Proposals
Below are some proposals for talks from the past (and current). By clicking on the ID number, more details are shown. By default, these are sorted chronologically (recent first) and by then by last name. The data can be sorted by alternate means by using the links at the top right, each allowing ascending or descending orders.
Displaying 421-440 of 471 results.
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ID:
120
Year: 2005
Name: Jeremy Alm
Institution: Iowa State University
Subject area(s): Algebra, Logic
Title of Talk: Don't Be So Sensitive! --On the Definition(s) of a Group
Abstract: We have all seen different variations on the definition of a group, and we all know that each one admits "the same structures". There are, however, some subtle but important differences among them. The class of groups and the properties that it has are sensitive to the signature (or similarity type) in which the groups are defined. In particular, in some signatures equational definitions are possible and in others they are not.
Year: 2005
Name: Jeremy Alm
Institution: Iowa State University
Subject area(s): Algebra, Logic
Title of Talk: Don't Be So Sensitive! --On the Definition(s) of a Group
Abstract: We have all seen different variations on the definition of a group, and we all know that each one admits "the same structures". There are, however, some subtle but important differences among them. The class of groups and the properties that it has are sensitive to the signature (or similarity type) in which the groups are defined. In particular, in some signatures equational definitions are possible and in others they are not.
ID:
119
Year: 2005
Name: Christopher French
Institution: Grinnell College
Subject area(s): convex geometry
Title of Talk: Graphs of Polytopes
Abstract: A polytope is a bounded intersection of half-spaces in R^n. The vertices and edges of a polytope form a graph. The graph of a 3 dimensional polytope is planar, since the surface of the polytope is homeomorphic to a sphere. It follows that such graphs cannot have K_5 minors. We generalize this fact, showing that graphs of n-dimensional polytopes cannot have K_{n+2} minors.
Year: 2005
Name: Christopher French
Institution: Grinnell College
Subject area(s): convex geometry
Title of Talk: Graphs of Polytopes
Abstract: A polytope is a bounded intersection of half-spaces in R^n. The vertices and edges of a polytope form a graph. The graph of a 3 dimensional polytope is planar, since the surface of the polytope is homeomorphic to a sphere. It follows that such graphs cannot have K_5 minors. We generalize this fact, showing that graphs of n-dimensional polytopes cannot have K_{n+2} minors.
ID:
118
Year: 2005
Name: Charles Jepsen
Institution: Grinnell College
Subject area(s): Geometry
Title of Talk: Equidissections of Trapezoids
Abstract: Denote by T(a) the trapezoid with vertices (0,0), (1,0), (0,1), (a,1). We are interested in dissections of T(a) into triangles of equal areas (i.e., equidissections of T(a)). What numbers of triangles are possible? We answer this question for certain infinite collections of trapezoids where a has the form a = p + q*sqrt(d). These results lead to a conjecture as to what might be true for all such values of a .
Year: 2005
Name: Charles Jepsen
Institution: Grinnell College
Subject area(s): Geometry
Title of Talk: Equidissections of Trapezoids
Abstract: Denote by T(a) the trapezoid with vertices (0,0), (1,0), (0,1), (a,1). We are interested in dissections of T(a) into triangles of equal areas (i.e., equidissections of T(a)). What numbers of triangles are possible? We answer this question for certain infinite collections of trapezoids where a has the form a = p + q*sqrt(d). These results lead to a conjecture as to what might be true for all such values of a .
ID:
117
Year: 2005
Name: Eugene Herman
Institution: Grinnell College
Subject area(s): Linear geometry
Title of Talk: Equidistant Sets and Similarity Transformations
Abstract: The main result to be presented is the following: If f is a nonconstant function from R^n to R^n that preserves equality of distances, then f is a similarity transformation. A key concept in the proof is a special type of affinely independent set of points -- a set of points that are equidistant from one another. The proof uses elementary linear algebra and geometric reasoning and little else. Much of the emphasis in the presentation will be on the interplay of algebra and geometry. Also, there will be some remarks on the connections with classical geometry, including the Fundamental Theorem of Affine Geometry.
Year: 2005
Name: Eugene Herman
Institution: Grinnell College
Subject area(s): Linear geometry
Title of Talk: Equidistant Sets and Similarity Transformations
Abstract: The main result to be presented is the following: If f is a nonconstant function from R^n to R^n that preserves equality of distances, then f is a similarity transformation. A key concept in the proof is a special type of affinely independent set of points -- a set of points that are equidistant from one another. The proof uses elementary linear algebra and geometric reasoning and little else. Much of the emphasis in the presentation will be on the interplay of algebra and geometry. Also, there will be some remarks on the connections with classical geometry, including the Fundamental Theorem of Affine Geometry.
ID:
116
Year: 2005
Name: Sean Bradley
Institution: Clarke College
Subject area(s):
Title of Talk: Generalized Arithmetic Triangles via Convolution
Abstract: Pascal
Year: 2005
Name: Sean Bradley
Institution: Clarke College
Subject area(s):
Title of Talk: Generalized Arithmetic Triangles via Convolution
Abstract: Pascal
ID:
115
Year: 2005
Name: Mahmoud Almanassra
Institution: Wartburg College
Subject area(s):
Title of Talk: On the Negative Mass Assigned By the Univariate Zao-Tsiatis and Wang Estimators
Abstract: The Zhao-Tsiatis estimator, for the restricted quality adjusted lifetime (RQAL), is not a monotonic estimator and hence it is not a proper survival function. The Wang estimator, which is a modified version of the ZT-estimator, is also not a monotonic estimator. Both the ZT-estimator and the W-estimator are consistent and reasonably efficient estimators. The simple weighted estimator is monotonic and consistent, but it is less efficient than the other two estimators mentioned above. I will identify the jump points of the simple weighted estimator, the ZT-estimator and the W-estimator. I will also identify which of these points are assigned a negative mass by the estimator. Moreover, I will propose two new consistent estimators for the survival functions of the RQAL.
Year: 2005
Name: Mahmoud Almanassra
Institution: Wartburg College
Subject area(s):
Title of Talk: On the Negative Mass Assigned By the Univariate Zao-Tsiatis and Wang Estimators
Abstract: The Zhao-Tsiatis estimator, for the restricted quality adjusted lifetime (RQAL), is not a monotonic estimator and hence it is not a proper survival function. The Wang estimator, which is a modified version of the ZT-estimator, is also not a monotonic estimator. Both the ZT-estimator and the W-estimator are consistent and reasonably efficient estimators. The simple weighted estimator is monotonic and consistent, but it is less efficient than the other two estimators mentioned above. I will identify the jump points of the simple weighted estimator, the ZT-estimator and the W-estimator. I will also identify which of these points are assigned a negative mass by the estimator. Moreover, I will propose two new consistent estimators for the survival functions of the RQAL.
ID:
114
Year: 2005
Name: Karen Shuman
Institution: Grinnell College
Subject area(s): mathematics education
Title of Talk: Getting Students to Read a Linear Algebra Text--Methods and Reactions
Abstract: Linear algebra may be the first undergraduate course in which is it crucial for students to understand definitions, theorems, and special examples. Exposing students to new material for the first time in class can take up a lot of time and prevent other, deeper material from being covered. This talk will focus on how I have gotten students to write and think about new material that they read on their own, how I have responded to them, and how students have reacted to the experience.
Year: 2005
Name: Karen Shuman
Institution: Grinnell College
Subject area(s): mathematics education
Title of Talk: Getting Students to Read a Linear Algebra Text--Methods and Reactions
Abstract: Linear algebra may be the first undergraduate course in which is it crucial for students to understand definitions, theorems, and special examples. Exposing students to new material for the first time in class can take up a lot of time and prevent other, deeper material from being covered. This talk will focus on how I have gotten students to write and think about new material that they read on their own, how I have responded to them, and how students have reacted to the experience.
ID:
113
Year: 2005
Name: Brian Birgen
Institution: Wartburg College
Subject area(s):
Title of Talk: A Project Based Finite Math Course
Abstract: In order to breathe new life into a course populated by unenthusiastic non-majors, I have introduced a series of projects which both challenges students and answers the age-old question "When am I ever going to use this stuff?". Successes and failures will both be featured.
Year: 2005
Name: Brian Birgen
Institution: Wartburg College
Subject area(s):
Title of Talk: A Project Based Finite Math Course
Abstract: In order to breathe new life into a course populated by unenthusiastic non-majors, I have introduced a series of projects which both challenges students and answers the age-old question "When am I ever going to use this stuff?". Successes and failures will both be featured.
ID:
112
Year: 2005
Name: Alexander Kleiner
Institution: Drake University
Subject area(s): history of mathematics, analysis
Title of Talk: The Toeplitz-Silverman Theorem
Abstract: In the first two decades of the twentieth century summability developed from collection of special results used in other parts of analysis into a full-blown field. One of the main points of this transition was a collection of general results that gave conditions for a method to sum every convergent sequence. Papers by Toeplitz, Silverman, Kojima, Schur and others established these theorems. This note will look at the development of these conditions and, as time permits, the reoccurrence of these results in the early day of the "Polish" school of functional analysis.
Year: 2005
Name: Alexander Kleiner
Institution: Drake University
Subject area(s): history of mathematics, analysis
Title of Talk: The Toeplitz-Silverman Theorem
Abstract: In the first two decades of the twentieth century summability developed from collection of special results used in other parts of analysis into a full-blown field. One of the main points of this transition was a collection of general results that gave conditions for a method to sum every convergent sequence. Papers by Toeplitz, Silverman, Kojima, Schur and others established these theorems. This note will look at the development of these conditions and, as time permits, the reoccurrence of these results in the early day of the "Polish" school of functional analysis.
ID:
111
Year: 2005
Name: Kristen Meyer
Institution: Iowa State University
Subject area(s): Cryptography
Title of Talk: Message Authentication Codes and Quasigroups
Abstract: Message Authentication Codes, or MACs, are commonly used cryptographic tools to ensure that a message has not been changed in transit. MACs can be constructed from a variety of mathematical structures and in a variety of ways. In this talk, I will describe a new MAC (called QMAC) which is based on the non-associativity of quasigroups. In order to obtain security against forgeries, quasigroups of large order must be used. I will also discuss how to create and represent such quasigroups.
Year: 2005
Name: Kristen Meyer
Institution: Iowa State University
Subject area(s): Cryptography
Title of Talk: Message Authentication Codes and Quasigroups
Abstract: Message Authentication Codes, or MACs, are commonly used cryptographic tools to ensure that a message has not been changed in transit. MACs can be constructed from a variety of mathematical structures and in a variety of ways. In this talk, I will describe a new MAC (called QMAC) which is based on the non-associativity of quasigroups. In order to obtain security against forgeries, quasigroups of large order must be used. I will also discuss how to create and represent such quasigroups.
ID:
110
Year: 2005
Name: Jenelle McAtee
Institution: University of Iowa
Subject area(s): knot theory, differential geometry
Title of Talk: Knots of Constant Curvature
Abstract: In this paper, we use the method of Richard Koch and Christoph Engelhardt to construct many knots of constant curvature.
Year: 2005
Name: Jenelle McAtee
Institution: University of Iowa
Subject area(s): knot theory, differential geometry
Title of Talk: Knots of Constant Curvature
Abstract: In this paper, we use the method of Richard Koch and Christoph Engelhardt to construct many knots of constant curvature.
ID:
109
Year: 2005
Name: Charles Ashbacher
Institution:
Subject area(s): Recreational mathematics
Title of Talk: Searching For Images Embedded in Mathematics
Abstract: In the science fiction book
Year: 2005
Name: Charles Ashbacher
Institution:
Subject area(s): Recreational mathematics
Title of Talk: Searching For Images Embedded in Mathematics
Abstract: In the science fiction book
ID:
108
Year: 2005
Name: James Collingwood
Institution: Drake University
Subject area(s): History of Mathematics
Title of Talk: Rigor in Analysis: From Newton to Cauchy
Abstract: This paper seeks to examine the level of rigor which was present in work with the calculus from the time of its invention through Cauchy
Year: 2005
Name: James Collingwood
Institution: Drake University
Subject area(s): History of Mathematics
Title of Talk: Rigor in Analysis: From Newton to Cauchy
Abstract: This paper seeks to examine the level of rigor which was present in work with the calculus from the time of its invention through Cauchy
ID:
107
Year: 2005
Name: Scott Herriott
Institution: Maharishi University of Management
Subject area(s): Math education; college algebra
Title of Talk: The "Basic Four" Elementary Functions and Their Applications in College Algebra
Abstract: The "Basic Four" elementary functions are those that result from the association of an additive or multiplicative change in X with an additive or multiplicative change in Y (linear, exponential, logarithmic and power). We consider the importance of these functions in the college algebra course in terms of the breadth of their applications in the fields of study that college algebra students will major in.
Year: 2005
Name: Scott Herriott
Institution: Maharishi University of Management
Subject area(s): Math education; college algebra
Title of Talk: The "Basic Four" Elementary Functions and Their Applications in College Algebra
Abstract: The "Basic Four" elementary functions are those that result from the association of an additive or multiplicative change in X with an additive or multiplicative change in Y (linear, exponential, logarithmic and power). We consider the importance of these functions in the college algebra course in terms of the breadth of their applications in the fields of study that college algebra students will major in.
ID:
106
Year: 2005
Name: Scott Searcy
Institution: Waldorf College
Subject area(s): Data Compression
Title of Talk: The Efficiency of Morse Code as Data Compression.
Abstract: Morse code was invented to allow the efficient transmission of textual data in a digital mode. This talk examines the efficiency in comparison with more modern methods of textual data transmission.
Year: 2005
Name: Scott Searcy
Institution: Waldorf College
Subject area(s): Data Compression
Title of Talk: The Efficiency of Morse Code as Data Compression.
Abstract: Morse code was invented to allow the efficient transmission of textual data in a digital mode. This talk examines the efficiency in comparison with more modern methods of textual data transmission.
ID:
105
Year: 2005
Name: Nancy Hagelgans
Institution: Ursinus College
Subject area(s):
Title of Talk: Planar Linkages: Robot Arms, Carpenters' Rulers, and Other Devices
Abstract: A planar linkage is constructed in the plane from rigid links or rods that are connected with movable joints. Robot arms and carpenters' rulers are examples of planar linkages in which the links are connected to form a chain. We will examine the reachability region of robot arms, which are chains with one end fixed. Then we will go on to solve the minimal folding problem of carpenters' rulers with links of different lengths. Finally we will address some planar linkages that can be used to convert one type of motion to another type of motion.
Year: 2005
Name: Nancy Hagelgans
Institution: Ursinus College
Subject area(s):
Title of Talk: Planar Linkages: Robot Arms, Carpenters' Rulers, and Other Devices
Abstract: A planar linkage is constructed in the plane from rigid links or rods that are connected with movable joints. Robot arms and carpenters' rulers are examples of planar linkages in which the links are connected to form a chain. We will examine the reachability region of robot arms, which are chains with one end fixed. Then we will go on to solve the minimal folding problem of carpenters' rulers with links of different lengths. Finally we will address some planar linkages that can be used to convert one type of motion to another type of motion.
ID:
104
Year: 2005
Name: Joseph Keller
Institution: Iowa State University
Subject area(s): general relativity
Title of Talk: Explanation of Lepton and Meson Masses
Abstract: Let the muon be a gaussian distribution of electric charge, as small as the Heisenberg uncertainty principle allows. Using G.D. Birkhoff's theorem, apply the Schwarzschild metric as if electric force were the same as gravitational force. Hawking's theorem says that the entropy of a black hole is proportional to its area. Choosing the mass to maximize entropy per unit mass, gives the muon mass within about 1%. There will be an inner infinite redshift surface also. This surface encloses a "core". Choosing the mass just large enough to trap the "core", gives the mass of the tauon to better than 1%. Two quarks, one inside the other, give a model of mesons. Similar considerations give the charged pion, K, B and D meson masses to within about 1% or better.
Year: 2005
Name: Joseph Keller
Institution: Iowa State University
Subject area(s): general relativity
Title of Talk: Explanation of Lepton and Meson Masses
Abstract: Let the muon be a gaussian distribution of electric charge, as small as the Heisenberg uncertainty principle allows. Using G.D. Birkhoff's theorem, apply the Schwarzschild metric as if electric force were the same as gravitational force. Hawking's theorem says that the entropy of a black hole is proportional to its area. Choosing the mass to maximize entropy per unit mass, gives the muon mass within about 1%. There will be an inner infinite redshift surface also. This surface encloses a "core". Choosing the mass just large enough to trap the "core", gives the mass of the tauon to better than 1%. Two quarks, one inside the other, give a model of mesons. Similar considerations give the charged pion, K, B and D meson masses to within about 1% or better.
ID:
103
Year: 2005
Name: Matthew Johnson
Institution: University of Iowa
Subject area(s): Functional Analysis, C*-Algebras
Title of Talk: The Graph Traces of Finite Graphs and Applications to Tracial States of C*-Algebras
Abstract: We determine the extreme points of the set of graph traces of norm one for any finite graph E satisfying Condition (K). We also describe and application to the space of tracial states on the graph C*-algebra.
Year: 2005
Name: Matthew Johnson
Institution: University of Iowa
Subject area(s): Functional Analysis, C*-Algebras
Title of Talk: The Graph Traces of Finite Graphs and Applications to Tracial States of C*-Algebras
Abstract: We determine the extreme points of the set of graph traces of norm one for any finite graph E satisfying Condition (K). We also describe and application to the space of tracial states on the graph C*-algebra.
ID:
102
Year: 2005
Name: Joel Haack
Institution: University of Northern Iowa
Subject area(s): History of math, fourier series
Title of Talk: The Henrici Harmonic Analyser
Abstract: The mathematical basis for analysis of a periodic function was provided by J. B. J. Fourier in Paris in 1822 in the form of a series expansion. Calculations, however, were very tedious. Several ingenious mechanical devices to perform the analysis were devised in the late 19th Century and perfected in the early 20th Century. An important example is the Henrici analyzer, a working version of which is housed in the Department of Speech and Audiology at The University of Iowa. The mathematical background of the device will be described, and videos will be shown of the authors using the Iowa Henrici to analyze a waveform. Pictures and descriptions of another device at the Science Museum in South Kensington, London will also be presented.
Year: 2005
Name: Joel Haack
Institution: University of Northern Iowa
Subject area(s): History of math, fourier series
Title of Talk: The Henrici Harmonic Analyser
Abstract: The mathematical basis for analysis of a periodic function was provided by J. B. J. Fourier in Paris in 1822 in the form of a series expansion. Calculations, however, were very tedious. Several ingenious mechanical devices to perform the analysis were devised in the late 19th Century and perfected in the early 20th Century. An important example is the Henrici analyzer, a working version of which is housed in the Department of Speech and Audiology at The University of Iowa. The mathematical background of the device will be described, and videos will be shown of the authors using the Iowa Henrici to analyze a waveform. Pictures and descriptions of another device at the Science Museum in South Kensington, London will also be presented.
ID:
95
Year: 2004
Name: Al Hibbard
Institution: Central College
Subject area(s): Statistics
Title of Talk: Introduction to the statistical software Fathom
Abstract: This talk wiill give a brief introduction to how and why to use the Fathom software. If you are familiar with Geometer's Sketchpad, this produced by the same company and is similar in its ease of use
Year: 2004
Name: Al Hibbard
Institution: Central College
Subject area(s): Statistics
Title of Talk: Introduction to the statistical software Fathom
Abstract: This talk wiill give a brief introduction to how and why to use the Fathom software. If you are familiar with Geometer's Sketchpad, this produced by the same company and is similar in its ease of use