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Date
( Summer 2013 )
Category Seminar Info
2012/08/16 Graduate Seminar Series Place: MC103
Time: 12 - 12:30
Speaker: Rahul Garg
Affiliation: PhD Student, SABLE lab, McGill
Area: Programming Languages and Scientific Computing
Title: Portable Matrix Operation Library for GPUs
Abstract: Does your work involve matrix operations with large dense matrices? Not satisfied with speed you are getting on CPUs? Then you may be aware that modern GPUs provide considerably better performance on many types of matrix computations than most CPUs. However, so far you had to choose vendor-specific APIs (eg: Nvidia CUBLAS only works on Nvidia) making your code non-portable. I present a high-performance portable BLAS library that runs on many GPUs including AMD, Nvidia and Intel GPUs. I will present initial performance results, and discuss future plans.
2012/07/12 Graduate Seminar Series Place: MC103
Time: 12 - 12:30
Speaker: Yogesh Girdhar
Affiliation: PhD Candidate, McGill Center for Intelligent Machines
Area: computer vision and robotics
Title: ROST: Realtime Online Spatiotemporal Topics
Abstract: We describe a novel online topic modeling framework to compute a low dimension descriptor of visual observations made by a mobile robot, which is sensitive to the structural and thematic changes in the environment. Our approach is designed to run in realtime, and is suitable for long term execution on a robotic platform. Using this image descriptor we build online anytime summaries consisting of surprising observations experienced by a robot thus far. The observations in the summary are chosen such that they cover the set of all observations in topic space, while minimizing the cover radius. Like almost any summarization method, the technique is meant to produce data for human consumption. Thus, we assess our approach on 307 human subjects and compare it to the classic bag-of-words description based summaries, and find it superior.
2012/06/07 CQIL - Cryptography and Quantum Information Place: McConnell 320
Time: 14:00 - 15:00
Speaker: Eric Chitambar
Affiliation: Perimeter Institute
Title: LOCC Instruments
Abstract: In the “distant labs” setting of quantum information processing, a multipart quantum system is distributed to various parties who are separated by some large distance. The parties are allowed to perform local measurements on their respective subsystems while coordinating their actions through classical communication. This scenario is known as LOCC (local operations and classical communication) and it plays a fundamental role in some of the most important quantum information tasks such as teleportation and quantum cryptography. However, despite this relatively simple operational description, it is quite challenging to provide a precise mathematical characterization of LOCC operations. In this talk, I will define LOCC operations through the notion of quantum instruments, which is a useful formalism that captures both the classical and quantum outputs of a measurement. This will allow us to clearly differentiate between finite round LOCC, infinite round LOCC and asymptotic LOCC. In doing so, certain examples will be given that show these classes to be strictly different from one another. Additionally we will prove that the set of finite round, finite outcome LOCC instruments is compact, while the compactness breaks down when infinite round protocols are considered. Finally, we will discuss various open problems related to the structure of LOCC instruments.
2012/05/30 Graduate Seminar Series Place: MC103
Time: 12 - 12:30
Speaker: Ivan Savov
Affiliation: McGill
Area: Quantum Computing
Title: Coding For Classical-Quantum Channels
Abstract: The transmission of information through noisy communication channels is a fundamental problem of theoretical and practical importance. Given a probabilistic model of the noise in a communication channel, we can use Shannon's information theoretic techniques to calculate the maximum possible communication rates for that channel. Recently there has been interest in studying quantum channel models, which offer more accurate models for the encoding, transmission and decoding of the information. These models are relevant for communication systems in which the information carriers are quantum systems, like for example in the case of optical communication. This presentation will give an intuitive explanation of the Holevo-Schumacher-Westmoreland Theorem, which gives a precise characterization of the information carrying capacity of quantum channels. In closing we will discuss briefly the generalization of the HSW Theorem to quantum channels with many senders and/or many receivers (network information theory). Biography of Speaker:

Ivan Savov is a graduate student in the School of Computer Science at McGill Univeristy in Montreal Canada. Previously he received a B.Eng. degree in electrical engineering in 2005 and a M.Sc. degree in Physics in 2008, both from McGill University. His current research interest include network information theory, error correcting codes, quantum information theory and machine learning.


2012/05/11 Graduate Seminar Series Place: MC103
Time: 12 - 12:30
Speaker: Jordan Frank
Affiliation: McGill
Area: Machine Learning
Title: Stalking 2.0
Abstract: I have recently taken part in the Nokia Mobile Data Challenge (MDC). Nokia has provided over a year's worth of data collected from the mobile phones of 38 people in Lausanne, Switzerland. The data include wifi, gsm, and gps signal measurements, accelerometer measurements, call logs, and application usage. I will present a set of tools that I have developed to visualize and analyse this data, as well as some preliminary results from our paper "Generating storylines from mobile phone data" (submitted to the Nokia MDC Workshop), in which we proposed a method for translating from mobile phone sensor data to English-language descriptions of events.
2012/05/10 CQIL - Cryptography and Quantum Information Place: McConnell 320
Time: 14:00 - 15:00
Speaker: Patrick Hayden
Affiliation:
Area: Quantum information
Title: Leggett-Garg inequalities and the geometry of the cut polytope
Abstract: