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 261-280 of 471 results.
ID: 298
Year: 2010
Name: Luke Serafin
Institution: Coe College
Subject area(s):
Title of Talk: Explicit Constructions of Functions whose Graphs are Dense in The Plane

Abstract: A set D is dense in the plane if and only if every open ball in the plane contains an element of D. We prove that there exists a function f from the real line R to itself whose graph is dense in the plane by explicitly constructing it using a partition of the rationals into countably many subsets dense in R. We then use this method of construction to prove that there are 2^(2^\aleph_0) functions whose graphs are dense in the plane, and that there exists a function f: R ->R such that f(U) = R for every non-empty open set U in R.
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.
ID: 296
Year: 2010
Name: Subhra Bhattacharya
Institution: Iowa State University
Subject area(s): Mathematical Finance
Title of Talk: Stock Loan Subject to Bankruptcy

Abstract: In this paper, risk of bankruptcy has been introduced in the valuation of a financial derivative called stock loan. Bankruptcy has been modelled in both structural and reduced form approach. In structural form model, stock loan with finite maturity is considered following the Black-Cox specification of bankruptcy. It has been shown that the valuation of such an asset can be obtained explicitly in terms of the distribution of the first hitting time of Brownian motion and the pricing of the barrier options. In reduced form model, the default intensity has been introduced as in hazard rate models. A closed form solution of the initial value function is obtained, which implicitly defines the optimal exercise boundary. Moreover, this value function reflects an interrelationship between the optimal loan amount and the relevant variables (e.g. loan interest rate, stock price volatility etc). This interrelationship can be used to explain interesting issues such as: how does stock price volatility (or the reputation of the stock) or the loan interest rate affects the optimal loan amount?
ID: 295
Year: 2010
Name: Ranojoy Basu
Institution: Iowa State University
Subject area(s): Mathematical Finance
Title of Talk: Expected Utility Maximization in an Optimal stopping Environment

Abstract: In this paper we study an investment problem where an investor has the option to invest in a risk free asset (such as a bank account ) and a risky asset. His wealth can be transferred between the two assets and there are no transaction costs. The proportion of wealth in the risky asset is a priori chosen deterministic function of wealth. The objective is to …nd an optimal quitting time which maximizes the expected discounted utility from terminal wealth. First, we consider a situation when the wealth process is not subject to bankruptcy and obtain an optimal quitting time. Second, we consider the more realistic scenario when an investor’s wealth is subject to default. We develop necessary mathematical techniques to obtain an optimal selling time in both the circumstances. In both cases, it turned out that the optimal selling time is of threshold type. Numerical methods can easily be implemented to compute the optimal threshold.
ID: 293
Year: 2010
Name: Kenneth Driessel
Institution: Iowa State University
Subject area(s):
Title of Talk: Continuous Problems Are Easier Than Discrete Ones

Abstract: I claim: Continuous problems are (usually) easier than analogous discrete problems. Consequently, when teaching, we should emphasize the relation between continuous and discrete problems whenever possible. I shall use a historical example to support my claim. In particular, I shall review J.W.S. Rayleigh's treatment of beaded and continuous strings, which appears in his book "Theory of Sound" (Macmillan, 1894).
ID: 292
Year: 2010
Name: Jason Grout
Institution: Drake University
Subject area(s):
Title of Talk: SageTeX: Computing inside LaTeX documents

Abstract: I will talk about SageTeX, a system for embedding computer mathematical calculations or graphs inside TeX documents. The user simply puts a few simple commands in the TeX document and a computation is performed automatically and the output or graph appears in the PDF file. The system uses the powerful free open-source Sage computer algebra system (http://www.sagemath.org), but can also embed results and graphs from Mathematica, Maple, and a variety of other software. The author has used this in writing quizzes, tests, solution guides, papers, etc. Others have used SageTeX to generate interactive books and online worksheets.
ID: 291
Year: 2010
Name: Robert Keller
Institution: Loras College
Subject area(s): Collaborative learning, discrete math
Title of Talk: Discrete Observations or Continuous Ramblings: Some Thoughts on Historical Projects in Discrete Mathematics

Abstract: I will share some of my recent experiences on the use of historical projects in a discrete mathematics course. I used the projects to reinforce broad key topics from discrete in a provocative way. These topics included recursive vs. exact formulas, counting and patterns, and proof techniques such as induction. I will share some details on how I integrated the projects into the class and some (limited) responses from students.
ID: 290
Year: 2010
Name: Charles Ashbacher
Institution: #none
Subject area(s): Recreational mathematics
Title of Talk: Retrolife Generation of the Twelve Pentominoes

Abstract: The "Game of Life" invented by J. H. Conway has fascinated people for decades and was the impetus for the field of artificial life. Retrolife is determining if a specific pattern can be created from another with one iteration of the rules of life. This presentation will answer the question whether each of the twelve pentominoes can be generated via an iteration of the rules and poses new questions.
ID: 289
Year: 2010
Name: Ruth Berger
Institution: Luther College
Subject area(s): Algebra, Group Theory
Title of Talk: Exploring Group Theory with FGB

Abstract: Finite Group Behavior (FGB) is a free windows-based program that gives beginning group theory students a chance to explore abstract group theory concepts in a very concrete setting. The heart of the software is an extensive collection of Cayley tables of groups: Cyclic groups, Dihedral groups, and groups whose structure is not immediately recognizable. Students can explore relations among the elements of a group, determine the order of each element, and even make subgroups generated by selected elements of the group. This easy to use program also includes features that allow for the investigation of isomorphisms of groups, and it gives a nice visualization of how Cosets are formed. I will share some of the worksheets that I wrote for my Abstract Algebra students to gain some hands-on experience with these otherwise abstract concepts.
ID: 288
Year: 2010
Name: Travis Peters
Institution: Iowa State University
Subject area(s):
Title of Talk: Minimum rank, maximum nullity and zero forcing number for selected graph families

Abstract: The minimum rank of a simple graph G is defined to be the smallest possible rank over all symmetric real matrices whose ijth entry is nonzero whenever {i, j} is an edge in G and is zero otherwise. Maximum nullity is taken over the same set of matrices. The zero forcing number is the minimum size of a zero forcing set of vertices and bounds the maximum nullity from above. This talk discusses the graph families ciclos and estrellas. In particular, these families provide the examples showing that the maximum nullity of a graph and its dual may differ, and similarly for zero forcing number.
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: 286
Year: 2010
Name: Jitka Stehnova
Institution: Mt. Mercy College
Subject area(s): Number Theory, Representation Theory
Title of Talk: Representation Theory

Abstract: In this talk, we first give an introduction to the representation theory of p-adic groups. We will then focus on the subset of unitary groups, specifically U(1,1) and U(2) and show a process of parametrization of irreducible admissible supercuspidal representations.
ID: 285
Year: 2010
Name: Reza Rastegar
Institution: Iowa State University
Subject area(s): Probability
Title of Talk: Random walks in a sparse ``cookie" environment

Abstract: ``Cookie random walks" is a popular model of self-interacting random walks. Several variations of this model have been studied during the last decade. In this talk we will focus on the random walk on the integer lattice, where the ``cookies" perturbing the random walk are placed in a regular random sub-lattice of Z. We will present the model, briefly discuss an associated branching process, and then state criteria for transience and recurrence for this random walk.
ID: 284
Year: 2010
Name: Peter Blanchard
Institution: University of Iowa
Subject area(s): combinatorics, algebra
Title of Talk: Unit-connected pseudo-arithmetic super sets in the Gaussian Integers

Abstract: A set is pseudo-arithmetic if it has a difference which divides all other differences. A set is a pseudo-arithmetic super set if every subset is a pseudo-arithmetic set. Every pseudo-arithmetic super set can be contracted to have a unit difference, so the classification of pseudo-arithmetics super sets in Z[i] starts with the units. We give a complete classification of the unit-connected pseudo-arithmetic super sets in Z[i], and discuss which are maximal, which are bounded, and which may be extended.
ID: 283
Year: 2010
Name: Samuel Ferguson
Institution: University of Iowa
Subject area(s): Analysis, Teaching, Foundations
Title of Talk: Reals Revisited: NO SUP FOR YOU!

Abstract: Traditionally, first courses in analysis have started with certain axioms and then, in the course of deducing the consequences of these axioms, they prove the major theorems of calculus. The chief among these axioms is the "sup/least upper bound axiom," which seems obscure to most beginners. Where did such a thing come from, and how do we know that such a number system, satisfying such axioms, actually exists? Are the "reals" real? If teachers and students leave such questions unasked, they risk getting the impression that mathematics is just what happens when a somebody writes down a set of axioms and uses them to go on, in the words of Steven G. Krantz, "a magical mystery tour." Fortunately, in 1872 Dedekind and Cantor, independently and with different approaches, which have come to be known as the "Dedekind cut" approach to the "sup" and the "Cauchy sequence" approach to "completeness," constructed such real number systems, but their approaches are considered too complicated to present in their entirety at the beginning of most courses in analysis. In this talk, assisted by the intuition of Cauchy, Weierstrass, Courant, and others, we will give another (new?) construction of the reals, which has the advantages of both of the other constructions discussed and the complications of neither. Time permitting, the number "e" will be defined with this approach, or the Intermediate Value Theorem will be proved.
ID: 282
Year: 2010
Name: Brian Patterson
Institution: Iowa State University
Subject area(s): Real Analysis, Computability Theory
Title of Talk: Multi-Resolution Cellular Automata for Real Computation

Abstract: We will first briefly review cellular automata and why representing and computing with real numbers with a computer is problematic. Then we will discuss a new approach that uses the concept of fissioning cells to approximate real-valued regions. I will close with a brief explanation of my simulator.
ID: 281
Year: 2010
Name: Henry Walker
Institution: Grinnell College
Subject area(s): Placement,
Title of Talk: A System to Place Incoming Students in Computer Science, Mathematics and Statistics

Abstract: Joint work with Andrew Hirakawa and Russel Steinbach. Colleges utilize various methods of placing students, but many methods are time intensive, have limited scope, or lack precision. The placement system described here resolves many of these issues using a PHP based inference engine with extensively-researched rules. The system's placements compare favorably with those created manually by faculty, and students perform well in the system-recommended courses. Scripts store placements in a MySQL database and later generate individual LaTeX-based letter for each student. The scripts from this project run efficiently, follow established software-engineering principles, and are easily modifiable. The project automates every step of the process from loading student data into the database to generating individual letters for students.
ID: 280
Year: 2010
Name: Theron Hitchman
Institution: University of Northern Iowa
Subject area(s): combinatorics, number theory, undergraduate research
Title of Talk: Patterns and Structure in M-ary Partitions

Abstract: For a fixed natural number m, an m-ary partition of another number n is a way to write n as a sum of powers of m. For example 7= 3^0 + 3^1+3^1 is a 3-ary partition of 7. For each m, we can describe a sequence b_m(n) which counts the number of m-ary paritions of n, and this sequence has some some beautiful number theoretic properties. In joint work with James Sellers (Penn State) and Mac Roepke (UNI student), we describe and explain rich structure inside the m-ary partition sequences with a surprisingly straight-forward computation, and hint at other questions to come.
ID: 279
Year: 2010
Name: Christian Roettger
Institution: Iowa State University
Subject area(s): ODE, recurrence, power series, experimental mathematics
Title of Talk: Recurrences, power series, and ODE

Abstract: A three-term recurrence is connected to a power series, which solves a second-order ODE. The recurrence can be helpful in solving the ODE explicitly, and in approximating the power series. As is well-known, its growth rate is related to the radius of convergence of the power series. We will use a simple example straight from the textbook to investigate this in the case of a recurrence with *non-constant* coefficients. While the growth rate turns out to be surprisingly resistant to attack, it has great potential to be explored experimentally as well as theoretically - an opportunity for open-ended student projects.
ID: 278
Year: 2010
Name: K Stroyan
Institution: University of Iowa
Subject area(s):
Title of Talk: Projects in Calculus Class

Abstract: My favorite calculus question is: Why did we eradicate polio by vaccination, but not measles? I use this as a training project for student projects in calculus. I'll talk about my experience with "modeling" projects in calculus.