# InTheLoop | 04.05.2010

April 5, 2010

## NERSC Helps Locate Jupiter’s Missing Neon

It's raining helium on Jupiter—and as these droplets fall towards the planet's deeper interior, they are bringing neon down with them. Researchers at UC Berkeley were able to solve this decade-old mystery with help from NERSC's supercomputers. Learn more.

## NERSC Helps Shed Light on the Nature of Antimatter

Using NERSC’s Parallel Distributed Systems Facility (PDSF) and the Brookhaven National Laboratory’s Relativistic Heavy Ion Collider (RHIC), physicists have detected and confirmed the first-ever antimatter hypernucleus, called “antihypertriton.” Learn more.

## Simulations Reveal Secrets of Massive Star-Forming Galaxies

Astronomers have in recent years been surprised to find hulking brutes among the baby galaxies of the early Universe. Once considered oddities, these galaxies are now thought to be the engines that drove the Universe’s most active period of star formation. Using NERSC’s supercomputers, astronomers are successfully simulating these massive galaxies to understand how they came to be so quickly and what has happened to them in our modern Universe. Learn more.

## CCSE Has Opening for Project Scientist

The Center for Computational Sciences and Engineering (CCSE) in CRD is looking for an experienced candidate to join CCSE for two years as a Project Scientist. The successful candidate must be able to contribute to ongoing research projects in computational astrophysics. See job details. The Lab’s Employee Referral Incentive Program (ERIP) awards $1,000 (net) to employees whose referral of an external candidate leads to a successful hire.

## MathWorks Offers MATLAB Seminars on Wednesday

Jamie Winter of MathWorks will offer two complimentary MATLAB seminars Wednesday afternoon in the Building 50 Auditorium. Register here to ensure seating.

Session 1, 1:00–2:30 pm **Introduction to Statistical Analysis and Curve Fitting with MATLAB**

This seminar will focus on statistical and data analysis, using functionality from the Statistics and Curve Fitting Toolboxes. Automating and sharing analyses will be highlighted. With a workflow demo, we will design an experiment to optimize control parameters to affect a desired outcome. Topics covered in the seminar will include:

- Dataset arrays
- Descriptive statistics
- Hypothesis testing
- ANOVA
- Regression
- DOE

Session 2, 2:45–4:00 pm**Speeding Up MATLAB Applications**

In this session we will discuss and demonstrate simple ways to improve and optimize your code that can boost execution speed by orders of magnitude. We will also address common pitfalls in writing m-code, explore the use of the MATLAB Profiler to find bottlenecks, and briefly introduce our Parallel Computing Toolbox and Distributed Computing Server to solve computationally and data-intensive problems on multicore computers and clusters. Highlights include:

- Understand memory usage and vectorization in MATLAB
- Address bottlenecks in your programs
- Optimize file I/O to streamline your code
- Transition from serial to parallel MATLAB programs

## This Week’s Computing Sciences Seminars

**Multi-Scale, Multi-Physics Modeling of Solid Oxide Fuel Cells**

Tuesday, April 6, 2:00–3:00 pm, 50F-1647

Zijing Lin, University of Science and Technology, Hefei, China

Solid oxide fuel cell (SOFC) represents a well developed, yet immature technology. Theory and modeling can play an important role in speeding up the technology development. A comprehensive theoretical framework with multi-scale, multi-physics modeling capabilities for the cell and stack design and the optimization of material properties is described. The theoretical approach consists of effective material and electrochemistry models for porous electrodes at the particle scale, and continuum models for electrochemistry, gas transport and current conduction at the cell and stack scales. The modeling tool is being used to assist in the design of cells and stacks for improved performance. As examples, the optimizations of the electrode microstructure and the thickness of the electrode layers, the relationship between the optimal rib width and the contact resistance, and the manifold design for the flow uniformity of realistic planar SOFC stack are discussed in detail.

**Advances in Embedded Software Synthesis from Dataflow Models**

Tuesday, April 6, 4:00–5:00 pm, Cory Hall, 540 A/B

Soheil Ghiasi, University of California Davis

Multiprocessor systems are going to find a larger share in the embedded application space, due to a number of economical and technical imperatives. Productive development of applications for multiprocessors, however, remains to be challenging. In this context, I present our results on synthesis of streaming applications from dataflow models targeting such parallel platforms. I present a provably effective algorithm for task assignment — a key step in the compilation flow — to two parallel processors, when the limited memory resources and application throughput form the outstanding constraints and objective, respectively. The technique is versatile in that it is formally extensible to a number of different formulations. In addition, I present our results on code size optimization, via enhanced buffer allocation during software synthesis from models, to deal with processors’ limited memory resources.

**The Algebra of Fast Transforms: Banded Matrices with Banded Inverses**

Wednesday, April 7, 11:10 am–12:00 pm, 380 Soda Hall

Gilbert Strang, MIT

The success of wavelets depends on the property that the inverse wavelet transform also involves finite length filters. So the transform and its inverse are both represented by *banded matrices*. We provide a new factorization for all matrices (many of them far from wavelets!) with this exceptional property. An unsolved combinatorial question about permutation matrices (banded of course) will also arise.

**About Computing Sciences at Berkeley Lab**

The

**Lawrence Berkeley National Laboratory**(Berkeley Lab)

**Computing Sciences**organization provides the computing and networking resources and expertise critical to advancing the Department of Energy's research missions: developing new energy sources, improving energy efficiency, developing new materials and increasing our understanding of ourselves, our world and our universe.

ESnet, the

**Energy Sciences Network**, provides the high-bandwidth, reliable connections that link scientists at 40 DOE research sites to each other and to experimental facilities and supercomputing centers around the country. The

**National Energy Research Scientific Computing Center**(NERSC) powers the discoveries of 6,000 scientists at national laboratories and universities, including those at Berkeley Lab's Computational Research Division (CRD). CRD conducts research and development in mathematical modeling and simulation, algorithm design, data storage, management and analysis, computer system architecture and high-performance software implementation. NERSC and ESnet are DOE Office of Science User Facilities.

Lawrence Berkeley National Laboratory addresses the world's most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab's scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the DOE’s Office of Science.

**DOE’s Office of Science** is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.