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InTheLoop | 06.03.2013

June 3, 2013

CRD’s Arie Shoshani, Peter Nugent Win Director’s Achievement Awards

The recipients of the Berkeley Lab Director’s Lifetime and Exceptional Achievement Awards have been announced. Arie Shoshani, head of the Scientific Data Management Group in the Computational Research Division, is one of two recipients of the Berkeley Lab Prize Lifetime Achievement Award. Exceptional Achievement honorees in the Science category include Peter Nugent, co-leader of the Computational Cosmology Group in CRD. Read more.


Researchers Model Impact of Aerosols over California

For the first time ever, researchers from the Pacific Northwest National Laboratory (PNNL), Colorado State University and the California Air Resources Board have characterized the relative, direct influence of different aerosol species on seasonal atmospheric warming and cooling over California using supercomputers at NERSC and at PNNL. The scientists found that aerosols have a net cooling effect on California’s atmosphere, but individual species contribute differently. While sulfates contributed the most to cooling, black carbon particles, or soot, were responsible for up to 95 percent of countervailing warming. Read more.


ESnet Staff to Present Paper, Participate in Two Demos at Europe’s Largest Networking Conference

From June 3–6, more than 500 networking researchers from across Europe and around the world will meet in Maastricht, The Netherlands for TNC2013, the TERENA Networking Conference. Among them will be several staff members from ESnet who will present a paper and co-lead two demonstrations, including one showcasing the world’s first intercontinental 100 gigabit-per-second link for research and education. TNC is Europe’s largest and most prestigious research networking conference.

As part of the Monday, June 3, opening program, ESnet will join five of the world’s other leading research and education (R&E) networks and two commercial partners to demonstrate for the first time a trans-Atlantic 100 Gbps transmission link for research and education between North America and Europe. Read more. In conjunction with this, ESnet Chief Technologist Inder Monga will lead a demo “Visualize 100G traffic,” showing the total traffic on the 100 Gbps link between New York and the conference in Maastricht. ESnet’s Jon Dugan is a prime contributor to the demo, while Patrick Dorn also contributed.

On Tuesday, June 4, during the “Big Data, Big Deal” session, ESnet’s Bill Johnston will present “Enabling high throughput in widely distributed data management and analysis systems: Lessons from the LHC.” The paper was co-authored by Michael Ernst of Brookhaven National Lab and ESnet’s Eli Dart and Brian Tierney.

On Wednesday, June 6, Monga will lead a demo on “How many modern servers can fill a 100 Gbps Transatlantic Circuit?” The demonstration will show that with the proper tuning and tools, only two hosts on each continent can generate almost 80 Gbps of traffic. Tierney and Chin Guok of ESnet are supporting the demo, which is collaboration with the University of Amsterdam.


NERSC Strategic Plan Is Now Online

The NERSC Strategic Plan for FY2014–2023 is now online (PDF | 3.2MB). Requested by the DOE Office of Advanced Scientific Computing Research as input for ASCR’s long-term planning, the strategic plan discusses NERSC’s mission, goals, science drivers, planned initiatives, and technology strategy, among other topics. Find more NERSC publications and reports.


Computing Sciences Summer Student Program Begins Tomorrow

The Computing Sciences Summer Student Program begins on June 4 with a lunch and a welcome from CRD Director David Brown. Thirty-five students will be working on a variety of projects with CRD, ESnet, and NERSC staff. Osni Marques chairs the program this year, with help from David Skinner, Elizabeth Bautista, Brian Tierney, Marcia Ocon-Leimer, Maria Maroudas, Jeff Todd, and Teresa Montero.

A poster session on August 1 will give students the opportunity to prepare and present a tabletop poster that summarizes their work, describes their Lab experiences, and presents the results of their research during their stay at the Lab. Prizes will be awarded for the best, most innovative, and most original posters.

A series of talks and tours throughout the summer will familiarize the students with research in Computing Sciences and at Berkeley Lab.


NERSC Turns 40 in 2014; CS Staff Invited to Suggest a Theme

Established in 1974, NERSC is likely the longest running supercomputing center for open science. Planning is just beginning for the 40th anniversary, and one of the first goals is to choose a theme for the anniversary. Have an idea or two? Please send them to Jon Bashor.


City College of San Francisco Students Visit NERSC

On May 28, some City College of San Francisco students got a look at the inner workings of the NERSC machine room, with Nick Cardo and David Paul leading the way. Elizabeth Bautista organized the tour, and Margie Wylie took photos. View the photos on Facebook.


This Week’s Computing Sciences Seminars

Learning from Subsampled Data: Active and Randomized Strategies

Monday, June 3, 2:00–3:00 pm, 50A-5132

Fabian Wauthier, University of California BerkeleyJon Bashor

In modern machine learning applications, we frequently encounter situations where enormous amounts of data are available. This trend puts stress on current computational resources and motivates learning from a small subsample of data. Depending on the circumstances, subsampling can be active (i.e. active learning) or randomized. In this talk I will show work on both fronts.

Active Learning: As models become more complex, active learning tends to become harder. For example, consider complex Bayesian models, which often rely on an MCMC-based method for inference. Here, active learning is commonly thought to be computationally infeasible, since a naive scoring implementation would require running many additional MCMC chains. I propose a new MCMC-based framework for tractable approximate active learning which reuses samples from an existing MCMC chain for approximate scoring. This avoids running extra MCMC chains and outperforms the naive approach.

Randomized Subsampling: A fundamental theoretical question related to randomized subsampling looks at the sample complexity of a statistical model. I will focus on two simple randomized algorithms for ranking from pairwise comparisons and will show sample complexities that in expectation achieve a corresponding lower bound. Additionally, the algorithms possess interesting recovery properties: One algorithm recovers the rank with uniform quality across a permutation, while the other recovers the rank more accurately near the top than the bottom.

OSF Brown Bag: Nagios Downtime Scripts

Tuesday, June 4, 12:00–1:00 pm, OSF room 238

Patrick Buddeberg, NERSC/ESnet Operations

The Nagios web interface to downtime management works well for small scale usage, but it does not scale very well to the many host (i.e., nodes) environment at NERSC. Additionally, it will not give a warning that a downtime will be ending shortly. To alleviate these issue, the Nagios downtimes scripts were created to form a command line interface for working with many hosts and services at once, and a script to be run as a cron job to give warning of ending downtimes. This second feature also is capable of reducing mail volume.

CS Summer Student Program Lunch Kickoff

Tuesday, June 4, 12:00–1:30 pm, 50A-5132

David Brown, LBNL/CRD

CS Summer Student Brown Bag: High-Order Discontinuous Galerkin Methods for Conservation Laws (tentative)

Thursday, June 6, 12:00–1:00 pm, 70-191

Per-Olof Persson, UC Berkeley and LBNL/CRD