Search NASA⌕ Search

SEARCH · Search NASA

Results for “PETASCALE”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Community Petascale Project for Accelerator Science and Simulation

The UCLA Plasma Simulation Group is a major partner of the "Community Petascale Project for Accelerator Science and Simulation. This is the final technical report. We include an overall summary, a list of publications and individual progress reports for each years. During the past five years we have made tremendous progress in enhancing the capabilities of OSIRIS and QuickPIC, in developing new algorithms and data structures for PIC codes to run on GPUS and many future core architectures, and in using these codes to model experiments and in making new scientific discoveries. Here we summarize some highlights for which SciDAC was a major contributor.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2013

Final Report for "Community Petascale Project for Accelerator Science and Simulations"

This final report describes the work that has been accomplished over the past 5 years under the Community Petascale Project for Accelerator and Simulations (ComPASS) at Tech-X Corporation. Tech-X had been involved in the full range of ComPASS activities with simulation of laser plasma accelerator concepts, mainly in collaboration with LOASIS program at LBNL, simulation of coherent electron cooling in collaboration with BNL, modeling of electron clouds in high intensity accelerators, in collaboration with researchers at Fermilab and accurate modeling of superconducting RF cavity in collaboration with Fermilab, JLab and Cockcroft Institute in the UK.

43 PARTICLE ACCELERATORS↗
DOE OSTI2013

Enhancing the MPI Programming Model for PetaScale Systems (Final Report)

This project performed research into enhancing the MPI programming model in two ways: developing improved algorithms and implementation strategies, tested and realized in the MPICH implementation, and exploring extensions to the MPI standard to better support PetaScale and ExaScale systems.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2014

Scalable Statistical Analysis of Gaussian Models for Petascale Spatiotemporal Data (Final Technical Report)

Gaussian process models for spatial and spatiotemporal data are ubiquitous in scientific and engineering applications. Likelihood-based methods for fitting such models, which includes all Bayesian methods, have desirable statistical properties and are thus the methods of choice when feasible. However, calculating the likelihood function even once can be a challenge for N irregularly sited observations from such a process, requiring O(N 2 ) memory and O(N 3 ) complexity. Thus, there is a need for fast and accurate likelihood approximation even for N on the order of 10 5 , not to mention the 10 15 implied by petascale data. The main objective of this research was to develop computational tools for the statistical analysis of massive spatiotemporal datasets based on Gaussian process models. Another important objective was the development of appropriate statistical models for specific spatiotemporal processes arising in the physical sciences.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2015

First-Principles Petascale Simulations for Predicting Deflagration to Detonation Transition in Hydrogen-Oxygen Mixtures

Hydrogen has emerged as an important fuel across a range of industries as a means of achieving energy independence and to reduce emissions. DDT and the resulting detonation waves in hydrogen-oxygen can have especially catastrophic consequences in a variety of industrial and energy producing settings related to hydrogen. First-principles numerical simulations of flame acceleration and DDT are required for an in-depth understanding of the phenomena and facilitating design of safe hydrogen systems. The goals of this project were (1) to develop first-principles petascale reactive flow Navier-Stokes simulation code for predicting gaseous high-speed combustion and detonation (HSCD) phenomena and (2) demonstrate feasibility of first-principles simulations of rapid flame acceleration and deflagration-to-detonation transition (DDT) in stoichiometric hydrogen-oxygen mixture (2H 2 + O 2 ). The goals of the project have been accomplished. We have developed a novel numerical simulation code, named HSCD, for performing first-principles direct numerical simulations of high-speed hydrogen combustion. We carried out a series of validating numerical simulations of inert and reactive shock reflection experiments in shock tubes. We then performed a pilot numerical simulation of flame acceleration in a long pipe. The simulation showed the transition of the rapidly accelerating flame into a detonation. The DDT simulations were performed using BG/Q Mira at the Argonne National Laboratory, currently the fourth fastest super-computer in the world.

08 HYDROGEN↗
DOE OSTI2014

Probabilistic Photometric Redshifts in the Era of Petascale Astronomy

With the growth of large photometric surveys, accurately estimating photometric redshifts, preferably as a probability density function (PDF), and fully understanding the implicit systematic uncertainties in this process has become increasingly important. These surveys are expected to obtain images of billions of distinct galaxies. As a result, storing and analyzing all of these photometric redshift PDFs will be non-trivial, and this challenge becomes even more severe if a survey plans to compute and store multiple different PDFs. In this thesis, we have developed an end-to-end framework that will compute accurate and robust photometric redshift PDFs for massive data sets by using two new, state-of-the-art machine learning techniques that are based on a random forest and a random atlas, respectively. By using data from several photometric surveys, we demonstrate the applicability of these new techniques, and we demonstrate that our new approach is among the best techniques currently available. We also show how different techniques can be combined by using novel Bayesian techniques to improve the photometric redshift precision to unprecedented levels while also presenting new approaches to better identify outliers. In addition, our framework provides supplementary information regarding the data being analyzed, including unbiased estimates of the accuracy of the technique without resorting to a validation data set, identification of poor photometric redshift areas within the parameter space occupied by the spectroscopic training data, and a quantification of the relative importance of the variables used during the estimation process. Furthermore, we present a new approach to represent and store photometric redshift PDFs by using a sparse representation with outstanding compression and reconstruction capabilities. We also demonstrate how this framework can also be directly incorporated into cosmological analyses. The new techniques presented in this thesis are crucial to enable the development of precision cosmology in the era of petascale astronomical surveys.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

Active Storage with Analytics Capabilities and I/O Runtime System for Petascale Systems

Computational scientists must understand results from experimental, observational and computational simulation generated data to gain insights and perform knowledge discovery. As systems approach the petascale range, problems that were unimaginable a few years ago are within reach. With the increasing volume and complexity of data produced by ultra-scale simulations and high-throughput experiments, understanding the science is largely hampered by the lack of comprehensive I/O, storage, acceleration of data manipulation, analysis, and mining tools. Scientists require techniques, tools and infrastructure to facilitate better understanding of their data, in particular the ability to effectively perform complex data analysis, statistical analysis and knowledge discovery. The goal of this work is to enable more effective analysis of scientific datasets through the integration of enhancements in the I/O stack, from active storage support at the file system layer to MPI-IO and high-level I/O library layers. We propose to provide software components to accelerate data analytics, mining, I/O, and knowledge discovery for large-scale scientific applications, thereby increasing productivity of both scientists and the systems. Our approaches include 1) design the interfaces in high-level I/O libraries, such as parallel netCDF, for applications to activate data mining operations at the lower I/O layers; 2) Enhance MPI-IO runtime systems to incorporate the functionality developed as a part of the runtime system design; 3) Develop parallel data mining programs as part of runtime library for server-side file system in PVFS file system; and 4) Prototype an active storage cluster, which will utilize multicore CPUs, GPUs, and FPGAs to carry out the data mining workload.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2015

UCLA Final Technical Report for the "Community Petascale Project for Accelerator Science and Simulation”.

The UCLA Plasma Simulation Group is a major partner of the “Community Petascale Project for Accelerator Science and Simulation”. This is the final technical report. We include an overall summary, a list of publications, progress for the most recent year, and individual progress reports for each year. We have made tremendous progress during the three years. SciDAC funds have contributed to the development of a large number of skeleton codes that illustrate how to write PIC codes with a hierarchy of parallelism. These codes cover 2D and 3D as well as electrostatic solvers (which are used in beam dynamics codes and quasi-static codes) and electromagnetic solvers (which are used in plasma based accelerator codes). We also used these ideas to develop a GPU enabled version of OSIRIS. SciDAC funds were also contributed to the development of strategies to eliminate the Numerical Cerenkov Instability (NCI) which is an issue when carrying laser wakefield accelerator (LWFA) simulations in a boosted frame and when quantifying the emittance and energy spread of self-injected electron beams. This work included the development of a new code called UPIC-EMMA which is an FFT based electromagnetic PIC code and to new hybrid algorithms in OSIRIS. A new hybrid (PIC in r-z and gridless in φ) algorithm was implemented into OSIRIS. In this algorithm the fields and current are expanded into azimuthal harmonics and the complex amplitude for each harmonic is calculated separately. The contributions from each harmonic are summed and then used to push the particles. This algorithm permits modeling plasma based acceleration with some 3D effects but with the computational load of an 2D r-z PIC code. We developed a rigorously charge conserving current deposit for this algorithm. Very recently, we made progress in combining the speed up from the quasi-3D algorithm with that from the Lorentz boosted frame. SciDAC funds also contributed to the improvement and speed up of the quasi-static PIC code QuickPIC. We have also used our suite of PIC codes to make scientific discovery. Highlights include supporting FACET experiments which achieved the milestones of showing high beam loading and energy transfer efficiency from a drive electron beam to a witness electron beam and the discovery of a self-loading regime a for high gradient acceleration of a positron beam. Both of these experimental milestones were published in Nature together with supporting QuickPIC simulation results. Simulation results from QuickPIC were used on the cover of Nature in one case. We are also making progress on using highly resolved QuickPIC simulations to show that ion motion may not lead to catastrophic emittance growth for tightly focused electron bunches loaded into nonlinear wakefields. This could mean that fully self-consistent beam loading scenarios are possible. This work remains in progress. OSIRIS simulations were used to discover how 200 MeV electron rings are formed in LWFA experiments, on how to generate electrons that have a series of bunches on nanometer scale, and how to transport electron beams from (into) plasma sections into (from) conventional beam optic sections.

43 PARTICLE ACCELERATORS↗
NASA NTRS2011

Using 100G Network Technology in Support of Petascale Science

NASA in collaboration with a number of partners conducted a set of individual experiments and demonstrations during SC 10 that collectively were titled "Using 100G Network Technology in Support of Petascale Science". The partners included the iCAIR, Internet2, LAC, MAX, National LambdaRail (NLR), NOAA and SCinet Research Sandbox (SRS) as well as the vendors Ciena, Cisco, ColorChip, cPacket, Extreme Networks, Fusion-io, HP and Panduit who most generously allowed some of their leading edge 40G/100G optical transport, Ethernet switch and Internet Protocol router equipment and file server technologies to be involved. The experiments and demonstrations featured different vendor-provided 40G/100G network technology solutions for full-duplex 40G and 100G LAN data flows across SRS-deployed single-node fiber-pairs among the Exhibit Booths of NASA, the National Center for Data lining, NOAA and the SCinet Network Operations Center, as well as between the NASA Exhibit Booth in New Orleans and the Starlight Communications Exchange facility in Chicago across special SC 10- only 80- and 100-Gbps wide area network links provisioned respectively by the NLR and Internet2, then on to GSFC across a 40-Gbps link. provisioned by the Mid-Atlantic Crossroads. The networks and vendor equipment were load-stressed by sets of NASA/GSFC High End Computer Network Team-built, relatively inexpensive, net-test-workstations that are capable of demonstrating greater than 100Gbps uni-directional nuttcp-enabled memory-to-memory data transfers, greater than 80-Gbps aggregate--bidirectional memory-to-memory data transfers, and near 40-Gbps uni-directional disk-to-disk file copying. This paper will summarize the background context, key accomplishments and some significances of these experiments and demonstrations.

Gary, James P.↗
DOE OSTI2011

Commnity Petascale Project for Accelerator Science And Simulation: Advancing Computational Science for Future Accelerators And Accelerator Technologies

The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors.

43 PARTICLE ACCELERATORS↗
DOE OSTI2013

Fortran Transformational Tools in Support of Scientific Application Development for Petascale Computer Architectures

This document is the final report for a multi-year effort building infrastructure to support tool development for Fortran programs. We also investigated static analysis and code transformation methods relevant to scientific programmers who are writing Fortran programs for petascale-class high performance computing systems. This report details our accomplishments, technical approaches, and provides information on where the research results and code may be obtained from an open source software repository. The report for the first year of the project that was performed at the University of Oregon prior to the PI moving to Galois, Inc. is included as an appendix.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2015

Multi-petascale highly efficient parallel supercomputer

A Multi-Petascale Highly Efficient Parallel Supercomputer of 100 petaOPS-scale computing, at decreased cost, power and footprint, and that allows for a maximum packaging density of processing nodes from an interconnect point of view. The Supercomputer exploits technological advances in VLSI that enables a computing model where many processors can be integrated into a single Application Specific Integrated Circuit (ASIC). Each ASIC computing node comprises a system-on-chip ASIC utilizing four or more processors integrated into one die, with each having full access to all system resources and enabling adaptive partitioning of the processors to functions such as compute or messaging I/O on an application by application basis, and preferably, enable adaptive partitioning of functions in accordance with various algorithmic phases within an application, or if I/O or other processors are underutilized, then can participate in computation or communication nodes are interconnected by a five dimensional torus network with DMA that optimally maximize the throughput of packet communications between nodes and minimize latency.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2017

MAESTRO, CASTRO, and SEDONA -- Petascale Codes for Astrophysical Applications

Performing high-resolution, high-fidelity, three-dimensional simulations of Type Ia supernovae (SNe Ia) requires not only algorithms that accurately represent the correct physics, but also codes that effectively harness the resources of the most powerful supercomputers. We are developing a suite of codes that provide the capability to perform end-to-end simulations of SNe Ia, from the early convective phase leading up to ignition to the explosion phase in which deflagration/detonation waves explode the star to the computation of the light curves resulting from the explosion. In this paper we discuss these codes with an emphasis on the techniques needed to scale them to petascale architectures. We also demonstrate our ability to map data from a low Mach number formulation to a compressible solver.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2018

Multi-petascale highly efficient parallel supercomputer

A Multi-Petascale Highly Efficient Parallel Supercomputer of 100 petaflop-scale includes node architectures based upon System-On-a-Chip technology, where each processing node comprises a single Application Specific Integrated Circuit (ASIC). The ASIC nodes are interconnected by a five dimensional torus network that optimally maximize the throughput of packet communications between nodes and minimize latency. The network implements collective network and a global asynchronous network that provides global barrier and notification functions. Integrated in the node design include a list-based prefetcher. The memory system implements transaction memory, thread level speculation, and multiversioning cache that improves soft error rate at the same time and supports DMA functionality allowing for parallel processing message-passing.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2015

TECA: Petascale pattern recognition for climate science

Climate Change is one of the most pressing challenges facing humanity in the 21st century. Climate simulations provide us with a unique opportunity to examine effects of anthropogenic emissions. Highresolution climate simulations produce “Big Data”: contemporary climate archives are ≈ 5PB in size and we expect future archives to measure on the order of Exa-Bytes. In this work, we present the successful application of TECA (Toolkit for Extreme Climate Analysis) framework, for extracting extreme weather patterns such as Tropical Cyclones, Atmospheric Rivers and Extra-Tropical Cyclones from TB-sized simulation datasets. TECA has been run at full-scale on Cray XE6 and IBM BG/Q systems, and has reduced the runtime for pattern detection tasks from years to hours. TECA has been utilized to evaluate the performance of various computational models in reproducing the statistics of extreme weather events, and for characterizing the change in frequency of storm systems in the future.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

Interoperable Technologies for Advanced Petascale Simulations

Our final report on the accomplishments of ITAPS at Stony Brook during period covered by the research award includes component service, interface service and applications. On the component service, we have designed and implemented a robust functionality for the Lagrangian tracking of dynamic interface. We have migrated the hyperbolic, parabolic and elliptic solver from stage-wise second order toward global second order schemes. We have implemented high order coupling between interface propagation and interior PDE solvers. On the interface service, we have constructed the FronTier application programer's interface (API) and its manual page using doxygen. We installed the FronTier functional interface to conform with the ITAPS specifications, especially the iMesh and iMeshP interfaces. On applications, we have implemented deposition and dissolution models with flow and implemented the two-reactant model for a more realistic precipitation at the pore level and its coupling with Darcy level model. We have continued our support to the study of fluid mixing problem for problems in inertial confinement fusion. We have continued our support to the MHD model and its application to plasma liner implosion in fusion confinement. We have simulated a step in the reprocessing and separation of spent fuels from nuclear power plant fuel rods. We have implemented the fluid-structure interaction for 3D windmill and parachute simulations. We have continued our collaboration with PNNL, BNL, LANL, ORNL, and other SciDAC institutions.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2014

Final Report: Correctness Tools for Petascale Computing

In the course of developing parallel programs for leadership computing systems, subtle programming errors often arise that are extremely difficult to diagnose without tools. To meet this challenge, University of Maryland, the University of Wisconsin—Madison, and Rice University worked to develop lightweight tools to help code developers pinpoint a variety of program correctness errors that plague parallel scientific codes. The aim of this project was to develop software tools that help diagnose program errors including memory leaks, memory access errors, round-off errors, and data races. Research at Rice University focused on developing algorithms and data structures to support efficient monitoring of multithreaded programs for memory access errors and data races. This is a final report about research and development work at Rice University as part of this project.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2014

Hierarchical Petascale Simulation Framework for Stress Corrosion Cracking

Reaction Dynamics in Energetic Materials: Detonation is a prototype of mechanochemistry, in which mechanically and thermally induced chemical reactions far from equilibrium exhibit vastly different behaviors. It is also one of the hardest multiscale physics problems, in which diverse length and time scales play important roles. The CACS group has performed multimillion-atom reactive MD simulations to reveal a novel two-stage reaction mechanism during the detonation of cyclotrimethylenetrinitramine (RDX) crystal. Rapid production of N2 and H2O within ~10 ps is followed by delayed production of CO molecules within ~ 1 ns. They found that further decomposition towards the final products is inhibited by the formation of large metastable C- and O-rich clusters with fractal geometry. The CACS group has also simulated the oxidation dynamics of close-packed aggregates of aluminum nanoparticles passivated by oxide shells. Their simulation results suggest an unexpectedly active role of the oxide shell as a nanoreactor.

20 FOSSIL-FUELED POWER PLANTS↗