# Spring 2019 Colloquia

# Upcoming Events › STOR Colloquium

## January 2019

### STOR Colloquium: Bikram Karmakar, University of Pennsylvania

Bikram Karmakar Statistics Department, The Wharton School, University of Pennsylvania Evidence factors for observational studies: methodology, computation and applications. Observational studies aim to elucidate cause-and-effect relationships from situations in which treatment is not randomly assigned. A sensitivity analysis for an observational study assesses how much bias, due to non-random assignment of treatment, would be necessary to change the conclusions of an analysis that assumes treatment assignment was effectively random. Causal conclusions gain strength from a demonstration that they are…

Find out more »### STOR Colloquium: Joshua Cape, Johns Hopkins

Joshua Cape Johns Hopkins University Statistical analysis and spectral methods for signal-plus-noise matrix models Estimating eigenvectors and principal subspaces is of fundamental importance for numerous problems in statistics, data science, and network analysis, including covariance matrix estimation, principal component analysis, and community detection. For each of these problems, we obtain foundational results that precisely quantify the local (e.g., entrywise) behavior of sample eigenvectors within the context of a unified signal-plus-noise matrix framework. Our methods and results collectively address…

Find out more »### STOR Colloquium: Yanglei Song, University of Illinios

Yanglei Song University of Illinois at Urbana-Champaign Asymptotically optimal multiple testing with streaming data The problem of testing multiple hypotheses with streaming (sequential) data arises in diverse applications such as multi-channel signal processing, surveillance systems, multi-endpoint clinical trials, and online surveys. In this talk, we investigate the problem under two generalized error metrics. Under the first one, the probability of at least k mistakes, of any kind, is controlled. Under the second, the probabilities of at least k1 false…

Find out more »### STOR Colloquium: Vince Lyzinski, Univ. of Massachusetts Amherst

Vince Lyzinski The University of Massachusetts Amherst Graph matching in edge-independent networks The graph matching problem seeks to find an alignment between the vertex sets of two graphs that best preserves common structure across graphs. Here, we consider the closely related problem of graph matchability: Given a latent alignment between the vertex sets of two graphs, under what conditions will the solution to the graph matching optimization problem recover this alignment in the presence of shuffled vertex labels? …

Find out more »### STOR Colloquium: Jingshen Wang, University of Michigan

Jingshen Wang University of Michigan Inference on Treatment Effects after Model Selection Inferring cause-effect relationships between variables is of primary importance in many sciences. In this talk, I will discuss two approaches for making valid inference on treatment effects when a large number of covariates are present. The first approach is to perform model selection and then to deliver inference based on the selected model. If the inference is made ignoring the randomness of the model selection process,…

Find out more »### STOR Colloquium: Geoffrey Schiebinger, MIT and Harvard

Geoffrey Schiebinger The Broad Institute of MIT and Harvard and the MIT Statistics and Data Science Center Towards a mathematical theory of development In this talk we introduce a mathematical model to describe temporal processes like embryonic development and cellular reprogramming. We consider stochastic processes in gene expression space to represent developing populations of cells, and we use optimal transport to recover the temporal couplings of the process. We apply these ideas to study 315,000 single-cell RNA-sequencing profiles collected…

Find out more »### STOR Colloquium: Jeffrey Regier, Univ. of California, Berkeley

Jeffrey Regier University of California, Berkeley Statistical Inference for Cataloging the Visible Universe A key task in astronomy is to locate astronomical objects in images and to characterize them according to physical parameters such as brightness, color, and morphology. This task, known as cataloging, is challenging for several reasons: many astronomical objects are much dimmer than the sky background, labeled data is generally unavailable, overlapping astronomical objects must be resolved collectively, and the datasets are enormous -- terabytes now,…

Find out more »### STOR Colloquium: Pragya Sur, Stanford University

Pragya Sur Stanford University A modern maximum-likelihood approach for high-dimensional logistic regression Logistic regression is arguably the most widely used and studied non-linear model in statistics. Classical maximum-likelihood theory based statistical inference is ubiquitous in this context. This theory hinges on well-known fundamental results: (1) the maximum-likelihood-estimate (MLE) is asymptotically unbiased and normally distributed, (2) its variability can be quantified via the inverse Fisher information, and (3) the likelihood-ratio-test (LRT) is asymptotically a Chi-Squared. In this talk, I…

Find out more »## February 2019

### STOR Colloquium: Elina Robeva, MIT

Elina Robeva Massachusetts Institute of Technology Maximum likelihood estimation under total positivity Nonparametric density estimation is a challenging statistical problem -- in general the maximum likelihood estimate (MLE) does not even exist! Introducing shape constraints allows a path forward. In this talk I will discuss non-parametric density estimation under total positivity (i.e. log-supermodularity). Though they possess very special structure, totally positive random variables are quite common in real world data and exhibit appealing mathematical properties. Given i.i.d. samples from…

Find out more »### STOR Colloquium: Abishek Sankararaman, UT-Austin

Abishek Sankararaman The University of Texas at Austin Interference Queuing Networks and Spatial Birth-Death Processes Motivated by applications in wireless networks, we consider a class of spatial birth death process, both on the continuum and on the discrete space of grids. In the continuum, we consider an interacting particle birth death process on a compact torus and study questions of stochastic stability. In the discrete setting, we consider a countably infinite collection of coupled queues representing a large…

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