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Full-Text Articles in Physical Sciences and Mathematics

Countable Groups As Fundamental Groups Of Compacta In Four-Dimensional Euclidean Space, Ziga Virk Aug 2009

Countable Groups As Fundamental Groups Of Compacta In Four-Dimensional Euclidean Space, Ziga Virk

Doctoral Dissertations

This dissertation addresses the question of realization of countable groups as funda- mental groups of continuum. In first chapter we discuss classical realizations in the category of CW complexes. We introduce Eilenberg-Maclane spaces and their topological properties. The second chapter provides recent developments on realization question such as those of Shelah, Keesling, ... The third chapter proves the realization theorem for countable groups. The re- sulting space is compact path connected, connected subspace of four dimensional Euclidean space.


Optimal Control Applied To Population And Disease Models, Rachael Lynn Miller Neilan Aug 2009

Optimal Control Applied To Population And Disease Models, Rachael Lynn Miller Neilan

Doctoral Dissertations

This dissertation considers the use of optimal control theory in population models for the purpose of characterizing strategies of control which minimize an invasive or infected population with the least cost. Three different models and optimal control problems are presented. Each model describes population dynamics via a system of differential equations and includes the effects of one or more control methods.

The first model is a system of two ordinary differential equations describing dynamics between a native population and an invasive population. Population growth terms are functions of the control, constructed so that the value of the control may affect …


Two-Step Variations For Processes Driven By Fractional Brownian Motion With Application In Testing For Jumps From The High Frequency Data, Shiying Si Aug 2009

Two-Step Variations For Processes Driven By Fractional Brownian Motion With Application In Testing For Jumps From The High Frequency Data, Shiying Si

Doctoral Dissertations

In this dissertation we introduce the realized two-step variation of stochastic processes and develop its asymptotic theory for processes based on fractional Brownian motion and on more general Gaussian processes with stationary increments. The realized two-step variation is analogous to the realized 1, 1-order bipower variation introduced by Barndorff-Nielsen and Shephard [8] but mathematically is simpler to deal with. The powerful techniques of Wiener/Itˆo/Malliavin calculus for establishing limit laws play a key rule in our proofs. We include some stochastic simulations as an illustration of our theory. As a result of our study, we provide test statistics for testing for …


Correction To “The Theory Of Quaternion Orthogonal Designs”, Tadeusz Wysocki, Beata Wysocki, Sarah Spence Adams Jul 2009

Correction To “The Theory Of Quaternion Orthogonal Designs”, Tadeusz Wysocki, Beata Wysocki, Sarah Spence Adams

Sarah Spence Adams

Seberry et al. claimed that even though the dual-polarized transmission channel cannot be considered as described by means of a single quaternionic gain, the maximum-likelihood (ML) decoding rule can be decoupled for orthogonal space–time-polarization block codes (OSTPBCs) derived from quaternion orthogonal designs (QODs) [1, Sec. IV]. Regretfully, a correction is necessary, and we will show that decoupled decoding using the method presented therein is only optimal for codes derived from certain QODs, not from arbitrary QODs as previously suggested.


Statistical Investigation Of Structure In The Discrete Logarithm, Andrew Hoffman Jul 2009

Statistical Investigation Of Structure In The Discrete Logarithm, Andrew Hoffman

Mathematical Sciences Technical Reports (MSTR)

The absence of an efficient algorithm to solve the Discrete Logarithm Problem is often exploited in cryptography. While exponentiation with a modulus is extremely fast with a modern computer, the inverse is decidedly not. At the present time, the best algorithms assume that the inverse mapping is completely random. Yet there is at least some structure, and to uncover additional structure that may be useful in constructing or refining algorithms, statistical methods are employed to compare modular exponential mappings to random mappings. More concretely, structure will be defined by representing the mappings as functional graphs and using parameters from graph …


Discrete Logarithm Over Composite Moduli, Marcus L. Mace Jul 2009

Discrete Logarithm Over Composite Moduli, Marcus L. Mace

Mathematical Sciences Technical Reports (MSTR)

In an age of digital information, security is of utmost importance. Many encryption schemes, such as the Diffie-Hellman Key Agreement and RSA Cryptosystem, use a function which maps x to y by a modular power map with generator g. The inverse of this function - trying to find x from y - is called the discrete logarithm problem. In most cases, n is a prime number. In some cases, however, n may be a composite number. In particular, we will look at when n = p^b for a prime p. We will show different techniques of obtaining graphs of this …


Structural Properties Of Power Digraphs Modulo N, Joseph Kramer-Miller Jul 2009

Structural Properties Of Power Digraphs Modulo N, Joseph Kramer-Miller

Mathematical Sciences Technical Reports (MSTR)

We define G(n, k) to be a directed graph whose set of vertices is {0, 1, ..., n−1} and whose set of edges is defined by a modular relation. We say that G(n, k) is symmetric of order m if we can partition G(n, k) into subgraphs, each containing m components, such that all the components in a subgraph are isomorphic. We develop necessary and sufficient conditions for G(n, k) to contain symmetry when n is odd and square-free. Additionally, we use group theory to describe the structural properties of the subgraph of G(n, k) containing only those vertices relatively …


Comic Books That Teach Mathematics, Bruce Kessler Jul 2009

Comic Books That Teach Mathematics, Bruce Kessler

Bruce Kessler

During the 2008--2009 academic year, the author embarked on an extremely non-standard curriculum path: developing comic books with embedded mathematics appropriate for 3rd through 6th grade students. With the help of an education professor to measure impact, an elementary-school principal, and talented undergraduate illustrators, this project came to fruition and the comics were implemented in elementary classrooms at Cumberland Trace Elementary in the Warren County School System in Bowling Green, Kentucky. This talk gives the motivation for the idea, introduces the characters, and how the comics integrated the math content into the stories.


Comic Books That Teach Mathematics, Bruce Kessler Jul 2009

Comic Books That Teach Mathematics, Bruce Kessler

Bruce Kessler

During the 2008--2009 academic year, the author embarked on an extremely non-standard curriculum path: developing comic books with embedded mathematics appropriate for 3rd through 6th grade students. With the help of an education professor to measure impact, an elementary-school principal, and talented undergraduate illustrators, this project came to fruition and the comics were implemented in elementary classrooms at Cumberland Trace Elementary in the Warren County School System in Bowling Green, Kentucky. This manuscript gives the history of this idea, the difficulties of developing the content of the comics and getting them illustrated, and the implementation plan in the school.

A …


Using Works Of Visual Art To Teach Matrix Transformations, James Luke Akridge, Rachel Bowman, Peter Hamburger, Bruce Kessler Jul 2009

Using Works Of Visual Art To Teach Matrix Transformations, James Luke Akridge, Rachel Bowman, Peter Hamburger, Bruce Kessler

Bruce Kessler

The authors present a modern technique for teaching matrix transformations on $\R^2$ that incorporates works of visual art and computer programming. Two of the authors were undergraduate students in Dr. Hamburger's linear algebra class, where this technique was implemented as a special project for the students. The two students generated the images seen in this paper, and the movies that can be found on the accompanying webpage www.wku.edu/\~bruce.kessler/.


Isomorphism Of Schwartz Spaces Under Fourier Transform., Joydip Jana Dr. Jul 2009

Isomorphism Of Schwartz Spaces Under Fourier Transform., Joydip Jana Dr.

Doctoral Theses

Classical Fourier analysis derives much of its power from the fact that there are three function spaces whose images under the Fourier transform can be exactly determined. They are the Schwartz space, the L2 space and the space of all C ∞ functions of compact support. The determination of the image is obtained from the definition in the case of Schwartz space, through the Plancherel theorem for the L 2space and through the Paley-Wiener theorem for the other space.In harmonic analysis of semisimple Lie groups, function spaces on various restricted set-ups are of interest. Among the multitude of these spaces …


Versal Deformations Of Leibniz Algebra., Ashis Mandal Dr. Jul 2009

Versal Deformations Of Leibniz Algebra., Ashis Mandal Dr.

Doctoral Theses

No abstract provided.


Khovanov Homology, Sutured Floer Homology, And Annular Links, J. Elisenda Grigsby, Stephan M. Wehrli Jul 2009

Khovanov Homology, Sutured Floer Homology, And Annular Links, J. Elisenda Grigsby, Stephan M. Wehrli

Mathematics - All Scholarship

Lawrence Roberts, extending the work of Ozsvath-Szabo, showed how to associate to a link, L, in the complement of a fixed unknot, B in S3, a spectral sequence from the Khovanov homology of a link in a thickened annulus to the knot Floer homology of the preimage of B inside the double-branched cover of L. In a previous paper, we extended Ozsvath-Szabo's spectral sequence in a different direction, constructing for each knot K in S3 and each positive integer n, a spectral sequence from Khovanov's categorification of the reduced, n-colored Jones polynomial to the sutured Floer homology …


On The Naturality Of The Spectral Sequence From Khovanov Homology To Heegaard Floer Homology, J. Elisenda Grigsby, Stephan M. Wehrli Jul 2009

On The Naturality Of The Spectral Sequence From Khovanov Homology To Heegaard Floer Homology, J. Elisenda Grigsby, Stephan M. Wehrli

Mathematics - All Scholarship

Ozsvath and Szabo have established an algebraic relationship, in the form of a spectral sequence, between the reduced Khovanov homology of (the mirror of) a link L in S3 and the Heegaard Floer homology of its double-branched cover. This relationship has since been recast by the authors as a specific instance of a broader connection between Khovanov- and Heegaard Floer-type homology theories, using a version of Heegaard Floer homology for sutured manifolds developed by Juhasz. In the present work we prove the naturality of the spectral sequence under certain elementary TQFT operations, using a generalization of Juhasz's surface decomposition …


Quasiplurisubharmonic Green Functions, Dan Coman, Vincent Guedj Jul 2009

Quasiplurisubharmonic Green Functions, Dan Coman, Vincent Guedj

Mathematics - All Scholarship

Given a compact Kahler manifold X, a quasiplurisubharmonic function is called a Green function with pole at p in X if its Monge-Ampere measure is supported at p. We study in this paper the existence and properties of such functions, in connection to their singularity at p. A full characterization is obtainedin concrete cases, such as (multi)projective spaces.


Using Works Of Visual Art To Teach Matrix Transformations, James Luke Akridge, Rachel Bowman, Peter Hamburger, Bruce Kessler Jul 2009

Using Works Of Visual Art To Teach Matrix Transformations, James Luke Akridge, Rachel Bowman, Peter Hamburger, Bruce Kessler

Mathematics Faculty Publications

The authors present a modern technique for teaching matrix transformations on $\R^2$ that incorporates works of visual art and computer programming. Two of the authors were undergraduate students in Dr. Hamburger's linear algebra class, where this technique was implemented as a special project for the students. The two students generated the images seen in this paper, and the movies that can be found on the accompanying webpage www.wku.edu/\~{\space}bruce.kessler/.


Period-Doubling Bifurcation In An Array Of Coupled Stochastically Excitable Elements Subjected To Global Periodic Forcing, Robert Rovetti Jul 2009

Period-Doubling Bifurcation In An Array Of Coupled Stochastically Excitable Elements Subjected To Global Periodic Forcing, Robert Rovetti

Mathematics, Statistics and Data Science Faculty Works

The collective behaviors of coupled, stochastically excitable elements subjected to global periodic forcing are investigated numerically and analytically. We show that the whole system undergoes a period-doubling bifurcation as the driving period decreases, while the individual elements still exhibit random excitations. Using a mean-field representation, we show that this macroscopic bifurcation behavior is caused by interactions between the random excitation, the refractory period, and recruitment (spatial cooperativity) of the excitable elements.


Z-Transform Methods For The Optimal Design Of One-Dimensional Layered Elastic Media, Ani P. Velo, George A. Gazonas, Takanobu Ameya Jul 2009

Z-Transform Methods For The Optimal Design Of One-Dimensional Layered Elastic Media, Ani P. Velo, George A. Gazonas, Takanobu Ameya

Mathematics: Faculty Scholarship

In this work, we develop a finite trigonometric series representation for the stress in a multilayered Goupillaud-type elastic strip subjected to transient Heaviside loading on one end while the other end is held fixed. This representation is achieved by means of the z-transform method and involves the so-called base angles. Generally, different layered designs could share the same set of base angles, and the more layers the design has, the more base angles are expected. Necessary conditions for the base angles and design parameters for any given design are described. As a result of the stress representation, we are able …


Four-Body Problem With Collision Singularity, Duokui Yan Jul 2009

Four-Body Problem With Collision Singularity, Duokui Yan

Theses and Dissertations

In this dissertation, regularization of simultaneous binary collision, existence of a Schubart-like periodic orbit, existence of a planar symmetric periodic orbit with multiple simultaneous binary collisions, and their linear stabilities are studied. The detailed background of those problems is introduced in chapter 1. The singularities of simultaneous binary collision in the collinear four-body problem is regularized in chapter 2. We use canonical transformations to collectively analytically continue the singularities of the simultaneous binary collision solutions in both the decoupled case and the coupled case. All the solutions are found and more importantly, we find a crucial first integral which describes …


Wavelet Deconvolution In A Periodic Setting Using Cross-Validation, Leming Qu, Partha Routh, Kyungduk Ko Jul 2009

Wavelet Deconvolution In A Periodic Setting Using Cross-Validation, Leming Qu, Partha Routh, Kyungduk Ko

Kyungduk Ko

The wavelet deconvolution method WaveD using band-limited wavelets offers both theoretical and computational advantages over traditional compactly supported wavelets. The translation-invariant WaveD with a fast algorithm improves further. The twofold cross-validation method for choosing the threshold parameter and the finest resolution level in WaveD is introduced. The algorithm’s performance is compared with the fixed constant tuning and the default tuning in WaveD.


Bayesian Wavelet-Based Methods For The Detection Of Multiple Changes Of The Long Memory Parameter, Kyungduk Ko Jul 2009

Bayesian Wavelet-Based Methods For The Detection Of Multiple Changes Of The Long Memory Parameter, Kyungduk Ko

Kyungduk Ko

Long memory processes are widely used in many scientific fields, such as economics, physics, and engineering. Change point detection problems have received considerable attention in the literature because of their wide range of possible applications. Here we describe a wavelet-based Bayesian procedure for the estimation and location of multiple change points in the long memory parameter of Gaussian autoregressive fractionally integrated moving average models (ARFIMA(p, d, q)), with unknown autoregressive and moving average parameters. Our methodology allows the number of change points to be unknown. The reversible jump Markov chain Monte Carlo algorithm is used for posterior inference. The method …


Fixed Point Theory For Admissible Type Maps With Applications, Ravi P. Agarwal, Donal O'Regan Jul 2009

Fixed Point Theory For Admissible Type Maps With Applications, Ravi P. Agarwal, Donal O'Regan

Mathematics and System Engineering Faculty Publications

We present new Leray-Schauder alternatives, Krasnoselskii and Lefschetz fixed point theory for multivalued maps between Fréchet spaces. As an application we show that our results are directly applicable to establish the existence of integral equations over infinite intervals. Copyright © 2009 R. P. Agarwal and D. O'Regan


The Research On Optimization Of Liner Route Between China To Middle East, Tingyi Chen Jul 2009

The Research On Optimization Of Liner Route Between China To Middle East, Tingyi Chen

World Maritime University Dissertations

No abstract provided.


Research On Value-At-Risk In International Crude Oil Shipping Market, Xiaoyin Cui Jul 2009

Research On Value-At-Risk In International Crude Oil Shipping Market, Xiaoyin Cui

World Maritime University Dissertations

No abstract provided.


Economic Approach Of Piracy Along The Maritime Silk Road And Cost Analysis Of The Northern Sea Route, Petros Kelaiditis Jul 2009

Economic Approach Of Piracy Along The Maritime Silk Road And Cost Analysis Of The Northern Sea Route, Petros Kelaiditis

World Maritime University Dissertations

No abstract provided.


The Research On Risk Evaluation Of Shanghai Lng Import Program, Chao Lin Jul 2009

The Research On Risk Evaluation Of Shanghai Lng Import Program, Chao Lin

World Maritime University Dissertations

No abstract provided.


Research On Brand Strategies Of Cdl Company, Wei Gu Jul 2009

Research On Brand Strategies Of Cdl Company, Wei Gu

World Maritime University Dissertations

No abstract provided.


Marketing Analysis Of The Chinese Coffee Market: Suggestions For A Logistic System For The Colombian Coffee Exporters, Soraya Margarita Herrera Jaramillo Jul 2009

Marketing Analysis Of The Chinese Coffee Market: Suggestions For A Logistic System For The Colombian Coffee Exporters, Soraya Margarita Herrera Jaramillo

World Maritime University Dissertations

No abstract provided.


The Construction And Development Of Shanghai International Shipping Center, Shimin Wang Jul 2009

The Construction And Development Of Shanghai International Shipping Center, Shimin Wang

World Maritime University Dissertations

No abstract provided.


The Feasibility Analysis Of The Third Euro-Asia Continental Bridge, Tongyou Weng Jul 2009

The Feasibility Analysis Of The Third Euro-Asia Continental Bridge, Tongyou Weng

World Maritime University Dissertations

No abstract provided.