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14 January 2019

Speaker: Radia Perlman, Dell EMC
Title: Computer Networks: Myths, Missteps, and Mysteries
Host School: UNC
Location: SN011
Host: Donald Porter (porter at

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The only reason networks look like they do today is because of history. Nobody would have designed what exists today.  It just evolved.  This talk focuses on the role of IP and Ethernet in the Internet.  Why do we need both of them?  (The answer may surprise you).  Is IP the best possible network protocol?  In 1992, the proposal was to replace IP with CLNP (the comparable protocol to IP, but designed by ISO). Would this have been an incompatible change to the Internet, whereas converting to IPv6 will just be a simple upgrade to a new version of IP?  What is the difference between a “different protocol” and a “new version of the same protocol”? This talk will explore some of these mysteries.


Radia Perlman’s work has had a profound impact on how computer networks work today. It enables huge networks, like the Internet, to be robust, scalable, and largely self-managing. Her technology also transformed Ethernet from a technology that could support a few hundred nodes within a building, into a technology that could support networks of hundreds of thousands of nodes. She has also made important contributions in network security, including robustness despite malicious trusted participants, assured delete, key management for data at rest encryption, and DDOS defense.

She is currently a Fellow at Dell EMC, and has taught as adjunct faculty at MIT, Harvard, and University of Washington.  She wrote the textbook “Interconnections”, and co-wrote the textbook “Network Security”.  She holds over 100 issued patents. She has received numerous awards including induction into the Inventor Hall of Fame, lifetime achievement awards from ACM’s SIGCOMM and Usenix, election to National Academy of Engineering, induction into the Internet Hall of Fame, and an honorary doctorate from KTH. She has a PhD in Computer Science from MIT.

15 April 2019

Speaker: Devavrat Shah, Professor of electrical engineering and computer science at the Massachusetts Institute of Technology
Title: Multi-Dimensional Robust Synthetic Control: Exploring Counterfactuals and Predicting Cricket Scores
Host School: Duke
Location: LSRC D106
Host: Kamesh Munagala (kamesh at


The “what ifs?” or ability to explore counterfactuals is central to the study of causal inference. Randomized control and A/B testing provides an approach to address this when counterfactuals can be experimented simultaneously. However, in a large number of scenarios such as policy evaluation, this is not feasible: we can’t have two Massachusetts, one having Gun Control and the other not at the same time, so that we can evaluate the impact of Gun Control on crime rate!

To address this challenge in a data-driven manner, the method of synthetic control was proposed by Abadie et al (2003) where synthetic or virtual counterfactuals are formed using historical data: impose Gun Control in Massachusetts to observe the crime rate under Gun Control and estimate the crime rate of Massachusetts without Gun Control as a combination of the crime rate of other states (without Gun Control). Despite tremendous success of this method, it suffers from two limitations: it is not robust to noisy, missing observations and it is not able to incorporate auxiliary information such as High School Dropout rate for estimating counterfactuals with respect to Crime Rate. In this talk, we will describe a method to address these limitations building on recent advances in Matrix and Tensor estimation, and present a novel application as a forecasting method for time series trajectories exemplified through the game of Cricket.

This is based on a collection of works in collaboration with Anish Agarwal, Muhammad J Amjad, Dennis Shen, Dogyoon Song (all at MIT) and Vishal Misra (Columbia).


Devavrat Shah is a Professor with the department of Electrical Engineering and Computer Science at the Massachusetts Institute of Technology. His current research interests are at the interface of Statistical Inference and Social Data Processing. His work has been recognized through prize paper awards in Machine Learning, Operations Research and Computer Science, as well as career prizes including 2010 Erlang prize from the INFORMS Applied Probability Society and 2008 ACM Sigmetrics Rising Star Award. He is a distinguished young alumni of his alma mater IIT Bombay.

22 April 2019

Speaker: Margo Seltzer, Herchel Smith Professor of Computer Science, University of British Columbia
Title: Systems Research — Construed Broadly
Host School: Duke
Location: LSRC D106
Host: Cynthia Rudin (cynthia at


Once upon a time, Computer Systems was a broad field encompassing everything from hardware to software. The incredible growth and success that our field has experienced over the past half a century has had the side effect of transforming systems into a constellation of siloed fields. I’m going to make the case that we should return to a broad interpretation of systems, undertake bolder, higher risk projects, and be intentional about how we interact with other fields. I’ll support the case with examples of several research projects that embody this approach.


Margo Seltzer is the Canada 150 Research Chair in Computer Systems and the Cheriton Family chair in Computer Science at the University of British Columbia. Her research interests are in systems, construed quite broadly: systems for capturing and accessing data provenance, file systems, databases, transaction processing systems, storage and analysis of graph-structured data, new architectures for parallelizing execution, and systems that apply technology to problems in healthcare. Dr. Seltzer was a co-founder and CTO of Sleepycat Software, the makers of Berkeley DB and is now an Architect for Oracle Corporation. She serves on the Computer Science and Telecommunications Board (CSTB) of the (US) National Academies. She is recognized as an outstanding teacher and mentor, having received the Phi Beta Kappa teaching award in 1996, the Abrahmson Teaching Award in 1999, the Capers and Marion McDonald Award for Excellence in Mentoring and Advising in 2010, and the CRA-E Undergraduate Research Mentoring Award in 2017.