R₀ Spaces, R₁ Spaces, And Hyperspaces (open access)

R₀ Spaces, R₁ Spaces, And Hyperspaces

The purpose of this paper is to further investigate R0 spaces, R1 spaces, and hyperspaces. The R0 axiom was introduced by N. A. Shanin in 1943. Later, in 1961, A. S. Davis investigated R0 spaces and introduced R1 spaces. Then, in 1975, William Dunham further investigated R1 spaces and proved that several well-known theorems can be generalized from a T2 setting to an R1 setting. In Chapter II R0 and R1 spaces are investigated and additional theorems that can be generalized from a T2 setting to an R1 setting are obtained.
Date: December 1976
Creator: Dorsett, Charles I.
System: The UNT Digital Library
T-Sets of Normed Linear Spaces (open access)

T-Sets of Normed Linear Spaces

This paper is a study of T-sets of normed linear spaces. Geometrical properties of normed linear spaces are developed in terms of intersection properties shared by a subcollection of T-sets of the space and in terms of special spanning properties shared by each T-set of a subcollection of T-sets of the space. A characterization of the extreme points of the unit ball of the dual of a normed linear space is given in terms of the T-sets of the space. Conditions on the collection of T-sets of a normed linear space are determined so that the normed linear space has the property that extreme points of the unit ball of the dual space map canonically to extreme points of the unit ball of the third dual space.
Date: December 1976
Creator: McCormick, Robert E.
System: The UNT Digital Library
Tauberian Theorems for Certain Regular Processes (open access)

Tauberian Theorems for Certain Regular Processes

In 1943 R. C. Buck showed that a sequence x is convergent if some regular matrix sums every subsequence of x. Thus, for example, if every subsequence of x is Cesaro summable, then x is actually convergent. Buck's result was quite surprising, since research in summability theory up to that time gave no hint of such a remarkable theorem. The appearance of Buck's result in the Bulletin of the American Mathematical Society (3) created immediate interest and has prompted considerable research which has taken the following directions: (i) to study regular matrix transformations in order to shed light on Buck's theorem, (ii) to extend Buck's theorem, (iii) to obtain analogs of Buck's theorem for sequence spaces other than the space of convergent sequences, and (iv) to obtain analogs of Buck's theorem involving processes other than subsequencing, such as stretching. The purpose of the present paper is to contribute to all facets of the problem, particularly to (i), (iii), and (iv).
Date: August 1975
Creator: Keagy, Thomas A.
System: The UNT Digital Library
Generalized C-sets (open access)

Generalized C-sets

The problem undertaken in this paper is to determine what the algebraic structure of the class of C-sets is, when the notion of sum is to be the "set sum. " While the preliminary work done by Appling took place in the space of additive and bounded real valued functions, the results here are found in the more general setting of a complete lattice ordered group. As a conseque n c e , G . Birkhof f' s book, Lattice Theory, is used as the standard reference for most of the terminology used in the paper. The direction taken is prompted by a paper by W. D. L. Appling, "A Generalization of Absolute Continuity and of an Analogue of the Lebesgue Decomposition Theorem. " Since some of the results obtained provide another approach to a problem originally studied by Nakano, and improved upon by Bernau, reference is made to their work to provide other terminology and examples of alternative approaches to the problem of lateral completion. Thus Chapter I contains a brief history of the notion of C-sets and their relationship to lattice ordered groups, along with a summary of the properties of lattice ordered groups needed for later developments. …
Date: August 1974
Creator: Keisler, D. Michael
System: The UNT Digital Library
Hyperspaces (open access)

Hyperspaces

This paper is an exposition of the theory of the hyperspaces 2^X and C(X) of a topological space X. These spaces are obtained from X by collecting the nonempty closed and nonempty closed connected subsets respectively, and are topologized by the Vietoris topology. The paper is organized in terms of increasing specialization of spaces, beginning with T1 spaces and proceeding through compact spaces, compact metric spaces and metric continua. Several basic techniques in hyperspace theory are discussed, and these techniques are applied to elucidate the topological structure of hyperspaces.
Date: December 1976
Creator: Voas, Charles H.
System: The UNT Digital Library
Integrability, Measurability, and Summability of Certain Set Functions (open access)

Integrability, Measurability, and Summability of Certain Set Functions

The purpose of this paper is to investigate the integrability, measurability, and summability of certain set functions. The paper is divided into four chapters. The first chapter contains basic definitions and preliminary remarks about set functions and absolute continuity. In Chapter i, the integrability of bounded set functions is investigated. The chapter culminates with a theorem that characterizes the transmission of the integrability of a real function of n bounded set functions. In Chapter III, measurability is defined and a characterization of the transmission of measurability by a function of n variables is provided, In Chapter IV, summability is defined and the summability of set functions is investigated, Included is a characterization of the transmission of summability by a function of n variables.
Date: December 1977
Creator: Dawson, Dan Paul
System: The UNT Digital Library
Valuations on Fields (open access)

Valuations on Fields

This thesis investigates some properties of valuations on fields. Basic definitions and theorems assumed are stated in Capter I. Chapter II introduces the concept of a valuation on a field. Real valuations and non-Archimedean valuations are presented. Chapter III generalizes non-Archimedean valuations. Examples are described in Chapters I and II. A result is the theorem stating that a real valuation of a field K is non-Archimedean if and only if $(a+b) < max4# (a), (b) for all a and b in K. Chapter III generally defines a non-Archimedean valuation as an ordered abelian group. Real non-Archimedean valuations are either discrete or nondiscrete. Chapter III shows that every valuation ring identifies a non-Archimedean valuation and every non-Archimedean valuation identifies a valuation ring.
Date: May 1977
Creator: Walker, Catherine A.
System: The UNT Digital Library
Interpolation and Approximation (open access)

Interpolation and Approximation

In this paper, there are three chapters. The first chapter discusses interpolation. Here a theorem about the uniqueness of the solution to the general interpolation problem is proven. Then the problem of how to represent this unique solution is discussed. Finally, the error involved in the interpolation and the convergence of the interpolation process is developed. In the second chapter a theorem about the uniform approximation to continuous functions is proven. Then the best approximation and the least squares approximation (a special case of best approximation) is discussed. In the third chapter orthogonal polynomials as discussed as well as bounded linear functionals in Hilbert spaces, interpolation and approximation and approximation in Hilbert space.
Date: May 1977
Creator: Lal, Ram
System: The UNT Digital Library
Subdirectly Irreducible Semigroups (open access)

Subdirectly Irreducible Semigroups

Definition 1.1. The ordered pair (S,*) is a semi-group iff S is a set and * is an associative binary operation (multiplication) on S. Notation. A semigroup (S,*) will ordinarily be referred to by the set S, with the multiplication understood. In other words, if (a,b)e SX , then *[(a,b)] = a*b = ab. The proof of the following proposition is found on p. 4 of Introduction to Semigroups, by Mario Petrich. Proposition 1.2. Every semigroup S satisfies the general associative law.
Date: December 1978
Creator: Winton, Richard Alan
System: The UNT Digital Library
Complete Ordered Fields (open access)

Complete Ordered Fields

The purpose of this thesis is to study the concept of completeness in an ordered field. Several conditions which are necessary and sufficient for completeness in an ordered field are examined. In Chapter I the definitions of a field and an ordered field are presented and several properties of fields and ordered fields are noted. Chapter II defines an Archimedean field and presents several conditions equivalent to the Archimedean property. Definitions of a complete ordered field (in terms of a least upper bound) and the set of real numbers are also stated. Chapter III presents eight conditions which are equivalent to completeness in an ordered field. These conditions include the concepts of nested intervals, Dedekind cuts, bounded monotonic sequences, convergent subsequences, open coverings, cluster points, Cauchy sequences, and continuous functions.
Date: August 1977
Creator: Arnold, Thompson Sharon
System: The UNT Digital Library
The Wallman Spaces and Compactifications (open access)

The Wallman Spaces and Compactifications

If X is a topological space and Y is a ring of closed sets, then a necessary and sufficient condition for the Wallman space W(X,F) to be a compactification of X is that X be T1 andYF separating. A necessary and sufficient condition for a Wallman compactification to be Hausdoff is that F be a normal base. As a result, not all T, compactifications can be of Wallman type. One point and finite Hausdorff compactifications are of Wallman type.
Date: December 1976
Creator: Liu, Wei-kong
System: The UNT Digital Library
Properties of Limit Functions (open access)

Properties of Limit Functions

The purpose of this paper is to investigate properties of functions which are limits of functions with prescribed properties. Chapter II asks the question "Does a function which is the limit of a sequence of functions each of which is endowed with a certain property necessarily have that property?"
Date: December 1972
Creator: Coppin, Anthony M.
System: The UNT Digital Library
Semitopological Groups (open access)

Semitopological Groups

This thesis is a study of semitopological groups, a similar but weaker notion than that of topological groups. It is shown that all topological groups are semitopological groups but that the converse is not true. This thesis investigates some of the conditions under which semitopological groups are, in fact, topological groups. It is assumed that the reader is familiar with basic group theory and topology.
Date: December 1971
Creator: Scroggs, Jack David
System: The UNT Digital Library
Near-Rings (open access)

Near-Rings

The primary objective of this work is to discuss some of the elementary properties of near-rings as they are related to rings. This study is divided into three subdivisions: (1) Basic Properties and Concepts of Near-Rings; (2) The Ideal Structure of Near-Rings; and (3) Homomorphism and Isomorphism of Near-Rings.
Date: May 1972
Creator: Baker, Edmond L.
System: The UNT Digital Library
The Riemann-Complete Integral (open access)

The Riemann-Complete Integral

The problem with which this paper is concerned is that of defining the Riemann-Complete Integral and comparing it with the Riemann and the Lebesgue Integrals.
Date: May 1972
Creator: Boyd, Eddie
System: The UNT Digital Library
Completeness Axioms in an Ordered Field (open access)

Completeness Axioms in an Ordered Field

The purpose of this paper was to prove the equivalence of the following completeness axioms. This purpose was carried out by first defining an ordered field and developing some basic theorems relative to it, then proving that lim [(u+u)*]^n = z (where u is the multiplicative identity, z is the additive identity, and * indicates the multiplicative inverse of an element), and finally proving the equivalence of the five axioms.
Date: December 1971
Creator: Carter, Louis Marie
System: The UNT Digital Library
The Fundamental Group of Certain Toplogical Spaces (open access)

The Fundamental Group of Certain Toplogical Spaces

The problem confronted in this thesis is that of determining direct calculations of the fundamental group of certain topological spaces.
Date: December 1971
Creator: Hopkins, Billy L.
System: The UNT Digital Library
Inequalities and Set Function Integrals (open access)

Inequalities and Set Function Integrals

This thesis investigates some inequalities and some relationships between function properties and integral properties.
Date: December 1971
Creator: Milligan, Kenneth Wayne
System: The UNT Digital Library
Uniform Locally Compact Spaces (open access)

Uniform Locally Compact Spaces

The purpose of this paper is to develop some properties of uniformly locally compact spaces. The terminology and symbology used are the same as those used in General Topology, by J. L. Kelley.
Date: December 1971
Creator: Page, Perman Hutson
System: The UNT Digital Library
G-domains, G-ideals, and Hilbert Rings (open access)

G-domains, G-ideals, and Hilbert Rings

The problem with which this investigation is concerned is that of determining the properties of the following: a particular type of integral domain, the G-domain; a type of prime ideal, the G-ideal; and a special type of ring, the Hilbert ring.
Date: August 1972
Creator: Draper, Ruben P.
System: The UNT Digital Library
Concerning Measure Theory (open access)

Concerning Measure Theory

The purpose of this thesis is to study the concept of measure and associated concepts. The study is general in nature; that is, no particular examples of a measure are given.
Date: August 1972
Creator: Glasscock, Robert Ray
System: The UNT Digital Library
A Generalization of the Weierstrass Approximation Theorem (open access)

A Generalization of the Weierstrass Approximation Theorem

A presentation of the Weierstrass approximation theorem and the Stone-Weierstrass theorem and a comparison of these two theorems are the objects of this thesis.
Date: August 1972
Creator: Murchison, Jo Denton
System: The UNT Digital Library
The Lp Spaces of Equivalence Classes of Lebesgue Integrable Functions (open access)

The Lp Spaces of Equivalence Classes of Lebesgue Integrable Functions

The purpose of the paper is to prove that the Lp spaces, p ≥ 1, of equivalence classes of functions are Banach spaces.
Date: August 1972
Creator: Peel, Jerry
System: The UNT Digital Library
Development of a Geometry from a Set of Axioms (open access)

Development of a Geometry from a Set of Axioms

The purpose of this paper is to develop a geometry based on fourteen axioms and four undefined terms.
Date: May 1973
Creator: Glasscock, Anita Louise
System: The UNT Digital Library