Title

Scheduled Speakers, Spring 2021

 All meetings will be virtual, Mondays at 4pm. zoom link

Date Speaker Title Abstract
2/8/21

Jennifer Pawlewicz, Ithaca College Career Services

How to get a job, internship, or summer research experience

Students, have you ever wondered what opportunities are available for you, as a math major or minor?  Come find out about job, internship, and summer research opportunities.  Find out what's out there and how you can increase your chances of getting the experience you want!

2/15/21

Courtney Gibbons, Hamilton College

The Determinant Trick

Some people say there's more to life than linear algebra. They're not wrong — there are other types of algebra too! This talk will take one of those things everyone sees in linear algebra, the determinant, and use it in surprising ways for the noble purpose of proving a result (or two!) in commutative algebra. You don't need to know what commutative algebra is (it's better if you don't!) to enjoy this talk.

2/22/21

Tony Wong, Rochester Institute of Technology

Evaluating the Sensitivity of SARS-CoV-2 Infection Rates on College Campuses to Wastewater Surveillance

As college campuses reopen in Spring 2021, we are thrust into yet another large-scale experiment on the efficacy of various strategies to contain the SARS-CoV-2 virus. Traditional individual surveillance testing via nasal swabs and/or saliva are among the measures that colleges are pursuing to reduce the spread of the virus on campus. Additionally, some colleges are testing wastewater on their campuses for signs of infection, which can provide an early warning signal for campuses to locate COVID-positive individuals. We will discuss the implementation of a new model component for wastewater surveillance within an established epidemiological compartment model for the spread of COVID-19 on college campuses. We use a hypothetical residential university to evaluate the efficacy of wastewater surveillance for maintaining low infection rates. We find that wastewater sampling with a 1-day lag to initiate individual screening tests, plus completing the subsequent tests within a 4-day period can keep overall infections within 5% of the infection rates seen with weekly traditional individual surveillance testing. Our results also indicate that wastewater surveillance can be an effective way to dramatically reduce the number of false positive cases by identifying subpopulations for surveillance testing where infectious individuals are more likely to be found. Through a Monte Carlo risk analysis, we find that surveillance testing that relies solely on wastewater sampling can be fragile against scenarios with high viral reproductive numbers and high rates of infection of campus community members by outside sources. These results point to the practical importance of additional surveillance measures to limit the spread of the virus on campus and the necessity of a proactive response to the initial signs of outbreak.

3/1/21

Andrew Dykstra, Hamilton College

Complexity for symbolic dynamical systems

 In this talk, we will discuss dynamical systems that are symbolic in nature, meaning that points in the system are infinite sequences of symbols.  For example, the set of all possible infinite sequences of 0’s and 1’s, i.e., the set of all binary sequences, is a symbolic space which (as we will discuss) can be thought of as a dynamical system.  Whenever you have a symbolic dynamical system like this, it is natural to look for ways to measure how rich (or complicated) the system is.  One way of doing this is to calculate the entropy of a system. As we will see, even within the special class of systems that have entropy zero, it is still possible to distinguish among systems by measuring their complexity.  In particular, we will show how to use complexity to characterize important properties of systems such as recurrence, minimality, and transitivity.

3/8/21

Frank LiCausi,  Instructional Math Coach, Sweet Home Central Schools

Using math routines to build and deepen understanding

Jean Piaget once said, “Each time one prematurely teaches a child something he could have discovered himself, that child is kept from inventing it and consequently from understanding it completely.”

            Over the past 10 years, math education has undergone a major transformation towards Piaget’s ideal. As a math coach, it has been my role to convince both teachers and students this transformation is worth pursuing.  Our work is grounded in the math practices that will lend themselves to the critical thinking, problem solving and communication skills needed in today’s world. Today, we will explore some of the routines we have used to allow students to discover the and develop their own deep understanding of the world around us.

3/15/21

Nigar Altindis

Supporting students' meaningful understanding of functions: A learning ecology framework

In this talk, I introduce a learning-ecology framework that supports students’ meaningful understanding of functions. The learning-ecology framework consisted of three components: enacted task characteristics, teacher pedagogical moves, and small- and whole-group dynamics. In particular, I introduce enacted-tasks and tasks characteristics that might develop students’ meaningful understanding of functions.

3/22/21

Anca Radulescu, SUNY-New Paltz

Architecture-dependent bifurcations and clustering in brain networks

Modeling complex networks, and understanding how their hardwired circuitry relates to their dynamic evolution in time, can be of great importance to applications in the life sciences. However, the effect of connectivity patterns on network dynamics is only in the first stages of being understood. When the system is the brain, this becomes one of the most daunting current research questions: can brain connectivity (the “connectome”) be used to predict brain function and ultimately behavior?

We will start by describing an original study of neuroimaging data in humans, analyzing differences within a group of subjects with wide differences in vulnerability to stress (from extremely stress resilient to extremely anxious). Our statistical analysis found that connectivity patterns between prefrontal and limbic regions could explain differences in emotion regulation efficiency between the two groups. We interpret this result within the theoretical framework of oriented networks with nonlinear nodes, by studying the relationship between edge configuration and ensemble dynamics.

We first illustrate this framework on networks of Wilson-Cowan oscillators (a historic ODE model describing mean-field firing dynamics in coupled neural populations). We use configuration dependent phase spaces and probabilistic bifurcation diagrams to investigate the relationship between classes of system architectures and classes of their possible dynamics. We differentiate between the effects on dynamics of altering edge weights, density, and configuration.

Since Wilson-Cowan is a mean-field model, it can only predict population-wide behavior, and does not offer any insight into spiking dynamics and individual synaptic restructuring. To illustrate the effects of network architecture on dynamical patterns at this level, we test the same framework on networks of reduced Hodgkin-Huxley type single neurons. Building upon a model of cluster synchronization in all-to-all inhibitory networks (by Golomb and Rinzel), we study the contributions of more complex network architectures to the clustering phenomenon.

3/29/21 NO COLLOQUIUM    
4/5/21

Chad Topaz, Williams College

Quantitative Approaches to Social Justice

Civil rights leader, educator, and investigative journalist Ida B. Wells said that "the way to right wrongs is to shine the light of truth upon them."  This talk will demonstrate how quantitative and computational approaches can shine a light on social injustices and help build solutions to remedy them.  I will present quantitative social justice projects on topics ranging from diversity in art museums to equity in criminal sentencing to affirmative action, health care access, and more.  I hope that this talk leaves you informed about the breadth of social justice applications that one can tackle using accessible mathematical tools.

4/12/21

Dave Gondek, Leann Kanda, Ted Galanthay;

Ithaca College

COVID Modeling at Ithaca College

Mathematical modeling of the COVID19 pandemic cases at Ithaca College was an essential tool in planning for our Fall '20 & Spring '21 Semesters. Join us to learn why modeling is critical in a public health response, which model to choose, and how cross-disciplinary skills are needed to work in a dynamic environment. Get answers to these questions, come with your questions, and find out how Ithaca College professors advised campus decision-makers on COVID testing policy.

4/19/21

Sedar Ngoma, SUNY-Geneseo

An Overview of Inverse Problems

 In order to find approximate solutions to problems emanating from science, engineering, mathematics, and many other fields, a process called model is described in detail and an appropriate input called a cause is supplied. One is then required to find the unique output (or approximate solution) called effect. This is known as direct or forward problems, in which the media properties of a given model described by equations (for example, equation coefficients) are assumed to be known. However, media properties are often not readily observable. This lack of specification in the model leads to inverse problems, in which one is required to find the cause of the effect given the effect. For example, one can try to determine the equation coefficients (which usually represent important media properties) from the information about solutions of the direct problem. 

One of the downsides of inverse problems is that their approximate solutions are almost always ill-posed in the sense that they may not be unique or stable. In this talk we introduce inverse problems, investigate some examples, and describe analytically and numerically a regularization technique used to combat instability in the solutions. We conclude the talk with a time-dependent inverse source problem for a parabolic partial differential equation.

4/26/21

Kenan Ince, Westiminster College

Analysis of racial and gender bias in SLCPD's use of force and street checks, 2014-2017

Using data shared by the Salt Lake City Police Department (SLCPD) related to use of force and street checks between 2014 and 2017, we utilize a chi-squared test to determine whether SLCPD uses force and street checks against Black and Indigenous people and people of color (BIPOC) disproportionate to their prevalence in the Salt Lake City population. We find that Black and Indigenous Salt Lakers are disproportionately targeted by police force, while Black Salt Lakers are disproportionately targeted by street checks. Asian and Pacific Islanders are underrepresented as subjects of both use of force and street checks.

5/3/21

Ahmad Almomani, SUNY-Geneseo

Hybrid Optimization Algorithms

The demand for Hybrid Optimization Algorithms is increasing in the last two decades to minimize the weaknesses in the individual algorithm. In particular, Derivative-Free Optimization (DFO) methods are applicable for these problems where the derivatives are not available or hard to compute. Hybridizing different stochastic methods to form a robust algorithm deals with slow convergence and minimizes problems.  This talk will introduce hybrid algorithms between global and local optimization solvers and give many real-life applications.

 

Prior Semesters

Scheduled Speakers, Fall 2020

 All meetings will be virtual, Mondays at 4pm. zoom link

Date Speaker Title Abstract
9/28/20 Peter Maceli Graphs and Algorithms Graph theory is a young and exciting area of discrete mathematics. Visually, a graph is just a collection of dots together with lines joining certain pairs of these dots. Though at first glance graphs may seem like simple objects to study, the field of graph theory contains some of the deepest and most beautiful mathematics of the last fifty years. Being an extremely visual field, many questions and problems in graph theory are easily stated,yet have complex solutions with far reaching implications and applications.In this talk, we will explore the close relationship shared between graphs and algorithms. Describing how certain families of graphs “look” and can be“built,” and how, in turn, this allows one to efficiently solve certain important combinatorial problems.
10/5/20   A Virtual Escape Room Today we change gears from our typical talk. We'll break into teams to try out a virtual escape room! If you have a team in mind, email Matt Thomas (mthomas7@ithaca.edu) with your team. Otherwise, just show up and we'll make some teams!
10/12/20 Priya V. Prasad, University of Texas at San Antonio Teaching Geometric Congruence Euclid and Hilbert both based their developments of axiomatic geometry on metric definitions of congruence, but current state standards (such as the Common Core State Standards for Mathematics and the Texas Essential Knowledge and Skills Standards) implicitly rely on an isometric definition of congruence. So how can teacher educators prepare future secondary geometry teachers to teach an axiomatically coherent geometry based on this definition? We developed a task using Taxicab geometry that can perturb students’ internalized metric definition of congruence. This talk is based on work done with Steven Boyce at Portland State University.
10/19/20 Benjamin Levy, Fitchburg State University An Introduction to Disease Modeling with an Application to HIV/AIDS in Kenya

One can use mathematical techniques to model disease outbreaks such as COVID-19, Ebola, or HIV/AIDS. We can then use model simulations to make future projections about the number of cases, consider the impact of intervention strategies, or analyze other key characteristics of an epidemic.

This presentation will begin by introducing the compartmental framework commonly used to model infectious diseases, which will be illustrated by some simple models. After we lay some groundwork, a specific application to modeling HIV/AIDS in Kenya will be presented. In this application we formulate a compartmental system of ordinary differential equations (ODEs) to consider how stigma towards people living with HIV/AIDS has impeded the response to the disease. We take a data-driven approach to embed a time-dependent stigma function within our model for HIV dynamics and estimate model parameters from published data. We then explore a range of scenarios to understand the potential impact of different public health interventions on key HIV metrics such as prevalence and disease-related death, and to see how close Kenya will get to achieving UN Goals for these HIV and stigma metrics by 2030.

10/26/20 Emilie Wiesner, Ithaca College Ping Pong and Sleeping Beauty: Playing with Paradoxes We'll spend the first part of the hour thinking and talking about ping pong and Sleeping Beauty (two of my favorite paradoxes). The second part of the hour we'll have some paradox show and tell, so come prepared with your own favorite paradox.
11/2/20 John Gemmer, Wake Forest University Why is Lettuce so Wrinkly? Many patterns in Nature and industry arise from the system minimizing an appropriate energy. Examples range from the periodic rippling in hanging drapes to the six-fold symmetries observed in snowflakes. Torn plastic sheets and growing leaves provide striking examples of pattern forming systems which can transition from single wavelength geometries (leaves) to complex fractal like shapes (lettuce). These fractal like patterns seem to have many length scales - the same amount of extra detail can be seen when looking closer (“statistical self-similarity”). It is a mystery how such complex patterns could arise from energy minimization alone. In this talk I will address this puzzle by showing that such patterns naturally arise from the sheet adopting a hyperbolic non-Euclidean geometry. However, there are many different hyperbolic geometries that the growing leaf could select. I will show using techniques from analysis, differential geometry and numerical optimization that the fractal like patterns are indeed the natural minimizers for the system.
11/16/20 Gabe Pesco, Rachel King, and Jake Brown Summer research/jobs panel Come join us to hear about some of the work being done over the summers! Hear about what they did, and how they applied for and did their work. Ask questions to start thinking about what you might do next summer.
12/7/20 Mingyue Wang, Incyte On selecting the t best Bernoulli Treatments

In many situations we are faced with the problem of choosing among several alternatives. We may want to make a decision about which alternative(s) are the best. Considering a typical clinical trial setting, we set the goal of selecting among k ( > 0) experimental Bernoulli treatments the t (1 < t < k) best treatments provided that they are significantly better than the control. If fewer than t treatments are significantly better than the control, our goal is to retain the control. A fixed-sample-size procedure and a curtailed procedure are proposed to reach the goal. We adopt the two-stage selection/testing approach considered by Thall, Simon, and Ellenberg (1988) in both procedures. Properties of the proposed procedures will be presented through theorems and numerical results.

Scheduled Speakers, Spring 2020

Date Speaker Title Abstract
Feb 17, 2020 Xingye Qiao, Binghamton University Data Science in Action: Set-valued Classification and Applications to Precision Medicine Classification is a common machine learning task. Precision Medicine refers to selecting treatments that are most likely to help patients based on the patient's unique characteristics. In this lecture, I will talk about the fundamentals of classification, set-valued classification, and how the latter can be applied to achieve precision medicine. I will also talk about the research and education development of data science programs at Binghamton University. No particular knowledge is needed for the talk though knowledge of probability theory and some linear algebra will be helpful.
March 2, 2020 Megan Martinez Crocheting Mathematics Crocheting is a process that turns yarn into fabric. It has been used for centuries to painstakingly create one-of-a-kind fabrics and clothing. More recently, the art of crochet has been used to create physical models of mathematical structures, such as hyperbolic planes, spheres, and manifolds. This provides us a tactile (and crafty!) way to engage with mathematics; indeed, the very process of making a crochet pattern requires a deep understanding of the model you are constructing. In this talk, we will give an overview of different ways crochet has been used to make models, and then dive specifically into how we can construct patterns for volumes of revolution (the ones from Calc II!).
April 20, 2020 Stan Seltzer, by zoom - click here Gerrymandering Every ten years the United States conducts a census, after which the 435 seats in the House of Representatives are apportioned to the states.  The final step in all but the very smallest states that are entitled to one representative is the process of dividing each state into the appropriate number of congressional districts.  (State, county, and municipal districts may also have to be redrawn.)  When districting is done in a way intended to establish an unfair political advantage for a particular party or group by manipulating district boundaries, it is known as gerrymandering.

This brief introduction, based on the gerrymandering unit in Math, Fairness, and Democracy (MATH 16400), will include redistricting principles, gerrymandering strategies, historical and legal background, and some topics that are more mathematical: winner’s bonus, partisan symmetry, efficiency gap, and measures of compactness.  Also lots of pictures and quotes.

Scheduled Speakers, Fall 2019

Date Speaker Title Abstract
Sept 16, 2019 Dave Brown American Revolutionary and Civil War Cryptography

“One if by Land Two if by Sea”

This line from Longfellow’s poem describes a secret signal to the patriots about approaching British troops and goes on to commemorate Paul Revere’s Midnight Ride. At the same time, the poem reveals that Revere served as a spy and that the colonists engaged in early attempts at cryptology — sending, receiving, and decoding secret messages. We will explore the role that spycraft and cryptology played in the American Revolution and in the U.S. Civil War. 

Sept 30, 2019 Molly Noel and Jamie Woodworth Summer Research Molly and Jamie will share their experiences from their summer research.
Oct 14, 2019 Ted Galanthay

Shall we play a game? Hawks, Doves, and More

In the 1960's, ecologists began to use game theory to study evolutionary questions on topics such as animal aggression, the sex ratio, and altruism. Further study led to the creation of evolutionary game theory. In contrast to traditional game theory, evolutionary game theory seeks to describe changes in the frequency of strategies over repeated iterations of a game. Typically, the number of players in the game is fixed. In this talk, I will describe recent efforts to integrate population dynamics and evolutionary game theory models to answer questions about the evolution of animal aggression.

Oct 28, 2019 Math Department Preview of Spring Courses Join the department to hear about the courses being offered in the spring!
Nov 11, 2019 Josh Hayden and Heetisha Inderjeet Two Part Talk On Mathematics and Community

Part 1: Data and Donations, Joshua Hayden

A talk on using data to help project donations and find top donor prospects for the Ithaca State Theatre. How data analysis and machine learning can be put to work in the non-profit space to help communities.

Part 2: Application of Math in Real Life, Heetisha Inderjeet

As a math major, people sometimes expect that the only career goal is to teach. However, math can be a career in different ways. This project which involves working with Matthew LeRoux from the Cornell Cooperative Extension (Tompkins County) is a good example. This project consists of working with the cooperative extension partner to evaluate a meat pricing calculator and drill down on significant statistical numbers which will be able to be used for workshops and grant writing.

Dec 2, 2019 Xingye Qiao, Binghamton University Postponed due to snow