Physical Sciences and Mathematics Commons^™

Some Studies On Shape Of Dot Patterns., Anirban Ray Chaudhuri Dr.

Doctoral Theses

The important visual characteristics of an object are shape, size, color, brightness, contrast and texture. Of them, shape is a multidimensional concept that is difficult to define. It takes different meanings in different contexts. We try to explain it in terms of their attributes like elongation, roundness, and symmetry: although these terms do not capture the complete notion of shape.Perhaps Gestalt theory Koffka 351 is the first attempt to study the principles of visual perception in a systematic manner. The central concept of this theory is Gestalt' which means form or configuration. In this theory form is examined from physical. …

Studies Of Supply Responses In Indian Agriculture: Some Models For Planning Rational Food Supply., Nilabja Ghosh Dr.

Doctoral Theses

This thesis deals with food supply in a less developed country.In a world where social awareness together with technical progress is offering advances in all spheres of life, the persisting presence of hunger and malnutrition in any corner of the earth casts a shadow on all human achievements. It is said that over 800 million human beings in this world are suffering from hunger and a great majority of them live in Asia. Food problem has many dimensions (Timmer et al, 1983), but the solution lies mostly in adequate supply of foodgrains and proper distribution of the same. Any shortfall …

Time-Space Harmonic Polynomials For Stochastic Processes., Arindam Sengupta Dr.

Doctoral Theses

The sequence of polynomials of a single variable known as the Hermite polynomialshala) = ), k21, (-1)* ha(z) =has many close links with the Normal distribution. Their association goes very doep, and extends to several connections bet ween the two-variable Hermite polynomialsHll, 2) = the(z/t), . k21.and the prime example of Gaussian processes, that is Brownian motion, as well. Much of this connection stems from what we term the time-space harmonic property of these polynomials for the Brownian motion process. An exact definition of this property follows later. A natural question that arises is, for stochastic processes in general, when …

Pattern Classification Using Genetic Algorithms., Sanghamitra Bandyopadhyay Dr.

Doctoral Theses

Pattern recognition and machine learning form a major area of research and develop- ment activity that encompasses the processing of pictorial and other non-numerical information obtained from the interaction between science, technology and society. A motivation for the spurt of activity in this field is the need for people to com- municate with the computing machines in their natural mode of communication. Another important motivation is that the scientists are also concerned with the idea of designing and making intelligent machines that can carry out certain tasks that we human beings do. The most salient outcome of these is the …

Muyltivariate And Regression Analysis Based On The Geometry Of Data Clouds., Biman Chakraborty Dr.

Doctoral Theses

Median is a natural estimate of location of a data set, and there are several versions of inultivariate median studied in the literature, each of which is an interesting descriptive statistic for multivariate data and provides some nice geometric insights into the data cloud. One would expect that multidimensional median will be a natural estimate for the center of symmetry of a multivariate distribution. However, there is no unique concept of symmetry in multivariate problems. The center of symmetry can be defined in several ways there. For example, the d-dimensional random variable X is spherically symmetric about e €Rd if …

A Priori Lρ Error Estimates For Galerkin Approximations To Porous Medium And Fast Diffusion Equations, Dongming Wei, Lew Lefton

Mathematics Faculty Publications

Galerkin approximations to solutions of a Cauchy-Dirichlet prob-

lem governed by a generalized porous medium equation.

Computer Assistance For "Discovering'' Formulas In System Engineering And Operator Theory, J. W. Helton, Mark Stankus

Mathematics

The objective of this paper is two-fold. First we present a methodology for using a combination of computer assistance and human intervention to discover highly algebraic theorems in operator, matrix, and linear systems engineering theory. Since the methodology allows limited human intervention, it is slightly less rigid than an algorithm. We call it a strategy. The second objective is to illustrate the methodology by deriving four theorems. The presentation of the methodology is carried out in three steps. The first step is introducing an abstraction of the methodology which we call an idealized strategy. This abstraction facilitates a high level …

Invariant Measure For Diffusions With Jumps, Jose-Luis Menaldi, Maurice Robin

Mathematics Faculty Research Publications

Our purpose is to study an ergodic linear equation associated to diffusion processes with jumps in the whole space. This integro-differential equation plays a fundamental role in ergodic control problems of second order Markov processes. The key result is to prove the existence and uniqueness of an invariant density function for a jump diffusion, whose lower order coefficients are only Borel measurable. Based on this invariant probability, existence and uniqueness (up to an additive constant) of solutions to the ergodic linear equation are established.

Woven Rope Friezes, Frank A. Farris, Nils Kristian Rossing

Mathematics and Computer Science

Here we present a complete set of recipes showing how to construct smooth curves with any desired frieze symmetry; we provide examples woven by Rossing for many of the pattern types, and invite readers to make others. We review the concept of frieze symmetry, develop the formulas for parametric equations with given symmetries, and pose some open questions raised by our analysis.

Magic "Squares" Indeed, Arthur T. Benjamin, Kan Yasuda '97

All HMC Faculty Publications and Research

No abstract provided in this article.

Heating Water Vapor In A Square Cavity Using Molecular And Particle Mechanics, Donald Greenspan

Mathematics Technical Papers

This paper explores the computer simulation of heating water vapor in a square cavity. Both molecular and particle mechanics are applied. A particular parameter called vel, found on the micro level, is shown to be applicable on the macro level in generating both laminar and turbulent flows.

A Quadratic Fredholm Integral Equation And Its Solution For Various Kernels, Merlynd K. Nestell, Mostafa Ghandehari

Mathematics Technical Papers

Consider the Fredholm integral equation [see pdf for notation], a parameter. The solution of this equation is discussed for separable, difference and distribution kernels. Existence, uniqueness and bifurcation questions are explored for various assumptions on the kernel.

Single-Change Circular Covering Designs, John P. Mcsorley

Articles and Preprints

A single-change circular covering design (scccd) based on the set [v] = {1, . . . ,v} with block size k is an ordered collection of b blocks, B = {B₁, . . . ,B_b}, each B_i ⊂ [v], which obey: (1) each block differs from the previous block by a single element, as does the last from the first, and, (2) every pair of [v] is covered by some Bi. The object is to minimize b for a fixed v and k. …

Structure-Function Relationships In The Pulmonary Arterial Tree, Christopher A. Dawson, Gary S. Krenz, Kelly Lynn Karau, Steven Thomas Haworth, Christopher C. Hanger, John H. Linehan

Mathematics, Statistics and Computer Science Faculty Research and Publications

Knowledge of the relationship between structure and function of the normal pulmonary arterial tree is necessary for understanding normal pulmonary hemodynamics and the functional consequences of the vascular remodeling that accompanies pulmonary vascular diseases. In an effort to provide a means for relating the measurable vascular geometry and vessel mechanics data to the mean pressure-flow relationship and longitudinal pressure profile, we present a mathematical model of the pulmonary arterial tree. The model is based on the observation that the normal pulmonary arterial tree is a bifurcating tree in which the parent-to-daughter diameter ratios at a bifurcation and vessel distensibility are …

A Theoretical Study Of Bubble Motion In Surfactant Solutions, Yanping Wang

Dissertations

We examine the effect of surfactants on a spherical gas bubble rising steadily in an infinite fluid at low and order one Reynolds number with order one and larger Peclet numbers. Our mathematical model is based on the Navier-Stokes equations coupled with a convection-diffusion equation together with appropriate interfacial conditions. The nonlinearity of the equations and boundary conditions, and the coupling between hydrodynamics and surfactant transport make the problem very challenging.

When a bubble rises in a fluid containing surface-active agents, surfactant adsorbs onto the bubble surface at the leading edge, convects to the trailing edge by the surface flow …

Composition Operators On Hardy Spaces Of A Half-Plane, Valentin Matache

Mathematics Faculty Publications

We consider composition operators on Hardy spaces of a half-plane. We mainly study boundedness and compactness. We prove that on these spaces there are no compact composition operators.

Some Recent Developments In Difference Sets, James A. Davis, Jonathan Jedwab

Department of Math & Statistics Faculty Publications

There are five known parameter families for (v, k, λ, n)- difference sets satisfying gcd(v, n)>1: the Hadamard, McFarland, Spence, Davis-Jedwab, and Chen families. The authors recently gave a recursive unifying construction for difference sets from the first four families which relies on relative difference sets. We give an overview of this construction and show that, by modifying it to use divisible difference sets in place of relative difference sets, the recent difference set discoveries of Chen can be brought within the unifying framework. We also demonstrate the recursive use of an auxiliary construction for …

Elementary Inversion Of The Laplace Transform, Kurt M. Bryan

Mathematical Sciences Technical Reports (MSTR)

This paper provides an elementary derivation of a very simple "closed-form"

inversion formula for the Laplace Transform.

Relations In The Homotopy Of Simplicial Abelian Hopf Algebras, James M. Turner

University Faculty Publications and Creative Works

In this paper, we analyze the structure possessed by the homotopy groups of a simplicial abelian Hopf algebra over the field F2. Specifically, we review the higher-order structure that the homotopy groups of a simplicial commutative algebra and simplicial cocommutative coalgebra possess. We then demonstrate how these structures interact under the added conditions present in a Hopf algebra.

Constructing Kaleidscopic Tiling Polygons In The Hyperbolic Plane, Sean A. Broughton

Mathematical Sciences Technical Reports (MSTR)

We have all seen many of the beautiful patterns obtained by tiling the hyperbolic plane H by repeated reflection in the sides of a "kaleidoscopic" polygon. Though there are such patterns on the sphere and the euclidean plane, these positively curved and fiat geometries lack the richness we see in the hyperbolic plane. Many of these patterns have been popularized by the beautiful art of M.C. Escher. For a list of references and a more complete discussion on the construction of artistic tilings see [6].

Even Subgraphs Of A Graph, Hong-Jian Lai, Zhi-Hong Chen

Scholarship and Professional Work - LAS

No abstract provided.

A Sheaf Theoretic Approach To Consciousness, Goro Kato, Daniele C. Struppa

Mathematics

A new fundamental mathematical model of consciousness based on category theory is presented. The model is based on two philosophical-theological assumptions: a) the universe is a sea of consciousness, and b) time is multi-dimensional and non-linear.

Lack Of Time-Delay Robustness For Stabilization Of A Structural Acoustics Model, George Avalos, Irena Lasiecka, Richard Rebarber

Department of Mathematics: Faculty Publications

In this paper we consider a natural robustness question for a model for structural acoustics. This model, which has been of great interest in recent years, is represented by a wave equation in R^2 coupled to a Kelvin--Voigt beam; the coupling is natural physically, and is represented mathematically by highly unbounded operators. We assume that the observation consists of point evaluation of the beam position, the beam velocity, and the wave velocity. We are interested in the effect of arbitrarily small delays in the feedback loop on a controller that uses these observations. We show that it is not possible …

Martin Gardner = Mint! Grand! Rare!, Jeremiah Farrell

Scholarship and Professional Work - LAS

Jeremiah Farrell's contirbution to "The Mathemagician and Pied Puzzler: A Collection in Tribute to Martin Gardner"

Related works:

The puzzle from figure one is also available in Colloquy (Wordways 14,2) online at: http://digitalcommons.butler.edu/wordways/vol14/iss2/8/

Cube Puzzles, Jeremiah Farrell

Scholarship and Professional Work - LAS

Jeremiah Farrell's contribution to "The Mathemagician and Pied Puzzler: A Collection in Tribute to Martin Gardner"

03. Preface Of Design And Analysis Of Experiments - 1st Edition, Angela Dean, Dan Voss, Danel Draguljic

Design and Analysis of Experiments

Preface of the first edition of Design and Analysis of Experiments.

Time Delay In The Kuramoto Model Of Coupled Oscillators, Stephen M.K. Yeung, S H. Strogatz

Mathematics

We generalize the Kuramoto model of coupled oscillators to allow time-delayed interactions. New phenomena include bistability between synchronized and incoherent states, and unsteady solutions with time-dependent order parameters. We derive exact formulas for the stability boundaries of the incoherent and synchronized states, as a function of the delay, in the special case where the oscillators are identical. The experimental implications of the model are discussed for populations of chirping crickets, where the finite speed of sound causes communication delays, and for physical systems such as coupled phase-locked loops or lasers.

The Topological Snake Lemma And Corona Algebras, Claude Schochet

Mathematics Faculty Research Publications

We establish versions of the Snake Lemma from homological algebra in the context of topological groups, Banach spaces, and operator algebras. We apply this tool to demonstrate that if ƒ : B → B′ is a quasi-unital C^*-map of separable C^*-algebras, so that it induces a map of Corona algebras ƒ̄ : QB → QB′, and if ƒ is mono, then the induced map ƒ̄ is also mono.

Combinatorics Of Open Covers Vi: Selectors For Sequences Of Dense Sets, Marion Scheepers

Mathematics Faculty Publications and Presentations

We consider the following two selection principles for topological spaces:

[Principle 1:] { For each sequence of dense subsets, there is a sequence of points from the space, the n-th point coming from the n-th dense set, such that this set of points is dense in the space;

[Principle 2:]{ For each sequence of dense subsets, there is a sequence of finite sets, the n-th a subset of the n-th dense set, such that the union of these finite sets is dense in the space.

We show that for separable metric space X one of these principles holds for the …

Path Decompositions Of A Brownian Bridge Related To The Ratio Of Its Maximum And Amplitude, Jim Pitman, Marc Yor

Jim Pitman

We give two new proofs of Csaki's formula for the law of the ratio 1-Q of the maximum relative to the amplitude (i.e. the maximum minus minimum) for a standard Brownian bridge. The second of these proofs is based on an absolute continuity relation between the law of the Brownian bridge restricted to the event (Q < v) and the law of a process obtained by a Brownian scaling operation after back-to back joining of two independent three-dimensional Bessel processes, each started at v and run until it first hits 1. Variants of this construction and some properties of the joint law of Q and the amplitude are described.