# Colloquia

Unless otherwise noted, all talks are in 120 Hanes Hall, at 3:30 PM on Mondays. Prior to the talk, from 3:00-3:30 PM, the audience is invited for refreshments in the lounge on the 3rd floor of Hanes Hall. If you would like to suggest a speaker, or get on our mailing list, please send an email to Dr. Gabor Pataki or Dr. Vladas Pipiras.

In addition to weekly colloquia and seminars, Hotelling lectures are held to honor the memory of Professor Harold Hotelling, first chairman of the “Department of Mathematical Statistics.”

Quick access to previous talks:

- Spring 2018 Colloquia
- Fall 2017 Colloquia
- Spring 2017 Colloquia
- Fall 2016 Colloquia
- Spring 2016 Colloquia
- Talks given before 2016

## January 2018

### STOR Colloquium: Jason Xu, UCLA

Enabling likelihood-based inference for complex and dependent data The likelihood function is central to many statistical procedures, but poses challenges in classical and modern data settings. Motivated by emergent cell lineage tracking experiments to study blood cell production, we present recent methodology enabling likelihood-based inference for partially observed data arising from continuous-time stochastic processes with countable state space. These computational advances allow principled procedures such as maximum likelihood estimation, posterior inference, and expectation-maximization (EM) algorithms in previously intractable data…

Find out more »### STOR Colloquium: Shizhe Chen, Columbia University

Learning the Connectivity of Large Sets of Neurons New techniques in neuroscience have opened the door to rich new data sets of neural activities. These data sets shed light on the computational foundation of the brain, i.e., neurons and synapses. However, these data also present unprecedented challenges: novel statistical theory and methods are required to model neural activities, and well-designed experiments are needed to collect informative data. In this talk, we take on the task of learning connectivity among…

Find out more »### STOR Colloquium: Robin Gong, Harvard University

Bayes is sensitive. Is imprecise probability more sensible? Bayes is prized as principled and coherent, but its quality of inference is sensitive to prior and model misspecifications. Imprecise probability (IP) allows for the flexible expression of partially deficient probabilistic information. In our quest for minimal-assumption inference, is IP a more promising alternative to Bayes? In this talk, I showcase the power of IP with an application of the Dempster-Shafer theory of belief functions to the prior-free estimation of…

Find out more »### STOR Colloquium: Sara Algeri, Imperial College London

Testing One Hypothesis Multiple Times The identification of new rare signals in data, the detection of a sudden change in a trend, and the selection of competing models, are some among the most challenging problems in statistical practice. In this talk I discuss how these challenges can be tackled using a test of hypothesis where a nuisance parameter is present only under the alternative, and how a computationally efficient solution can be obtained by Testing One Hypothesis Multiple times…

Find out more »## February 2018

### STOR Colloquium: Jie Ding, Harvard University

Some New Foundational Principles and Fast Algorithms in Data Analytics Rapid developments in communications, networking, AI robots, 3D printing, genomics, blockchain, novel materials, and powerful computation platforms are rapidly bringing data-generating people, processes and devices together. The interactions between data analytics in multiple regimes (sparse, panel, big data, etc.) and other fields are exciting because the tools that are being invented now may enable new, faster and semi-automated methods of scientific discovery. These, in turn, might further amplify the…

Find out more »### STOR Colloquium: Jason Klusowski, Yale University

Counting connected components and motifs of large graphs via graph sampling Learning properties of large graphs from samples has been an important problem in statistical network analysis since the early work of Goodman (1949) and Frank (1978). We revisit a problem formulated by Frank of estimating the number of connected components in a large graph based on the subgraph sampling model, in which we randomly sample a subset of the vertices and observe the induced subgraph. The key question…

Find out more »### STOR Colloquium: Kai Zhang, UNC-Chapel Hill

Kai Zhang University of North Carolina, Chapel Hill BET on Independence We study the problem of nonparametric dependence detection. Many existing methods suffer severe power loss due to non-uniform consistency, which we illustrate with a paradox. To avoid such power loss, we approach the nonparametric test of independence through the new framework of binary expansion statistics (BEStat) and binary expansion testing (BET), which examine dependence through a novel binary expansion filtration approximation of the copula. Through a Hadamard transform,…

Find out more »### STOR Colloquium: Rick Kelly, Marsh & McLennan Agency, LLC

STOR Colloquium Wednesday, February 28th, 2018 120 Hanes Hall 3:30pm Rick Kelly FSA Division Manager, Marsh & McLennan Agency, LLC So you think you want to be an actuary? The actuarial profession is often promoted as a great career, but what does an actuarial analyst actually do? Led by the actuarial leadership of a national consulting firm, this course will introduce students to the healthcare industry and provide hands-on experience with key actuarial and analytical concepts that apply across the…

Find out more »## March 2018

### STOR Colloquium: Terry Soo, University of Kansas

The Department of Statistics and Operations Research The University of North Carolina at Chapel Hill STOR Colloquium Monday, March 19th, 2018 120 Hanes Hall 3:30pm Terry Soo University of Kansas ISOMORPHISMS IN PROBABILITY AND ERGODIC THEORY Two measure-preserving systems are isomorphic if there exists a measure-preserving bijection between them that respects the dynamics of the systems. Kolmogorov (1958) showed that Shannon entropy is an isomorphism invariant for independent and identically distributed systems, and Ornstein (1970) showed…

Find out more »## April 2018

### STOR Colloquium: Louigi Addario-Berry, McGill University

Louigi Addario-Berry McGill University Assumptionless bounds for Galton-Watson trees and random combinatorial trees. Let T be any Galton-Watson tree. Write vol(T) for the volume of T (the number of nodes), ht(T) for the height of T (the greatest distance of any node from the root) and wid(T) for the width of T (the greatest number of nodes at any level). We study the relation between vol(T), ht(T) and wid(T). In the case when the offspring distribution p…

Find out more »