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527 full-text articles. Page 1 of 17.

On The Graceful Cartesian Product Of Alpha-Trees, Christian Barrientos, Sarah Minion 2017 Clayton State University

On The Graceful Cartesian Product Of Alpha-Trees, Christian Barrientos, Sarah Minion

Theory and Applications of Graphs

A \emph{graceful labeling} of a graph $G$ of size $n$ is an injective assignment of integers from the set $\{0,1,\dots,n\}$ to the vertices of $G$ such that when each edge has assigned a \emph{weight}, given by the absolute value of the difference of the labels of its end vertices, all the weights are distinct. A graceful labeling is called an $\alpha$-labeling when the graph $G$ is bipartite, with stable sets $A$ and $B$, and the labels assigned to the vertices in $A$ are smaller than the labels assigned to the vertices in $B$. In ...


Tree Diagrams For String Links, Blake Mellor 2017 Loyola Marymount University

Tree Diagrams For String Links, Blake Mellor

Blake Mellor

In previous work, the author defined the intersection graph of a chord diagram associated with string links (as in the theory of finite type invariants). In this paper, we classify the trees which can be obtained as intersection graphs of string link diagrams.


Tree Diagrams For String Links Ii: Determining Chord Diagrams, Blake Mellor 2017 Loyola Marymount University

Tree Diagrams For String Links Ii: Determining Chord Diagrams, Blake Mellor

Blake Mellor

In previous work, we defined the intersection graph of a chord diagram associated with a string link (as in the theory of finite type invariants). In this paper, we look at the case when this graph is a tree, and we show that in many cases these trees determine the chord diagram (modulo the usual 1-term and 4-term relations).


Symmetries Of Embedded Complete Bipartite Graphs, Erica Flapan, Nicole Lehle, Blake Mellor, Matt Pittluck, Xan Vongsathorn 2017 Loyola Marymount University

Symmetries Of Embedded Complete Bipartite Graphs, Erica Flapan, Nicole Lehle, Blake Mellor, Matt Pittluck, Xan Vongsathorn

Blake Mellor

We characterize which automorphisms of an arbitrary complete bipartite graph Kn,m can be induced by a homeomorphism of some embedding of the graph in S3.


Chord Diagrams And Gauss Codes For Graphs, Thomas Fleming, Blake Mellor 2017 Loyola Marymount University

Chord Diagrams And Gauss Codes For Graphs, Thomas Fleming, Blake Mellor

Blake Mellor

Chord diagrams on circles and their intersection graphs (also known as circle graphs) have been intensively studied, and have many applications to the study of knots and knot invariants, among others. However, chord diagrams on more general graphs have not been studied, and are potentially equally valuable in the study of spatial graphs. We will define chord diagrams for planar embeddings of planar graphs and their intersection graphs, and prove some basic results. Then, as an application, we will introduce Gauss codes for immersions of graphs in the plane and give algorithms to determine whether a particular crossing sequence is ...


Investigations Into Difference Equations By De Moivre And D. Bernoulli, Dave Ruch 2017 Ursinus College

Investigations Into Difference Equations By De Moivre And D. Bernoulli, Dave Ruch

Discrete Mathematics

No abstract provided.


Positive Solutions Of A Singular Fractional Boundary Value Problem With A Fractional Boundary Condition, Jeffrey W. Lyons, Jeffrey T. Neugebauer 2017 Eastern Kentucky University

Positive Solutions Of A Singular Fractional Boundary Value Problem With A Fractional Boundary Condition, Jeffrey W. Lyons, Jeffrey T. Neugebauer

EKU Faculty and Staff Scholarship

For α (1,2], the singular fractional boundary value problem

D0α+x + f t,x,D0µ+x = 0, 0 < t < 1,

satisfying the boundary conditionsα β µ x(0) = D0β+x(1) = 0, where β (0,α−1], µ (0,α−1], and D0+, D0+ and D0+ are Riemann-Liouville derivatives of order α, β and µ respectively, is considered. Here f satisfies a local Carathéodory condition, and f(t,x,y) may be singular at the value 0 in its space variable x. Using regularization and sequential techniques and Krasnosel’skii ...


Edge Colorings Of K(M,N) With M+N-1 Colors Which Forbid Rainbow Cycles, Peter Johnson, Claire Zhang 2017 Auburn University Main Campus

Edge Colorings Of K(M,N) With M+N-1 Colors Which Forbid Rainbow Cycles, Peter Johnson, Claire Zhang

Theory and Applications of Graphs

For positive integers m, n, the greatest number of colors that can appear in an edge coloring of K(m,n) which avoids rainbow cycles is m + n - 1. Here these colorings are constructively characterized. It turns out that these colorings can be encoded by certain vertex labelings of full binary trees with m + n leafs.


An Eternal Domination Problem In Grids, William Klostermeyer, Margaret-Ellen Messinger, Alejandro Angeli Ayello 2017 University of North Florida

An Eternal Domination Problem In Grids, William Klostermeyer, Margaret-Ellen Messinger, Alejandro Angeli Ayello

Theory and Applications of Graphs

A dynamic domination problem in graphs is considered in which an infinite sequence of attacks occur at vertices with mobile guards; the guard at the attacked vertex is required to vacate the vertex by moving to a neighboring vertex with no guard. Other guards are allowed to move at the same time, and before and after each attack, the vertices containing guards must form a dominating set of the graph. The minimum number of guards that can defend the graph against such an arbitrary sequence of attacks is called the m-eviction number of the graph. In this paper, the m-eviction ...


Wholes And Parts In General Systems Methodology, Martin Zwick 2016 Portland State University

Wholes And Parts In General Systems Methodology, Martin Zwick

Martin Zwick

Reconstructability analysis (RA) decomposes wholes, namely data in the form either of set-theoretic relations or multivariate probability distributions, into parts, namely relations or distributions involving subsets of variables. Data is modeled and compressed by variablebased decomposition, by more general state-based decomposition, or by the use of latent variables. Models, which specify the interdependencies among the variables, are selected to minimize error and complexity.


Polynomial Reconstruction Of Signed Graphs Whose Least Eigenvalue Is Close To -2, Slobodan K. Simić, Zoran Stanic 2016 University of Belgrade

Polynomial Reconstruction Of Signed Graphs Whose Least Eigenvalue Is Close To -2, Slobodan K. Simić, Zoran Stanic

Electronic Journal of Linear Algebra

The polynomial reconstruction problem for simple graphs has been considered in the literature for more than forty years and is not yet resolved except for some special classes of graphs. Recently, the same problem has been put forward for signed graphs. Here, the reconstruction of the characteristic polynomial of signed graphs whose vertex-deleted subgraphs have least eigenvalue greater than $-2$ is considered.


Planar Graphs, Biplanar Graphs And Graph Thickness, Sean M. Hearon 2016 California State University - San Bernardino

Planar Graphs, Biplanar Graphs And Graph Thickness, Sean M. Hearon

Electronic Theses, Projects, and Dissertations

A graph is planar if it can be drawn on a piece of paper such that no two edges cross. The smallest complete and complete bipartite graphs that are not planar are K5 and K{3,3}. A biplanar graph is a graph whose edges can be colored using red and blue such that the red edges induce a planar subgraph and the blue edges induce a planar subgraph. In this thesis, we determine the smallest complete and complete bipartite graphs that are not biplanar.


Potentially Nilpotent Tridiagonal Sign Patterns Of Order 4, Yubin Gao, Yanling Shao 2016 North University of China

Potentially Nilpotent Tridiagonal Sign Patterns Of Order 4, Yubin Gao, Yanling Shao

Electronic Journal of Linear Algebra

An $n\times n$ sign pattern ${\cal A}$ is said to be potentially nilpotent (PN) if there exists some nilpotent real matrix $B$ with sign pattern ${\cal A}$. In [M.~Arav, F.~Hall, Z.~Li, K.~Kaphle, and N.~Manzagol.Spectrally arbitrary tree sign patterns of order $4$, {\em Electronic Journal of Linear Algebra}, 20:180--197, 2010.], the authors gave some open questions, and one of them is the following: {\em For the class of $4 \times 4$ tridiagonal sign patterns, is PN (together with positive and negative diagonal entries) equivalent to being SAP?}\ In this paper, a positive answer ...


Bounds On The Expected Size Of The Maximum Agreement Subtree, Colby Long, Daniel Irving Bernstein, Lam Si Tung Ho, Mike Steel, Katherine St. John, Seth Sullivant 2016 The Ohio State University

Bounds On The Expected Size Of The Maximum Agreement Subtree, Colby Long, Daniel Irving Bernstein, Lam Si Tung Ho, Mike Steel, Katherine St. John, Seth Sullivant

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


Exploring The Space Of Rna Secondary Structures, Heather C. Smith 2016 Georgia Institute of Technology

Exploring The Space Of Rna Secondary Structures, Heather C. Smith

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


Markov Chains On Graphical Models Of Gene Regulation, Megan Bernstein 2016 Georgia Institute of Technology

Markov Chains On Graphical Models Of Gene Regulation, Megan Bernstein

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


Genome Rearrangement: Graphs And Matrices, Jeffrey Davis 2016 Emory University

Genome Rearrangement: Graphs And Matrices, Jeffrey Davis

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


On The Expected Number Of Crossings In A Tanglegram, Eva Czabarka 2016 University of South Carolina

On The Expected Number Of Crossings In A Tanglegram, Eva Czabarka

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


On The Perfect Reconstruction Of The Structure Of Dynamic Networks, Alan Veliz-Cuba 2016 University of Dayton

On The Perfect Reconstruction Of The Structure Of Dynamic Networks, Alan Veliz-Cuba

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


Spectral Graph Theory And New Stability Measures For Deterministic Gene Regulatory Networks, Fusun Akman, Devin Akman 2016 Illinois State University

Spectral Graph Theory And New Stability Measures For Deterministic Gene Regulatory Networks, Fusun Akman, Devin Akman

Annual Symposium on Biomathematics and Ecology: Education and Research

No abstract provided.


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