Algebraic Statistics Seminar, Spring 2015

Previous semesters:
Summer 2014, Fall 2014, Spring 2014, Fall 2013.

General organizational notes:
The algebraic statistics reading/research group will meet approximately once a week, on Wednesdays from 3:15 until 4:30pm.
Currently, the location is E1-121, subject to change. Any changes will be announced in the email list and here.
If you would like to receive talk announcements, please sign up for the seminar mailing list here.

Date & Time Location Speaker/Title
Wed, Jan 14
3:15 pm
E1 121 Sonja Petrović
Sampling algorithms for hypergraphs and contingency tables

One of the basic statistical questions relies upon sampling the space of observations with a fixed statistics. Sampling algorithms are a basic buidling block of a scheme for testing how well a statistical model fits the observed data. This talk, adapted from a short talk just presented at the Joint Math Meetings in San Antonio, will explain what types of sampling problems on hypergraphs and tables arise in algebraic statistics.
Wed, Jan 21
3:15 pm
E1 121 Dane Wilburne, IIT Applied Math
A "Relaxed" Markov Basis for the No 3-way Interaction Model

In this talk, I will discuss a conjecture related to the computation of Markov bases for the no 3-way interaction model. I will define the no 3-way interaction model and give the appropriate background information necessary to understand the conjecture. The main references for the talk are: Chapter 9 of Markov Bases in Algebraic Statistics (Aoki, Hara, and Takemura) Section 3 of Toric Algebra of Hypergraphs (Petrović and Stasi, 2014) (definition of parameter hypergraph) For background on Markov bases in general, see Algebraic algorithms for sampling from conditional distributions (Diaconis and Sturmfels, 1998)

Wed, Jan 28
3:15 pm
E1 121 Group discussion.
Strategizing on the open problem for no-3-way interaction model presented the previous week.

Wed, Feb 4
3:15 pm
E1 121 In lieu of the usual seminar meeting, you are invited to the Department Colloquium, which takes place Wed 2/4 at 4:40pm.

The colloquium talk is in the area of discrete math. It takes place 4:40-5:40. For more information, see event detiails page.

Wed, Feb 11
3:15 pm
E1 121 No seminar talk.

The seminar on 2/11 is cancelled.
Please note: students are welcome to meet and discuss problems if they would like, the room is still reserved for the time slot.

Wed, Feb 18
3:15 pm
E1 121 Lulu Kang, IIT Applied Math
Computational algebra and experiment design

Reading of the paper "Design and analysis of fractional factorial experiments from the viewpoint of computational algebraic statistics" by Aoki and Takemura. Preprint here.

Wed, Feb 25
E1 121 Lulu Kang.

Continued from previous week.

Wed, Mar 4
3:15 pm
E1 121 Weronika Swiechowicz and Yuanfang Xiang
Estimating correlation coefficients in trivariate normal random vectors with fixed mean and variance

A report on a joint research project from summer 2014: Estimating correlation coefficients in trivariate normal random vectors with fixed mean and variance.

Wed, Mar 11
3:15 pm
E1 121 Dane Wilburne
Basics of polynomial homotopy continuation

An introduction to the method of polynomial homotopy continuation in numerical algebraic geometry. A good reference can be found here.

Wed, Mar 25
3:15 pm
E1 121 n/a
No seminar today.

Wed, Apr 8
3:15 pm
E1 121 Despina Stasi, University of Cyprus and IIT
Random Sampling in Computational Algebra: Helly Numbers and Violator Spaces.
Clarkson’s sampling algorithm was the first expected linear-time algorithm for solving linear programs with a fixed number of variables. It was later shown to apply to more general non-linear geometric problems called LP-type problems. Finally Gartner et al proposed Violator Spaces as the most general framework under which Clarkson’s algorithm applies. We show that two polynomial ideal problems can be formulated to fit into the Violator Space framework, thus enabling us to apply Clarkson’s algorithm to solve them. We employ a Helly-type result for algebraic varieties for one of the problems. This talk is based on joint work with Jesus A. De Loera and Sonja Petrovic.

Wed, Apr 15
3:15 pm
E1 121 speaker tbd
topic tbd

Wed, Apr 22
3:15 pm
E1 121 speaker tbd
topic tbd

Wed, Apr 29
3:15 pm
E1 121 speaker tbd
topic tbd

For more information, contact Dane Wilburne (or Sonja Petrović).