# All Seminars

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Title: The SMURFS Project: Simulation and Modeling for Understanding Resilience and Faults at Scale
Seminar: Computer Science
Speaker: Dorian Arnold of University of New Mexico
Contact: James Lu,
Date: 2017-02-09 at 4:00PM
Venue: W201
Abstract:
Current HPC research explorations target computer systems with exaflop (10^18 or a quintillion floating point operations per second) capabilities. Such computational power will enable new, important discoveries across all basic science domains. Application resilience is a major challenge to the realization of extreme scale computing systems. The SMURFS Project addresses this challenge by developing methods to improve our predictive understanding of the complex interactions amongst a given application, a given real or hypothetical hardware and software system environment and a given fault-tolerance strategy at extreme scale. Specifically, SMURFS explores: (1) Advanced simulation and modeling capabilities for studying application resilience at scale; (2) Comprehensive, comparative studies of existing and new fault-tolerance strategies; (3) Detailed understandings of how application features interplay with different fault-tolerance strategies and hardware technologies; and (4) Effective prescriptions to guide application developers, hardware architects and system designers to realize efficient, resilient extreme scale capabilities. (This project is a collaboration amongst the University of New Mexico, the University of Tennessee and the Sandia National Labs. It is funded in part by the National Science Foundation.)
Title: Grothendieck Groups and Algebraic K-Theory
Seminar: N/A
Speaker: Juan Villeta-Garcia of University of Illinois Urbana-Champaign
Contact: Bree Ettinger, bree.d.ettinger@emory.edu
Date: 2017-02-06 at 4:00PM
Venue: W303
Abstract:
Abstract: Mathematics has seen a considerable rise in the interplay of algebra and topology in the last three decades. Algebraic K-Theory, which assigns topological invariants to rings, has profited significantly, with new and profound insights coming out each year. We will give a gentle introduction to Grothendieck Groups (a classical form of Algebraic K-Theory), discuss how they lead to topology, and why trace methods might be useful in computing them.
Title: Privacy-aware task management for mobile crowd sensing
Defense: Dissertation
Speaker: Layla Pournajaf of Emory University
Contact: Layla Pournajaf, layla.pournajaf@emory.edu
Date: 2017-02-03 at 11:00AM
Venue: E408
Abstract:
Location-aware Mobile crowd sensing (MCS) has numerous applications in a wide range of domains including syndromic surveillance, crime mapping, traffic monitoring, and emergency response. Preserving the privacy of participants in such applications is one of the main challenges in developing effective task management solutions. Moreover, the inherent dynamic environment of MCS characterized by continuous change and uncertain participant movement information pose further challenges for coordination of tasks and participants. Therefore, we propose novel methods to build robust task management frameworks to handle uncertainty and ensure privacy in MCS applications. Our solutions not only increase the disposition of the participants to engage in data collection and sharing activity, but also ultimately lead to more effective MCS applications.
Title: Privacy-Preserving Inference of Social Relationships from Location Data
Seminar: Computer Science
Speaker: Cyrus Shahabi of University of Southern California
Contact: Li Xiong, lxiong@emory.edu
Date: 2017-02-03 at 3:00PM
Venue: W301
Abstract:
For decades, social scientists have been studying peoples social behaviors by utilizing sparse datasets obtained by observations and surveys. These studies received a major boost in the past decade due to the availability of web data (e.g., social networks, blogs and review web sites). However, due to the nature of the utilized dataset, these studies were confined to behaviors that were observed mostly in the virtual world. Differing from all the earlier work, here, we aim to study social behaviors by observing peoples behaviors in the real world. This is now possible due to the availability of large high-resolution spatiotemporal location data collected by GPS-enabled mobile devices through mobile apps (Googles Map/Navigation/Search/Chrome, Facebook, Foursquare, WhatsApp, Twitter) or through online services, such as geo-tagged contents (tweets from Twitter, pictures from Instagram, Flickr or Google+ Photo), etc. In particular, we focus on inferring two specific social measures: 1) pair-wise strength -- the strength of social connections between a pair of users, and 2) pair-wise influence - the amount of influence that an individual exerts on another, by utilizing the available high-fidelity location data representing peoples movements. Finally, we argue that due to the sensitivity of location data and user privacy concerns, these inferences cannot be largely carried out on individually contributed data without privacy guarantees. Hence, we discuss open problems in protecting individuals location information while enabling these inference analyses.
Title: Vector bundles and finite covers
Seminar: Algebra
Speaker: Anand Deopurkar of University of Georgia
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Date: 2017-01-31 at 4:00PM
Venue: W306
Abstract:
Let Y be a variety. A finite cover $X \to Y$ of Y gives a natural vector bundle on Y, namely the direct image of the structure sheaf of X. Which vector bundles on Y arise in this way? I will present an answer to an asymptotic version of this question when Y is a curve, generalizing previous results of Ballico and Kanev, and answering a question of Lazarsfeld. This is joint work with Anand Patel.
Title: Infinite Sidon sets contained in sparse random sets of integers
Seminar: Algebra
Speaker: Sang June Lee of Duksung University, Seoul
Contact: TBA
Date: 2017-01-23 at 4:00PM
Venue: W303
Abstract:
TBA
Title: Moonshine beyond the Monster
Seminar: Algebra
Speaker: Michael Mertens of Max-Planck-Institut f
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Date: 2017-01-17 at 4:00PM
Venue: W306
Abstract:
Over the last 35 years, Moonshine has been an intriguing subject in mathematics, providing a still somewhat mysterious connection among Number Theory, especially the theory of modular forms, Representation Theory of finite groups, and Mathematical Physics. In the first part of my talk, I explain the general phenomenon of Moonshine at the historically first instance of so-called Monstrous Moonshine, as well as the more recent case of Umbral Moonshine. In the second part of the talk, I intend to talk in a bit more detail on recent joint work with M. J. Griffin proving a conjecture by J. Harvey and B. Rayhaun on Moonshine for Thompsons sporadic simple group and some joint work in progress with J. F. R. Duncan and K. Ono.
Title: Quantum Symmetry
Colloquium: Algebra
Speaker: Chelsea Walton of Temple University
Contact: Victoria Powers, vicki@mathcs.emory.edu
Date: 2017-01-12 at 4:00PM
Venue: W304
Abstract:
Like Hopf algebras? You will after this talk! The aim of this lecture is to motivate and discuss "quantum symmetries" of quantum algebras (i.e. Hopf co/actions on noncommutative algebras). All basic terms will be defined, examples will be provided, along with a brief survey of recent results.
Title: p-torsion in class groups of number fields of arbitrary degree
Seminar: Algebra
Speaker: Lillian Pierce of Duke
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Date: 2017-01-10 at 4:00PM
Venue: W306
Abstract:
Fix a number field K of degree n over the rationals, and a prime p, and consider the p-torsion subgroup of the class group of K. How big is it? It is conjectured that this p-torsion subgroup should be very small (in an appropriate sense), relative to the absolute discriminant of the field. But it has so far proved difficult even to beat the trivial bound, that is, to show that the p-torsion subgroup is noticeably smaller than the full class group. In 2007, Ellenberg and Venkatesh shaved a power off the trivial bound by assuming GRH. This talk will discuss several new methods that recover this bound for certain families of fields, without assuming GRH.
Title: What to expect when you're unexpecting: The distribution of consecutive prime biases
Seminar: Algebra
Speaker: Robert Lemke Oliver of Tufts University
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Date: 2017-01-10 at 5:00PM
Venue: W306
Abstract:
In recent work with Soundararajan, we conjectured that the are large biases in the distribution of consecutive primes in arithmetic progressions to a fixed modulus. Here, we review this conjecture, and we discuss the distribution of the terms involved. This proves to be surprisingly subtle and connected to classical problems in analytic number theory.