria, involving the location of the zeros of $P(z)$, for these families to satisfy a central limit theorem (CLT) and even a local CLT (LCLT); the theorems hold in the sense of estimates valid for large $N$ (we assume that $Var(X)$ is large when $N$ is). For example, if all the zeros lie in the closed left half plane then $X$ is asymptotically normal, and when the zeros satisfy some additional conditions then $X$ satisfies an LCLT. We apply these results to cases in which $X$ counts the number of edges in the (random) set of "occupied" edges in a graph, with constraints on the number of occupied edges attached to a given vertex. Our results also apply to systems of interacting particles, with $X$ counting the number of particles in a box $\\Lambda$ whose size approaches infinity; $P(z)$ is then the grand canonical partition function and its zeros are the Lee-Yang zeros.
Chin, George; Marquez, Andres; Choudhury, Sutanay; Feo, John T.
2012-09-01T23:59:59.000Z
Triadic analysis encompasses a useful set of graph mining methods that is centered on the concept of a triad, which is a subgraph of three nodes and the configuration of directed edges across the nodes. Such methods are often applied in the social sciences as well as many other diverse fields. Triadic methods commonly operate on a triad census that counts the number of triads of every possible edge configuration in a graph. Like other graph algorithms, triadic census algorithms do not scale well when graphs reach tens of millions to billions of nodes. To enable the triadic analysis of large-scale graphs, we developed and optimized a triad census algorithm to efficiently execute on shared memory architectures. We will retrace the development and evolution of a parallel triad census algorithm. Over the course of several versions, we continually adapted the code’s data structures and program logic to expose more opportunities to exploit parallelism on shared memory that would translate into improved computational performance. We will recall the critical steps and modifications that occurred during code development and optimization. Furthermore, we will compare the performances of triad census algorithm versions on three specific systems: Cray XMT, HP Superdome, and AMD multi-core NUMA machine. These three systems have shared memory architectures but with markedly different hardware capabilities to manage parallelism.
Odd Components of Co-Trees and Graph Embeddings 1 Han Ren, Dengju Ma and Junjie Lu
[gm(G), gM (G)] as the odd components interval of G, where gm(G) = 1 2 ((G) - max{(T)}), gM (G) = 1 2 ((G) - min{(T)}). It follows from Theorem A that gM = M (G). Thus, we have that for each graph G, either [(G), M (G)] [gm(G), gM (G)] or [gm(G), gM (G)] [(G), M (G)]. If [(G), M (G)] [gm(G), gM (G
Leaf-to-leaf distances and their moments in finite and infinite m-ary tree graphs
Andrew M. Goldsborough; S. Alex Rautu; Rudolf A. Römer
2015-04-17T23:59:59.000Z
We study the leaf-to-leaf distances on full and complete m-ary graphs using a recursive approach. In our formulation, leaves are ordered along a line. We find explicit analytical formulae for the sum of all paths for arbitrary leaf-to-leaf distance r as well as the average path lengths and the moments thereof. We show that the resulting explicit expressions can be recast in terms of Hurwitz-Lerch transcendants. Results for periodic trees are also given. For incomplete random binary trees, we provide first results by numerical techniques; we find a rapid drop of leaf-to-leaf distances for large r.
Hively, Lee M.
2014-09-16T23:59:59.000Z
Data collected from devices and human condition may be used to forewarn of critical events such as machine/structural failure or events from brain/heart wave data stroke. By monitoring the data, and determining what values are indicative of a failure forewarning, one can provide adequate notice of the impending failure in order to take preventive measures. This disclosure teaches a computer-based method to convert dynamical numeric data representing physical objects (unstructured data) into discrete-phase-space states, and hence into a graph (structured data) for extraction of condition change.
Schlick, Tamar
2007-01-01T23:59:59.000Z
, please email: journals.permissions@oxfordjournals.org 1 RAGPOOLS: RNA-As-Graph-Pools A Web Server: Our RNA-As-Graph-Pools (RAGPOOLS) web server offers a theoretical companion tool for RNA in vitro. The companion RAGPOOLS web server ("Designer" component) provides optimized starting sequences, mixing matrices
is to facilitate the large- scale production of candidates by extraction. 2.1 Simplify programming MakingProceedings of the 2010 Workshop on Graph-based Methods for Natural Language Processing, ACL 2010LLinG: multilevel linguistic graphs for knowledge extraction Vincent Archer Laboratoire I3S (équipe RL), Université
Paris-Sud XI, Université de
Graphe de connectivité cérébrale et longue dépendance Florent CHATELAIN1, Sophie ACHARD1, Cédric GOUY-PAILLER2, Olivier MICHEL1, Pierre Olivier AMBLARD1,3 1 GIPSA-lab, CNRS, Université de Grenoble, 2 sans les progrès réalisés dans le domaine de 1S. Achard est partiellement financée par l'ANR 2010 JCJC
arXiv:1307.1718v1[cs.IR]5Jul2013 Graph-based Approach to Automatic Taxonomy Generation (GraBTax)
Giles, C. Lee
arXiv:1307.1718v1[cs.IR]5Jul2013 Graph-based Approach to Automatic Taxonomy Generation (Gra in optimizing the structure of the taxonomy. To automatically generate topic-dependent taxonomies from a large with Wikipedia categories. 1 Introduction A taxonomy organizes concepts into a hierarchical structure, where
Wagner, Stephan
, and each man ranks all women from best to worst. Now each woman should marry one of the men (and vice versa such that increasing subsequences are chains and decreasing subsequences are antichains (or vice versa).] 5. A graph town, there is an equal number of men and women. Each woman ranks all (C) men from best to worst
Siegel, Paul H.
in the Presence of ISI Mohammad H. Taghavi, Member, IEEE, and Paul H. Siegel, Fellow, IEEE Abstract--We propose a new graph representation for ISI channels that can be used for combined equalization and decoding to certain two-dimensional ISI chan- nels. However, for some other channel impulse responses, both decoders
Renau, Jose
RESULTS The graphs at right show overall variability distribution estimated for the Pentium D 800 where a core no longer works properly. In the Sun T1 Niagara cores this is done with a built-in- self processors we record the temperature at which the failure occurred and adjust to the frequencies
Quinn, M.J.
1983-01-01T23:59:59.000Z
The problem of developing efficient algorithms and data structures to solve graph theoretic problems on tightly-coupled MIMD comuters is addressed. Several approaches to parallelizing a serial algorithm are examined. A technique is developed which allows the prediction of the expected execution time of some kinds of parallel algorithms. This technique can be used to determine which parallel algorithm is best for a particular application. Two parallel approximate algorithms for the Euclidean traveling salesman problem are designed and analyzed. The algorithms are parallelizations of the farthest-insertion heuristic and Karp's partitioning algorithm. Software lockout, the delay of processes due to contention for shared data structure, can be a significant hindrance to obtaining satisfactory speedup. Using the tactics of indirection and replication, new data structures are devised which can reduce the severity of software lockout. Finally, an upper bound to the speedup of parallel branch-and-bound algorithms which use the best-bound search strategy is determined.
Specifying MultipleViewed Software Requirements With Conceptual Graphs Title Pages
Delugach, Harry S.
Planning Office. He was a computing analyst for the Department of Energy implementing a distributed engineering honor society Tau Beta Pi (VA A) in 1987, and is a member of the ACM and the IEEE Computer Society
Theory and Practice of Non-Binary Graph-Based Codes: A Combinatorial View
Amiri, Behzad
2015-01-01T23:59:59.000Z
17 Finite-Length Analysis and Design of Non-Binary Block85 Finite-Length Analysis and Design of Spatially-Coupledcodes: enumerators, analysis, and designs,” Submitted to
Alternative formulation for the operator algebra over the space of paths in a ADE $SU(3)$ graph
Jesús A. Pineda; Esteban Isasi; Mario I. Caicedo
2015-02-11T23:59:59.000Z
In this work we discuss the elements required for the construction of the operator algebra for the space of paths over a simply laced $SU(3)$ graph. These operators are an important step in the construction of the bialgebra required to find the partition functions of some modular invariant CFTs. We define the cup and cap operators associated with back-and-forth sequences and add them to the creation and annihilation operators in the operator algebra as they are required for the calculation of the full space of essential paths prescribed by the fusion algebra. These operators require collapsed triangular cells that had not been found in previous works; here we provide explicit values for these cells and show their importance in order for the cell system to fulfill the Kuperberg relations for $SU(3)$ tangles. We also find that demanding that our operators satisfy the Temperley-Lieb algebra leads one naturally to consider operators that create and annihilate closed triangular sequences, which in turn provides an alternative the cup and cap operators as they allow one to replace back-and-forth sequences with closed triangular ones. We finally show that the essential paths obtained by using closed triangles are equivalent to those obtained originally using back-and-forth sequences.
Alternative formulation for the operator algebra over the space of paths in a ADE $SU(3)$ graph
Pineda, Jesús A; Caicedo, Mario I
2015-01-01T23:59:59.000Z
In this work we discuss the elements required for the construction of the operator algebra for the space of paths over a simply laced $SU(3)$ graph. These operators are an important step in the construction of the bialgebra required to find the partition functions of some modular invariant CFTs. We define the cup and cap operators associated with back-and-forth sequences and add them to the creation and annihilation operators in the operator algebra as they are required for the calculation of the full space of essential paths prescribed by the fusion algebra. These operators require collapsed triangular cells that had not been found in previous works; here we provide explicit values for these cells and show their importance in order for the cell system to fulfill the Kuperberg relations for $SU(3)$ tangles. We also find that demanding that our operators satisfy the Temperley-Lieb algebra leads one naturally to consider operators that create and annihilate closed triangular sequences, which in turn provides an...
sin&cos 8/16/2007 1 2.2 The graphs of sin(x) and cos(x).
Taylor, Peter
sin&cos 8/16/2007 1 1 x sin()x cos( )x P O -1 -0.5 0 0.5 1 -1 -0.5 0 0.5 1 6 6 2 2 2 3 2 3 2 5 2 5 2 7 2 7 2 9 2 9 1 /6 /6 2 2 5 5 3 3 4 4 y= xsin( ) y= xcos( ) ) 6 cos( ) 6 sin( 2.2 The graphs of sin(x) and cos(x). Now I am going to define the two basic trig functions: sin(x) and cos(x). Study
Beichel, Reinhard; Bornik, Alexander; Bauer, Christian; Sorantin, Erich [Departments of Electrical and Computer Engineering and Internal Medicine, Iowa Institute for Biomedical Imaging, University of Iowa, Iowa City, Iowa 52242 (United States); Institute for Computer Graphics and Vision, Graz University of Technology, Inffeldgasse 16, A-8010 Graz (Austria); Department of Electrical and Computer Engineering, Iowa Institute for Biomedical Imaging, University of Iowa, Iowa City, Iowa 52242 (United States); Department of Radiology, Medical University Graz, Auenbruggerplatz 34, A-8010 Graz (Austria)
2012-03-15T23:59:59.000Z
Purpose: Liver segmentation is an important prerequisite for the assessment of liver cancer treatment options like tumor resection, image-guided radiation therapy (IGRT), radiofrequency ablation, etc. The purpose of this work was to evaluate a new approach for liver segmentation. Methods: A graph cuts segmentation method was combined with a three-dimensional virtual reality based segmentation refinement approach. The developed interactive segmentation system allowed the user to manipulate volume chunks and/or surfaces instead of 2D contours in cross-sectional images (i.e, slice-by-slice). The method was evaluated on twenty routinely acquired portal-phase contrast enhanced multislice computed tomography (CT) data sets. An independent reference was generated by utilizing a currently clinically utilized slice-by-slice segmentation method. After 1 h of introduction to the developed segmentation system, three experts were asked to segment all twenty data sets with the proposed method. Results: Compared to the independent standard, the relative volumetric segmentation overlap error averaged over all three experts and all twenty data sets was 3.74%. Liver segmentation required on average 16 min of user interaction per case. The calculated relative volumetric overlap errors were not found to be significantly different [analysis of variance (ANOVA) test, p = 0.82] between experts who utilized the proposed 3D system. In contrast, the time required by each expert for segmentation was found to be significantly different (ANOVA test, p = 0.0009). Major differences between generated segmentations and independent references were observed in areas were vessels enter or leave the liver and no accepted criteria for defining liver boundaries exist. In comparison, slice-by-slice based generation of the independent standard utilizing a live wire tool took 70.1 min on average. A standard 2D segmentation refinement approach applied to all twenty data sets required on average 38.2 min of user interaction and resulted in statistically not significantly different segmentation error indices (ANOVA test, significance level of 0.05). Conclusions: All three experts were able to produce liver segmentations with low error rates. User interaction time savings of up to 71% compared to a 2D refinement approach demonstrate the utility and potential of our approach. The system offers a range of different tools to manipulate segmentation results, and some users might benefit from a longer learning phase to develop efficient segmentation refinement strategies. The presented approach represents a generally applicable segmentation approach that can be applied to many medical image segmentation problems.
Branes, graphs and singularities
Vegh, David
2009-01-01T23:59:59.000Z
In this thesis, we study various aspects of string theory on geometric and nongeometric backgrounds in the presence of branes. In the first part of the thesis, we study non-compact geometries. We introduce "brane tilings" ...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirtA Journey Inside the Complex(MARSSIM) SiteOrganization Overview ofOverview
Albert, Réka
;#12;#12;#12;Vertex Pre Post a 1 8 b 2 7 c 3 6 d 4 2 e 5 1 f 6 4 g 7 3 h 8 5 #12;Properties of DFS trees for a link Pre Post a 1 8 b 2 7 e 3 6 g 4 5 c 5 4 h 6 3 d 7 2 f 8 1 #12;Properties of BFS traversal Corresponds the depth first search on its reverse and compute the post-order numbering. Then run the search again