Open Access. Powered by Scholars. Published by Universities.®

Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

2008

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 511 - 540 of 586

Full-Text Articles in Mathematics

Length Bias In The Measurements Of Carbon Nanotubes, Paul H. Kvam Jan 2008

Length Bias In The Measurements Of Carbon Nanotubes, Paul H. Kvam

Department of Math & Statistics Faculty Publications

To measure carbon nanotube lengths, atomic force microscopy and special software are used to identify and measure nanotubes on a square grid. Current practice does not include nanotubes that cross the grid, and, as a result, the sample is length-biased. The selection bias model can be demonstrated through Buffon’s needle problem, extended to general curves that more realistically represent the shape of nanotubes observed on a grid. In this article, the nonparametric maximum likelihood estimator is constructed for the length distribution of the nanotubes, and the consequences of the length bias are examined. Probability plots reveal that the corrected length …

Go to article

Degradation Models, Suk Joo Bae, Paul H. Kvam Jan 2008

Degradation Models, Suk Joo Bae, Paul H. Kvam

Department of Math & Statistics Faculty Publications

Reliability testing typically generates product lifetime data, but for some tests, covariate information about the wear and tear on the product during the life test can provide additional insight into the product’s lifetime distribution. This usage, or degradation, can be the physical parameters of the product (e.g., corrosion thickness on a metal plate) or merely indicated through product performance (e.g., the luminosity of a light emitting diode). The measurements made across the product’s lifetime are degradation data, and degradation analysis is the statistical tool for providing inference about the lifetime distribution from the degradation data.

Go to article

Indestructible Blaschke Products, William T. Ross Jan 2008

Indestructible Blaschke Products, William T. Ross

Department of Math & Statistics Faculty Publications

No abstract provided.

Go to article

G-Perfect Nonlinear Functions, James A. Davis, Laurent Poinsot Jan 2008

G-Perfect Nonlinear Functions, James A. Davis, Laurent Poinsot

Department of Math & Statistics Faculty Publications

Perfect nonlinear functions are used to construct DES-like cryptosystems that are resistant to differential attacks. We present generalized DES-like cryptosystems where the XOR operation is replaced by a general group action. The new cryptosystems, when combined with G-perfect nonlinear functions (similar to classical perfect nonlinear functions with one XOR replaced by a general group action), allow us to construct systems resistant to modified differential attacks. The more general setting enables robust cryptosystems with parameters that would not be possible in the classical setting. We construct several examples of G-perfect nonlinear functions, both Z2 -valued and Za …

Go to article

Load Sharing Models, Paul H. Kvam, Jye-Chyi Lu Jan 2008

Load Sharing Models, Paul H. Kvam, Jye-Chyi Lu

Department of Math & Statistics Faculty Publications

Consider a system of components whose lifetimes are governed by a probability distribution. Load sharing refers to a model of stochastic interdependency between components that operate within a system. If components are set up in a parallel system (see Parallel, Series, and Series–Parallel Systems) for example, the system survives as long as at least one component is operating. In a typical load-sharing system, once a component fails, the remaining components suffer an increase in failure rate due to the extra “load” they must encumber due to the failed component.

Go to article

Selecting U.S. Senators By The Original Method: Intersecting Mathematics And Social Studies, Bonnie H. Litwiller, David R. Duncan Jan 2008

Selecting U.S. Senators By The Original Method: Intersecting Mathematics And Social Studies, Bonnie H. Litwiller, David R. Duncan

Faculty Work

Mathematics teachers are concerned with incorporating connections with other academic areas in their mathematics curriculum. Social science provides a rich source of data which can be collected, organized, and interpreted by mathematics students. These data become of particular interest to many students if they involve political questions and processes.

Go to article

Statistical Issues In The Normalization Of Multi-Species Microarray Data, John R. Stevens, Balasubramanian Ganesan, Prerak Desai, Sweta Rajan, Bart C. Weimer Jan 2008

Statistical Issues In The Normalization Of Multi-Species Microarray Data, John R. Stevens, Balasubramanian Ganesan, Prerak Desai, Sweta Rajan, Bart C. Weimer

Mathematics and Statistics Faculty Publications

Several species of bacteria are involved in the production of cheese, including Lactobacillus brevis and Lactococcus lactis. A custom-designed Affymetrix microarray was recently developed to study gene expression in three organisms on a single chip. This array contains only perfect match features for the coding and non-coding regions in the genomes of all three sequences. The multi-species nature of this array version raises interesting questions regarding the preprocessing or normalization strategies for the analysis of gene expression data. We present and evaluate several possible strategies using both cDNA dilution data and experimental expression data from a repeated measures design. …

Go to article

Writing Representations Over Proper Division Subrings, Stephen P. Glasby Jan 2008

Writing Representations Over Proper Division Subrings, Stephen P. Glasby

All Faculty Scholarship for the College of the Sciences

Let �� be a division ring, and G a finite group of automorphisms of E whose elements are distinct modulo inner automorphisms of ��. Let �� = ��G be the division subring of elements of �� fixed by G. Given a representation p : �� →��d×d of an �� -algebra ��, we give necessary and sufficient conditions for p to be writable over ��. (Here ��d×d denotes the algebra of d×d matrices over ��, and a matrix A writes p over �� if A−1p(��)A ⊆ Fd×d.) We give an algorithm for constructing an …

Go to article

Modelling Asset Prices Under Regime Switching Diffusions Via First Passage Time, Xiaojing Xi Jan 2008

Modelling Asset Prices Under Regime Switching Diffusions Via First Passage Time, Xiaojing Xi

Theses and Dissertations (Comprehensive)

In this thesis we focus on the development of a new class of stochastic models for asset price processes and their application to option pricing and hedging. The asset price process involves analytical treatments for calculating first-hitting (or first-passage) times for a regular diffusion with killing in combination with Markov state-switching. The dynamics is naturally dictated by the underlying diffusion process itself rather than arising from some addition exogenous process. To date, this class of asset pricing models appears to be novel in the literature and, moreover, offers a significant to the standard geometric Brownian motion commonly used in the …

Go to article

Best P-Simultaneous Approximation In Some Metric Space, Mona Khandaqji, Wasfi Shatanawi Jan 2008

Best P-Simultaneous Approximation In Some Metric Space, Mona Khandaqji, Wasfi Shatanawi

Turkish Journal of Mathematics

Let X be a Banach space, (I,\mu) be a finite measure space, and \Phi be an increasing subadditive continuous function on [0,+\infty) with \Phi(0)=0. In the present paper, we discuss the best p-simultaneous approximation of L^\Phi(I,G) in L^\Phi(I,X) where G is a closed subspace of X.

Go to article

Trace Classes And Fixed Points For The Extended Modular Group \Overline{\Gamma}, Özden Koruoğlu, Recep Şahi̇n, Sebahatti̇n İki̇kardeş Jan 2008

Trace Classes And Fixed Points For The Extended Modular Group \Overline{\Gamma}, Özden Koruoğlu, Recep Şahi̇n, Sebahatti̇n İki̇kardeş

Turkish Journal of Mathematics

The extended modular group \overline{\Gamma}=PGL(2,\mathbb{Z}) is the group obtained by adding the reflection R(z)=1/\overline{z} to the generators of the modular group \Gamma =PSL(2, {Z}). In this paper, we find the trace classes of the extended modular group \overline{\Gamma}. Using this, we classify the elements of \overline{\Gamma}.

Go to article

On The Regular Elements In Z_N, Osama Alkam, Emad Abu Osba Jan 2008

On The Regular Elements In Z_N, Osama Alkam, Emad Abu Osba

Turkish Journal of Mathematics

All rings are assumed to be finite commutative with identity element. An element a \in R is called a regular element if there exists b \in R such that a=a^2b, the element b is called a von Neumann inverse for a. A characterization is given for regular elements and their inverses in Z_n, the ring of integers modulo n. The arithmetic function V(n), which counts the regular elements in Z_n is studied. The relations between V(n) and Euler's phi-function \varphi (n) are explored.

Go to article

A Decomposition Method For Solving Unsteady Convection-Diffusion Problems, Shaher Momani Jan 2008

A Decomposition Method For Solving Unsteady Convection-Diffusion Problems, Shaher Momani

Turkish Journal of Mathematics

In this study, a decomposition method for approximating the solutions of unsteady convection-diffusion problems is implemented. The approximate solution is calculated in the form of a convergent series with easily computable components. The calculations are accelerated by using the noise terms phenomenon for nonhomogeneous problems. Numerical examples are investigated to illustrate the pertinent features of the proposed algorithm.

Go to article

Mirror Principle For Flag Manifolds, Vehbi̇ Emrah Paksoy Jan 2008

Mirror Principle For Flag Manifolds, Vehbi̇ Emrah Paksoy

Turkish Journal of Mathematics

In this paper, using mirror principle developped by Lian, Liu and Yau [8, 9, 10, 11, 12, 13] we obtained the A and B series for the equivariant tangent bundles over homogenous spaces using Chern polynomial. This is necessary to obtain related cohomology valued series for given arbitrary vector bundle and multiplicative characteristic class. Moreover, this can be used as a valuable testing ground for the theories which associates quantum cohomologies and J functions of non-abelian quotient to abelian quotients via quantization.

Go to article

Mixed Type Of Integral Equation With Potential Kernel, Mohamed Abdella A. Abdou, Gamal Mohamed Abd Al-Kader Jan 2008

Mixed Type Of Integral Equation With Potential Kernel, Mohamed Abdella A. Abdou, Gamal Mohamed Abd Al-Kader

Turkish Journal of Mathematics

This paper presents the solution of an integral equation of a mixed type in three-dimensions in the space L_2 (\Omega) \times C[0,T], where T < \infty, and \Omega is the domain of integration with respect to position. The kernel of position integral term is considered in the potential function form, while the kernel of time is considered as a continuous kernel. A linear system of Fredholm integral equations of the first and second kinds are obtained and solved. Krein's method is used to solve the Fredholm integral equation of the first kind, while the second kind is solved numerically.

Go to article

Cover For Modules And Injective Modules, N. Amiri Jan 2008

Cover For Modules And Injective Modules, N. Amiri

Turkish Journal of Mathematics

Let R be a commutative ring with identity and M be an R-module with Spec(M) \neq \phi. A cover of the R-submodule K of M is a subset C of Spec(M) satisfying that for any x \in K, x \neq 0, there is N \in C such that ann(x) \subset (N:M). If we denote by J = \bigcap_{N \in C} (N:M) and assume that M is finitely generated, then JM=M implies that M=0, M is called C-injective provided each R-homomorphism \phi : (N:M) \rightarrow M with N \in C can be lifted to an R-homomorphism \lambda : R \rightarrow M. …

Go to article

Nonexistence Of Stable Exponentially Harmonic Maps From Or Into Compact Convex Hypersurfaces In R^{M+1}, Jiancheng Liu Jan 2008

Nonexistence Of Stable Exponentially Harmonic Maps From Or Into Compact Convex Hypersurfaces In R^{M+1}, Jiancheng Liu

Turkish Journal of Mathematics

In this paper, we study the nonexistence problems for stable exponentially harmonic map into or from compact convex hypersurface M^m \subset R^{m+1}, and show that every nonconstant exponentially harmonic map f, between M^m and any compact Riemannian manifold, is unstable if (4) holds.

Go to article

On Non-Existence Of Lightlike Hypersurfaces Of Indefinite Kenmotsu Space Form, Nesi̇p Aktan Jan 2008

On Non-Existence Of Lightlike Hypersurfaces Of Indefinite Kenmotsu Space Form, Nesi̇p Aktan

Turkish Journal of Mathematics

In this paper, lightlike hypersurfaces of indefinite Kenmotsu space form are studied. Some characterizations of non-existence of lightlike hypersurfaces of indefinite Kenmotsu space form are given.

Go to article

Cr-Submanifolds Of An S-Manifold, A. Alghanemi Jan 2008

Cr-Submanifolds Of An S-Manifold, A. Alghanemi

Turkish Journal of Mathematics

The study of CR-submanifolds of a Kaehler manifold was initiated by Bejancu [1]. Since then many papers have appeared on CR-submanifolds. The purpose of this paper is to studied the CR-submanifolds of an S-manifold. In particular, we studied the integrability of the distributions D and D^{\bot} of a CR-submanifold of an S-manifold.

Go to article

Real Gromov-Witten Invariants On The Moduli Space Of Genus 0 Stable Maps To A Smooth Rational Projective Space, Seongchun Kwon Jan 2008

Real Gromov-Witten Invariants On The Moduli Space Of Genus 0 Stable Maps To A Smooth Rational Projective Space, Seongchun Kwon

Turkish Journal of Mathematics

We characterize transversality, non-transversality properties on the moduli space of genus 0 stable maps to a rational projective surface. If a target space is equipped with a real structure, i.e, anti-holomorphic involution, then the results have real enumerative applications. Firstly, we can define a real version of Gromov-Witten invariants. Secondly, we can prove the invariance of Welschinger's invariant in algebraic geometric category.

Go to article

Proximinality In L^1(I,X), Sharifa Al-Sharif, R. Khalil Jan 2008

Proximinality In L^1(I,X), Sharifa Al-Sharif, R. Khalil

Turkish Journal of Mathematics

Let X be a Banach space and let (I,\Omega ,\mu) be a measure space. For 1 \leq p < \infty, let L^p(I,X) denote the space of Bochner p-integrable functions defined on I with values in X. The object of this paper is to give sufficient conditions for the proximinality of L^1(I,H)+L^1(I,G) in L^1(I,X), where H and G are two proximinal subspaces of X which include as a special case the proximality of L^1(I) \stackrel{\wedge}{\otimes} G + H \stackrel{\wedge}{\otimes} L^1(I) in L^1(I \times I).

Go to article

Posner´S Second Theorem And An Annihilator Condition With Generalized Derivations, Vincenzo De Filippis Jan 2008

Posner´S Second Theorem And An Annihilator Condition With Generalized Derivations, Vincenzo De Filippis

Turkish Journal of Mathematics

Let R be a prime ring of characteristic different from 2, with extended centroid C, U its two-sided Utumi quotient ring, \delta\neq 0 a non-zero generalized derivation of R, f(x_1,..,x_n) a non-central multilinear polynomial over C in n non-commuting variables, a \in R such that a[\delta(f(r_1,..,r_n)),f(r_1,..,r_n)]=0, for any r_1,..,r_n \in R. Then one of the following holds: 1. a=0; 2. there exists \lambda \in C such that \delta(x)=\lambda x, for all x \in R; 3. there exist q \in U and \lambda \in C such that \delta(x)=(q+\lambda)x+xq, for all x\in R, and f(x_1,..,x_n)^2 is central valued on R.

Go to article

Diametral Dimension And Köthe Spaces, Tosun Terzi̇oğlu Jan 2008

Diametral Dimension And Köthe Spaces, Tosun Terzi̇oğlu

Turkish Journal of Mathematics

We generalize some well-known results about the diametral dimension of classical Köthe spaces

Go to article

Metric Trees, Hyperconvex Hulls And Extensions, Asuman G. Aksoy, B. Maurizi Jan 2008

Metric Trees, Hyperconvex Hulls And Extensions, Asuman G. Aksoy, B. Maurizi

Turkish Journal of Mathematics

In this paper we examine the relationship between hyperconvex hulls and metric trees. After providing a linking construction for hyperconvex spaces, we show that the four-point property is inherited by the hyperconvex hull, which leads to the theorem that every complete metric tree is hyperconvex. We also consider some extension theorems for these spaces.

Go to article

Basic Properties And Multipliers Space On L^{1}(G)\Cap L(P,Q)(G) Spaces, İlker Eryilmaz, Cenap Duyar Jan 2008

Basic Properties And Multipliers Space On L^{1}(G)\Cap L(P,Q)(G) Spaces, İlker Eryilmaz, Cenap Duyar

Turkish Journal of Mathematics

Let G be locally compact Abelian group with Haar measure. First is discussed some properties of L^{1}(G) \cap L(p,q)(G) spaces. Then is mentioned the multipliers space on L^{1}(G) \cap L(p,q) (G) spaces.

Go to article

On The Distribution Of Random Dirichlet Series In The Whole Plane, Qiyu Jin, Daochun Sun Jan 2008

On The Distribution Of Random Dirichlet Series In The Whole Plane, Qiyu Jin, Daochun Sun

Turkish Journal of Mathematics

For some random Dirichlet series of order(R) infinite almost surely, every horizontal line is a strong Borel line of order(R) infinite and without exceptional Little functions.

Go to article

Lyapunov-Type Inequalities For Certain Nonlinear Systems On Time Scales, Mehmet Ünal, Devri̇m Çakmak Jan 2008

Lyapunov-Type Inequalities For Certain Nonlinear Systems On Time Scales, Mehmet Ünal, Devri̇m Çakmak

Turkish Journal of Mathematics

In this study, we prove Lyapunov-type inequalities for certain nonlinear systems on an arbitrary time scale T by using elementary time scale calculus. These inequalities enable us to obtain a criterion of disconjugacy for such systems. Special cases of our results contain the classical Lyapunov inequality for both differential and difference equations.

Go to article

On Some Algebraic Properties Of Semi-Discrete Hyperbolic Type Equations, İsmagi̇l Habibullin, Asli Pekcan, Natalya Zheltukhina Jan 2008

On Some Algebraic Properties Of Semi-Discrete Hyperbolic Type Equations, İsmagi̇l Habibullin, Asli Pekcan, Natalya Zheltukhina

Turkish Journal of Mathematics

Nonlinear semi-discrete equations of the form t_x(n+1) = f(t(n), t(n+1), t_x(n)) are studied. An adequate algebraic formulation of the Darboux integrability is discussed and an attempt to adopt this notion to the classification of Darboux integrable chains has been undertaken.

Go to article

On Certain Type Of Modular Sequence Spaces, Manjul Gupta, Shesadev Pradhan Jan 2008

On Certain Type Of Modular Sequence Spaces, Manjul Gupta, Shesadev Pradhan

Turkish Journal of Mathematics

In this paper we consider a particular type of modular sequence spaces defined with the help of a given sequence \alpha = {\alpha_n} of strictly positive real numbers \alpha_n's and an Orlicz function M. Indeed, if we define M_n(x) = M(\alpha_nx) and \tildeM_n(x)=M(x/\alpha_n), x\in[0, \infty), we consider the modular sequence spaces l{M_n} and l{\tildeM_n}, denoted by l_M^{\alpha} and l_{\alpha}^M respectively. These are known to be BK-spaces and if M satisfies \Delta_2-condition, they are AK-spaces as well. However, if we consider the spaces l_{\alpha}^M and l_n^{\alpha} corresponding to two complementary Orlicz functions M and N satisfying \Delta_2-condition, they are perfect sequence …

Go to article

On Generalized Solution Of A Class Of Higher Order Operator-Differential Equations, Rovshan Z. Gumbataliev Jan 2008

On Generalized Solution Of A Class Of Higher Order Operator-Differential Equations, Rovshan Z. Gumbataliev

Turkish Journal of Mathematics

In this paper the sufficient conditions on the existence and uniqueness of a generalized solution on the axis are obtained for higher order operator-differential equations, the main part of which is multi characteristic.

Go to article

First Prev Next Last