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Title: Geometric Range Search over Encrypted Spatial Data
Seminar: Computer Science
Speaker: Ming Li of University of Arizona
Contact: Vaidy Sunderam, vss@emory.edu
Date: 2015-11-06 at 3:00PM
Venue: W303
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Abstract:
Geometric range search is a fundamental primitive for spatial data analysis in SQL and NoSQL databases. It has extensive applications in Location-Based Services, computer-aided design and computational geometry. Due to the dramatic increase of data size, it is necessary for companies and organizations to outsource their spatial datasets to third-party cloud services (e.g. Amazon) in order to reduce storage and query processing costs, but meanwhile with the promise of no privacy leakage to the third party. Searchable encryption is a technique to perform meaningful queries on encrypted data without revealing privacy. However, geometric range search on spatial data has not been fully investigated nor supported by existing searchable encryption schemes. The main challenge, is that compute-and-then-compare operations required by many range search algorithms cannot be supported by any existing crypto primitives. In this talk, I will present our recent research progresses in privacy-preserving geometric range search over encrypted spatial data. The general approach is to adopt new representations of spatial data, and transform the range query algorithm to avoid compute-and-then-compare operations, so that existing efficient crypto primitives can be integrated. I will present two designs, the first one focuses on circular range search, and the second one can handle arbitrary geometric range query and is more efficient. The security of both schemes are formally proven under standard cryptographic assumptions. Finally, I will discuss some future research challenges and directions in this area.
Title: A generalization of the Euler-Glaisher bijection
Seminar: Algebra and Number Theory
Speaker: Andrew Sills of Georgia Southern University
Contact: Robert Schneider, robert.schneider@emory.edu
Date: 2015-11-03 at 4:00PM
Venue: W304
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Abstract:
In 1748, Euler published his Introductio in Analysin Infinitorum. Chapter 16 of this work is the first systematic study of integer partitions in the mathematical literature. In it, he introduces infinite product generating functions and uses them to derive what is now known as Euler’s partition identity, an English translation of which reads as follows: “The number of different ways a given number can be expressed as the sum of different whole numbers is the same as the number of ways in which the same number can be expressed as the sum of odd numbers, whether the same of different.” In modern terminology, the preceding is rephrased as “the number of partitions of n into distinct parts equals the number of partitions of n into odd parts.” In 1883, J.W.L. Glaisher published the first bijective proof of Euler’s partition identity, along with a natural generalization: “the number of partitions of n where no part appears more than m - 1 times equals the number of partitions of n where no part is divisible by m.” By combining a construction of P.A. MacMahon called “partitions of infinity” and knowledge of George Andrews' “partition ideals of order 1” with Glaisher’s bijective proof of Euler’s identity, we are led to discover a large class of partition identities with straightforward bijective proofs. This is joint work with James Sellers and Gary Mullen of Penn State. All terms will be defined and illustrated with concrete examples, so the required mathematical background will be minimal, and the talk should be accessible to all graduate students.
Title: Rationally isomorphic hermitian forms and torsors of some non-reductive groups
Seminar: Algebra and Number Theory
Speaker: Eva Bayer-Fluckiger of Ecole Polytechnique Federale de Lausanne
Contact: Raman Parimala, parimala@mathcs.emory.edu
Date: 2015-10-27 at 4:00PM
Venue: W304
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Abstract:
This is a joint work with Uriya First. Let R be a semi-local Dedekind domain. Under certain assumptions, we show that two (not necessarily unimodular) hermitian forms over an R-algebra with involution that are rationally isometric are isometric over R. The result can be regarded as a first step towards a version of the Grothendieck-Serre conjecture for certain non-reductive group schemes over Spec R.
Title: The Era of Big Spatial Data
Seminar: Computer Science
Speaker: Mohamed Mokbel of University of Minnesota
Contact: Li Xiong, lxiong@mathcs.emory.edu
Date: 2015-10-26 at 1:00PM
Venue: W302
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Abstract:
In recent years, there has been an explosion in the amounts of spatial and spatio-temporal data produced from several devices including smart phones, space telescopes, medical devices. Unfortunately, managing and analyzing such big spatial data is hampered by the lack of specialized systems, techniques, and algorithms. While big data is well supported with a variety of distributed systems and cloud infrastructure, none of these systems or infrastructure provide any special support for spatial or spatio-temporal data. This talk presents our efforts in indexing, querying, and visualizing big spatial and spatio-temporal data. We will describe our efforts within SpatialHadoop; our full-fledged MapReduce framework with native support for spatial data, including support for basic spatial operations, computational geometry, and spatial visualization. BIO: Mohamed F. Mokbel (Ph.D., Purdue University, MS, B.Sc., Alexandria University) is an Associate Professor in the Department of Computer Science and Engineering, University of Minnesota. His research interests include the interaction of GIS and location-based services with database systems and cloud computing. His research work has been recognized by five Best Paper Awards and by the NSF CAREER award. Mohamed was the program co-chair for the ACM SIGSPATIAL GIS conference from 2008 to 2010, IEEE MDM Conference 2011 and 2014, and the General Chair for SSTD 2011. He is an Asscoiate Editor for ACM TODS, ACM TSAS, VLDB journal, and GeoInformatica. Mohamed is a founding member of ACM SIGSPATIAL, and an elected Chair of ACM SIGSPATIAL 2014-2017. For more information, please visit: www.cs.umn.edu/~mokbel.
Title: The Georgia Algebraic Geometry Symposium
Seminar: Algebra
Speaker: gags.torsor.org of
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Date: 2015-10-23 at 9:00AM
Venue: E208
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Abstract:
The Georgia Algebraic Geometry Symposium is a conference series, jointly organized by the University of Georgia, Emory University and Georgia Tech. The conference will begin Friday afternoon and end Sunday, afternoons. See gags.torsor.org for more information. Confirmed speakers: Valery Alexeev (University of Georgia), Brian Conrad (Stanford University), Brian Lehman (Boston College), Max Lieblich (University of Washington), Alexander Merkurjev (UCLA), Alena Pirutka (École Polytechnique), Aaron Pixton (Harvard University), Tony Várilly-Alvarado (Rice University), Olivier Wittenberg (CNRS - École Normale Superieure)
Title: Rational points of rationally connected varieties over number fields, an overview (part 3)
Seminar: Algebra
Speaker: Olivier Wittenberg of
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Date: 2015-10-22 at 4:00PM
Venue: W304
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Abstract:
This will be a short course (3 lectures) aimed at graduate students.
Title: Rational points of rationally connected varieties over number fields, an overview (part 2)
Seminar: Algebra
Speaker: Olivier Wittenberg of
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Date: 2015-10-21 at 4:00PM
Venue: W301
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Abstract:
This will be a short course (3 lectures) aimed at graduate students.
Title: Rational points of rationally connected varieties over number fields, an overview (part 1)
Seminar: Algebra
Speaker: Olivier Wittenberg of
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Date: 2015-10-20 at 4:00PM
Venue: W304
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Abstract:
This will be a short course (3 lectures) aimed at graduate students.
Title: Some variational considerations of immersion
Seminar: Analysis and Differential Geometry
Speaker: John McCuan of Georgia Institute of Technology
Contact: Vladmir Oliker, oliker@mathcs.emory.edu
Date: 2015-10-20 at 4:00PM
Venue: W301
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Abstract:
Archimedes considered the effect of buoyancy when an object is immersed in a liquid bath. A theoretical framework has since been developed in which one can take account of capillary effects in this process, yet a precise geometric description of equilibrium configurations, their stability, and observational significance are all far from being completely understood in terms of the relevant parameters. In this talk we describe some aspects of the problem and consider some special cases which give some indications of what one can expect.
Title: Privacy-Preserving Query Processing over Encrypted Data in Cloud
Seminar: Computer Science
Speaker: Yousef Elmehdwi of Missouri ST University
Contact: Vaidy Sunderam, vss@mathcs.emory.edu
Date: 2015-10-16 at 3:00PM
Venue: W303
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Abstract:
The query processing of relational data has been studied extensively throughout the past decade. A number of theoretical and practical solutions to query processing have been proposed under various scenarios. With the recent popularity of cloud computing, data owners now have the opportunity to outsource not only their data, but also the data management tasks to the cloud. Because of data security and personal privacy concerns, sensitive data (e.g. medical records) should be encrypted before being outsourced to a cloud, and the cloud should perform query processing tasks on the encrypted data only. In this talk, I will present our current research on the development of secure distributed protocols to facilitate query processing over encrypted data hosted in the cloud. I will also explore possible future research directions.