[hpc-announce] CfP: SC16 Numerical Reproducibility at Exascale workshop (NRE-2016), Salt Lake City, UT, Nov 18, 2016 [Extended Dates]

Keyrouz, Walid (Fed) walid.keyrouz at nist.gov
Tue Sep 13 09:26:48 CDT 2016

!!!!!     Call for Participation     !!!!!

Numerical Reproducibility at Exascale Workshop (NRE2016)

Where:         In cooperation with SC16, Salt Lake City, Utah
When:          Friday morning, November 18, 2016
Web:           http://www.cs.fsu.edu/~nre
Submit:        https://easychair.org/conferences/?conf=nre2016
Deadline:      Monday, September 26, 2016 (was Aug. 29, 2016)
Notifications: Monday, October 10, 2016 (was Oct. 10, 2016)
Full Papers:   Monday, December 19, 2016
Organized by:  Walid Keyrouz (NIST) and Michael Mascagni (FSU & NIST)


Experimental reproducibility is a cornerstone of the scientific
method.  As computing has grown into a powerful tool for scientific
inquiry, computational reproducibility has been one of the core
assumptions underlying scientific computing.  With "traditional"
single-core CPUs, documenting a numerical result was relatively
straightforward.  However, hardware developments over the past several
decades have made it almost impossible to ensure computational
reproducibility or to even fully document a computation without
incurring a severe loss of performance.  This loss of reproducibility
started with CPUs that used out-of-order execution to improve
performance.  It has accelerated with recent architectural trends
towards platforms with increasingly large numbers of processing
elements, namely multicore CPUs and compute accelerators (GPUs, Intel
Xeon Phi, FPGAs).

Programmers targeting these platforms rely on tools and libraries to
produce codes or execute them efficiently.  As a result, codes can run
efficiently, but have execution details that can be impossible to
predict and are often very difficult to understand after execution.
Furthermore, parallel implementations often result in code with
varying execution orders between runs, leading to non-reproducible
computations.  The underlying reasons are that (1) the hardware and
system software allocate parallel work in ways that are not always
specifiable at compile time and (2) the execution often proceeds in an
opportunistic manner with the execution order changing between runs.
As such, floating-point computations, which are not commutative and
associative, can have different execution orders and execute on
different processing elements between runs, leading to runs with
varying results as a matter of fact.  The predictability of systems is
further complicated by two issues that are becoming more critical as
systems grow in scale: (1) interconnect systems with latencies that
are often outside the control of programmers and (2) reliability as
the mean time between failure (MTBF) is now measured in hours on large
systems.  This situation seriously affects the ability to rely on
scientific computations as a metrological substitute for

Previous Offerings

This is the second offering of Numerical Reproducibility at Exascale;
the first edition, NRE2015, was at SC15.

Workshop Scope

The workshop is meant to address the scope of the problems of
numerical reproducibility in HPC in general and those anticipated as
we scale to Exascale machines in the next decade.  We initially seek
contributions of extended abstracts (two pages) in the areas of
computational reproducibility in HPC from academic, government, and
industry stakeholders.  Areas of interest include, but are not limited

* Case studies of reproducibility or the lack of it
* Reproducibility issues in current HPC
* System-level solutions
* Algorithmic solutions
* Software solutions
* Uncertainty quantification in computational reproducibility
* Fundamental numerical analysis of reproducibility
* Future prospects

Workshop Format

The workshop will have:

* two plenary talks: Michael Wolfe (NVidia) & Michela Taufer (Uni. of Delaware)
* a morning of contributed talks
* a panel discussion to summarize the problem, current research, and
  prospects on long-term solutions

Papers submitted to the workshop will be reviewed.  The referees will
select the papers that will be presented in the workshop.  In
addition, a group of papers will be published in a special issue of
Mathematics and Computers in Simulation (MATCOM) devoted to Numerical


Submissions of two page extended abstracts are sought.  The format for
the abstracts is not specified, but full papers that are accepted will
be published in the MATCOM special issue.  The MATCOM instructions for
authors can be found on the MATCOM website.

The abstracts are to submitted as a PDF document using Easychair at

Travel Support

Some limited travel support may be available via NIST.  Important
Dates (all are Mondays)

Sep 26, 2016: submission deadline for two page abstracts via

Oct 10,  2016: notification of authors about their submissions based
    	      on: rejection, acceptance as a paper, acceptance as a
    	      paper and presentation

Dec 19, 2016: submission deadline for full papers for refereeing via
    	      the MATCOM site, the papers must be in MATCOM format

Organizers and Co-Editors of the MATCOM Special Issue

* Walid Keyrouz, National Institute of Standards and Technology (NIST), USA
* Michael Mascagni, National Institute of Standards and Technology
  (NIST) and Florida State University, USA

Steering Committee

* Dong H. Ahn, Lawrence Livermore National Lab, USA
* David Bailey, UC Davis, USA
* Mike Heroux, Sandia National Laboratory, USA
* David R. C. Hill, Université Blaise Pascal, Clermont-Ferrand, France
* Torsten Hoefler, ETH-Zurich, Switzerland
* Walid Keyrouz (co-organizer), NIST, USA
* Miriam Leeser, Northeastern University, USA
* Xiaoye Sherry Li, Lawrence Berkeley National Laboratory, USA
* Yaohang Li, Old Dominon University, USA
* Michael Mascagni (co-organizer), FSU/NIST, USA
* Junji Nagano, Insitute of Statistical Mathematics, Japan
* Nathalie Revol, INRIA/ENS-Lyon, France
* Siegfried Rump, University of Hamburg, Germany
* Michela Taufer, University of Delaware


E-mail: numerical.reproducibility.at.nist.gov (replace '.at.' by '@')

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