Applied Mathematics Commons^™

Stability Of A Viscoelastic Burgers Flow, D. Glenn Lasseigne, W. E. Olmstead

Mathematics & Statistics Faculty Publications

The system of equations proposed by Burgers to model turbulent flow in a channel is extended to include viscoelastic affects. The stability and bifurcation properties are examined in the neighborhood of the critical Reynolds number. For highly elastic fluids, the bifurcated state is periodic with a shift in frequency.

On The Equivalence Of The Operator Equations Xa + Bx = C And X - P(-B)Xp(A)(-1) = W In A Hilbert-Space, P A Polynomial, Tapas Mazumdar, David Miller

Mathematics and Statistics Faculty Publications

We consider the solution of (*) XA+BX = C for bounded operators A,B,C and X on a Hilbert space, A normal. We establish the existence of a polynomial p and a bounded operator W with the property that the unique solution X of (*) also solves X − p(−B)Xp(A)⁻¹ = W uniquely. A known iterative algorithm can be applied to the latter equation to solve (*).

Boundary Value Problems In Elasticity And Thermoelasticity, Stuart Davidson

Mathematics & Statistics Theses & Dissertations

In this dissertation the author solves a series of mixed boundary value problems arising from crack problems in elasticity and thermoelasticity. Using integral transform techniques and separation of variables appropriately, it is shown that the solutions can be found by solving a corresponding set of triple or dual integral equations in some instances, while in others the solutions of triple or dual series relations are required. These in turn reduce to various singular integral equations which are solved in closed form, in two cases, or by numerical methods. The stress intensity factors at the crack tips, the physical parameters of …

The Truncated Cauchy Distribution: Estimation Of Parameters And Application To Stock Returns, Paul G. Staneski

Mathematics & Statistics Theses & Dissertations

The problem addressed in this dissertation is the existence and estimation of the parameters of a truncated Cauchy distribution. It is known that when a number of distributions with infinite support are truncated to a finite interval that the maximum likelihood estimator of the scale parameter fails to exist with positive probability. In particular, necessary and sufficient conditions which give rise to instances of non-existence have been found for the exponential (Deemer and Votaw (1955)), gamma (Broeder (1955), Hegde and Dahiya (1989)), Weibull (Mittal and Dahiya (1989)) and normal distribution (Barndorff-Nielsen (1978), Mittal and Dahiya (1987), Hegde and Dahiya (1989)). …

Graphs, Maneuvers, And Turnpikes, Arthur T. Benjamin

All HMC Faculty Publications and Research

We address the problem of moving a collection of objects from one subset of Z^m to another at minimum cost. We show that underfairly natural rules for movement assumptions, if the origin and destination are far enough apart, then a near optimal solution with special structure exists: Our trajectory from the originto the destination accrues almost all of its cost repeatingat most m different patterns of movement. Directions for related research are identified.

On The Optimal Reward Function Of The Continuous Time Multiarmed Bandit Problem, José Luis Menaldi, Maurice Robin

Mathematics Faculty Research Publications

The optimal reward function associated with the so-called "multiarmed bandit problem" for general Markov-Feller processes is considered. It is shown that this optimal reward function has a simple expression (product form) in terms of individual stopping problems, without any smoothness properties of the optimal reward function neither for the global problem nor for the individual stopping problems. Some results relative to a related problem with switching cost are obtained.

On The Lie Curvature Of Dupin Hypersurfaces, Thomas E. Cecil

Mathematics and Computer Science Department Faculty Scholarship

A hypersurface M in a standard sphere Sⁿ is said to be Dupin if each of its principal curvatures is constant along its corresponding curvature surfaces. If the number of distinct principal curvatures is constant, then M is called a proper Dupin hypersurface. There is a close relationship between the class of compact proper Dupin hypersurfaces and the class of isoparametric hypersurfaces. Miinzner [11] showed that the number g of distinct principal curvatures of an isoparametric hypersurface must be 1, 2, 3, 4 or 6. Thorbergsson [15] then showed that the same restriction holds for a compact proper Dupin …

Remarks On Estimates For The Green Function, Jose Luis Menaldi

Mathematics Faculty Research Publications

No abstract provided.

Strong Maximum Principles For Parabolic Nonlinear Problems With Nonlocal Inequalities Together With Integrals, Ludwik Byszewski

Mathematics and System Engineering Faculty Publications

In [4] and [5], the author studied strong maximum principles for nonlinear parabolic problems with initial and nonlocal inequalities, respectively. Our purpose here is to extend results in [4] and [5] to strong maximum principles for nonlinear parabolic problems with nonlocal inequalities together with integrals. The results obtained in this paper can be applied in the theories of diffusion and heat conduction, since considered here integrals in nonlocal inequalities can be interpreted as mean amounts of the diffused substance or mean temperatures of the investigated medium.

Existence And Uniqueness Of Solutions Of Nonlocal Problems For Hyperbolic Equation Uxt=F(X, T, U, Ux), L. Byszewski

Mathematics and System Engineering Faculty Publications

The aim of the paper is to give two theorems about existence and uniqueness of continuous solutions for hyperbolic nonlinear differential problems with nonlocal conditions in bounded and unbounded domains. The results obtained in this paper can be applied in the theory of elasticity with better effect than analogous known results with classical initial conditions.

Asymptotic Optimality Of Experimental Designs In Estimating A Product Of Means, Kamel Rekab

Mathematics and System Engineering Faculty Publications

In nonlinear estimation problems with linear models, one difficulty in obtaining optimal designs is their dependence on the true value of the unknown parameters. A Bayesian approach is adopted with the assumption the means are independent apriori and have conjuguate prior distributions. The problem of designing an exper- iment to estimate the product of the means of two normal populations is considered. The main results determine an asymptotic lower bound for the Bayes risk, and a necessary and sufficient condition for any sequential procedure to achieve the bound.

Wings And Perfect Graphs, Stephan Olariu

Computer Science Faculty Publications

An edge uv of a graph G is called a wing if there exists a chordless path with vertices u, v, x, y and edges uv, vx, xy. The wing-graph W(G) of a graph G is a graph having the same vertex set as G; uv is an edge in W(G) if and only if uv is a wing in G. A graph G is saturated if G is isomorphic to W(G). A star-cutset in a graph G is a non-empty set of …

A Characterization Of The Solution Of A Fredholm Integral Equation With L∞ Forcing Term, Hideaki Kaneko, Richard Noren, Yuesheng Xu

Mathematics & Statistics Faculty Publications

In this paper we investigate the regularity properties of the Fredholm equation (Formula Presented) . The kernel is the product of the smooth function k and the singular function gα (Formula Presented). The forcing function f is in L∞. We obtain a decomposition of the solution as the sum of two functions—one with a discontinuity reflecting that of the forcing function—and the other a regular function. Our results extend those of C. Schneider [6], who assumes a condition that is stronger than f ∈ C[a, b] ∩ C^m(a,b) (for some integer m). © 1990 …

A Generalization Of Linear Multistep Methods, Leon Arriola

Mathematics & Statistics Theses & Dissertations

A generalization of the methods that are currently available to solve systems of ordinary differential equations is made. This generalization is made by constructing linear multistep methods from an arbitrary set of monotone interpolating and approximating functions. Local truncation error estimates as well as stability analysis is given. Specifically, the class of linear multistep methods of the Adams and BDF type are discussed.

Best Quasi-Convex Uniform Approximation, S. E. Weinstein, Yuesheng Xu

Mathematics & Statistics Faculty Publications

No abstract provided.

Bivariate C1 Quadratic Finite Elements And Vertex Splines, Tian-Xiao He

Scholarship

No abstract provided.

Synthesis Of An Efficient Band Mechanism For Robots And Prosthetic Devices, Run Chen Zhou

Mechanical & Aerospace Engineering Theses & Dissertations

A noncircular pulley has been applied to improve the system efficiency of an electrical-powered elbow prosthesis. The dynamics of the motor and the prosthetic arm have been incorporated into the kinematic synthesis relationships for determining the pulley profile that maximizes the efficiency of the elbow prosthesis.

The nonlinear dynamic equations have been solved by the code Differential Equation (DE) while determining the motor power and efficiency which are the criteria in the nonlinear programming problem. The optimal design variables for determining the pulley profile along with some simulation results have been obtained from an optimization program (based on the Generalized …

The Chromatic Sum And Efficient Tree Algorithms, Ewa Kubicka

Dissertations

In Chapter I this concept is introduced. It is shown that computing the chromatic sum is NP-complete. For every natural k the smallest tree which needs k colors to attain its chromatic sum is constructed. It is demonstrated that asymptotically, for each k, almost all trees require more than k colors to achieve their chromatic sums. Also a linear algorithm for a single tree is presented.

In Chapter II three constructions of graphs that require t colors beyond their chromatic number k to achieve their chromatic sum are presented, depending on the ratio ${\rm t}\over{\rm k}$. The order of the …

Measures Of Partial Association Based On Rank Estimates, Sudhakar H. Rao

Dissertations

No abstract provided.

Greatest Common Subgraphs, Grzegorz Kubicki

Dissertations

No abstract provided.

Spatial Critical Points Of Solutions Of A One-Dimensional Nonlinear Parabolic Problem, Larry Turyn

Mathematics and Statistics Faculty Publications

The number of spatial critical points is nonincreasing in time, for positive, analytic solutions of a scalar, nonlinear, parabolic partial differential equation in one space dimension. While proving this, we answer the question: What happens to a critical point which loses simplicity?

Nonnegative Solutions For A Class Of Radially Symmetric Nonpositone Problems, Alfonso Castro, Ratnasingham Shivaji

All HMC Faculty Publications and Research

We consider the existence of radially symmetric non-negative solutions for the boundary value problem

\begin{displaymath}\begin{array}{*{20}{c}} { - \Delta u(x) = \lambda f(u(x))\qua... ...\\ {u(x) = 0\quad \left\Vert x \right\Vert = 1} \\ \end{array} \end{displaymath}

where $ \lambda > 0,f(0) < 0$ (non-positone), $ f' \geq 0$ and $ f$ is superlinear. We establish existence of non-negative solutions for $ \lambda $ small which extends some work of our previous paper on non-positone problems, where we considered the case $ N = 1$. Our work also proves a recent conjecture by Joel Smoller and Arthur Wasserman.

On The Dimension Of Bivariate Superspline Spaces, Tian-Xiao He

Scholarship

A bivariate piecewise polynomial function of total degree d on some grid partition △ that has rth order continuous partial derivatives everywhere may have higher-order partial derivatives at the vertices of the grid partition. In finite element considerations and in the construction of vertex splines, it happens that only those functions with continuous partial derivatives of order higher than r at the vertices are needed to give the same full approximation order as the entire space of piecewise polynomials. This is certainly the case for d > 4r + 1. Such piecewise polynomial functions are called supersplines. This …

Mathematical Models Of Prevascular Tumor Growth By Diffusion, Sophia A. Maggelakis

Mathematics & Statistics Theses & Dissertations

A study of several complementary mathematical models that describe the early, prevascular stages of solid tumor growth by diffusion under various simplifying assumptions is presented. The advantage of these models is that their degree of complexity is relatively low, which ensures fairly straightforward comparisons with experimental or clinical data (as it becomes available), yet they are mathematically sophisticated enough to capture the main biological phenomena of interest.

The tumor growth and cell proliferation rate are assumed to depend on the local concentrations of nutrients and inhibitory factors. The effects of geometry and spatially non-uniform inhibitor production and non-uniform nutrient consumption …

Simulated Annealing On Np-Complete Problems, Russell W. Howell

ACMS Conference Proceedings 1989

The Random House Dictionary defines anneal as " ... to free (glass, metals, etc.) from internal stress by heating and gradually cooling." In the physical world, impurities are annealed out of a substance by heating it to a high temperature. As it is cooled, its molecular structure gradually settles into a stable "low-energy" configuration. It is important to cool the substance slowly, especially at lower temperatures, so that impurities do not get "frozen" into place. With careful cooling, a low-energy state can eventually be reached. This state may not be the one with the lowest potential energy, where the spins …

The Mathematical Intelligencer, Dmitrii Egorov: Mathematics And Theology In Russia, Charles E. Ford

ACMS Conference Proceedings 1989

This paper tells the story of Russian mathematician Dmitri Egorov, recounting his faith and contributions to the field of mathematics.

A Course On Mathematics And The Christian Faith, W. David Laverell, Carl J. Sinke

ACMS Conference Proceedings 1989

The January interim term at Calvin College provides an opportunity for developing and teaching courses outside a normal major program. As a result faculty members are frequently given the interim off to provide time for research and development of new courses. In 1987 we were given such a leave in order to pursue the questions of the relationship between mathematics and the Christian Faith. One result was our presentation at the 1987 Association of Christians in the Mathematical Sciences conference. Immediately thereafter we began to develop a specific interim course based on our studies. We offered the course during the …

The Bisexual Galton-Watson Branching Process, David M. Hull

ACMS Conference Proceedings 1989

I would like to present the bisexual Galton-Watson branching process. The word "bisexual" indicates that we will be considering a population of two sexes--which will be designated as the usual male and female. Here is a brief overview of what I would like to cover.

1. The bisexual process motivated: why is it needed?
2. The standard Galton-Watson branching process.
3. The state of affairs regarding two-sex models.
4. The nuts and bolts of the bisexual Galton-Watson branching process (parameters defined and how it works).
5. A review of published bisexual results to date.
6. What is to come?

Newton And Saccheri: Case Studies In The Interplay Of Mathematics And Religion, Tommy Leavelle

ACMS Conference Proceedings 1989

In the course of this paper I will try to present to you the basic facts and some of the subsequent assessments of the life and work of two mathematicians for whom the interplay of mathematics and religion was influential: Issac Newton and Girolamo Saccheri.

A Tutorial On Prolog, Russell C. Bjork

ACMS Conference Proceedings 1989

PROLOG is a programming language based on the use of mathematical logic—specifically the first order predicate calculus. The name is a contraction for “Programming in Logic”. PROLOG was developed in 1972 by Phillippe Roussel of the AI Group (Groupe d’Intelligence Artificielle) of the University of Marseille. Specifically, it is an outgrowth of research there on automatic theorem proving. PROLOG has been widely used by AI researchers in Europe and Japan. In fact, the Japanese have made it the basis for the software side of their “Fifth Generation” computer project. PROLOG is currently used in a wide variety of areas, not …