# All Seminars

Show:Title: Biomedical Data Recommendation Using Machine Learning and Crowdsourcing |
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Seminar: Computer Science |

Speaker: Xiaoqian Jiang, Ph.D. of Division of Biomedical Informatics, University of California at San Diego |

Contact: Li Xiong, lxiong@emory.edu |

Date: 2015-04-30 at 12:00AM |

Venue: Rollins School of Public Health, Claudia Nance Rollins Building, Room 1000 |

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Abstract:See downloadable flyer. |

Title: Ramsey Theorem and Ramsey Turan Type Results for Hypergraphs |
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Defense: Dissertation |

Speaker: Vindya Bhat of Emory University |

Contact: Vindya Bhat, vbhat@emory.edu |

Date: 2015-04-27 at 11:15AM |

Venue: W302 |

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Abstract:See downloadable flyer for full abstract. This thesis defense includes Ramsey Theorem type results and Ramsey-Turan type results. Both topics involve finding substructures within hypergraphs under certain conditions. |

Title: Extremal Problems In Combinatorics |
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Evans Hall Awards Ceremony and Lecture: Combinatorics |

Speaker: Mathias Schacht of University of Hamburg |

Contact: Steve Batterson, sb@mathcs.emory.edu |

Date: 2015-04-23 at 4:00PM |

Venue: MSC E208 |

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Abstract:TBA |

Title: Tropical schemes and the Berkovich analytification |
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Seminar: Algebra |

Speaker: Noah Giansiracusa of UGA |

Contact: David Zureick-Brown, dzb@mathcs.emory.edu |

Date: 2015-04-21 at 4:00PM |

Venue: W304 |

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Abstract:See downloadable flyer. |

Title: Proof of the Middle Levels Conjecture |
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Seminar: Combinatorics |

Speaker: Torsten Muetze of Georgia Tech |

Contact: Dwight Duffus, dwight@mathcs.emory.edu |

Date: 2015-04-20 at 4:00PM |

Venue: W302 |

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Abstract:Define the middle layer graph as the graph whose vertex set consists of all bitstrings of length $2n+1$ that have exactly $n$ or $n+1$ entries equal to 1, with an edge between any two vertices for which the corresponding bitstrings differ in exactly one bit. The middle levels conjecture asserts that this graph has a Hamilton cycle for every $ n \ge 1$. This conjecture originated probably with Havel, Buck and Wiedemann, but has also been (mis)attributed to Dejter, Erdos, Trotter and various others, and despite considerable efforts it remained open during the last 30 years. In this talk I present a proof of the middle levels conjecture. In fact, I show that the middle layer graph has $2^{2^{\Omega(n)}}$ different Hamilton cycles, which is best possible. |

Title: Extending Partial Geometric Representations of Graphs |
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Seminar: Combinatorics |

Speaker: Jan Kratochvil of Charles University, Prague |

Contact: Dwight Duffus, dwight@mathcs.emory.edu |

Date: 2015-04-17 at 4:00PM |

Venue: W303 |

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Abstract:Intersection-defined classes of graphs are intensively studied for their applications and interesting properties. Many of them allow polynomial-time algorithms for otherwise computationally hard problems such as independent set, clique or coloring problems. And many of them can be recognized in polynomial time. In fact the polynomial-time algorithms often need a representation to be given or constructed as the initial step. The rather natural question of extending a partial representation has been studied only recently. It falls into the more general paradigm of extending a partial solution of a problem. Sometimes a global solution can be reached by incremental steps from a partial one in polynomial-time, but in many cases an otherwise easy problem may become hard. Examples of such behavior can be found for instance in graph colorings (e.g., deciding if a partial edge-coloring of a cubic bipartite graph can be extended to a full 3-coloring of it is NP-complete, though it is well known that every cubic bipartite graph is 3-edge-colorable and such a coloring can be found in polynomial time). In this talk we survey the known results about the computational complexity of extending partial geometric representations of graphs. |

Title: A relative Szemeredi theorem |
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Colloquium: Department |

Speaker: David Conlon of The University of Oxford |

Contact: Dwight Duffus, Dwight@mathcs.emory.edu |

Date: 2015-04-13 at 4:00PM |

Venue: W303 |

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Abstract:The celebrated Green-Tao theorem states that there are arbitrarily long arithmetic progressions in the primes. The proof has two parts. The first part is a relative Szemeredi theorem which says that any subset of a pseudorandom set of integers of positive relative density contains long arithmetic progressions, where a set is pseudorandom if it satisfies two conditions, the linear forms condition and the correlation condition. The second part is in finding a pseudorandom set in which the primes have positive relative density. In this talk, we will discuss a simple proof for a strengthening of the relative Szemeredi theorem, showing that a weak linear forms condition is sufficient for the theorem to hold. By removing the correlation condition, our strengthened version can be applied to give a relative Szemeredi theorem for $k$-term arithmetic progressions in pseudorandom subsets of $\mathbb{Z}_N$ of density $N^{-c_k}$. It also simplifies the deduction of the Green-Tao theorem by removing the need for certain number theoretic estimates in the second part of their proof. Joint work with Jacob Fox and Yufei Zhao. |

Title: Music Information Retrieval |
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Colloquium: Department |

Speaker: Davide Fossati of Carnegie Mellon University in Qatar |

Contact: Ken Mandelberg, km@mathcs.emory.edu |

Date: 2015-04-10 at 3:00PM |

Venue: W303 |

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Abstract:What does it take to build a search engine for sound and music? How can computers "listen" to music and understand what you are playing? Currently, the most successful and widespread technologies for organizing and searching for information are based on text. Instead, the emerging field of Music Information Retrieval focuses on technology that operates directly on audio signals without relying on textual annotation. In this presentation I will give a brief overview of Music Information Retrieval: foundational ideas, methodology, and applications. We will see how sound can be represented, segmented, converted into a set of features, and classified. |

Title: Knots and Brauer groups of curves |
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Seminar: Algebra |

Speaker: Ted Chinburg of Penn |

Contact: David Zureick-Brown, dzb@mathcs.emory.edu |

Date: 2015-04-10 at 4:00PM |

Venue: W302 |

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Abstract:There has been a great deal of research over the last 20 years on invariants of knots on one hand and on Brauer groups of curves on the other. The goal of this talk is to link these two subjects. This is joint work with Alan Reid and Matt Stover. |

Title: Athens-Atlants joint number theory seminar |
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Seminar: Algebra |

Speaker: Dick Gross and Ted Chinburg of Harvard and Penn |

Contact: TBA |

Date: 2015-04-09 at 4:00PM |

Venue: At UGA |

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Abstract:TBA |