Physical Sciences and Mathematics Commons^™

Slow Flow Between Concentric Cones, O. Hall, C. P. Hills, A. D. Gilbert

Articles

This paper considers the low-Reynolds-number flow of an incompressible fluid contained in the gap between two coaxial cones with coincident apices and bounded by a spherical lid. The two cones and the lid are allowed to rotate independently about their common axis, generating a swirling motion. The swirl induces a secondary, meridional circulation through inertial effects. For specific configurations complex eigenmodes representing an infinite sequence of eddies, analogous to those found in two-dimensional corner flows and some three-dimensional geometries, form a component of this secondary circulation. When the cones rotate these eigenmodes, arising from the geometry, compete with the forced …

Krylov Subspaces From Bilinear Representations Of Nonlinear Systems, Marissa Condon, Rossen Ivanov

Articles

For efficient simulation of state-of-the-art dynamical systems as arise in all aspects of engineering, the development of reduced-order models is of paramount importance. While linear reduction techniques have received considerable study, increasingly nonlinear model reduction is becoming a significant field of interest. From a circuits and systems viewpoint, systems involving micromachined devices or systems involving mixed technologies necessitate the development of reduced-order nonlinear models. From a control systems viewpoint, the design of controllers for nonlinear systems is greatly facilitated by nonlinear model reduction strategies. To this end, the paper proposes two novel model-reduction strategies for nonlinear systems. The first involves …

Water Waves And Integrability, Rossen Ivanov

Articles

The Euler’s equations describe the motion of inviscid fluid. In the case of shallow water, when a perturbative asymtotic expansion of the Euler’s equations is taken (to a certain order of smallness of the scale parameters), relations to certain integrable equations emerge. Some recent results concerning the use of integrable equation in modeling the motion of shallow water waves are reviewed in this contribution.

Generalised Fourier Transform For The Camassa-Holm Hierarchy, Adrian Constantin, Vladimir Gerdjikov, Rossen Ivanov

Articles

The squared eigenfunctions of the spectral problem associated to the Camassa-Holm equation represent a complete basis of functions, which helps to describe the Inverse Scattering Transform for the Camassa-Holm hierarchy as a Generalised Fourier transform. The main result of this work is the derivation of the completeness relation for the squared solutions of the Camassa-Holm spectral problem. We show that all the fundamental properties of the Camassa-Holm equation such as the integrals of motion, the description of the equations of the whole hierarchy and their Hamiltonian structures can be naturally expressed making use of the completeness relation and the recursion …

Torsion-Free Groups And Modules With The Involution Property, Brendan Goldsmith, C. Meehan, S.L. Wallutis

Articles

An Abelian group or module is said to have the involution property if every endomorphism is the sum of two automorphisms, one of which is an involution. We investigate this property for completely decomposable torsion-free Abelian groups and modules over the ring of -adic integers.

Impulse Formulations Of The Euler Equations For Incompressible And Compressible Fluids, Victor David Pareja

Electronic Theses and Dissertations

The purpose of this paper is to consider the impulse formulations of the Euler equations for incompressible and compressible fluids. Different gauges are considered. In particular, the Kuz'min gauge provides an interesting case as it allows the fluid impulse velocity to describe the evolution of material surface elements. This result affords interesting physical interpretations of the Kuz'min invariant. Some exact solutions in the impulse formulation are studied. Finally, generalizations to compressible fluids are considered as an extension of these results. The arrangement of the paper is as follows: in the first chapter we will give a brief explanation on the …

Statistical Models For Hot Electron Degradation In Nano-Scaled Mosfet Devices, Suk Joo Bae, Seong-Joon Kim, Way Kuo, Paul H. Kvam

Department of Math & Statistics Faculty Publications

In a MOS structure, the generation of hot carrier interface states is a critical feature of the item's reliability. On the nano-scale, there are problems with degradation in transconductance, shift in threshold voltage, and decrease in drain current capability. Quantum mechanics has been used to relate this decrease to degradation, and device failure. Although the lifetime, and degradation of a device are typically used to characterize its reliability, in this paper we model the distribution of hot-electron activation energies, which has appeal because it exhibits a two-point discrete mixture of logistic distributions. The logistic mixture presents computational problems that are …

Centers And Shore Points In Λ-Dendroids, Van C. Nall

Department of Math & Statistics Faculty Publications

A dendroid is the disjoint union of the set of centers and the set of shore points. We show this is also true for λ-dendroids and use this fact to show that the finite union of shore continua in a λ-dendroid is a shore set.

An Observation About Frostman Shifts, William T. Ross, Alec L. Matheson

Department of Math & Statistics Faculty Publications

A classical theorem of Frostman says that if B is a Blaschke product (or any inner function), then its Frostman shifts B_w = (B − w)(1 – w­­¯B)⁻¹ are Blaschke products for all |w| < 1 except possibly for w in a set of logarithmic capacity zero. If B is a Frostman Blaschke product, equivalently an inner multiplier for the space of Cauchy transforms of measures on the unit circle, we show that for all |w| < 1, B_w is indeed another Frostman Blaschke product.

Pi-Calculus In Logical Form, Marcello M. Bonsangue, Alexander Kurz

Engineering Faculty Articles and Research

Abramsky’s logical formulation of domain theory is extended to encompass the domain theoretic model for picalculus processes of Stark and of Fiore, Moggi and Sangiorgi. This is done by defining a logical counterpart of categorical constructions including dynamic name allocation and name exponentiation, and showing that they are dual to standard constructs in functor categories. We show that initial algebras of functors defined in terms of these constructs give rise to a logic that is sound, complete, and characterises bisimilarity. The approach is modular, and we apply it to derive a logical formulation of pi-calculus. The resulting logic is a …

2007 Undergraduate Mathematics Day Poster, University Of Dayton. Department Of Mathematics

Undergraduate Mathematics Day: Programs, Lectures, Promotional Materials

No abstract provided.

Garden-Variety Symmetry (Abstract), Colleen Hoover

Undergraduate Mathematics Day: Programs, Lectures, Promotional Materials

After a gentle introduction to the topic of symmetry, we will explore the symmetry groups of bounded plane figures, pulling examples from the garden.

2007 Program And Abstracts, University Of Dayton. Department Of Mathematics

Undergraduate Mathematics Day: Programs, Lectures, Promotional Materials

No abstract provided.

Eighth Kenneth C. Schraut Memorial Lecture (Poster), University Of Dayton. Department Of Mathematics

Kenneth C. Schraut Memorial Lectures

No abstract provided.

An Euler Trifecta (Abstract), William Dunham

Kenneth C. Schraut Memorial Lectures

To recognize Leonhard Euler’s 300th birthday, we sketch his life and give a brief survey of some of his mathematical achievements.

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 …

Stone's Representation Theorem, Ion Radu

Theses Digitization Project

The thesis analyzes some aspects of the theory of distributive lattices, particularly two representation theorems: Birkhoff's representation theorem for finite distributive lattices and Stone's representation theorem for infinite distributive lattices.

Mordell-Weil Theorem And The Rank Of Elliptical Curves, Hazem Khalfallah

Theses Digitization Project

The purpose of this thesis is to give a detailed group theoretic proof of the rank formula in a more general setting. By using the proof of Mordell-Weil theorem, a formula for the rank of the elliptical curves in certain cases over algebraic number fields can be obtained and computable.

Construction Of Finite Homomorphic Images, Jane Yoo

Theses Digitization Project

The purpose of this thesis is to construct finite groups as homomorphic images of progenitors.

Tutte Polynomial In Knot Theory, David Alan Petersen

Theses Digitization Project

This thesis reviews the history of knot theory with an emphasis on the diagrammatic approach to studying knots. Also covered are the basic concepts and notions of graph theory and how these two fields are related with an example of a knot diagram and how to associate it to a graph.

The Wright Message, 2007, University Of Northern Iowa. Department Of Mathematics.

The Wright Message

Inside this issue:

-- Dear Department Alumni and Friends
-- 2007 - 2008 Tenure or Tenure-Track Faculty
-- New Faces in the Mathematics Department
-- Faculty Notes
-- Alumni Survey Conducted
-- Actuarial Program Thrives
-- Board of Regents Collaborative Mathematics and Science Initiative
-- TEAM News
-- DoDEA/UNI Project
-- Online Course Development
-- Math Day at UNI
-- First Millar Scholarship Awarded
-- In Memory of Paul Trafton
-- Major Gifts to the Department

Programming With Perltex, Andrew Mertz, William Slough

Faculty Research and Creative Activity

PerlTEX couples two well-known worlds—the Perl programming language and the LATEX typesetting system. The resulting system provides users with a way to augment LATEX macros with Perl code, thereby adding programming capabilities to LATEX that would otherwise be difficult to express. In this paper, we illus- trate the use of PerlTEX with a variety of examples and explain the associated Perl code. Although Perl may perhaps be best known for its string manipula- tion capabilities, we demonstrate how PerlTEX indirectly provides support for “programming” graphics through the use of additional packages such as TikZ.

A Philosophical Examination Of Proofs In Mathematics, Eric Almeida

Undergraduate Review

No abstract provided.

The Sheffer Group And The Riordan Group, Tian-Xiao He, Peter Shiue, Leetsch Hsu

Scholarship

We define the Sheffer group of all Sheffer-type polynomials and prove the isomorphism between the Sheffer group and the Riordan group. An equivalence of the Riordan array pair and generalized Stirling number pair is also presented. Finally, we discuss a higher dimensional extension of Riordan array pairs.

Construction Of Biorthogonal B-Spline Type Wavelet Sequences With Certain Regularities, Tian-Xiao He

Scholarship

No abstract provided.

Two Number-Theoretic Problems That Illustrate The Power And Limitations Of Randomness, Andrew Shallue

Scholarship

This thesis contains work on two problems in algorithmic number theory. The first problem is to give an algorithm that constructs a rational point on an elliptic curve over a finite field. A fast and easy randomized algorithm has existed for some time. We prove that in the case where the finite field has characteristic 2, there is a deterministic algorithm with the same asymptotic running time as the existing randomized algorithm.

Some Transitivity Results For Torsion Abelian Groups, Brendan Goldsmith, Lutz Strungmann

Articles

We introduce a new class of fully transitive and transitive Abelian p-groups and study the new concept of weak transitivity which is the missing link between full transitivity and transitivity.

Shellability Of Noncrossing Partition Lattices, Colum Watt, Thomas Brady, Christos Athanasiadis

Articles

We give a case-free proof that the lattice of noncrossing partitions associated to any finite real reflection group is EL-shellable. Shellability of these lattices was open for the groups of type $D_n$ and those of exceptional type and rank at least three.

[Introduction To] Nonparametric Statistics With Applications To Science And Engineering, Paul Kvam, Brani Vidakovic

Bookshelf

This book presents a practical approach to nonparametric statistical analysis and provides comprehensive coverage of both established and newly developed methods. With the use of MATLAB, the authors present information on theorems and rank tests in an applied fashion, with an emphasis on modern methods in regression and curve fitting, bootstrap confidence intervals, splines, wavelets, empirical likelihood, and goodness-of-fit testing.

Nonparametric Statistics with Applications to Science and Engineering begins with succinct coverage of basic results for order statistics, methods of categorical data analysis, nonparametric regression, and curve fitting methods. The authors then focus on nonparametric procedures that are becoming more …

[Introduction To] Schaum's Outline Of Data Structures With Java, John R. Hubbard

Bookshelf

Schaum's Outlines are the key to faster learning and higher grades in every subject. Each Outline presents all the essential course information in an easy-to-follow, topic-by-topic format. You also get hundreds of examples, solved problems, and practice exercises to test your skills.

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Fully compatible with your classroom text, Schaum's highlights all the important facts you need to know.