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 121-140 of 471 results.
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.
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.
ID: 238
Year: 2008
Name: Le Gui
Institution: University of Iowa
Subject area(s): 94A12
Title of Talk: Digitalization in the signal processing

Abstract: In real life when we store and transmit analog audio or video signals, we first obtain a digital representation of the signal. This process is called Digitalization or Analog-to-Digital (A/D) conversion and consists of two steps: sampling and quantization. In the "sampling" step we restrict time to a discrete sample of the continuous times. In the "quantization" step we discretize the real values of the time-discrete sample of the first step. We will discuss different quantization methods based on binary expansion or Beta-expansion and compare their "accuracy." "Accuracy" means that we can re-construct a good approximation of the original signal from its digitalization. Or "can you hear me now?"
ID: 497
Year: 2018
Name: Kevin Bombardier
Institution: University of Iowa
Subject area(s): Commutative Ring Theory, Algebra
Title of Talk: An Exploration of Factorization: Mathematical Atoms

Abstract: The mathematical system of the integers has many useful properties. One of these is unique factorization. For example, we can write the number 14 in a unique way: 14 = 2 * 7. However, the numbers 2 and 7 cannot be factored into "smaller pieces" in a nontrivial way. So in this sense, they could be called atoms of this mathematical system. Other mathematical systems usually do not have all of the nice properties that the integers do. Some useful properties can still be salvaged in certain cases. An atomic domain is a special mathematical system where its members have a factorization into a product of atoms. However, despite the ability to still factor elements into atoms, some are not as well-behaved as the integers were. For example, there are atomic domains where elements have an infinite number of distinct factorizations! We will discuss some important cases of these atomic domains. Of particular interest will be an atomic domain that only has finitely many atoms.
ID: 242
Year: 2008
Name: Palle Jorgensen
Institution: University of Iowa
Subject area(s): Analysis
Title of Talk: Matrix functions

Abstract: When I was little my father, for reasons unbeknownst to me, told me about low-pass and high-pass filters. He was a telephone engineer and worked on filters in signal processing. The 'high' and 'low' part of the story refers to frequency bands. Not that this meant much to me at the time. Rather, I was fascinated by the pictures of filter designs in the EE journals stacked up on the floor. And it was only many years later I came across this stuff in mathematics: quadrature mirror filters and all that; yet the visual impression still lingered. The talk will cover some of this math, especially wavelets: Subband filters define operators in Hilbert space which satisfy all kinds of abstract relations, and they are terribly useful. They are used in math and in signal processing. Matrix functions from math are called poly-phase matrices by engineers, and they are scattering matrices in other circles, and quantum gates in physics. In fact a lot of the things we do in math are known and used in other fields, but under different names, and known in different ways.
ID: 498
Year: 2018
Name: Wako Bungula
Institution: University of Iowa
Subject area(s): Topological Data Analysis
Title of Talk: Filtration and Stability of Mapper Graph for Point Cloud Data

Abstract: Filtration and stability of TDA Mapper graph for topological spaces have been studied; and using a generalization of the Bottleneck distance called interleaving distance, the stability of Mapper graph for the topological spaces has been proven. A problem arises when trying to extend this stability theorem to the point cloud data case because clustering algorithms do not usually give filtration. I will be talking about the conditions required for the stability theorem to be extended to point cloud data case.
ID: 472
Year: 2017
Name: Corissa Goertzen
Institution: University of Dubuque
Subject area(s):
Title of Talk: STEMulating Activities

Abstract: With the emphasis on STEM in the K-12 grades, colleges are stepping up to hold STEM related events. We will discuss the activities we have used at STEM festivals and how we encouraged college students to get involved. Time will allow for sharing of ideas.
ID: 546
Year: 2019
Name: Melanie King
Institution: The University of Iowa
Subject area(s): Math Education
Title of Talk: Introducing College Algebra Students to the IBL Learning Style

Abstract: Learning driven by student curiosity is more difficult in a setting such as College Algebra, where students typically have lower moral for learning math effectively. The purpose of this talk is to propose a general guideline for understanding the problems of students in College Algebra and address these problems using some IBL techniques. Here are some noted problems framed as student responses: "I hate/am not good at math”, “Can I cancel these?”, "I don't know how to start this", and "This problem wasn't on the homework/practice quiz, so I didn't know how to do it on the quiz/test". I will suggest learning techniques to help students tap into their curiosities without relying solely on teacher intervention to solve problems as is true to the IBL style of learning. I will also discuss some intermediary results of implementing some strategies in a blackboard section of College Algebra in Fall 2019 at the University of Iowa.
ID: 572
Year: 2021
Name: Catherine Hsu
Institution: Swarthmore College
Subject area(s):
Title of Talk: Projective and Non-Abelian SET

Abstract: Mathematicians love SET. On the surface, this classic game is a con test of pattern recognition, but it also presents an interesting way to visualize the geometry of a torus over a finite field. In this talk, we will discuss some of the mathematics connected to SET and then explore several new versions of the game, including one arising from projective geometry and one arising from non-abelian groups. In particular, we will see how these non-abelian variations on SET can give intuitive visualizations of abstract group structures.
ID: 53
Year: 2004
Name: Stephen Walk
Institution: St. Cloud State University
Subject area(s):
Title of Talk: Avoiding Paradoxes in Joker Poker

Abstract: If we add a Joker to an ordinary deck of cards, we'll find that the three-of-a-kind hands are more prevalent than the two-pair hands. (By convention, the Joker is always interpreted to make the hand's rank as high as possible.) Since the two-pair hands are rarer, by all rights they should outrank the threes-of-a-kind. But if the ranking is redone so that two-pair hands rank higher, then some of the Joker hands have to be interpreted as two-pair hands instead of threes-of-a-kind, and as a result the two-pair hands are again more prevalent than threes-of-a-kind. There is simply no consistent way to rank the poker hands in this Joker deck. It's enough to make Bret Maverick spin in his grave. \par What if we don't confine ourselves to the ordinary deck? Is it possible to find a deck that avoids paradoxes like the one above? Yes! Is it \emph{easy} to avoid paradoxes? Sure---if the deck is big enough. This talk will include the results of an investigation into this situation as well as a few details about the methodology. Only decks of size smaller than one million are considered; bigger decks become somewhat difficult to shuffle.
ID: 512
Year: 2018
Name: Katherine Vance
Institution: Simpson College
Subject area(s):
Title of Talk: Sine, Cosine, and Euler

Abstract: In mid-September, I attended a training workshop for the TRIUMPHS project. The goal of the project is to develop materials to teach core mathematical content using primary historical sources and active learning techniques. At the end of September, I site-tested one of the TRIUMPHS Primary Source Projects, ``The Derivatives of the Sine and Cosine Functions," in my Calculus 1 class. I will give a little bit of background on the TRIUMPHS project and share my experience as a site tester.
ID: 267
Year: 2009
Name: Martha Ellen Waggoner
Institution: Simpson College
Subject area(s): Teaching
Title of Talk: Using Toilet Paper to Help Students Make Generalizations

Abstract: When students are given a specific problem to solve, they do not naturally create a general solution method that could be applied in other situations. In this presentation, I will discuss a project that I use to help students learn the value of generalization and give them an introduction to sensitivity testing. The project starts by having students find the number of sheets of paper on a specific sealed roll of toilet paper, but they must take that method and produce a formula that could find the number of sheets of paper on a general roll of perforated paper. They then test the various models created by the class for sensitivity to measurement error to find the
ID: 273
Year: 2010
Name: Martha Ellen Waggoner
Institution: Simpson College
Subject area(s): linear algebra, teaching
Title of Talk: Linear Algebra: When am I ever going to use this?

Abstract: I tell my students that linear algebra is the most useful mathematical subject they will take, and of course, they expect me to support that claim. In this talk I will discuss applications that I use in both Linear Algebra and Mathematical Modeling that require matrix operations. I will focus on the difference between a forward problem and an inverse problem. The subject areas will include games, historical geography, and ray-based tomography.
ID: 540
Year: 2019
Name: Katherine Vance
Institution: Simpson College
Subject area(s): Topology; Knot Theory; Statistics
Title of Talk: Random Grid Diagrams

Abstract: This is joint work with undergraduate students Max Folkers, Eli Marriott, and Miguel Sanchez. We look at the distribution of the number of components in the population of knots and links represented by grid diagrams. We write programs in the R programming language to generate random samples of grid diagrams. We analyze the number of components and splittability of the links in these samples using statistical methods to gain a better understanding of the population of grid diagrams and the knots and links they represent.
ID: 287
Year: 2010
Name: Debra Czarneski
Institution: Simpson College
Subject area(s):
Title of Talk: Introduction to Mathematical Research through Graph Theory

Abstract: In the fall semester of 2009, I taught an Introduction to Mathematical Research through Graph Theory course for incoming first-year students. Students learned how to ask questions, how to form conjectures, and how to present their findings orally and in writing. This talk will discuss the course format, topics covered, and course outcomes.
ID: 50
Year: 2004
Name: Rick Spellerberg
Institution: Simpson College
Subject area(s): Game Theory
Title of Talk: The Sequence Prediction Game

Abstract: This talk will center on a review of a paper that appeared in the International Journal of Game Theory authored by David Blackwell who is a member of the statistics department at the University of California at Berkeley. In his paper, Blackwell considered the problem of predicting the short-term future behavior of a sequence, after observing it as long as you please, so as to achieve a specified reliability against all possible sequences. In particular, predicting when in a sequence of 0
ID: 306
Year: 2011
Name: Martha Ellen Waggoner
Institution: Simpson College
Subject area(s):
Title of Talk: Discovery learning in linear algebra using dynamical geometry software.

Abstract: I have developed several Geometers Sketchpad sketches that students can use to help them understand transformations, eigenvalues, eigenvectors and a geometrical interpretation of the determinant. These dynamic sketches are used in discovery learning exercises in a computer classroom. In this talk I will demonstrate a couple of sketches and explain how they are used in the classroom.
ID: 311
Year: 2011
Name: Debra Czarneski
Institution: Simpson College
Subject area(s):
Title of Talk: Mathematics and Writing

Abstract: Each fall at Simpson College, Student Support Services helps a group of new students transition to college through the week-long CampusConnect program. The students in the program must be from low-income families, be first-generation college students, and/or have a disability. A one-week course is offered as part of the program. This fall I team-taught a Mathematics and Writing course with the Director of Writing Across the Curriculum. This talk will discuss the topics covered, the assignments given, and student responses to the class.
ID: 324
Year: 2012
Name: Courtney Sherwood
Institution: Simpson College
Subject area(s): Math Biology
Title of Talk: A Model of Invertebrate Richness on Restored Prairies

Abstract: We will present a differential equations model of prairie restoration. Here, species richness is considered as an indicator of prairie restoration, with the variables for the equation being invertebrate and plant species richness and time. We will incorporate field work from a prairie in Nebraska as an example of our model. Our main goal is determining if planting fewer seeds will yield similar invertebrate richness as planting more seeds, that is, a more cost effective approach.
ID: 74
Year: 2004
Name: Rick Spellerberg
Institution: Simpson College
Subject area(s):
Title of Talk: Capstone Course In Mathematics. Components For Success.

Abstract: In the fall of 1998, the Simpson College Mathematics Department started offering a capstone course in mathematics called Senior Seminar. This talk will focus on the evolution of this course and what has taken place that has made this course the success it is today.