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 441-460 of 471 results.
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ID:
201
Year: 2007
Name: Henry Walker
Institution: Grinnell College
Subject area(s):
Title of Talk: Ethics and Standards
Abstract: The MAA Committee on the Profession (CotP) has been asked by the MAA Board of Governors to draft a Statement of Ethics Standards. This talk will provide an overview to the work on this project and encourage reactions to the current working draft.
Year: 2007
Name: Henry Walker
Institution: Grinnell College
Subject area(s):
Title of Talk: Ethics and Standards
Abstract: The MAA Committee on the Profession (CotP) has been asked by the MAA Board of Governors to draft a Statement of Ethics Standards. This talk will provide an overview to the work on this project and encourage reactions to the current working draft.
ID:
149
Year: 2006
Name: Zhongming WANG
Institution: Iowa State University
Subject area(s):
Title of Talk: computing multivalued velocity and electric field of 1D Euler-Poisson equation
Abstract: We develop a level set method for the computation of multi-valued velocity and electric fields of one-dimensional Euler-Poisson equations. The sys- tem of these equations arises in the semiclassical approximation of Schrodinger- Poisson equations and semiconductor modeling. This method uses an implicit Eulerian formulation in an extended space | called field space, which incorpo- rates both velocity and electric fields into the configuration space. Multi-valued velocity and electric fields are captured through common zeros of two level set functions, which solve a linear homogeneous transport equation in the field space. Numerical examples are presented to validate the proposed level set method.
Year: 2006
Name: Zhongming WANG
Institution: Iowa State University
Subject area(s):
Title of Talk: computing multivalued velocity and electric field of 1D Euler-Poisson equation
Abstract: We develop a level set method for the computation of multi-valued velocity and electric fields of one-dimensional Euler-Poisson equations. The sys- tem of these equations arises in the semiclassical approximation of Schrodinger- Poisson equations and semiconductor modeling. This method uses an implicit Eulerian formulation in an extended space | called field space, which incorpo- rates both velocity and electric fields into the configuration space. Multi-valued velocity and electric fields are captured through common zeros of two level set functions, which solve a linear homogeneous transport equation in the field space. Numerical examples are presented to validate the proposed level set method.
ID:
220
Year: 2008
Name: Zhongming WANG
Institution: Iowa State University
Subject area(s):
Title of Talk: Bloch Band Based Level Set Method for the Schrodinger Equation
Abstract: We develop a Bloch band based level set method for capturing the semiclassical limit of one-dimensional Schrodinger equations in periodic medium. A hybrid of the WKB approximation and homogenization leads to the Bloch eigenvalue problem and an associated Hamilton-Jacobi system for the phase, with Hamiltonian being the Bloch eigenvalues. Following the level set methodology , we develop a Bloch band based level set method, which are hybrid numerical schemes -- splitting the solution process into several parts: i) band decomposition of the initial data and construction of the initial level set function; ii) solve the Bloch eigenvalue problem; iii) evolve the band level set equation to compute multi-valued velocity and density on each Bloch band; iv)the total position density over a sample set of bands is evaluated using Bloch waves and band densities obtained in step ii) and iii), respectively. Numerical results with different number of bands are provided to demonstrate the good quality of the method.
Year: 2008
Name: Zhongming WANG
Institution: Iowa State University
Subject area(s):
Title of Talk: Bloch Band Based Level Set Method for the Schrodinger Equation
Abstract: We develop a Bloch band based level set method for capturing the semiclassical limit of one-dimensional Schrodinger equations in periodic medium. A hybrid of the WKB approximation and homogenization leads to the Bloch eigenvalue problem and an associated Hamilton-Jacobi system for the phase, with Hamiltonian being the Bloch eigenvalues. Following the level set methodology , we develop a Bloch band based level set method, which are hybrid numerical schemes -- splitting the solution process into several parts: i) band decomposition of the initial data and construction of the initial level set function; ii) solve the Bloch eigenvalue problem; iii) evolve the band level set equation to compute multi-valued velocity and density on each Bloch band; iv)the total position density over a sample set of bands is evaluated using Bloch waves and band densities obtained in step ii) and iii), respectively. Numerical results with different number of bands are provided to demonstrate the good quality of the method.
ID:
357
Year: 2013
Name: Nathan Warnberg
Institution: Iowa State University
Subject area(s): Combinatorial Matrix Theory
Title of Talk: Graph Forcing Games
Abstract: Let G be a graph with some vertex set initially colored blue and the rest of the vertices colored white. The goal of the game is to color the entire graph blue, based on some a set of rules. Depending on which set of rules are used the minimum number of initial blue vertices needed to force the entire graph blue has implications for the minimum rank of the graph's corresponding matrix family. We will demonstrate some of these games and show the connections with the minimum rank problem.
Year: 2013
Name: Nathan Warnberg
Institution: Iowa State University
Subject area(s): Combinatorial Matrix Theory
Title of Talk: Graph Forcing Games
Abstract: Let G be a graph with some vertex set initially colored blue and the rest of the vertices colored white. The goal of the game is to color the entire graph blue, based on some a set of rules. Depending on which set of rules are used the minimum number of initial blue vertices needed to force the entire graph blue has implications for the minimum rank of the graph's corresponding matrix family. We will demonstrate some of these games and show the connections with the minimum rank problem.
ID:
180
Year: 2007
Name: Wendy Weber
Institution: Central College
Subject area(s): teaching prospective teachers
Title of Talk: Mathematical Questions from the Classroom
Abstract: How can we bridge the gap between prospective teachers
Year: 2007
Name: Wendy Weber
Institution: Central College
Subject area(s): teaching prospective teachers
Title of Talk: Mathematical Questions from the Classroom
Abstract: How can we bridge the gap between prospective teachers
ID:
479
Year: 2017
Name: Jake Weber
Institution: University of Northern Iowa
Subject area(s):
Title of Talk: Exploration of Counter Examples of Balance Sets
Abstract: With large data sets, one might ask if substructure exists, and if so, how large should the data subset be in order to guarantee this substructure. We investigated data subsets of Zp × Zp which are on the boundary, just short of enough data to guarantee substructure, specifically categorizing the data subsets that don’t have substruc- ture. First by brute force checking, we determined the counter examples (graphs with no substructure) for Z5 × Z5. These exam- ples guided our search into Zp × Zp where p ≥ 7. From there, we proved there are four categories of counter examples that do not have a balanced subset in Zp × Zp.
Year: 2017
Name: Jake Weber
Institution: University of Northern Iowa
Subject area(s):
Title of Talk: Exploration of Counter Examples of Balance Sets
Abstract: With large data sets, one might ask if substructure exists, and if so, how large should the data subset be in order to guarantee this substructure. We investigated data subsets of Zp × Zp which are on the boundary, just short of enough data to guarantee substructure, specifically categorizing the data subsets that don’t have substruc- ture. First by brute force checking, we determined the counter examples (graphs with no substructure) for Z5 × Z5. These exam- ples guided our search into Zp × Zp where p ≥ 7. From there, we proved there are four categories of counter examples that do not have a balanced subset in Zp × Zp.
ID:
236
Year: 2008
Name: Fengrong Wei
Institution: University of Iowa
Subject area(s):
Title of Talk: variable selection in high dimensional regression
Abstract: My research work studies statistical regression models for data sets with a small sample but huge number of variables. For example, we may wish to study the same 5000 genes in only 200 individuals with the goal of predicting whether they will develop a certain rare cancer. A classical linear regression for the cancer outcome in terms of the 5000 genes does not work with only 200 data points because the associated linear equations are not full rank. We might choose 200 of the genes and do a regression, but there are over 10^363 such choices. My work uses "penalty functions" add to the linear equations which will make the problem solvable. Theoretically, we can show that the result have the "oracle" property which means it will give us the baseline true model with probability going to 1.
Year: 2008
Name: Fengrong Wei
Institution: University of Iowa
Subject area(s):
Title of Talk: variable selection in high dimensional regression
Abstract: My research work studies statistical regression models for data sets with a small sample but huge number of variables. For example, we may wish to study the same 5000 genes in only 200 individuals with the goal of predicting whether they will develop a certain rare cancer. A classical linear regression for the cancer outcome in terms of the 5000 genes does not work with only 200 data points because the associated linear equations are not full rank. We might choose 200 of the genes and do a regression, but there are over 10^363 such choices. My work uses "penalty functions" add to the linear equations which will make the problem solvable. Theoretically, we can show that the result have the "oracle" property which means it will give us the baseline true model with probability going to 1.
ID:
237
Year: 2008
Name: Fengrong Wei
Institution: University of Iowa
Subject area(s): biomathematics
Title of Talk: variable selection in high dimensional regression
Abstract: My research work studies statistical regression models for data sets with a small sample but huge number of variables. For example, we may wish to study the same 5000 genes in only 200 individuals with the goal of predicting whether they will develop a certain rare cancer. A classical linear regression for the cancer outcome in terms of the 5000 genes does not work with only 200 data points because the associated linear equations are not full rank. We might choose 200 of the genes and do a regression, but there are over 10^363 such choices. My work uses "penalty functions" add to the linear equations which will make the problem solvable. Theoretically, we can show that the result have the "oracle" property which means it will give us the baseline true model with probability going to 1.
Year: 2008
Name: Fengrong Wei
Institution: University of Iowa
Subject area(s): biomathematics
Title of Talk: variable selection in high dimensional regression
Abstract: My research work studies statistical regression models for data sets with a small sample but huge number of variables. For example, we may wish to study the same 5000 genes in only 200 individuals with the goal of predicting whether they will develop a certain rare cancer. A classical linear regression for the cancer outcome in terms of the 5000 genes does not work with only 200 data points because the associated linear equations are not full rank. We might choose 200 of the genes and do a regression, but there are over 10^363 such choices. My work uses "penalty functions" add to the linear equations which will make the problem solvable. Theoretically, we can show that the result have the "oracle" property which means it will give us the baseline true model with probability going to 1.
ID:
269
Year: 2009
Name: Jonathan White
Institution: Coe College
Subject area(s): Teaching & Learning of Mathematics
Title of Talk: Essay Questions on Calculus Exams?
Abstract: How should a Calculus class be different at a liberal arts college? I present one aspect of my own answer to this question, namely that assessing students
Year: 2009
Name: Jonathan White
Institution: Coe College
Subject area(s): Teaching & Learning of Mathematics
Title of Talk: Essay Questions on Calculus Exams?
Abstract: How should a Calculus class be different at a liberal arts college? I present one aspect of my own answer to this question, namely that assessing students
ID:
70
Year: 2004
Name: Jonathan White
Institution: Coe College
Subject area(s): Undergraduate Mathematics Education
Title of Talk: Some Research-based Results on Technology and Visualization in Multivariable Calculus
Abstract: This talk will summarize some results of a multi-year study on the effects of technology use in multivariable calculus classes. The research focused especially on some differences in visualization skills between students who used computer algebra systems and others who did not.
Year: 2004
Name: Jonathan White
Institution: Coe College
Subject area(s): Undergraduate Mathematics Education
Title of Talk: Some Research-based Results on Technology and Visualization in Multivariable Calculus
Abstract: This talk will summarize some results of a multi-year study on the effects of technology use in multivariable calculus classes. The research focused especially on some differences in visualization skills between students who used computer algebra systems and others who did not.
ID:
340
Year: 2012
Name: Jonathan White
Institution: Coe College
Subject area(s): Teaching Mathematics
Title of Talk: Math Culture Points at Coe
Abstract: Coe has been using a "Math Culture Points" system for several years now to encourage and reward students for relevant activities outside of class, inspired by the article "Culture Points: Engaging Students outside the Classroom" by Fraboni and Hartshorn in PRIMUS v17. We have had excellent results, particularly including enthusiastic student participation in activities. We will discuss our implementations of the system, which differ from Fraboni and Hartshorn
Year: 2012
Name: Jonathan White
Institution: Coe College
Subject area(s): Teaching Mathematics
Title of Talk: Math Culture Points at Coe
Abstract: Coe has been using a "Math Culture Points" system for several years now to encourage and reward students for relevant activities outside of class, inspired by the article "Culture Points: Engaging Students outside the Classroom" by Fraboni and Hartshorn in PRIMUS v17. We have had excellent results, particularly including enthusiastic student participation in activities. We will discuss our implementations of the system, which differ from Fraboni and Hartshorn
ID:
404
Year: 2014
Name: Jonathan White
Institution: Coe College
Subject area(s): Pedagogy/Transition to Proof
Title of Talk: Constructing the Naturals -- An Inquiry-Based Approach
Abstract: The construction of the natural numbers via the Peano Axioms is a strangely neglected backwater of the undergraduate curriculum. It deserves more attention. Meanwhile, although inquiry-based learning has gained some traction, it usually is considered a binary decision, where a course either is or is not taught using an IBL approach. I propose a standalone unit, giving our number systems the foundation they deserve, and offering a "trial size" taste of IBL.
Year: 2014
Name: Jonathan White
Institution: Coe College
Subject area(s): Pedagogy/Transition to Proof
Title of Talk: Constructing the Naturals -- An Inquiry-Based Approach
Abstract: The construction of the natural numbers via the Peano Axioms is a strangely neglected backwater of the undergraduate curriculum. It deserves more attention. Meanwhile, although inquiry-based learning has gained some traction, it usually is considered a binary decision, where a course either is or is not taught using an IBL approach. I propose a standalone unit, giving our number systems the foundation they deserve, and offering a "trial size" taste of IBL.
ID:
560
Year: 2021
Name: Marshall Whittlesey
Institution: California State University San Marcos
Subject area(s): Geometry
Title of Talk: Using quaternions to prove theorems in spherical geometry
Abstract: It is well known that the complex numbers can be used to do transformation geometry in the plane. In particular, rotation by angle ϴ about the origin is accomplished via multiplication by the complex number e^iϴ=cos ϴ+ i sin ϴ. It is less well known that the quaternion algebra (consisting of expressions of the form a+bi+cj+dk with i^2=j^2=k^2=ijk=-1) can be used to do similar transformations in three dimensional space. In this talk we show how to use quaternions to prove an interesting classical theorem in spherical geometry. These methods are featured in the speaker's new book with CRC Press, "Spherical Geometry and its Applications", which the author hopes will be attractive for use in topics courses in geometry.
Year: 2021
Name: Marshall Whittlesey
Institution: California State University San Marcos
Subject area(s): Geometry
Title of Talk: Using quaternions to prove theorems in spherical geometry
Abstract: It is well known that the complex numbers can be used to do transformation geometry in the plane. In particular, rotation by angle ϴ about the origin is accomplished via multiplication by the complex number e^iϴ=cos ϴ+ i sin ϴ. It is less well known that the quaternion algebra (consisting of expressions of the form a+bi+cj+dk with i^2=j^2=k^2=ijk=-1) can be used to do similar transformations in three dimensional space. In this talk we show how to use quaternions to prove an interesting classical theorem in spherical geometry. These methods are featured in the speaker's new book with CRC Press, "Spherical Geometry and its Applications", which the author hopes will be attractive for use in topics courses in geometry.
ID:
297
Year: 2010
Name: Daniel Willis
Institution: Loras College
Subject area(s): K-12 Teaching; Geometry
Title of Talk: An Introduction to Logo
Abstract: An introduction to Logo (Turtle Geometry) using MSWLogo, a freeware version of Logo for 32-bit Windows. The talk will introduce basic commands, loops, procedures, and the use of variables, with applications to regular polygons, stars, tessellations, rotations, translations, reflections, and symmetry. The speaker has used Logo with teachers (and pre-service teachers) of elementary school, middle school, and high school mathematics.
Year: 2010
Name: Daniel Willis
Institution: Loras College
Subject area(s): K-12 Teaching; Geometry
Title of Talk: An Introduction to Logo
Abstract: An introduction to Logo (Turtle Geometry) using MSWLogo, a freeware version of Logo for 32-bit Windows. The talk will introduce basic commands, loops, procedures, and the use of variables, with applications to regular polygons, stars, tessellations, rotations, translations, reflections, and symmetry. The speaker has used Logo with teachers (and pre-service teachers) of elementary school, middle school, and high school mathematics.
ID:
232
Year: 2008
Name: Dan Willis
Institution: Loras College
Subject area(s): Preservice Teachers
Title of Talk: Math for Elementary Teachers
Abstract: The speaker will survey some of the available research on the mathematics content needs of elementary school teachers and future teachers. He will also discuss the impact this research has had on the development of a two-course 8-credit sequence "Math for Elementary Teachers I/II" at Loras College. This new two-course sequence is a program requirement for all Elementary Education majors at Loras College.
Year: 2008
Name: Dan Willis
Institution: Loras College
Subject area(s): Preservice Teachers
Title of Talk: Math for Elementary Teachers
Abstract: The speaker will survey some of the available research on the mathematics content needs of elementary school teachers and future teachers. He will also discuss the impact this research has had on the development of a two-course 8-credit sequence "Math for Elementary Teachers I/II" at Loras College. This new two-course sequence is a program requirement for all Elementary Education majors at Loras College.
ID:
75
Year: 2004
Name: Stephen Willson
Institution: Iowa State University
Subject area(s): graph theory
Title of Talk: Building supertrees using distances
Abstract: Suppose that a family of rooted phylogenetic trees Ti with different sets Xi of leaves is given. A supertree for the family would be a single rooted tree T whose leaf set is the union of all the Xi, such that the branching information in T corresponds to the branching information in all the trees Ti. This talk proposes a polynomial-time method BUILD-WITH-DISTANCES that makes essential use of distance information provided on the trees Ti to construct a rooted tree T. When a supertree containing also the distance information exists, then the method produces a supertree T. This supertree often shows increased resolution over the trees found by methods that utilize only the topology of the input trees.
Year: 2004
Name: Stephen Willson
Institution: Iowa State University
Subject area(s): graph theory
Title of Talk: Building supertrees using distances
Abstract: Suppose that a family of rooted phylogenetic trees Ti with different sets Xi of leaves is given. A supertree for the family would be a single rooted tree T whose leaf set is the union of all the Xi, such that the branching information in T corresponds to the branching information in all the trees Ti. This talk proposes a polynomial-time method BUILD-WITH-DISTANCES that makes essential use of distance information provided on the trees Ti to construct a rooted tree T. When a supertree containing also the distance information exists, then the method produces a supertree T. This supertree often shows increased resolution over the trees found by methods that utilize only the topology of the input trees.
ID:
402
Year: 2014
Name: Stephen Willson
Institution: Iowa State University
Subject area(s): Teaching techniques
Title of Talk: Using short "lecture challenge questions" in large lecture courses
Abstract: The talk describes my use of daily "lecture challenges" in large lecture courses such as Calculus or Mathematical Ideas. These "lecture challenges" are one-problem quizzes on material presented in the same lecture. Problems are typically easy problems that might be test questions. There is no partial credit. Students get one point for a wrong answer, two points for a correct answer. Absent students get no points, so students are motivated to attend. The problems are very fast to grade. Students may help and teach each other.
Year: 2014
Name: Stephen Willson
Institution: Iowa State University
Subject area(s): Teaching techniques
Title of Talk: Using short "lecture challenge questions" in large lecture courses
Abstract: The talk describes my use of daily "lecture challenges" in large lecture courses such as Calculus or Mathematical Ideas. These "lecture challenges" are one-problem quizzes on material presented in the same lecture. Problems are typically easy problems that might be test questions. There is no partial credit. Students get one point for a wrong answer, two points for a correct answer. Absent students get no points, so students are motivated to attend. The problems are very fast to grade. Students may help and teach each other.
ID:
154
Year: 2006
Name: Stephen Willson
Institution: Iowa State University
Subject area(s): Graph theory / mathematical biology
Title of Talk: Reconstructing genomes in the presence of hybridizations
Abstract: A homoplasy at a site in the DNA occurs when the value of a character (A, C, G, or T) changes more than once in the evolutionary history. Homoplasies create extra difficulties for reconstructing the evolutionary history of a collection of taxa. Recent interest has grown concerning evolutionary histories that are not described by trees but rather by more general networks that allow for hybridization events. A natural question is, in an idealized situation where homoplasies occur only at hybridization events, whether the characters at the leaves and the root of the network determine the characters at the internal vertices. Mathematically, one has a directed rooted acyclic graph in which the vertices correspond to taxa. At each vertex there is a set of genes. Under appropriate assumptions, the genes at all vertices are determined by the genes at the root and at the leaves.
Year: 2006
Name: Stephen Willson
Institution: Iowa State University
Subject area(s): Graph theory / mathematical biology
Title of Talk: Reconstructing genomes in the presence of hybridizations
Abstract: A homoplasy at a site in the DNA occurs when the value of a character (A, C, G, or T) changes more than once in the evolutionary history. Homoplasies create extra difficulties for reconstructing the evolutionary history of a collection of taxa. Recent interest has grown concerning evolutionary histories that are not described by trees but rather by more general networks that allow for hybridization events. A natural question is, in an idealized situation where homoplasies occur only at hybridization events, whether the characters at the leaves and the root of the network determine the characters at the internal vertices. Mathematically, one has a directed rooted acyclic graph in which the vertices correspond to taxa. At each vertex there is a set of genes. Under appropriate assumptions, the genes at all vertices are determined by the genes at the root and at the leaves.
ID:
210
Year: 2007
Name: Stephen Willson
Institution: Iowa State University
Subject area(s):
Title of Talk: On the Mathematics of Juggling
Abstract: The mathematical analysis of juggling gives interesting examples of permutations and uses of modular arithmetic. Simple mathematical notation can be used to describe many different ways of juggling. The descriptions can tell which periodic patterns give valid juggling methods.
Year: 2007
Name: Stephen Willson
Institution: Iowa State University
Subject area(s):
Title of Talk: On the Mathematics of Juggling
Abstract: The mathematical analysis of juggling gives interesting examples of permutations and uses of modular arithmetic. Simple mathematical notation can be used to describe many different ways of juggling. The descriptions can tell which periodic patterns give valid juggling methods.
ID:
214
Year: 2007
Name: Kliemann Wolfgang
Institution: Iowa State University
Subject area(s):
Title of Talk: Linear Differential Equations
Abstract: Spectral properties of matrices can be characterized in various ways: The algebraic approach via the characteristic polynomial yields the eigenvalues and corresponding (generalized) eigenspaces resulting in the Jordan normal form. The linear-algebraic approach using similarity of matrices again re- sults in a characterization via the Jordan form. Furthermore, the dynamical approach via di
Year: 2007
Name: Kliemann Wolfgang
Institution: Iowa State University
Subject area(s):
Title of Talk: Linear Differential Equations
Abstract: Spectral properties of matrices can be characterized in various ways: The algebraic approach via the characteristic polynomial yields the eigenvalues and corresponding (generalized) eigenspaces resulting in the Jordan normal form. The linear-algebraic approach using similarity of matrices again re- sults in a characterization via the Jordan form. Furthermore, the dynamical approach via di