Mathematics Commons^™

Estimating Winning Probabilities In Backgammon Races, Andrew M. Ross, Arthur T. Benjamin, Michael Munson '94

All HMC Faculty Publications and Research

In modern backgammon, it is advantageous to know the chances each player has of winning, and to be able to compute the chances without the aid of calculators or pencil and paper. A simple model of backgammon is used to approximate those chances, and a readily computable and sufficiently accurate approximation of that is developed. From there, the model is compared to simulated backgammon games, and the previous approximation is modified to fit the real data.

A Model Of Dna Knotting And Linking, Erica Flapan, Dorothy Buck

Pomona Faculty Publications and Research

We present a model of how DNA knots and links are formed as a result of a single recombination event, or multiple rounds of (processive) recombination events, starting with an unknotted, unlinked, or a (2,m)-torus knot or link substrate. Given these substrates, according to our model all DNA products of a single recombination event or processive recombination fall into a single family of knots and links.

Real Aspects Of The Moduli Space Of Genus Zero Stable Maps, Seongchun Kwon

Turkish Journal of Mathematics

We show that the moduli space of genus zero stable maps is a real projective variety if the target space is a smooth convex real projective variety. We show that evaluation maps, forgetful maps are real morphisms. We analyze the real part of the moduli space.

A Philosophical Examination Of Proofs In Mathematics, Eric Almeida

Undergraduate Review

No abstract provided.

K-41 Optimized Approximate Deconvolution Models, William Layton, Iuliana Stanculescu

Mathematics Faculty Articles

If the Navier-Stokes equations are averaged with a local, spacial convolution type filter, φ = gδ ∗ φ , the resulting system is not closed due to the filtered nonlinear term uu. An approximate deconvolution operator D is a bounded linear operator which satisfies

u = D(u) + O(δ α ),

where δ is the filter width and α ≥ 2. Using a deconvolution operator as an approximate filter inverse yields the closure

uu = D(u)D(u) + O(δ α ).

We derive optimal approximate deconvolution models for 3D turbulence. Specifically, we find the optimal parameters that minimize the time averaged …

On The Complete Join Of Permutative Combinatorial Rees–Sushkevich Varieties, Edmond W. H. Lee

Mathematics Faculty Articles

A semigroup variety is a Rees–Sushkevich variety if it is contained in a periodic variety generated by 0-simple semigroups. The collection of all permutative combinatorial Rees–Sushkevich varieties constitutes an incomplete lattice that does not contain the complete join J of all its varieties. The objective of this article is to investigate the subvarieties of J. It is shown that J is locally finite, non-finitely generated, and contains only finitely based subvarieties. The subvarieties of J are precisely the combinatorial Rees–Sushkevich varieties that do not contain a certain semigroup of order four.

Review: On A Class Of Reflexive Toeplitz Operators, Stephan Ramon Garcia

Pomona Faculty Publications and Research

No abstract provided.

Review: Certain Shifts On Banach Spaces Of Formal Power Series, Stephan Ramon Garcia

Pomona Faculty Publications and Research

No abstract provided.

A Robust Measure Of Correlation Between Two Genes On A Microarray, Johanna S. Hardin, Aya Mitani '06, Leanne Hicks, Brian Vankoten

Pomona Faculty Publications and Research

Background

The underlying goal of microarray experiments is to identify gene expression patterns across different experimental conditions. Genes that are contained in a particular pathway or that respond similarly to experimental conditions could be co-expressed and show similar patterns of expression on a microarray. Using any of a variety of clustering methods or gene network analyses we can partition genes of interest into groups, clusters, or modules based on measures of similarity. Typically, Pearson correlation is used to measure distance (or similarity) before implementing a clustering algorithm. Pearson correlation is quite susceptible to outliers, however, an unfortunate characteristic when dealing …

Frobenius Problem And The Covering Radius Of A Lattice, Lenny Fukshansky, Sinai Robins

CMC Faculty Publications and Research

Abstract. Let N ≥ 2 and let 1 < a(1) < ... < a(N) be relatively prime integers. The Frobenius number of this N-tuple is defined to be the largest positive integer that cannot be expressed as Sigma(N)(i=1) a(i) x(i) where x(1),..., x(N) are non-negative integers. The condition that gcd(a(1),..., a(N)) = 1 implies that such a number exists. The general problem of determining the Frobenius number given N and a(1),..., a(N) is NP-hard, but there have been a number of different bounds on the Frobenius number produced by various authors. We use techniques from the geometry of numbers to produce a new bound, relating the Frobenius number to the covering radius of the null-lattice of this N-tuple. Our bound is particularly interesting in the case when this lattice has equal successive minima, which, as we prove, happens infinitely often.

A Centre-Stable Manifold For The Focussing Cubic Nls In R 1+3, Marius Beceanu

Mathematics and Statistics Faculty Scholarship

Consider the focussing cubic nonlinear Schr\"odinger equation in R 3 : iψ t +Δψ=−|ψ| 2 ψ.

It admits special solutions of the form e itα ϕ , whereϕ is a Schwartz function and a positive (ϕ>0 ) solution of −Δϕ+αϕ=ϕ 3 .

The space of all such solutions, together with those obtained from them by rescaling and applying phase and Galilean coordinate changes, called standing waves, is the eight-dimensional manifold that consists of functions of the form e i(v⋅+Γ) ϕ(⋅−y,α) . We prove that any solution starting sufficiently close to a standing wave in the Σ=W 1,2 (R 3 …

An Augustinian Perspective On The Philosophy Of Mathematics, James Bradley

ACMS Journal 2007

From a Christian perspective, both modern and post-modern approaches to the philosophy of mathematics have significant shortcomings. This paper explores an alternative. It summarizes Augustine of Hippo’s views on the four classical themes of the philosophy of mathematics-the ontology of mathematical objects, their epistemology, the nature of truth in mathematics, and how we account for the effectiveness of mathematics in describing the natural world. It then traces what has happened to Augustine’s perspective in the roughly 1600 years since it was written concluding with a discussion of some spiritual and intellectual problems with the currently dominant secular perspective.

Green And Poisson Functions With Wentzell Boundary Conditions, José-Luis Menaldi, Luciano Tubaro

Mathematics Faculty Research Publications

We discuss the construction and estimates of the Green and Poisson functions associated with a parabolic second order integro-di erential operator with Wentzell boundary conditions.

The Relaxed Game Chromatic Index Of K-Degenerate Graphs, Charles Dunn

Faculty Publications

The (r, d)-relaxed coloring game is a two-player game played on the vertex set of a graph G. We consider a natural analogue to this game on the edge set of G called the (r, d)-relaxed edge-coloring game. We consider this game on trees and more generally, on k-degenerate graphs. We show that if G is k-degenerate with ∆(G) = ∆, then the first player, Alice, has a winning strategy for this game with r = ∆+k−1 and d≥2k² + 4k.

An Examination Of The Effectiveness Of The Adomian Decomposition Method In Fluid Dynamic Applications, Sonia Holmquist

Electronic Theses and Dissertations

Since its introduction in the 1980's, the Adomian Decomposition Method (ADM) has proven to be an efficient and reliable method for solving many types of problems. Originally developed to solve nonlinear functional equations, the ADM has since been used for a wide range of equation types (like boundary value problems, integral equations, equations arising in flow of incompressible and compressible fluids etc...). This work is devoted to an evaluation of the effectiveness of this method when used for fluid dynamic applications. In particular, the ADM has been applied to the Blasius equation, the Falkner-Skan equation, and the Orr-Sommerfeld equation. This …

Sp-Scattered Spaces: A New Generalization Of Scattered Spaces, Melvin Henriksen, Robert M. Raphael, R. G. Woods

All HMC Faculty Publications and Research

The set of isolated points (resp. P-points) of a Tychonoff space X is denoted by Is(X) (resp. P(X)). Recall that X is said to be scattered if Is(A) ≠ ∅ whenever ∅ ≠ A ⊂ X. If instead we require only that P(A) has nonempty interior whenever ∅ ≠ A ⊂ X, we say that X is SP-scattered. Many theorems about scattered spaces hold or have analogs for SP-scattered spaces. For example, the union of a locally finite collection of SP-scattered spaces is SP-scattered. Some known theorems about Lindelöf or paracompact scattered spaces hold also in case the spaces …

Removing Sets From Connected Spaces While Preserving Connectedness, Melvin Henriksen, Amir Nikou

All HMC Faculty Publications and Research

As per the title, the nature of sets that can be removed from a product of more than one connected, arcwise connected, or point arcwise connected spaces while preserving the appropriate kind of connectedness is studied. This can depend on the cardinality of the set being removed or sometimes just on the cardinality of what is removed from one or two factor spaces. Sometimes it can depend on topological properties of the set being removed or its trace on various factor spaces. Some of the results are complicated to prove while being easy to state. Sometimes proofs for different kinds …

Seeking Bang-Bang Solutions Of Mixed Immuno-Chemotherapy Of Tumors, Lisette G. De Pillis, K Renee Fister, Weiqing Gu, Craig Collins, Michael Daub, David Gross '08, James Moore '07, Benjamin Preskill '09

All HMC Faculty Publications and Research

It is known that a beneficial cancer treatment approach for a single patient often involves the administration of more than one type of therapy. The question of how best to combine multiple cancer therapies, however, is still open. In this study, we investigate the theoretical interaction of three treatment types (two biological therapies and one chemotherapy) with a growing cancer, and present an analysis of an optimal control strategy for administering all three therapies in combination. In the situations with controls introduced linearly, we find that there are conditions on which the controls exist singularly. Although bang-bang controls (on-off) reflect …

Turing Patterns On Growing Spheres: The Exponential Case, Julijana Gjorgjieva, Jon T. Jacobsen

All HMC Faculty Publications and Research

We consider Turing patterns for reaction-diffusion systems on the surface of a growing sphere. In particular, we are interested in the effect of dynamic growth on the pattern formation. We consider exponential isotropic growth of the sphere and perform a linear stability analysis and compare the results with numerical simulations.

Modeling Core Generation And Transport Phenomena Of Microcapsules, Xiaoshuo Wu

Doctoral Dissertations

Microcapsules play an important role in chemical, biomedical, and medical research. Of importance is their potential use as bio-sensors, as microreactors, and for drug delivery. In this dissertation, Computational Fluid Dynamics methodology is used to model the generation of droplets or cores (using alginate and oil) and to determine from the model process parameters needed for generating cores of homogeneous size for the manufacturing of microcapsules. Also, material diffusion through a microcapsule for controlled release is modeled based on finite difference methodology. The model was applied to experimental data on dextran release from microcapsules in order to estimate the diffusion …

On The Exact Multiplicity Of Solutions For Boundary-Value Problems Via Computing The Direction Of Bifurcations, Joaquin Riviera, Yi Li

Mathematics and Statistics Faculty Publications

No abstract provided.

On The Direction Of Pitchfork Bifurcation, Xiaojie Hou, Philip Korman, Yi Li

Mathematics and Statistics Faculty Publications

We present an algorithm for computing the direction of pitchfork bifurcation for two-point boundary value problems. The formula is rather involved, but its computational evaluation is quite feasible. As an application, we obtain a multiplicity result.

A Comparison Of Graphical Methods For Assessing The Proportional Hazards Assumptions In The Cox Model, Inger Persson, Harry J. Khamis

Mathematics and Statistics Faculty Publications

Six graphical procedures to check the assumption of proportional hazards for the Cox model are described and compared. A new way of comparing the graphical procedures using a Kolmogorov-Smirnov like maximum deviation criterion for rejection is derived for each procedure. The procedures are evaluated in a simulation study under proportional hazards and five different forms of nonproportional hazards: (1) increasing hazards, (2) decreasing hazards, (3) crossing hazards, (4) diverging hazards, and (5) nonmonotonic hazards. The procedures are compared in the two-sample case corresponding to two groups with different hazard functions. None of the procedures under consideration require partitioning of the …

Projective-Planar Signed Graphs And Tangled Signed Graphs, Dan Slilaty

Mathematics and Statistics Faculty Publications

A projective-planar signed graph has no two vertex-disjoint negative circles. We prove that every signed graph with no two vertex-disjoint negative circles and no balancing vertex is obtained by taking a projective-planar signed graph or a copy of −K5" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 16.2px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">−K5 and then taking 1-, 2-, and 3-sums with balanced signed grap

Generic Subideals Of Graph Ideals And Free Resolutions, Leah Gold

Mathematics and Statistics Faculty Publications

For a graph of an n-cycle Δ with Alexander dual Δ∗, we study the free resolution of a subideal G (n) of the Stanley-Reisner ideal IΔ∗. We prove that if G(n) is generated by 3 generic elements of IΔ∗, then the second syzygy module of G(n) is isomorphic to the second syzygy module of (x1,x2,... ,x n). A result of Bruns shows that there is always a 3-generated ideal with this property. We show that it can be chosen to have a particularly nice form.

Reaction-Diffusion In Nonsmooth And Closed Domains, Ugur G. Abdulla

Mathematics and System Engineering Faculty Publications

We investigate the Dirichlet problem for the parabolic equation in a nonsmooth and closed domain possibly formed with irregular surfaces and having a characteristic vertex point. Existence, boundary regularity, uniqueness, and comparison results are established. The main objective of the paper is to express the criteria for the well-posedness in terms of the local modulus of lower semicontinuity of the boundary manifold. The two key problems in that context are the boundary regularity of the weak solution and the question whether any weak solution is at the same time a viscosity solution.

Philos-Type Oscillation Criteria For Second Order Half-Linear Dynamic Equations On Time Scales, Ravi P. Agarwal, Donal O'Regan, Samir H. Saker

Mathematics and System Engineering Faculty Publications

In this paper we establish some oscillation theorems for the second order half-linear dynamic equation (r(t)(x Δ(t) γ) Δ + p(t)x γ(t) = 0, ∈ [a,b], on time scales. Special cases of our results include some well-known oscillation results for second-order differential and half-linear differential equations. Our results are new for difference, generalized difference and q difference half-linear equations. Copyright © 2007 Rocky Mountain Mathematics Consortium.

New Integral Inequalities For Iterated Integrals With Applications, Ravi P. Agarwal, Cheonseoung Ryoo

Mathematics and System Engineering Faculty Publications

Some new nonlinear retarded integral inequalities of Gronwall type are established. These inequalities can be used as basic tools in the study of certain classes of integrodifferential equations.

Lectures In Computational Fluid Dynamics Of Incompressible Flow: Mathematics, Algorithms And Implementations, James M. Mcdonough

Mechanical Engineering Textbook Gallery

From Prologue:

The present lecture notes are written to emphasize the mathematics of the Navier–Stokes (N.–S.) equations of incompressible flow and the algorithms that have been developed over the past 30 years for solving them.

Lectures In Basic Computational Numerical Analysis, James M. Mcdonough

Mathematics Textbook Gallery

No abstract provided.