All Seminars

Title: Computing and Autism: A role for technology and technologists
Seminar: Computer Science
Speaker: Professor Gregory Abowd of Georgia Institute of Technology
Contact: Valerie Summet, valerie@mathcs.emory.edu
Date: 2010-10-22 at 3:00PM
Venue: MSC W301
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Abstract:
Within the past two decades, autism has gone from being a hidden condition to a rather prominent phenomenon. Almost everyone knows someone impacted by autism, and I am no exception. I have two boys on the autism spectrum, and this experience has driven me to consider how information technology research can play a role in understanding and supporting the many challenges individuals and our society faces. In this talk, I will give an overview of my research in this area. This is not simply a feel good story of one researcher doing work to benefit himself and others. It is a story of how to connect life's real challenges to the work computing researchers do without having to sacrifice a career, or the career of others. I will present a human-centered research agenda with deep ties into areas of computer science, an agenda I hope will cause others to rethink how to motivate their own work. Gregory Abowd is a Distinguished Professor in the School of Interactive Computing and the W. George Professor and Director of the Health Systems Institute at the Georgia Institute of Technology. His research since 1994 has been in the area of ubiquitous computing, and he has attempted to create living laboratories of this third generation of computing in offices, classrooms, and homes. Some of his major project efforts are Classroom 2000 and the Aware Home Research Initiative. Over the past decade, he has focused on problems relating to home and health, with a particular emphasis on technology and autism. He is an ACM Fellow and member of the CHI Academy. In 2007, he received the ACM SIGCHI Social Impact Award and in 2009, he received the ACM Eugene Lawler Humanitarian Award.
Title: More-part Sperner Families and Transversals
Seminar: Combinatorics
Speaker: Peter Erdos of A. Renyi Institute of Mathematics, Hungarian Academy of Sciences, Budapest
Contact: Dwight Duffus, dwight@mathcs.emory.edu
Date: 2010-10-22 at 4:00PM
Venue: W306
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Abstract:
In this talk we give a short (and far from complete) survey of developments on the theory of more-part Sperner problems over the past 5 years. A complete list of all maximum 2-part Sperner families will be reported. We also will discuss the connection of these problems with (generalized) transversals. Finally some consequences for mixed orthogonal arrays will be presented.
Title: Quadratic field, cubic equation and the first derivative of L-functions
Seminar: Algebra and Number Theory
Speaker: Wei Zhang of Harvard University
Contact: Zachary Kent, kent@mathcs.emory.edu
Date: 2010-10-21 at 3:00PM
Venue: MSC E408
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Abstract:
There has been a long history on how to construct all rational solutions of cubic equations of two variables like $y^2=4x^3+ax+b$. We will see how imaginary quadratic fields, together with the study of some L-functions, can be used to partially solve the question. We will also mention some recent progress that leads us to a broader perspective.
Title: EUMMA-Graduate Student Panel
Seminar: N/A
Speaker: Dr. Yang, Dr. Summet of Emory University
Contact: Jodi-Ann Wray, jcwray@emory.edu
Date: 2010-10-20 at 7:00PM
Venue: MSC W301
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Title: Higher-dimensional Tate-Shafarevich groups
Seminar: Algebra and number theory
Speaker: Daniel Krashen of University of Georgia
Contact: Skip Garibaldi, skip@mathcs.emory.edu
Date: 2010-10-19 at 3:00PM
Venue: MSC E408
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Abstract:
his talk will examine local-global principles for objects defined over fields of the form $K(X)$ where $K$ is a complete discretely valued field and $X/K$ is a curve. In particular, we will examine torsors for linear algebraic groups and the measure the failure/success of local-global principles defined with respect to a variety of different types of ``local versions" of our fields. This is joint work with David Harbater and Julia Hartmann.
Title: Sum rules for eigenvalues of differential equations on surfaces and graphs
Seminar: Analysis and Differential Geometry
Speaker: Professor Evans Harrell of Georgia Institute of Technology
Contact: Vladimir Oliker, oliker@mathcs.emory.edu
Date: 2010-10-19 at 4:00PM
Venue: MSC W301
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Abstract:
I will discuss ``sum rule'' identities that can be derived at the level of operator algebra, and their uses to prove sharp inequalities for eigenvalues of elliptic differential operators on manifolds and on metric graphs.  Three uses of the sum rules are to find connections between Laplace spectra and curvature on "quantum waveguides," to find connections between Schr\"odinger spectra and topology on "quantum graphs," and to yield short, efficient derivation of sharp semiclassical estimates of Lieb-Thirring type in the same situations.  Parts of this work are joint with Demirel, Hermi, and Stubbe.
Title: Breaking the O($n^2$) bit barrier: Scalable Byzantine Agreement with an Adaptive adversary
Seminar: Computer Science
Speaker: Jared Saia of University of New Mexico
Contact: Michelangelo Grigni, mic@mathcs.emory.edu
Date: 2010-10-19 at 4:00PM
Venue: MSC W201
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Abstract:
We present an algorithm for Byzantine agreement that is scalable in the sense that each processor sends only soft-O($sqrt(n)$) bits, where n is the total number of processors. Our algorithm succeeds with high probability against an adaptive adversary, which can take over processors at any time during the protocol, up to the point of taking over arbitrarily close to a 1/3 fraction. Moreover, our algorithm works in the presence of flooding: processors controlled by the adversary can send out any number of messages. We assume the existence of private channels between all pairs of processors but make no other cryptographic assumptions. Finally, our algorithm has latency that is polylogarithmic in n. To the best of our knowledge, ours is the first algorithm to solve Byzantine agreement against an adaptive adversary, while requiring o($n^2$) total bits of communication.\\ \\ Jared Saia obtained his PhD from the University of Washington and is now an Associate Professor at the University of New Mexico. His broad research interests are in theory and algorithms with strong interests in distributed algorithms, game theory, security, and spectral methods. A current interest is determining how large groups can function effectively when there is no leader. He is the recipient of several awards including the NSF CAREER Award, the UNM Junior Faculty Research Excellence Award, and several best paper awards.
Title: Sesquilinear forms
Seminar: Algebra and number theory
Speaker: Eva Bayer-Fluckiger of Swiss Federal Institute of Technology, Lausanne (EPFL)
Contact: R. Parimala, parimala@mathcs.emory.edu
Date: 2010-10-15 at 3:00PM
Venue: MSC E408
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Abstract:
The aim of this talk is to show how classification questions concerning sesquilinear forms (without symmetry) over rings with involution can be reduced to questions on hermitian forms in certain hermitian categories. Using the theory of Quebbemann, Scharlau and Schulte, one can then obtain results such as Witt cancellation as well as some base change properties in the case where the ring is a finite dimensional algebra over a field of characteristic not 2.
Title: Degree Ramsey Numbers of Graphs
Seminar: Combinatorics
Speaker: Kevin Milans of The University of South Carolina
Contact: Dwight Duffus, dwight@mathcs.emory.edu
Date: 2010-10-15 at 4:00PM
Venue: W306
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Abstract:
A graph H arrows a graph G if every 2-edge-coloring of H contains a monochromatic copy of G. The degree Ramsey number of G is the minimum k such that some graph with maximum degree k arrows G. Burr, Erdos, and Lovasz found the degree Ramsey number of stars and complete graphs. We establish the degree Ramsey number exactly for double stars and for the cycle on four vertices. We prove that the degree Ramsey number of the n-cycle is at most 96 when n is even and at most 3458 in general. Consequently, there are very sparse graphs that arrow large cycles. We present a family of graphs in which the degree Ramsey number of G is bounded by a function of the maximum degree of G and ask which graph families have this property. This is joint work with Tao Jiang, Bill Kinnersley, and Douglas B. West.
Title: Mining Medical Data To Improve Disease Diagnosis and Treatment
Seminar: Computer Science
Speaker: Carlos Ordonez of University of Houston
Contact: Li Xiong, lxiong@mathcs.emory.edu
Date: 2010-10-14 at 4:00PM
Venue: MSC W301
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Abstract:
Abstract: Medical data sets have been generally analyzed with statistical techniques like regression, time series and statistical tests, among others. In this talk we will motivate how data mining techniques, traditionally used on large databases, can improve medical data analysis, where data sets are generally much smaller and attributes exhibit high variability. We will emphasize the importance of association rules and OLAP cubes. From a medical standpoint, we will summarize how our research helps heart disease and cancer diagnosis and treatment.\\ \\ Bio: Carlos Ordonez received a degree in applied mathematics and an M.S. degree in computer science, from UNAM University, Mexico, in 1992 and 1996, respectively. He got a Ph.D. degree in Computer Science from the Georgia Institute of Technology, in 2000. Dr Ordonez worked six years extending the Teradata DBMS with data mining algorithms. He is currently an Assistant Professor at the University of Houston. His research is centered on the integration of statistical and data mining techniques into database systems and their application to scientific problems.