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Thursday April 11, 2013
1:00pm
Powell-Booth Room 100
“Turning Large Simulations into Numerical Laboratories”
Alex Szalay, Alumni Centennial Professor, Department of Physics and Astronomy, The Johns Hopkins University
The talk will discuss how large (100TB+) supercomputer-scale simulations can be turned into interactive public laboratories. Examples include simulations of turbulence and various cosmological simulations, soon to reach the PB scale.
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Jan 31, 2013 1:00 PM
Keith Spalding 410
Andrew Drake, CACR
We have performed an extensive search for RR Lyrae among the 500 million sources observed by the Catalina Surveys. We detect ~26,000 type-AB RR Lyrae (of which 20,000 are new discoveries) from a region spanning 3/4 of the sky. By determining accurate distances to the stars, we investigate the spatial distribution of structures within the Milky Way halo. Combining the RR Lyrae distances with SDSS spectroscopy we are able accurately trace the velocities and metallicities of hundreds of sources within the Sagittarius tidal streams system. We find the first strong evidence for a dense tidal stream that overlaps the Sagittarius system to distances beyond 100kpc, yet remains unexplained by any existing model.
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Tuesday, January 29th
12:00 – 1:00pm
105 Annenberg
*Lunch will be provided*
SPEAKER:
Alexandre Cunha
Center for Advanced Computing Research and Elliot Meyerowitz Lab, Caltech
TITLE:
Collaborative Image Analysis with the Masses: Challenges and Opportunities
ABSTRACT:
Extracting reliable quantitative information from digital images in an automatic fashion continues to be a difficult task. In many situations classical and contemporary algorithms only provide partial and sub-optimal results that might not be sufficient to carry on research studies thus leading practitioners to rely on manual annotations. We present our work on collaborative image segmentation, an online crowdsourcing system where computers, experts, and non-experts cooperate to produce robust results supporting the research of plant biologists. We address some of the technical and nontechnical challenges in building such a system and discuss the potential in employing the vision of crowds to help solve image processing problems which are still poorly solved by computers alone.
This is a work in progress in collaboration with Elliot Meyerowitz lab at Caltech and with Tsang Ing Ren lab at UFPE, Brazil.
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Tuesday November 27, 2012
Powell Booth Room 100
1:30PM
“General purpose GPU programming by CUDA—an introductory tutorial”
Dr. Hailiang Zhang, Caltech Center for Advanced Computing Research (CACR)
Abstract:
In recent years, various fields of large-scale scientific computations
have greatly benefit from the massively parallel programming. This talk
presents a brief introduction and tutorial on the state-of-the-art
general-purpose GPU programming platform—CUDA. The GPU device
architecture, memory hierarchy, and the general CUDA programming model
will be introduced. The CUDA numerical schemes of some vector and matrix
operations will be demonstrated as examples. Some CUDA applications on
molecular and biophysical modeling will be presented. The standard CUDA
toolkit libraries and some third party APIs will also be introduced.
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Thursday, October 18, 2012
Annenberg 105
4PM
“Software Challenges for Extreme Scale Systems”
Vivek Sarkar, E.D. Butcher Chair in Engineering, Professor of Computer Science, Rice University
ABSTRACT:
It is widely recognized that computer systems anticipated in the
2020 timeframe will be qualitatively different from current
and past computer systems. Specifically, they will be built using
homogeneous and heterogeneous many-core processors with 100’s of
cores per chip, their performance will be driven by parallelism
(million-way parallelism just for a departmental server), and
constrained by energy and data movement. They will also be subject to
frequent faults and failures. Unlike previous generations of hardware
evolution, these Extreme Scale systems will have a profound impact on
future software. The software challenges are further compounded by
the need to support new workloads and application domains
that have traditionally not had to worry about large scales of
parallelism in the past.
The challenges across the entire software stack for Extreme Scale
systems are driven by programmability and performance requirements,
and impose new requirements on programming models, languages, compilers, and runtime systems.
We focus on the critical role played by the runtime
system in enabling programmability in upper layers of the software
stack that interface with the programmer, and in enabling performance
in lower levels of the software stack that interface with the
hardware. Examples of key runtime primitives will be drawn from early
experiences in the Habanero Multicore Software Research project
(http://habanero.rice.edu) which targets a wide range of homogeneous
and heterogeneous manycore processors. On the programmability front,
the runtime primitives are shown to support important semantic guarantees
for different classes of programs. On the performance front, we show how general structures for
task creation, synchronization, and termination can be implemented in a scalable manner
on manycore processor testbeds that are representative of the challenges
that we will face in future Extreme Scale processors.
BIO:
Vivek Sarkar conducts research in multiple aspects of parallel
software including programming languages, program analysis, compiler
optimizations and runtimes for parallel and high performance computer
systems. He currently leads the Habanero Multicore Software Research
project at Rice University, and serves as Associate Director of the
NSF Expeditions project on the Center for Domain-Specific Computing.
Prior to joining Rice in July 2007, Vivek was Senior Manager of
Programming Technologies at IBM Research. His responsibilities at IBM
included leading IBM’s research efforts in programming model, tools,
and productivity in the PERCS project during 2002- 2007 as part of the
DARPA High Productivity Computing System program. His past projects
include the X10 programming language, the Jikes Research Virtual
Machine for the Java language, the MIT RAW multicore project, the ASTI
optimizer used in IBM’s XL Fortran product compilers, the PTRAN
automatic parallelization system, and profile-directed partitioning
and scheduling of Sisal programs. Vivek holds a B.Tech. degree from
the Indian Institute of Technology, Kanpur, an M.S. degree from
University of Wisconsin-Madison, and a Ph.D. from Stanford University.
He became a member of the IBM Academy of Technology in 1995, the
E.D. Butcher Chair in Engineering at Rice University in 2007, and was
inducted as an ACM Fellow in 2008. Vivek has been serving as a member
of the US Department of Energy’s Advanced Scientific Computing
Advisory Committee (ASCAC) since 2009.
