Mathematics Commons^™

The Game Chromatic Number Of Trees And Forests, Charles Dunn, Victor Larsen, Troy Retter, Kira Lindke, Dustin Toci

Faculty Publications

While the game chromatic number of a forest is known to be at most 4, no simple criteria are known for determining the game chromatic number of a forest. We first state necessary and sufficient conditions for forests with game chromatic number 2 and then investigate the differences between forests with game chromatic number 3 and 4. In doing so, we present a minimal example of a forest with game chromatic number 4, criteria for determining in polynomial time the game chromatic number of a forest without vertices of degree 3, and an example of a forest with maximum degree …

Factorial Growth Rates For The Number Of Hyperbolic 3-Manifolds Of A Given Volume, Christian Millichap

Faculty Publications

The work of Jørgensen and Thurston shows that there is a finite number N(v) of orientable hyperbolic 3-manifolds with any given volume v. In this paper, we construct examples showing that the number of hyperbolic knot complements with a given volume v can grow at least factorially fast with v. A similar statement holds for closed hyperbolic 3-manifolds, obtained via Dehn surgery. Furthermore, we give explicit estimates for lower bounds of N(v) in terms of v for these examples. These results improve upon the work of Hodgson and Masai, which describes examples that grow exponentially fast with v …

The Schwartz Space: Tools For Quantum Mechanics And Infinite Dimensional Analysis, Jeremy Becnel, Ambar Sengupta

Faculty Publications

An account of the Schwartz space of rapidly decreasing functions as a topological vector space with additional special structures is presented in a manner that provides all the essential background ideas for some areas of quantum mechanics along with infinite-dimensional distribution theory.

Extremal Theorems For Degree Sequence Packing And The Two-Color Discrete Tomography Problem, Jennifer Diemunsch, Michael Ferrara, Sogol Jahanbekam, James Shook

Faculty Publications

No abstract provided.

Lucky Choice Number Of Planar Graphs With Given Girth, Axel Brandt, Jennifer Diemunsch, Sogol Jahanbekam

Faculty Publications

No abstract provided.

Smooth Positive Solutions To An Elliptic Model With C2 Functions, Joon Hyuk Kang

Faculty Publications

Two species of animals are competing or cooperating in the same environment. Under what conditions do they coexist peacefully? Or under what conditions does either one of the two species become extinct, that is, is either one of the two species excluded by the other? We investigate this phenomena in mathematical point of view.

In this paper we concentrate on coexistence solutions of the competition or cooperation model

This system is the general model for the steady state of a competitive or cooperative interacting system depending on growth conditions for and . The techniques used in this paper are elliptic …

A Curve Satisfying T/K=S With Constant K>0, Yun Myung Oh, Ye Lim Seo

Faculty Publications

In the present paper, we investigate a space curve in which the curvature is constant and the torsion is a linear function. The aim of this paper is to find an explicit formula for this space curve when the ratio of the torsion to the curvature is a linear function when the curvature is constant.

The Lp Relaxation Orthogonal Array Polytope And Its Permutation Symmetries, Andrew J. Geyer, Dursun A. Bulutoglu, Steven J. Rosenberg

Faculty Publications

Symmetry plays a fundamental role in design of experiments. In particular, symmetries of factorial designs that preserve their statistical properties are exploited to find designs with the best statistical properties. By using a result proved by Rosenberg [6], the concept of the LP relaxation orthogonal array polytope is developed and studied. A complete characterization of the permutation symmetry group of this polytope is made. Also, this characterization is verified computationally for many cases. Finally, a proof is provided.

Casimir Energies In Spherically Symmetric Background Potentials Revisited, Matthew Beauregard, Michael Bordag, Klaus Kirsten

Faculty Publications

In this paper we reconsider the formulation for the computation of the Casimir energy in spherically symmetric background potentials. Compared to the previous analysis, the technicalities are much easier to handle and final answers are surprisingly simple.

Living At The Friendship House: Findings From Thetransition Planning Inventory, Jane E. Finn, Vicky-Lynn Holmes, Rebecca Johnson

Faculty Publications

A residential initiative, named the Friendship House, was created through advocates focused on helping people with intellectual disabilities live independently in affordable and safe housing on a university campus. The Friendship House is a small residence hall where individuals with intellectual disabilities live side-by-side with similarly aged and same gendered university students. Qualitative finding as in resident reports and observational data provides support that the Friendship House experience has been successful. However, to better equip these residents with intellectual disabilities, it is important to assess the program in terms of post school transition acquisition skills. This study focuses on whether …

Antimagic-Type Labelings, Sogol Jahanbekam

Faculty Publications

No abstract provided.

A Note On Independent Sets In Graphs With Large Minimum Degree And Small Cliques, Jeremy Lyle

Faculty Publications

Graphs with large minimum degree containing no copy of a clique on r vertices (K_r) must contain relatively large independent sets. A classical result of Andrásfai, Erdös, and Sós implies that K_r-free graphs G with degree larger than ((3r − 7)/(3r − 4))|V(G)| must be (r − 1)-partite. An obvious consequence of this result is that the same degree threshold implies an independent set of order (1/(r − 1))|V(G)|. The following paper provides improved bounds on the minimum degree which would imply the …

Reducing The Size And Number Of Linear Programs In A Dynamic Gröbner Basis Algorithm, Massimo Caboara, John Edward Perry Iii

Faculty Publications

The goal of the Dynamic Buchberger Algorithm is to compute a Gröbner basis quickly by adjusting the term ordering as the computation proceeds. A known problem concerns the size and number of linear progams to be solved when refining the ordering. This paper describes two methods for reducing both their size and number.

On The Dynamic Coloring Of Cartesian Product Graphs., Saieed Akbari, Maryam Ghanbari, S. Jahanbekam

Faculty Publications

No abstract provided.

Global Existence And Finite Time Blow-Up In A Class Of Stochastic Nonlinear Wave Equations, Rana D. Parshad, Matthew Beauregard, Aslan Kasimov, Belkacem Said-Houari

Faculty Publications

We consider a stochastic extension of a class of wave equations with nonlinear viscoelastic damping and nonlinear forcing. We show the global existence of the solution of the stochastic equation and, additionally, when the source term dominates the damping term and when the initial data are large enough, we show that the expected value of the L p norm of the solution, blows up in finite time. In the presence of noise, we extend the previously known range of initial data corresponding to blow-up. Furthermore we use a spectral stochastic Galerkin method to perform numerical simulations that verify certain special …

On The Dynamic Coloring Of Strongly Regular Graphs, Saieed Akbari, Maryam Ghanbari, Sogol Jahanbekam

Faculty Publications

No abstract provided.

A Mathematical Model Of Collagen Lattice Contraction, J. C. Dallon, Emily J. Evans, H Paul Erhlich

Faculty Publications

Two mathematical models for fibroblast-collagen interaction are proposed which reproduce qualitative features of fibroblast populated collagen lattice contraction in time. Both models are force based and model the cells as individual entities with discrete attachment sites however the collagen lattice is modeled differently for each model. In the collagen lattice model the lattice is more interconnected and formed by triangulating nodes to form the fibrous structure. In the collagen fiber model the nodes are not triangulated, are less interconnected, and the collagen fibers are modeled as a string of nodes. Both models suggest that the overall increase in stress of …

Measuring A Circle: A Math Lesson For Grades 5-10, Robert C. Moore

Faculty Publications

This article is designed to promote teaching methods that engage students in active learning and result in deep conceptual understanding by offering a sample lesson to help students (grades 5-10, ages 10-15) answer questions about and gain a deeper understanding of how to measure the circumference and area of a circle.

Variation Of Instructor-Student Interactions In An Introductory Interactive Physics Course, Emily West, Cassandra Paul, David Webb, Wendell Potter

Faculty Publications

The physics instruction at UC Davis for life science majors takes place in a long-standing reformed large-enrollment physics course in which the discussion or laboratory instructors (primarily graduate student teaching assistants) implement the interactive-engagement (IE) elements of the course. Because so many different instructors participate in disseminating the IE course elements, we find it essential to the instructors’ professional development to observe and document the student-instructor interactions within the classroom. Out of this effort, we have developed a computerized real-time instructor observation tool (RIOT) to take data of student-instructor interactions. We use the RIOT to observe 29 different instructors for …

Riemannian Submersions And Lagrangian Isometric Immerson 1, Yun Myung Oh

Faculty Publications

In [1], it has shown that if a Riemannian manifold admits a non- trivial Riemannian submersion with total geodesic fibers, then it cannot be isometrically immersed in any Riemannian manifold of non-positive sectional curvature as a minimal submanifold. In this paper, we consider a nontrivial Riemannian submersion and investigate some properties on Lagrangian iso- metric immersions using the submersion invariant.

Laughing At The Looking Glass: Does Humor Style Serve As An Interpersonal Signal?, Virgil Zeigler-Hill, Avi Besser, Stephanie E. Jett

Faculty Publications

Objective: The provision of information appears to be an important feature of humor. The present studies examined whether humor serves as an interpersonal signal such that an individual's style of humor is associated with how the individual is perceived by others. Method: We examined this issue across two studies. In Study 1, undergraduate participants (257 targets) were rated more positively by their friends and family members (1194 perceivers) when they possessed more benign humor styles. In Study 2, 1190 community participants rated the romantic desirability of targets ostensibly possessing different humor styles. Results: Across both studies, our results were consistent …

Probability Inequalities For The Sum Of Random Variables When Sampling Without Replacement, Jeremy Becnel, Kent Riggs, Dean Young

Faculty Publications

Exponential-type upper bounds are formulated for the probability that the maximum of the partial sample sums of discrete random variables having finite equispaced support exceeds or differs from the population mean by a specified positive constant. The new inequalities extend the work of Serfling (1974). An example of the results are given to demonstrate their efficacy.

Cell Speed Is Independent Of Force In A Mathematical Model Of Amoeboidal Cell Motion With Random Switching Terms., J. C. Dallon, Emily J. Evans, Christopher Grant, William V. Smith

Faculty Publications

In this paper the motion of a single cell is modeled as a nucleus and multiple integrin based adhesion sites. Numerical simulations and analysis of the model indicate that when the stochastic nature of the adhesion sites is a memoryless and force independent random process, the cell speed is independent of the force these adhesion sites exert on the cell. Furthermore, understanding the dynamics of the attachment and detachment of the adhesion sites is key to predicting cell speed. We introduce a differential equation describing the cell motion and then introduce a conjecture about the expected drift of the cell, …

A Force Based Model Of Individual Cell Migration With Discrete Attachment Sites And Random Switching Terms, J. C. Dallon, Matthew Scott, William V. Smith

Faculty Publications

A force based model of cell migration is presented which gives new insight into the importance of the dynamics of cell binding to the substrate. The main features of the model are the focus on discrete attachment dynamics, the treatment of the cellular forces as springs, and an incorporation of the stochastic nature of the attachment sites. One goal of the model is to capture the effect of the random binding and unbinding of cell attachments on global cell motion. Simulations reveal one of the most important factor influencing cell speed is the duration of the attachment to the substrate. …

On The Independent Domination Number Of Regular Graphs, Wayne Goddard, Michael A. Henning, Jeremy Lyle, Justin Southey

Faculty Publications

A set S of vertices in a graph G is an independent dominating set of G if S is an independent set and every vertex not in S is adjacent to a vertex in S. In this paper, we consider questions about independent domination in regular graphs.

Linear Combinations Of Heuristics For Examination Timetabling, Jay Yellen, Edmund K. Burke, Nam Pham

Faculty Publications

Although they are simple techniques from the early days of timetabling research, graph colouring heuristics are still attracting significant research interest in the timetabling research community. These heuristics involve simple ordering strategies to first select and colour those vertices that are most likely to cause trouble if deferred until later. Most of this work used a single heuristic to measure the difficulty of a vertex. Relatively less attention has been paid to select an appropriate colour for the selected vertex. Some recent work has demonstrated the superiority of combining a number of different heuristics for vertex and colour selection. In …

The 1, 2-Conjecture For Graphs With Relatively Small Chromatic Number, Sogol Jahanbekam, Douglas West

Faculty Publications

No abstract provided.

Complete Multipartite Graphs And The Relaxed Coloring Game, Charles Dunn

Faculty Publications

Let k be a positive integer, d be a nonnegative integer, and G be a finite graph. Two players, Alice and Bob, play a game on G by coloring the uncolored vertices with colors from a set X of k colors. At all times, the subgraph induced by a color class must have maximum degree at most d. Alice wins the game if all vertices are eventually colored; otherwise, Bob wins. The least k such that Alice has a winning strategy is called the d-relaxed game chromatic number of G, denoted χ _g^d (G). …

Oyun: A New, Free Program For Iterated Prisoner’S Dilemma Tournaments In The Classroom, Charles H. Pence, Lara Buchak

Faculty Publications

Evolutionary applications of game theory present one of the most pedagogically accessible varieties of genuine, contemporary theoretical biology. We present here Oyun (oy-oon, http://charlespence.net/oyun), a program designed to run iterated prisoner's dilemma tournaments, competitions between prisoner's dilemma strategies developed by the students themselves. Using this software, students are able to readily design and tweak their own strategies, and to see how they fare both in round-robin tournaments and in “evolutionary” tournaments, where the scores in a given “generation” directly determine contribution to the population in the next generation. Oyun is freely available, runs on Windows, Mac, and Linux computers, …

Using Self Organizing Maps To Analyze Demographics And Swing State Voting In The 2008 U.S. Presidential Election, Paul T. Pearson, Cameron I. Cooper

Faculty Publications

Emergent self-organizing maps (ESOMs) and k-means clustering are used to cluster counties in each of the states of Florida, Pennsylvania, and Ohio by demographic data from the 2010 United States census. The counties in these clusters are then analyzed for how they voted in the 2008 U.S. Presidential election, and political strategies are discussed that target demographically similar geographical regions based on ESOM results. The ESOM and k-means clusterings are compared and found to be dissimilar by the variation of information distance function.