An Optimized Parallel FDTD Topology for Challenging Electromagnetic Simulations on Supercomputers

Directory of Open Access Journals (Sweden)

Shugang Jiang

2015-01-01

Full Text Available It may not be a challenge to run a Finite-Difference Time-Domain (FDTD code for electromagnetic simulations on a supercomputer with more than 10 thousands of CPU cores; however, to make FDTD code work with the highest efficiency is a challenge. In this paper, the performance of parallel FDTD is optimized through MPI (message passing interface virtual topology, based on which a communication model is established. The general rules of optimal topology are presented according to the model. The performance of the method is tested and analyzed on three high performance computing platforms with different architectures in China. Simulations including an airplane with a 700-wavelength wingspan, and a complex microstrip antenna array with nearly 2000 elements are performed very efficiently using a maximum of 10240 CPU cores.

Supercomputer debugging workshop 1991 proceedings

Energy Technology Data Exchange (ETDEWEB)

Brown, J.

1991-01-01

This report discusses the following topics on supercomputer debugging: Distributed debugging; use interface to debugging tools and standards; debugging optimized codes; debugging parallel codes; and debugger performance and interface as analysis tools. (LSP)

Supercomputer debugging workshop 1991 proceedings

Energy Technology Data Exchange (ETDEWEB)

Brown, J.

1991-12-31

This report discusses the following topics on supercomputer debugging: Distributed debugging; use interface to debugging tools and standards; debugging optimized codes; debugging parallel codes; and debugger performance and interface as analysis tools. (LSP)

Parallel supercomputing: Advanced methods, algorithms, and software for large-scale linear and nonlinear problems

Energy Technology Data Exchange (ETDEWEB)

Carey, G.F.; Young, D.M.

1993-12-31

The program outlined here is directed to research on methods, algorithms, and software for distributed parallel supercomputers. Of particular interest are finite element methods and finite difference methods together with sparse iterative solution schemes for scientific and engineering computations of very large-scale systems. Both linear and nonlinear problems will be investigated. In the nonlinear case, applications with bifurcation to multiple solutions will be considered using continuation strategies. The parallelizable numerical methods of particular interest are a family of partitioning schemes embracing domain decomposition, element-by-element strategies, and multi-level techniques. The methods will be further developed incorporating parallel iterative solution algorithms with associated preconditioners in parallel computer software. The schemes will be implemented on distributed memory parallel architectures such as the CRAY MPP, Intel Paragon, the NCUBE3, and the Connection Machine. We will also consider other new architectures such as the Kendall-Square (KSQ) and proposed machines such as the TERA. The applications will focus on large-scale three-dimensional nonlinear flow and reservoir problems with strong convective transport contributions. These are legitimate grand challenge class computational fluid dynamics (CFD) problems of significant practical interest to DOE. The methods developed and algorithms will, however, be of wider interest.

The new landscape of parallel computer architecture

International Nuclear Information System (INIS)

Shalf, John

2007-01-01

The past few years has seen a sea change in computer architecture that will impact every facet of our society as every electronic device from cell phone to supercomputer will need to confront parallelism of unprecedented scale. Whereas the conventional multicore approach (2, 4, and even 8 cores) adopted by the computing industry will eventually hit a performance plateau, the highest performance per watt and per chip area is achieved using manycore technology (hundreds or even thousands of cores). However, fully unleashing the potential of the manycore approach to ensure future advances in sustained computational performance will require fundamental advances in computer architecture and programming models that are nothing short of reinventing computing. In this paper we examine the reasons behind the movement to exponentially increasing parallelism, and its ramifications for system design, applications and programming models

The new landscape of parallel computer architecture

Energy Technology Data Exchange (ETDEWEB)

Shalf, John [NERSC Division, Lawrence Berkeley National Laboratory 1 Cyclotron Road, Berkeley California, 94720 (United States)

2007-07-15

The past few years has seen a sea change in computer architecture that will impact every facet of our society as every electronic device from cell phone to supercomputer will need to confront parallelism of unprecedented scale. Whereas the conventional multicore approach (2, 4, and even 8 cores) adopted by the computing industry will eventually hit a performance plateau, the highest performance per watt and per chip area is achieved using manycore technology (hundreds or even thousands of cores). However, fully unleashing the potential of the manycore approach to ensure future advances in sustained computational performance will require fundamental advances in computer architecture and programming models that are nothing short of reinventing computing. In this paper we examine the reasons behind the movement to exponentially increasing parallelism, and its ramifications for system design, applications and programming models.

Supercomputers Of The Future

Science.gov (United States)

Peterson, Victor L.; Kim, John; Holst, Terry L.; Deiwert, George S.; Cooper, David M.; Watson, Andrew B.; Bailey, F. Ron

1992-01-01

Report evaluates supercomputer needs of five key disciplines: turbulence physics, aerodynamics, aerothermodynamics, chemistry, and mathematical modeling of human vision. Predicts these fields will require computer speed greater than 10(Sup 18) floating-point operations per second (FLOP's) and memory capacity greater than 10(Sup 15) words. Also, new parallel computer architectures and new structured numerical methods will make necessary speed and capacity available.

Computational plasma physics and supercomputers

International Nuclear Information System (INIS)

Killeen, J.; McNamara, B.

1984-09-01

The Supercomputers of the 80's are introduced. They are 10 to 100 times more powerful than today's machines. The range of physics modeling in the fusion program is outlined. New machine architecture will influence particular codes, but parallel processing poses new coding difficulties. Increasing realism in simulations will require better numerics and more elaborate mathematics

A Parallel Supercomputer Implementation of a Biological Inspired Neural Network and its use for Pattern Recognition

International Nuclear Information System (INIS)

De Ladurantaye, Vincent; Lavoie, Jean; Bergeron, Jocelyn; Parenteau, Maxime; Lu Huizhong; Pichevar, Ramin; Rouat, Jean

2012-01-01

A parallel implementation of a large spiking neural network is proposed and evaluated. The neural network implements the binding by synchrony process using the Oscillatory Dynamic Link Matcher (ODLM). Scalability, speed and performance are compared for 2 implementations: Message Passing Interface (MPI) and Compute Unified Device Architecture (CUDA) running on clusters of multicore supercomputers and NVIDIA graphical processing units respectively. A global spiking list that represents at each instant the state of the neural network is described. This list indexes each neuron that fires during the current simulation time so that the influence of their spikes are simultaneously processed on all computing units. Our implementation shows a good scalability for very large networks. A complex and large spiking neural network has been implemented in parallel with success, thus paving the road towards real-life applications based on networks of spiking neurons. MPI offers a better scalability than CUDA, while the CUDA implementation on a GeForce GTX 285 gives the best cost to performance ratio. When running the neural network on the GTX 285, the processing speed is comparable to the MPI implementation on RQCHP's Mammouth parallel with 64 notes (128 cores).

Parallel processor programs in the Federal Government

Science.gov (United States)

Schneck, P. B.; Austin, D.; Squires, S. L.; Lehmann, J.; Mizell, D.; Wallgren, K.

1985-01-01

In 1982, a report dealing with the nation's research needs in high-speed computing called for increased access to supercomputing resources for the research community, research in computational mathematics, and increased research in the technology base needed for the next generation of supercomputers. Since that time a number of programs addressing future generations of computers, particularly parallel processors, have been started by U.S. government agencies. The present paper provides a description of the largest government programs in parallel processing. Established in fiscal year 1985 by the Institute for Defense Analyses for the National Security Agency, the Supercomputing Research Center will pursue research to advance the state of the art in supercomputing. Attention is also given to the DOE applied mathematical sciences research program, the NYU Ultracomputer project, the DARPA multiprocessor system architectures program, NSF research on multiprocessor systems, ONR activities in parallel computing, and NASA parallel processor projects.

A visual analytics system for optimizing the performance of large-scale networks in supercomputing systems

Directory of Open Access Journals (Sweden)

Takanori Fujiwara

2018-03-01

Full Text Available The overall efficiency of an extreme-scale supercomputer largely relies on the performance of its network interconnects. Several of the state of the art supercomputers use networks based on the increasingly popular Dragonfly topology. It is crucial to study the behavior and performance of different parallel applications running on Dragonfly networks in order to make optimal system configurations and design choices, such as job scheduling and routing strategies. However, in order to study these temporal network behavior, we would need a tool to analyze and correlate numerous sets of multivariate time-series data collected from the Dragonfly’s multi-level hierarchies. This paper presents such a tool–a visual analytics system–that uses the Dragonfly network to investigate the temporal behavior and optimize the communication performance of a supercomputer. We coupled interactive visualization with time-series analysis methods to help reveal hidden patterns in the network behavior with respect to different parallel applications and system configurations. Our system also provides multiple coordinated views for connecting behaviors observed at different levels of the network hierarchies, which effectively helps visual analysis tasks. We demonstrate the effectiveness of the system with a set of case studies. Our system and findings can not only help improve the communication performance of supercomputing applications, but also the network performance of next-generation supercomputers. Keywords: Supercomputing, Parallel communication network, Dragonfly networks, Time-series data, Performance analysis, Visual analytics

Massively Parallel QCD

International Nuclear Information System (INIS)

Soltz, R; Vranas, P; Blumrich, M; Chen, D; Gara, A; Giampap, M; Heidelberger, P; Salapura, V; Sexton, J; Bhanot, G

2007-01-01

The theory of the strong nuclear force, Quantum Chromodynamics (QCD), can be numerically simulated from first principles on massively-parallel supercomputers using the method of Lattice Gauge Theory. We describe the special programming requirements of lattice QCD (LQCD) as well as the optimal supercomputer hardware architectures that it suggests. We demonstrate these methods on the BlueGene massively-parallel supercomputer and argue that LQCD and the BlueGene architecture are a natural match. This can be traced to the simple fact that LQCD is a regular lattice discretization of space into lattice sites while the BlueGene supercomputer is a discretization of space into compute nodes, and that both are constrained by requirements of locality. This simple relation is both technologically important and theoretically intriguing. The main result of this paper is the speedup of LQCD using up to 131,072 CPUs on the largest BlueGene/L supercomputer. The speedup is perfect with sustained performance of about 20% of peak. This corresponds to a maximum of 70.5 sustained TFlop/s. At these speeds LQCD and BlueGene are poised to produce the next generation of strong interaction physics theoretical results

Proceedings of the first energy research power supercomputer users symposium

International Nuclear Information System (INIS)

1991-01-01

The Energy Research Power Supercomputer Users Symposium was arranged to showcase the richness of science that has been pursued and accomplished in this program through the use of supercomputers and now high performance parallel computers over the last year: this report is the collection of the presentations given at the Symposium. ''Power users'' were invited by the ER Supercomputer Access Committee to show that the use of these computational tools and the associated data communications network, ESNet, go beyond merely speeding up computations. Today the work often directly contributes to the advancement of the conceptual developments in their fields and the computational and network resources form the very infrastructure of today's science. The Symposium also provided an opportunity, which is rare in this day of network access to computing resources, for the invited users to compare and discuss their techniques and approaches with those used in other ER disciplines. The significance of new parallel architectures was highlighted by the interesting evening talk given by Dr. Stephen Orszag of Princeton University

Development of seismic tomography software for hybrid supercomputers

Science.gov (United States)

Nikitin, Alexandr; Serdyukov, Alexandr; Duchkov, Anton

2015-04-01

Seismic tomography is a technique used for computing velocity model of geologic structure from first arrival travel times of seismic waves. The technique is used in processing of regional and global seismic data, in seismic exploration for prospecting and exploration of mineral and hydrocarbon deposits, and in seismic engineering for monitoring the condition of engineering structures and the surrounding host medium. As a consequence of development of seismic monitoring systems and increasing volume of seismic data, there is a growing need for new, more effective computational algorithms for use in seismic tomography applications with improved performance, accuracy and resolution. To achieve this goal, it is necessary to use modern high performance computing systems, such as supercomputers with hybrid architecture that use not only CPUs, but also accelerators and co-processors for computation. The goal of this research is the development of parallel seismic tomography algorithms and software package for such systems, to be used in processing of large volumes of seismic data (hundreds of gigabytes and more). These algorithms and software package will be optimized for the most common computing devices used in modern hybrid supercomputers, such as Intel Xeon CPUs, NVIDIA Tesla accelerators and Intel Xeon Phi co-processors. In this work, the following general scheme of seismic tomography is utilized. Using the eikonal equation solver, arrival times of seismic waves are computed based on assumed velocity model of geologic structure being analyzed. In order to solve the linearized inverse problem, tomographic matrix is computed that connects model adjustments with travel time residuals, and the resulting system of linear equations is regularized and solved to adjust the model. The effectiveness of parallel implementations of existing algorithms on target architectures is considered. During the first stage of this work, algorithms were developed for execution on

Tryton Supercomputer Capabilities for Analysis of Massive Data Streams

Directory of Open Access Journals (Sweden)

Krawczyk Henryk

2015-09-01

Full Text Available The recently deployed supercomputer Tryton, located in the Academic Computer Center of Gdansk University of Technology, provides great means for massive parallel processing. Moreover, the status of the Center as one of the main network nodes in the PIONIER network enables the fast and reliable transfer of data produced by miscellaneous devices scattered in the area of the whole country. The typical examples of such data are streams containing radio-telescope and satellite observations. Their analysis, especially with real-time constraints, can be challenging and requires the usage of dedicated software components. We propose a solution for such parallel analysis using the supercomputer, supervised by the KASKADA platform, which with the conjunction with immerse 3D visualization techniques can be used to solve problems such as pulsar detection and chronometric or oil-spill simulation on the sea surface.

Supercomputer algorithms for reactivity, dynamics and kinetics of small molecules

International Nuclear Information System (INIS)

Lagana, A.

1989-01-01

Even for small systems, the accurate characterization of reactive processes is so demanding of computer resources as to suggest the use of supercomputers having vector and parallel facilities. The full advantages of vector and parallel architectures can sometimes be obtained by simply modifying existing programs, vectorizing the manipulation of vectors and matrices, and requiring the parallel execution of independent tasks. More often, however, a significant time saving can be obtained only when the computer code undergoes a deeper restructuring, requiring a change in the computational strategy or, more radically, the adoption of a different theoretical treatment. This book discusses supercomputer strategies based upon act and approximate methods aimed at calculating the electronic structure and the reactive properties of small systems. The book shows how, in recent years, intense design activity has led to the ability to calculate accurate electronic structures for reactive systems, exact and high-level approximations to three-dimensional reactive dynamics, and to efficient directive and declaratory software for the modelling of complex systems

Parallel adaptation of a vectorised quantumchemical program system

International Nuclear Information System (INIS)

Van Corler, L.C.H.; Van Lenthe, J.H.

1987-01-01

Supercomputers, like the CRAY 1 or the Cyber 205, have had, and still have, a marked influence on Quantum Chemistry. Vectorization has led to a considerable increase in the performance of Quantum Chemistry programs. However, clockcycle times more than a factor 10 smaller than those of the present supercomputers are not to be expected. Therefore future supercomputers will have to depend on parallel structures. Recently, the first examples of such supercomputers have been installed. To be prepared for this new generation of (parallel) supercomputers one should consider the concepts one wants to use and the kind of problems one will encounter during implementation of existing vectorized programs on those parallel systems. The authors implemented four important parts of a large quantumchemical program system (ATMOL), i.e. integrals, SCF, 4-index and Direct-CI in the parallel environment at ECSEC (Rome, Italy). This system offers simulated parallellism on the host computer (IBM 4381) and real parallellism on at most 10 attached processors (FPS-164). Quantumchemical programs usually handle large amounts of data and very large, often sparse matrices. The transfer of that many data can cause problems concerning communication and overhead, in view of which shared memory and shared disks must be considered. The strategy and the tools that were used to parallellise the programs are shown. Also, some examples are presented to illustrate effectiveness and performance of the system in Rome for these type of calculations

Productive Parallel Programming: The PCN Approach

Directory of Open Access Journals (Sweden)

Ian Foster

1992-01-01

Full Text Available We describe the PCN programming system, focusing on those features designed to improve the productivity of scientists and engineers using parallel supercomputers. These features include a simple notation for the concise specification of concurrent algorithms, the ability to incorporate existing Fortran and C code into parallel applications, facilities for reusing parallel program components, a portable toolkit that allows applications to be developed on a workstation or small parallel computer and run unchanged on supercomputers, and integrated debugging and performance analysis tools. We survey representative scientific applications and identify problem classes for which PCN has proved particularly useful.

Computational plasma physics and supercomputers. Revision 1

International Nuclear Information System (INIS)

Killeen, J.; McNamara, B.

1985-01-01

The Supercomputers of the 80's are introduced. They are 10 to 100 times more powerful than today's machines. The range of physics modeling in the fusion program is outlined. New machine architecture will influence particular models, but parallel processing poses new programming difficulties. Increasing realism in simulations will require better numerics and more elaborate mathematical models

Direct exploitation of a top 500 Supercomputer for Analysis of CMS Data

International Nuclear Information System (INIS)

Cabrillo, I; Cabellos, L; Marco, J; Fernandez, J; Gonzalez, I

2014-01-01

The Altamira Supercomputer hosted at the Instituto de Fisica de Cantatbria (IFCA) entered in operation in summer 2012. Its last generation FDR Infiniband network used (for message passing) in parallel jobs, supports the connection to General Parallel File System (GPFS) servers, enabling an efficient simultaneous processing of multiple data demanding jobs. Sharing a common GPFS system and a single LDAP-based identification with the existing Grid clusters at IFCA allows CMS researchers to exploit the large instantaneous capacity of this supercomputer to execute analysis jobs. The detailed experience describing this opportunistic use for skimming and final analysis of CMS 2012 data for a specific physics channel, resulting in an order of magnitude reduction of the waiting time, is presented.

Hierarchical approach to optimization of parallel matrix multiplication on large-scale platforms

KAUST Repository

Hasanov, Khalid; Quintin, Jean-Noë l; Lastovetsky, Alexey

2014-01-01

-scale parallelism in mind. Indeed, while in 1990s a system with few hundred cores was considered a powerful supercomputer, modern top supercomputers have millions of cores. In this paper, we present a hierarchical approach to optimization of message-passing parallel

Supercomputer applications in nuclear research

International Nuclear Information System (INIS)

Ishiguro, Misako

1992-01-01

The utilization of supercomputers in Japan Atomic Energy Research Institute is mainly reported. The fields of atomic energy research which use supercomputers frequently and the contents of their computation are outlined. What is vectorizing is simply explained, and nuclear fusion, nuclear reactor physics, the hydrothermal safety of nuclear reactors, the parallel property that the atomic energy computations of fluids and others have, the algorithm for vector treatment and the effect of speed increase by vectorizing are discussed. At present Japan Atomic Energy Research Institute uses two systems of FACOM VP 2600/10 and three systems of M-780. The contents of computation changed from criticality computation around 1970, through the analysis of LOCA after the TMI accident, to nuclear fusion research, the design of new type reactors and reactor safety assessment at present. Also the method of using computers advanced from batch processing to time sharing processing, from one-dimensional to three dimensional computation, from steady, linear to unsteady nonlinear computation, from experimental analysis to numerical simulation and so on. (K.I.)

Parallel computing works!

CERN Document Server

Fox, Geoffrey C; Messina, Guiseppe C

2014-01-01

A clear illustration of how parallel computers can be successfully appliedto large-scale scientific computations. This book demonstrates how avariety of applications in physics, biology, mathematics and other scienceswere implemented on real parallel computers to produce new scientificresults. It investigates issues of fine-grained parallelism relevant forfuture supercomputers with particular emphasis on hypercube architecture. The authors describe how they used an experimental approach to configuredifferent massively parallel machines, design and implement basic systemsoftware, and develop

Supercomputational science

CERN Document Server

Wilson, S

1990-01-01

In contemporary research, the supercomputer now ranks, along with radio telescopes, particle accelerators and the other apparatus of "big science", as an expensive resource, which is nevertheless essential for state of the art research. Supercomputers are usually provided as shar.ed central facilities. However, unlike, telescopes and accelerators, they are find a wide range of applications which extends across a broad spectrum of research activity. The difference in performance between a "good" and a "bad" computer program on a traditional serial computer may be a factor of two or three, but on a contemporary supercomputer it can easily be a factor of one hundred or even more! Furthermore, this factor is likely to increase with future generations of machines. In keeping with the large capital and recurrent costs of these machines, it is appropriate to devote effort to training and familiarization so that supercomputers are employed to best effect. This volume records the lectures delivered at a Summer School ...

KAUST Supercomputing Laboratory

KAUST Repository

Bailey, April Renee

2011-11-15

KAUST has partnered with IBM to establish a Supercomputing Research Center. KAUST is hosting the Shaheen supercomputer, named after the Arabian falcon famed for its swiftness of flight. This 16-rack IBM Blue Gene/P system is equipped with 4 gigabyte memory per node and capable of 222 teraflops, making KAUST campus the site of one of the world’s fastest supercomputers in an academic environment. KAUST is targeting petaflop capability within 3 years.

KAUST Supercomputing Laboratory

KAUST Repository

Bailey, April Renee; Kaushik, Dinesh; Winfer, Andrew

2011-01-01

KAUST has partnered with IBM to establish a Supercomputing Research Center. KAUST is hosting the Shaheen supercomputer, named after the Arabian falcon famed for its swiftness of flight. This 16-rack IBM Blue Gene/P system is equipped with 4 gigabyte memory per node and capable of 222 teraflops, making KAUST campus the site of one of the world’s fastest supercomputers in an academic environment. KAUST is targeting petaflop capability within 3 years.

Porting Ordinary Applications to Blue Gene/Q Supercomputers

Energy Technology Data Exchange (ETDEWEB)

Maheshwari, Ketan C.; Wozniak, Justin M.; Armstrong, Timothy; Katz, Daniel S.; Binkowski, T. Andrew; Zhong, Xiaoliang; Heinonen, Olle; Karpeyev, Dmitry; Wilde, Michael

2015-08-31

Efficiently porting ordinary applications to Blue Gene/Q supercomputers is a significant challenge. Codes are often originally developed without considering advanced architectures and related tool chains. Science needs frequently lead users to want to run large numbers of relatively small jobs (often called many-task computing, an ensemble, or a workflow), which can conflict with supercomputer configurations. In this paper, we discuss techniques developed to execute ordinary applications over leadership class supercomputers. We use the high-performance Swift parallel scripting framework and build two workflow execution techniques-sub-jobs and main-wrap. The sub-jobs technique, built on top of the IBM Blue Gene/Q resource manager Cobalt's sub-block jobs, lets users submit multiple, independent, repeated smaller jobs within a single larger resource block. The main-wrap technique is a scheme that enables C/C++ programs to be defined as functions that are wrapped by a high-performance Swift wrapper and that are invoked as a Swift script. We discuss the needs, benefits, technicalities, and current limitations of these techniques. We further discuss the real-world science enabled by these techniques and the results obtained.

Integration of Panda Workload Management System with supercomputers

Science.gov (United States)

De, K.; Jha, S.; Klimentov, A.; Maeno, T.; Mashinistov, R.; Nilsson, P.; Novikov, A.; Oleynik, D.; Panitkin, S.; Poyda, A.; Read, K. F.; Ryabinkin, E.; Teslyuk, A.; Velikhov, V.; Wells, J. C.; Wenaus, T.

2016-09-01

The Large Hadron Collider (LHC), operating at the international CERN Laboratory in Geneva, Switzerland, is leading Big Data driven scientific explorations. Experiments at the LHC explore the fundamental nature of matter and the basic forces that shape our universe, and were recently credited for the discovery of a Higgs boson. ATLAS, one of the largest collaborations ever assembled in the sciences, is at the forefront of research at the LHC. To address an unprecedented multi-petabyte data processing challenge, the ATLAS experiment is relying on a heterogeneous distributed computational infrastructure. The ATLAS experiment uses PanDA (Production and Data Analysis) Workload Management System for managing the workflow for all data processing on over 140 data centers. Through PanDA, ATLAS physicists see a single computing facility that enables rapid scientific breakthroughs for the experiment, even though the data centers are physically scattered all over the world. While PanDA currently uses more than 250000 cores with a peak performance of 0.3+ petaFLOPS, next LHC data taking runs will require more resources than Grid computing can possibly provide. To alleviate these challenges, LHC experiments are engaged in an ambitious program to expand the current computing model to include additional resources such as the opportunistic use of supercomputers. We will describe a project aimed at integration of PanDA WMS with supercomputers in United States, Europe and Russia (in particular with Titan supercomputer at Oak Ridge Leadership Computing Facility (OLCF), Supercomputer at the National Research Center "Kurchatov Institute", IT4 in Ostrava, and others). The current approach utilizes a modified PanDA pilot framework for job submission to the supercomputers batch queues and local data management, with light-weight MPI wrappers to run singlethreaded workloads in parallel on Titan's multi-core worker nodes. This implementation was tested with a variety of Monte-Carlo workloads

Enabling department-scale supercomputing

Energy Technology Data Exchange (ETDEWEB)

Greenberg, D.S.; Hart, W.E.; Phillips, C.A.

1997-11-01

The Department of Energy (DOE) national laboratories have one of the longest and most consistent histories of supercomputer use. The authors summarize the architecture of DOE`s new supercomputers that are being built for the Accelerated Strategic Computing Initiative (ASCI). The authors then argue that in the near future scaled-down versions of these supercomputers with petaflop-per-weekend capabilities could become widely available to hundreds of research and engineering departments. The availability of such computational resources will allow simulation of physical phenomena to become a full-fledged third branch of scientific exploration, along with theory and experimentation. They describe the ASCI and other supercomputer applications at Sandia National Laboratories, and discuss which lessons learned from Sandia`s long history of supercomputing can be applied in this new setting.

Visualizing quantum scattering on the CM-2 supercomputer

International Nuclear Information System (INIS)

Richardson, J.L.

1991-01-01

We implement parallel algorithms for solving the time-dependent Schroedinger equation on the CM-2 supercomputer. These methods are unconditionally stable as well as unitary at each time step and have the advantage of being spatially local and explicit. We show how to visualize the dynamics of quantum scattering using techniques for visualizing complex wave functions. Several scattering problems are solved to demonstrate the use of these methods. (orig.)

FPS scientific and supercomputers computers in chemistry

International Nuclear Information System (INIS)

Curington, I.J.

1987-01-01

FPS Array Processors, scientific computers, and highly parallel supercomputers are used in nearly all aspects of compute-intensive computational chemistry. A survey is made of work utilizing this equipment, both published and current research. The relationship of the computer architecture to computational chemistry is discussed, with specific reference to Molecular Dynamics, Quantum Monte Carlo simulations, and Molecular Graphics applications. Recent installations of the FPS T-Series are highlighted, and examples of Molecular Graphics programs running on the FPS-5000 are shown

Visualization environment of the large-scale data of JAEA's supercomputer system

Energy Technology Data Exchange (ETDEWEB)

Sakamoto, Kensaku [Japan Atomic Energy Agency, Center for Computational Science and e-Systems, Tokai, Ibaraki (Japan); Hoshi, Yoshiyuki [Research Organization for Information Science and Technology (RIST), Tokai, Ibaraki (Japan)

2013-11-15

On research and development of various fields of nuclear energy, visualization of calculated data is especially useful to understand the result of simulation in an intuitive way. Many researchers who run simulations on the supercomputer in Japan Atomic Energy Agency (JAEA) are used to transfer calculated data files from the supercomputer to their local PCs for visualization. In recent years, as the size of calculated data has gotten larger with improvement of supercomputer performance, reduction of visualization processing time as well as efficient use of JAEA network is being required. As a solution, we introduced a remote visualization system which has abilities to utilize parallel processors on the supercomputer and to reduce the usage of network resources by transferring data of intermediate visualization process. This paper reports a study on the performance of image processing with the remote visualization system. The visualization processing time is measured and the influence of network speed is evaluated by varying the drawing mode, the size of visualization data and the number of processors. Based on this study, a guideline for using the remote visualization system is provided to show how the system can be used effectively. An upgrade policy of the next system is also shown. (author)

Parallel R-matrix computation

International Nuclear Information System (INIS)

Heggarty, J.W.

1999-06-01

For almost thirty years, sequential R-matrix computation has been used by atomic physics research groups, from around the world, to model collision phenomena involving the scattering of electrons or positrons with atomic or molecular targets. As considerable progress has been made in the understanding of fundamental scattering processes, new data, obtained from more complex calculations, is of current interest to experimentalists. Performing such calculations, however, places considerable demands on the computational resources to be provided by the target machine, in terms of both processor speed and memory requirement. Indeed, in some instances the computational requirements are so great that the proposed R-matrix calculations are intractable, even when utilising contemporary classic supercomputers. Historically, increases in the computational requirements of R-matrix computation were accommodated by porting the problem codes to a more powerful classic supercomputer. Although this approach has been successful in the past, it is no longer considered to be a satisfactory solution due to the limitations of current (and future) Von Neumann machines. As a consequence, there has been considerable interest in the high performance multicomputers, that have emerged over the last decade which appear to offer the computational resources required by contemporary R-matrix research. Unfortunately, developing codes for these machines is not as simple a task as it was to develop codes for successive classic supercomputers. The difficulty arises from the considerable differences in the computing models that exist between the two types of machine and results in the programming of multicomputers to be widely acknowledged as a difficult, time consuming and error-prone task. Nevertheless, unless parallel R-matrix computation is realised, important theoretical and experimental atomic physics research will continue to be hindered. This thesis describes work that was undertaken in

High Performance Networks From Supercomputing to Cloud Computing

CERN Document Server

Abts, Dennis

2011-01-01

Datacenter networks provide the communication substrate for large parallel computer systems that form the ecosystem for high performance computing (HPC) systems and modern Internet applications. The design of new datacenter networks is motivated by an array of applications ranging from communication intensive climatology, complex material simulations and molecular dynamics to such Internet applications as Web search, language translation, collaborative Internet applications, streaming video and voice-over-IP. For both Supercomputing and Cloud Computing the network enables distributed applicati

Extending ATLAS Computing to Commercial Clouds and Supercomputers

CERN Document Server

Nilsson, P; The ATLAS collaboration; Filipcic, A; Klimentov, A; Maeno, T; Oleynik, D; Panitkin, S; Wenaus, T; Wu, W

2014-01-01

The Large Hadron Collider will resume data collection in 2015 with substantially increased computing requirements relative to its first 2009-2013 run. A near doubling of the energy and the data rate, high level of event pile-up, and detector upgrades will mean the number and complexity of events to be analyzed will increase dramatically. A naive extrapolation of the Run 1 experience would suggest that a 5-6 fold increase in computing resources are needed - impossible within the anticipated flat computing budgets in the near future. Consequently ATLAS is engaged in an ambitious program to expand its computing to all available resources, notably including opportunistic use of commercial clouds and supercomputers. Such resources present new challenges in managing heterogeneity, supporting data flows, parallelizing workflows, provisioning software, and other aspects of distributed computing, all while minimizing operational load. We will present the ATLAS experience to date with clouds and supercomputers, and des...

Computational Dimensionalities of Global Supercomputing

Directory of Open Access Journals (Sweden)

Richard S. Segall

2013-12-01

Full Text Available This Invited Paper pertains to subject of my Plenary Keynote Speech at the 17th World Multi-Conference on Systemics, Cybernetics and Informatics (WMSCI 2013 held in Orlando, Florida on July 9-12, 2013. The title of my Plenary Keynote Speech was: "Dimensionalities of Computation: from Global Supercomputing to Data, Text and Web Mining" but this Invited Paper will focus only on the "Computational Dimensionalities of Global Supercomputing" and is based upon a summary of the contents of several individual articles that have been previously written with myself as lead author and published in [75], [76], [77], [78], [79], [80] and [11]. The topics of these of the Plenary Speech included Overview of Current Research in Global Supercomputing [75], Open-Source Software Tools for Data Mining Analysis of Genomic and Spatial Images using High Performance Computing [76], Data Mining Supercomputing with SAS™ JMP® Genomics ([77], [79], [80], and Visualization by Supercomputing Data Mining [81]. ______________________ [11.] Committee on the Future of Supercomputing, National Research Council (2003, The Future of Supercomputing: An Interim Report, ISBN-13: 978-0-309-09016- 2, http://www.nap.edu/catalog/10784.html [75.] Segall, Richard S.; Zhang, Qingyu and Cook, Jeffrey S.(2013, "Overview of Current Research in Global Supercomputing", Proceedings of Forty- Fourth Meeting of Southwest Decision Sciences Institute (SWDSI, Albuquerque, NM, March 12-16, 2013. [76.] Segall, Richard S. and Zhang, Qingyu (2010, "Open-Source Software Tools for Data Mining Analysis of Genomic and Spatial Images using High Performance Computing", Proceedings of 5th INFORMS Workshop on Data Mining and Health Informatics, Austin, TX, November 6, 2010. [77.] Segall, Richard S., Zhang, Qingyu and Pierce, Ryan M.(2010, "Data Mining Supercomputing with SAS™ JMP®; Genomics: Research-in-Progress, Proceedings of 2010 Conference on Applied Research in Information Technology, sponsored by

Lattice gauge theory using parallel processors

International Nuclear Information System (INIS)

Lee, T.D.; Chou, K.C.; Zichichi, A.

1987-01-01

The book's contents include: Lattice Gauge Theory Lectures: Introduction and Current Fermion Simulations; Monte Carlo Algorithms for Lattice Gauge Theory; Specialized Computers for Lattice Gauge Theory; Lattice Gauge Theory at Finite Temperature: A Monte Carlo Study; Computational Method - An Elementary Introduction to the Langevin Equation, Present Status of Numerical Quantum Chromodynamics; Random Lattice Field Theory; The GF11 Processor and Compiler; and The APE Computer and First Physics Results; Columbia Supercomputer Project: Parallel Supercomputer for Lattice QCD; Statistical and Systematic Errors in Numerical Simulations; Monte Carlo Simulation for LGT and Programming Techniques on the Columbia Supercomputer; Food for Thought: Five Lectures on Lattice Gauge Theory

Japanese supercomputer technology

International Nuclear Information System (INIS)

Buzbee, B.L.; Ewald, R.H.; Worlton, W.J.

1982-01-01

In February 1982, computer scientists from the Los Alamos National Laboratory and Lawrence Livermore National Laboratory visited several Japanese computer manufacturers. The purpose of these visits was to assess the state of the art of Japanese supercomputer technology and to advise Japanese computer vendors of the needs of the US Department of Energy (DOE) for more powerful supercomputers. The Japanese foresee a domestic need for large-scale computing capabilities for nuclear fusion, image analysis for the Earth Resources Satellite, meteorological forecast, electrical power system analysis (power flow, stability, optimization), structural and thermal analysis of satellites, and very large scale integrated circuit design and simulation. To meet this need, Japan has launched an ambitious program to advance supercomputer technology. This program is described

An assessment of worldwide supercomputer usage

Energy Technology Data Exchange (ETDEWEB)

Wasserman, H.J.; Simmons, M.L.; Hayes, A.H.

1995-01-01

This report provides a comparative study of advanced supercomputing usage in Japan and the United States as of Spring 1994. It is based on the findings of a group of US scientists whose careers have centered on programming, evaluating, and designing high-performance supercomputers for over ten years. The report is a follow-on to an assessment of supercomputing technology in Europe and Japan that was published in 1993. Whereas the previous study focused on supercomputer manufacturing capabilities, the primary focus of the current work was to compare where and how supercomputers are used. Research for this report was conducted through both literature studies and field research in Japan.

An efficient parallel algorithm for matrix-vector multiplication

Energy Technology Data Exchange (ETDEWEB)

Hendrickson, B.; Leland, R.; Plimpton, S.

1993-03-01

The multiplication of a vector by a matrix is the kernel computation of many algorithms in scientific computation. A fast parallel algorithm for this calculation is therefore necessary if one is to make full use of the new generation of parallel supercomputers. This paper presents a high performance, parallel matrix-vector multiplication algorithm that is particularly well suited to hypercube multiprocessors. For an n x n matrix on p processors, the communication cost of this algorithm is O(n/[radical]p + log(p)), independent of the matrix sparsity pattern. The performance of the algorithm is demonstrated by employing it as the kernel in the well-known NAS conjugate gradient benchmark, where a run time of 6.09 seconds was observed. This is the best published performance on this benchmark achieved to date using a massively parallel supercomputer.

Engineering-Based Thermal CFD Simulations on Massive Parallel Systems

KAUST Repository

Frisch, Jé rô me; Mundani, Ralf-Peter; Rank, Ernst; van Treeck, Christoph

2015-01-01

The development of parallel Computational Fluid Dynamics (CFD) codes is a challenging task that entails efficient parallelization concepts and strategies in order to achieve good scalability values when running those codes on modern supercomputers

Supercomputations and big-data analysis in strong-field ultrafast optical physics: filamentation of high-peak-power ultrashort laser pulses

Science.gov (United States)

Voronin, A. A.; Panchenko, V. Ya; Zheltikov, A. M.

2016-06-01

High-intensity ultrashort laser pulses propagating in gas media or in condensed matter undergo complex nonlinear spatiotemporal evolution where temporal transformations of optical field waveforms are strongly coupled to an intricate beam dynamics and ultrafast field-induced ionization processes. At the level of laser peak powers orders of magnitude above the critical power of self-focusing, the beam exhibits modulation instabilities, producing random field hot spots and breaking up into multiple noise-seeded filaments. This problem is described by a (3  +  1)-dimensional nonlinear field evolution equation, which needs to be solved jointly with the equation for ultrafast ionization of a medium. Analysis of this problem, which is equivalent to solving a billion-dimensional evolution problem, is only possible by means of supercomputer simulations augmented with coordinated big-data processing of large volumes of information acquired through theory-guiding experiments and supercomputations. Here, we review the main challenges of supercomputations and big-data processing encountered in strong-field ultrafast optical physics and discuss strategies to confront these challenges.

Status of supercomputers in the US

International Nuclear Information System (INIS)

Fernbach, S.

1985-01-01

Current Supercomputers; that is, the Class VI machines which first became available in 1976 are being delivered in greater quantity than ever before. In addition, manufacturers are busily working on Class VII machines to be ready for delivery in CY 1987. Mainframes are being modified or designed to take on some features of the supercomputers and new companies with the intent of either competing directly in the supercomputer arena or in providing entry-level systems from which to graduate to supercomputers are springing up everywhere. Even well founded organizations like IBM and CDC are adding machines with vector instructions in their repertoires. Japanese - manufactured supercomputers are also being introduced into the U.S. Will these begin to compete with those of U.S. manufacture. Are they truly competitive. It turns out that both from the hardware and software points of view they may be superior. We may be facing the same problems in supercomputers that we faced in videosystems

Patterns for Parallel Software Design

CERN Document Server

Ortega-Arjona, Jorge Luis

2010-01-01

Essential reading to understand patterns for parallel programming Software patterns have revolutionized the way we think about how software is designed, built, and documented, and the design of parallel software requires you to consider other particular design aspects and special skills. From clusters to supercomputers, success heavily depends on the design skills of software developers. Patterns for Parallel Software Design presents a pattern-oriented software architecture approach to parallel software design. This approach is not a design method in the classic sense, but a new way of managin

Supercomputing and related national projects in Japan

International Nuclear Information System (INIS)

Miura, Kenichi

1985-01-01

Japanese supercomputer development activities in the industry and research projects are outlined. Architecture, technology, software, and applications of Fujitsu's Vector Processor Systems are described as an example of Japanese supercomputers. Applications of supercomputers to high energy physics are also discussed. (orig.)

Parallel-Vector Algorithm For Rapid Structural Anlysis

Science.gov (United States)

Agarwal, Tarun R.; Nguyen, Duc T.; Storaasli, Olaf O.

1993-01-01

New algorithm developed to overcome deficiency of skyline storage scheme by use of variable-band storage scheme. Exploits both parallel and vector capabilities of modern high-performance computers. Gives engineers and designers opportunity to include more design variables and constraints during optimization of structures. Enables use of more refined finite-element meshes to obtain improved understanding of complex behaviors of aerospace structures leading to better, safer designs. Not only attractive for current supercomputers but also for next generation of shared-memory supercomputers.

Parallel hierarchical global illumination

Energy Technology Data Exchange (ETDEWEB)

Snell, Quinn O. [Iowa State Univ., Ames, IA (United States)

1997-10-08

Solving the global illumination problem is equivalent to determining the intensity of every wavelength of light in all directions at every point in a given scene. The complexity of the problem has led researchers to use approximation methods for solving the problem on serial computers. Rather than using an approximation method, such as backward ray tracing or radiosity, the authors have chosen to solve the Rendering Equation by direct simulation of light transport from the light sources. This paper presents an algorithm that solves the Rendering Equation to any desired accuracy, and can be run in parallel on distributed memory or shared memory computer systems with excellent scaling properties. It appears superior in both speed and physical correctness to recent published methods involving bidirectional ray tracing or hybrid treatments of diffuse and specular surfaces. Like progressive radiosity methods, it dynamically refines the geometry decomposition where required, but does so without the excessive storage requirements for ray histories. The algorithm, called Photon, produces a scene which converges to the global illumination solution. This amounts to a huge task for a 1997-vintage serial computer, but using the power of a parallel supercomputer significantly reduces the time required to generate a solution. Currently, Photon can be run on most parallel environments from a shared memory multiprocessor to a parallel supercomputer, as well as on clusters of heterogeneous workstations.

Getting To Exascale: Applying Novel Parallel Programming Models To Lab Applications For The Next Generation Of Supercomputers

Energy Technology Data Exchange (ETDEWEB)

Dube, Evi [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shereda, Charles [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Nau, Lee [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Harris, Lance [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2010-09-27

As supercomputing moves toward exascale, node architectures will change significantly. CPU core counts on nodes will increase by an order of magnitude or more. Heterogeneous architectures will become more commonplace, with GPUs or FPGAs providing additional computational power. Novel programming models may make better use of on-node parallelism in these new architectures than do current models. In this paper we examine several of these novel models – UPC, CUDA, and OpenCL –to determine their suitability to LLNL scientific application codes. Our study consisted of several phases: We conducted interviews with code teams and selected two codes to port; We learned how to program in the new models and ported the codes; We debugged and tuned the ported applications; We measured results, and documented our findings. We conclude that UPC is a challenge for porting code, Berkeley UPC is not very robust, and UPC is not suitable as a general alternative to OpenMP for a number of reasons. CUDA is well supported and robust but is a proprietary NVIDIA standard, while OpenCL is an open standard. Both are well suited to a specific set of application problems that can be run on GPUs, but some problems are not suited to GPUs. Further study of the landscape of novel models is recommended.

Visualization on supercomputing platform level II ASC milestone (3537-1B) results from Sandia.

Energy Technology Data Exchange (ETDEWEB)

Geveci, Berk (Kitware, Inc., Clifton Park, NY); Fabian, Nathan; Marion, Patrick (Kitware, Inc., Clifton Park, NY); Moreland, Kenneth D.

2010-09-01

This report provides documentation for the completion of the Sandia portion of the ASC Level II Visualization on the platform milestone. This ASC Level II milestone is a joint milestone between Sandia National Laboratories and Los Alamos National Laboratories. This milestone contains functionality required for performing visualization directly on a supercomputing platform, which is necessary for peta-scale visualization. Sandia's contribution concerns in-situ visualization, running a visualization in tandem with a solver. Visualization and analysis of petascale data is limited by several factors which must be addressed as ACES delivers the Cielo platform. Two primary difficulties are: (1) Performance of interactive rendering, which is most computationally intensive portion of the visualization process. For terascale platforms, commodity clusters with graphics processors(GPUs) have been used for interactive rendering. For petascale platforms, visualization and rendering may be able to run efficiently on the supercomputer platform itself. (2) I/O bandwidth, which limits how much information can be written to disk. If we simply analyze the sparse information that is saved to disk we miss the opportunity to analyze the rich information produced every timestep by the simulation. For the first issue, we are pursuing in-situ analysis, in which simulations are coupled directly with analysis libraries at runtime. This milestone will evaluate the visualization and rendering performance of current and next generation supercomputers in contrast to GPU-based visualization clusters, and evaluate the performance of common analysis libraries coupled with the simulation that analyze and write data to disk during a running simulation. This milestone will explore, evaluate and advance the maturity level of these technologies and their applicability to problems of interest to the ASC program. Scientific simulation on parallel supercomputers is traditionally performed in four

A parallel orbital-updating based plane-wave basis method for electronic structure calculations

International Nuclear Information System (INIS)

Pan, Yan; Dai, Xiaoying; Gironcoli, Stefano de; Gong, Xin-Gao; Rignanese, Gian-Marco; Zhou, Aihui

2017-01-01

Highlights: • Propose three parallel orbital-updating based plane-wave basis methods for electronic structure calculations. • These new methods can avoid the generating of large scale eigenvalue problems and then reduce the computational cost. • These new methods allow for two-level parallelization which is particularly interesting for large scale parallelization. • Numerical experiments show that these new methods are reliable and efficient for large scale calculations on modern supercomputers. - Abstract: Motivated by the recently proposed parallel orbital-updating approach in real space method , we propose a parallel orbital-updating based plane-wave basis method for electronic structure calculations, for solving the corresponding eigenvalue problems. In addition, we propose two new modified parallel orbital-updating methods. Compared to the traditional plane-wave methods, our methods allow for two-level parallelization, which is particularly interesting for large scale parallelization. Numerical experiments show that these new methods are more reliable and efficient for large scale calculations on modern supercomputers.

TOP500 Supercomputers for June 2004

Energy Technology Data Exchange (ETDEWEB)

Strohmaier, Erich; Meuer, Hans W.; Dongarra, Jack; Simon, Horst D.

2004-06-23

23rd Edition of TOP500 List of World's Fastest Supercomputers Released: Japan's Earth Simulator Enters Third Year in Top Position MANNHEIM, Germany; KNOXVILLE, Tenn.;&BERKELEY, Calif. In what has become a closely watched event in the world of high-performance computing, the 23rd edition of the TOP500 list of the world's fastest supercomputers was released today (June 23, 2004) at the International Supercomputer Conference in Heidelberg, Germany.

MILC Code Performance on High End CPU and GPU Supercomputer Clusters

Science.gov (United States)

DeTar, Carleton; Gottlieb, Steven; Li, Ruizi; Toussaint, Doug

2018-03-01

With recent developments in parallel supercomputing architecture, many core, multi-core, and GPU processors are now commonplace, resulting in more levels of parallelism, memory hierarchy, and programming complexity. It has been necessary to adapt the MILC code to these new processors starting with NVIDIA GPUs, and more recently, the Intel Xeon Phi processors. We report on our efforts to port and optimize our code for the Intel Knights Landing architecture. We consider performance of the MILC code with MPI and OpenMP, and optimizations with QOPQDP and QPhiX. For the latter approach, we concentrate on the staggered conjugate gradient and gauge force. We also consider performance on recent NVIDIA GPUs using the QUDA library.

MILC Code Performance on High End CPU and GPU Supercomputer Clusters

Directory of Open Access Journals (Sweden)

DeTar Carleton

2018-01-01

Full Text Available With recent developments in parallel supercomputing architecture, many core, multi-core, and GPU processors are now commonplace, resulting in more levels of parallelism, memory hierarchy, and programming complexity. It has been necessary to adapt the MILC code to these new processors starting with NVIDIA GPUs, and more recently, the Intel Xeon Phi processors. We report on our efforts to port and optimize our code for the Intel Knights Landing architecture. We consider performance of the MILC code with MPI and OpenMP, and optimizations with QOPQDP and QPhiX. For the latter approach, we concentrate on the staggered conjugate gradient and gauge force. We also consider performance on recent NVIDIA GPUs using the QUDA library.

TOP500 Supercomputers for June 2005

Energy Technology Data Exchange (ETDEWEB)

Strohmaier, Erich; Meuer, Hans W.; Dongarra, Jack; Simon, Horst D.

2005-06-22

25th Edition of TOP500 List of World's Fastest Supercomputers Released: DOE/L LNL BlueGene/L and IBM gain Top Positions MANNHEIM, Germany; KNOXVILLE, Tenn.; BERKELEY, Calif. In what has become a closely watched event in the world of high-performance computing, the 25th edition of the TOP500 list of the world's fastest supercomputers was released today (June 22, 2005) at the 20th International Supercomputing Conference (ISC2005) in Heidelberg Germany.

Comparison of some parallelization strategies of thermalhydraulic codes on GPUs

International Nuclear Information System (INIS)

Jendoubi, T.; Bergeaud, V.; Geay, A.

2013-01-01

Modern supercomputers architecture is now often based on hybrid concepts combining parallelism to distributed memory, parallelism to shared memory and also to GPUs (Graphic Process Units). In this work, we propose a new approach to take advantage of these graphic cards in thermohydraulics algorithms. (authors)

Hierarchical approach to optimization of parallel matrix multiplication on large-scale platforms

KAUST Repository

Hasanov, Khalid

2014-03-04

© 2014, Springer Science+Business Media New York. Many state-of-the-art parallel algorithms, which are widely used in scientific applications executed on high-end computing systems, were designed in the twentieth century with relatively small-scale parallelism in mind. Indeed, while in 1990s a system with few hundred cores was considered a powerful supercomputer, modern top supercomputers have millions of cores. In this paper, we present a hierarchical approach to optimization of message-passing parallel algorithms for execution on large-scale distributed-memory systems. The idea is to reduce the communication cost by introducing hierarchy and hence more parallelism in the communication scheme. We apply this approach to SUMMA, the state-of-the-art parallel algorithm for matrix–matrix multiplication, and demonstrate both theoretically and experimentally that the modified Hierarchical SUMMA significantly improves the communication cost and the overall performance on large-scale platforms.

Modeling radiative transport in ICF plasmas on an IBM SP2 supercomputer

International Nuclear Information System (INIS)

Johansen, J.A.; MacFarlane, J.J.; Moses, G.A.

1995-01-01

At the University of Wisconsin-Madison the authors have integrated a collisional-radiative-equilibrium model into their CONRAD radiation-hydrodynamics code. This integrated package allows them to accurately simulate the transport processes involved in ICF plasmas; including the important effects of self-absorption of line-radiation. However, as they increase the amount of atomic structure utilized in their transport models, the computational demands increase nonlinearly. In an attempt to meet this increased computational demand, they have recently embarked on a mission to parallelize the CONRAD program. The parallel CONRAD development is being performed on an IBM SP2 supercomputer. The parallelism is based on a message passing paradigm, and is being implemented using PVM. At the present time they have determined that approximately 70% of the sequential program can be executed in parallel. Accordingly, they expect that the parallel version will yield a speedup on the order of three times that of the sequential version. This translates into only 10 hours of execution time for the parallel version, whereas the sequential version required 30 hours

Engineering-Based Thermal CFD Simulations on Massive Parallel Systems

KAUST Repository

Frisch, Jérôme

2015-05-22

The development of parallel Computational Fluid Dynamics (CFD) codes is a challenging task that entails efficient parallelization concepts and strategies in order to achieve good scalability values when running those codes on modern supercomputers with several thousands to millions of cores. In this paper, we present a hierarchical data structure for massive parallel computations that supports the coupling of a Navier–Stokes-based fluid flow code with the Boussinesq approximation in order to address complex thermal scenarios for energy-related assessments. The newly designed data structure is specifically designed with the idea of interactive data exploration and visualization during runtime of the simulation code; a major shortcoming of traditional high-performance computing (HPC) simulation codes. We further show and discuss speed-up values obtained on one of Germany’s top-ranked supercomputers with up to 140,000 processes and present simulation results for different engineering-based thermal problems.

Explaining the gap between theoretical peak performance and real performance for supercomputer architectures

International Nuclear Information System (INIS)

Schoenauer, W.; Haefner, H.

1993-01-01

The basic architectures of vector and parallel computers with their properties are presented. Then the memory size and the arithmetic operations in the context of memory bandwidth are discussed. For the exemplary discussion of a single operation micro-measurements of the vector triad for the IBM 3090 VF and the CRAY Y-MP/8 are presented. They reveal the details of the losses for a single operation. Then we analyze the global performance of a whole supercomputer by identifying reduction factors that bring down the theoretical peak performance to the poor real performance. The responsibilities of the manufacturer and of the user for these losses are dicussed. Then the price-performance ratio for different architectures in a snapshot of January 1991 is briefly mentioned. Finally some remarks to a user-friendly architecture for a supercomputer will be made. (orig.)

Algorithm comparison and benchmarking using a parallel spectra transform shallow water model

Energy Technology Data Exchange (ETDEWEB)

Worley, P.H. [Oak Ridge National Lab., TN (United States); Foster, I.T.; Toonen, B. [Argonne National Lab., IL (United States)

1995-04-01

In recent years, a number of computer vendors have produced supercomputers based on a massively parallel processing (MPP) architecture. These computers have been shown to be competitive in performance with conventional vector supercomputers for some applications. As spectral weather and climate models are heavy users of vector supercomputers, it is interesting to determine how these models perform on MPPS, and which MPPs are best suited to the execution of spectral models. The benchmarking of MPPs is complicated by the fact that different algorithms may be more efficient on different architectures. Hence, a comprehensive benchmarking effort must answer two related questions: which algorithm is most efficient on each computer and how do the most efficient algorithms compare on different computers. In general, these are difficult questions to answer because of the high cost associated with implementing and evaluating a range of different parallel algorithms on each MPP platform.

Radiation-magnetohydrodynamics of fusion plasmas on parallel supercomputers

International Nuclear Information System (INIS)

Yasar, O.; Moses, G.A.; Tautges, T.J.

1993-01-01

A parallel computational model to simulate fusion plasmas in the radiation-magnetohydrodynamics (R-MHD) framework is presented. Plasmas are often treated in a fluid dynamics context (magnetohydrodynamics, MHD), but when the flow field is coupled with the radiation field it falls into a more complex category, radiation magnetohydrodynamics (R-MHD), where the interaction between the flow field and the radiation field is nonlinear. The solution for the radiation field usually dominates the R-MHD computation. To solve for the radiation field, one usually chooses the S N discrete ordinates method (a deterministic method) rather than the Monte Carlo method if the geometry is not complex. The discrete ordinates method on a massively parallel processor (Intel iPSC/860) is implemented. The speedup is 14 for a run on 16 processors and the performance is 3.7 times better than a single CRAY YMP processor implementation. (orig./DG)

TOP500 Supercomputers for November 2003

Energy Technology Data Exchange (ETDEWEB)

Strohmaier, Erich; Meuer, Hans W.; Dongarra, Jack; Simon, Horst D.

2003-11-16

22nd Edition of TOP500 List of World s Fastest Supercomputers Released MANNHEIM, Germany; KNOXVILLE, Tenn.; BERKELEY, Calif. In what has become a much-anticipated event in the world of high-performance computing, the 22nd edition of the TOP500 list of the worlds fastest supercomputers was released today (November 16, 2003). The Earth Simulator supercomputer retains the number one position with its Linpack benchmark performance of 35.86 Tflop/s (''teraflops'' or trillions of calculations per second). It was built by NEC and installed last year at the Earth Simulator Center in Yokohama, Japan.

A training program for scientific supercomputing users

Energy Technology Data Exchange (ETDEWEB)

Hanson, F.; Moher, T.; Sabelli, N.; Solem, A.

1988-01-01

There is need for a mechanism to transfer supercomputing technology into the hands of scientists and engineers in such a way that they will acquire a foundation of knowledge that will permit integration of supercomputing as a tool in their research. Most computing center training emphasizes computer-specific information about how to use a particular computer system; most academic programs teach concepts to computer scientists. Only a few brief courses and new programs are designed for computational scientists. This paper describes an eleven-week training program aimed principally at graduate and postdoctoral students in computationally-intensive fields. The program is designed to balance the specificity of computing center courses, the abstractness of computer science courses, and the personal contact of traditional apprentice approaches. It is based on the experience of computer scientists and computational scientists, and consists of seminars and clinics given by many visiting and local faculty. It covers a variety of supercomputing concepts, issues, and practices related to architecture, operating systems, software design, numerical considerations, code optimization, graphics, communications, and networks. Its research component encourages understanding of scientific computing and supercomputer hardware issues. Flexibility in thinking about computing needs is emphasized by the use of several different supercomputer architectures, such as the Cray X/MP48 at the National Center for Supercomputing Applications at University of Illinois at Urbana-Champaign, IBM 3090 600E/VF at the Cornell National Supercomputer Facility, and Alliant FX/8 at the Advanced Computing Research Facility at Argonne National Laboratory. 11 refs., 6 tabs.

Integration of PanDA workload management system with Titan supercomputer at OLCF

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00300320; Klimentov, Alexei; Oleynik, Danila; Panitkin, Sergey; Petrosyan, Artem; Vaniachine, Alexandre; Wenaus, Torre; Schovancova, Jaroslava

2015-01-01

The PanDA (Production and Distributed Analysis) workload management system (WMS) was developed to meet the scale and complexity of LHC distributed computing for the ATLAS experiment. While PanDA currently distributes jobs to more than 100,000 cores at well over 100 Grid sites, next LHC data taking run will require more resources than Grid computing can possibly provide. To alleviate these challenges, ATLAS is engaged in an ambitious program to expand the current computing model to include additional resources such as the opportunistic use of supercomputers. We will describe a project aimed at integration of PanDA WMS with Titan supercomputer at Oak Ridge Leadership Computing Facility (OLCF). Current approach utilizes modi ed PanDA pilot framework for job submission to Titan's batch queues and local data management, with light-weight MPI wrappers to run single threaded workloads in parallel on Titan's multi-core worker nodes. It also gives PanDA new capability to collect, in real time, information about unused...

Integration of PanDA workload management system with Titan supercomputer at OLCF

CERN Document Server

Panitkin, Sergey; The ATLAS collaboration; Klimentov, Alexei; Oleynik, Danila; Petrosyan, Artem; Schovancova, Jaroslava; Vaniachine, Alexandre; Wenaus, Torre

2015-01-01

The PanDA (Production and Distributed Analysis) workload management system (WMS) was developed to meet the scale and complexity of LHC distributed computing for the ATLAS experiment. While PanDA currently uses more than 100,000 cores at well over 100 Grid sites with a peak performance of 0.3 petaFLOPS, next LHC data taking run will require more resources than Grid computing can possibly provide. To alleviate these challenges, ATLAS is engaged in an ambitious program to expand the current computing model to include additional resources such as the opportunistic use of supercomputers. We will describe a project aimed at integration of PanDA WMS with Titan supercomputer at Oak Ridge Leadership Computing Facility (OLCF). Current approach utilizes modified PanDA pilot framework for job submission to Titan's batch queues and local data management, with light-weight MPI wrappers to run single threaded workloads in parallel on Titan's multi-core worker nodes. It also gives PanDA new capability to collect, in real tim...

INTEL: Intel based systems move up in supercomputing ranks

CERN Multimedia

2002-01-01

"The TOP500 supercomputer rankings released today at the Supercomputing 2002 conference show a dramatic increase in the number of Intel-based systems being deployed in high-performance computing (HPC) or supercomputing areas" (1/2 page).

World's fastest supercomputer opens up to users

Science.gov (United States)

Xin, Ling

2016-08-01

China's latest supercomputer - Sunway TaihuLight - has claimed the crown as the world's fastest computer according to the latest TOP500 list, released at the International Supercomputer Conference in Frankfurt in late June.

A fast random number generator for the Intel Paragon supercomputer

Science.gov (United States)

Gutbrod, F.

1995-06-01

A pseudo-random number generator is presented which makes optimal use of the architecture of the i860-microprocessor and which is expected to have a very long period. It is therefore a good candidate for use on the parallel supercomputer Paragon XP. In the assembler version, it needs 6.4 cycles for a real∗4 random number. There is a FORTRAN routine which yields identical numbers up to rare and minor rounding discrepancies, and it needs 28 cycles. The FORTRAN performance on other microprocessors is somewhat better. Arguments for the quality of the generator and some numerical tests are given.

OpenMP Performance on the Columbia Supercomputer

Science.gov (United States)

Haoqiang, Jin; Hood, Robert

2005-01-01

This presentation discusses Columbia World Class Supercomputer which is one of the world's fastest supercomputers providing 61 TFLOPs (10/20/04). Conceived, designed, built, and deployed in just 120 days. A 20-node supercomputer built on proven 512-processor nodes. The largest SGI system in the world with over 10,000 Intel Itanium 2 processors and provides the largest node size incorporating commodity parts (512) and the largest shared-memory environment (2048) with 88% efficiency tops the scalar systems on the Top500 list.

Integration Of PanDA Workload Management System With Supercomputers for ATLAS and Data Intensive Science

Energy Technology Data Exchange (ETDEWEB)

De, K [University of Texas at Arlington; Jha, S [Rutgers University; Klimentov, A [Brookhaven National Laboratory (BNL); Maeno, T [Brookhaven National Laboratory (BNL); Nilsson, P [Brookhaven National Laboratory (BNL); Oleynik, D [University of Texas at Arlington; Panitkin, S [Brookhaven National Laboratory (BNL); Wells, Jack C [ORNL; Wenaus, T [Brookhaven National Laboratory (BNL)

2016-01-01

The Large Hadron Collider (LHC), operating at the international CERN Laboratory in Geneva, Switzerland, is leading Big Data driven scientific explorations. Experiments at the LHC explore the fundamental nature of matter and the basic forces that shape our universe, and were recently credited for the discovery of a Higgs boson. ATLAS, one of the largest collaborations ever assembled in the sciences, is at the forefront of research at the LHC. To address an unprecedented multi-petabyte data processing challenge, the ATLAS experiment is relying on a heterogeneous distributed computational infrastructure. The ATLAS experiment uses PanDA (Production and Data Analysis) Workload Management System for managing the workflow for all data processing on over 150 data centers. Through PanDA, ATLAS physicists see a single computing facility that enables rapid scientific breakthroughs for the experiment, even though the data centers are physically scattered all over the world. While PanDA currently uses more than 250,000 cores with a peak performance of 0.3 petaFLOPS, LHC data taking runs require more resources than Grid computing can possibly provide. To alleviate these challenges, LHC experiments are engaged in an ambitious program to expand the current computing model to include additional resources such as the opportunistic use of supercomputers. We will describe a project aimed at integration of PanDA WMS with supercomputers in United States, Europe and Russia (in particular with Titan supercomputer at Oak Ridge Leadership Computing Facility (OLCF), MIRA supercomputer at Argonne Leadership Computing Facilities (ALCF), Supercomputer at the National Research Center Kurchatov Institute , IT4 in Ostrava and others). Current approach utilizes modified PanDA pilot framework for job submission to the supercomputers batch queues and local data management, with light-weight MPI wrappers to run single threaded workloads in parallel on LCFs multi-core worker nodes. This implementation

Design considerations for parallel graphics libraries

Science.gov (United States)

Crockett, Thomas W.

1994-01-01

Applications which run on parallel supercomputers are often characterized by massive datasets. Converting these vast collections of numbers to visual form has proven to be a powerful aid to comprehension. For a variety of reasons, it may be desirable to provide this visual feedback at runtime. One way to accomplish this is to exploit the available parallelism to perform graphics operations in place. In order to do this, we need appropriate parallel rendering algorithms and library interfaces. This paper provides a tutorial introduction to some of the issues which arise in designing parallel graphics libraries and their underlying rendering algorithms. The focus is on polygon rendering for distributed memory message-passing systems. We illustrate our discussion with examples from PGL, a parallel graphics library which has been developed on the Intel family of parallel systems.

Massive hybrid parallelism for fully implicit multiphysics

International Nuclear Information System (INIS)

Gaston, D. R.; Permann, C. J.; Andrs, D.; Peterson, J. W.

2013-01-01

As hardware advances continue to modify the supercomputing landscape, traditional scientific software development practices will become more outdated, ineffective, and inefficient. The process of rewriting/retooling existing software for new architectures is a Sisyphean task, and results in substantial hours of development time, effort, and money. Software libraries which provide an abstraction of the resources provided by such architectures are therefore essential if the computational engineering and science communities are to continue to flourish in this modern computing environment. The Multiphysics Object Oriented Simulation Environment (MOOSE) framework enables complex multiphysics analysis tools to be built rapidly by scientists, engineers, and domain specialists, while also allowing them to both take advantage of current HPC architectures, and efficiently prepare for future supercomputer designs. MOOSE employs a hybrid shared-memory and distributed-memory parallel model and provides a complete and consistent interface for creating multiphysics analysis tools. In this paper, a brief discussion of the mathematical algorithms underlying the framework and the internal object-oriented hybrid parallel design are given. Representative massively parallel results from several applications areas are presented, and a brief discussion of future areas of research for the framework are provided. (authors)

Massive hybrid parallelism for fully implicit multiphysics

Energy Technology Data Exchange (ETDEWEB)

Gaston, D. R.; Permann, C. J.; Andrs, D.; Peterson, J. W. [Idaho National Laboratory, 2525 N. Fremont Ave., Idaho Falls, ID 83415 (United States)

2013-07-01

As hardware advances continue to modify the supercomputing landscape, traditional scientific software development practices will become more outdated, ineffective, and inefficient. The process of rewriting/retooling existing software for new architectures is a Sisyphean task, and results in substantial hours of development time, effort, and money. Software libraries which provide an abstraction of the resources provided by such architectures are therefore essential if the computational engineering and science communities are to continue to flourish in this modern computing environment. The Multiphysics Object Oriented Simulation Environment (MOOSE) framework enables complex multiphysics analysis tools to be built rapidly by scientists, engineers, and domain specialists, while also allowing them to both take advantage of current HPC architectures, and efficiently prepare for future supercomputer designs. MOOSE employs a hybrid shared-memory and distributed-memory parallel model and provides a complete and consistent interface for creating multiphysics analysis tools. In this paper, a brief discussion of the mathematical algorithms underlying the framework and the internal object-oriented hybrid parallel design are given. Representative massively parallel results from several applications areas are presented, and a brief discussion of future areas of research for the framework are provided. (authors)

MASSIVE HYBRID PARALLELISM FOR FULLY IMPLICIT MULTIPHYSICS

Energy Technology Data Exchange (ETDEWEB)

Cody J. Permann; David Andrs; John W. Peterson; Derek R. Gaston

2013-05-01

As hardware advances continue to modify the supercomputing landscape, traditional scientific software development practices will become more outdated, ineffective, and inefficient. The process of rewriting/retooling existing software for new architectures is a Sisyphean task, and results in substantial hours of development time, effort, and money. Software libraries which provide an abstraction of the resources provided by such architectures are therefore essential if the computational engineering and science communities are to continue to flourish in this modern computing environment. The Multiphysics Object Oriented Simulation Environment (MOOSE) framework enables complex multiphysics analysis tools to be built rapidly by scientists, engineers, and domain specialists, while also allowing them to both take advantage of current HPC architectures, and efficiently prepare for future supercomputer designs. MOOSE employs a hybrid shared-memory and distributed-memory parallel model and provides a complete and consistent interface for creating multiphysics analysis tools. In this paper, a brief discussion of the mathematical algorithms underlying the framework and the internal object-oriented hybrid parallel design are given. Representative massively parallel results from several applications areas are presented, and a brief discussion of future areas of research for the framework are provided.

Supercomputing - Use Cases, Advances, The Future (1/2)

CERN Multimedia

CERN. Geneva

2017-01-01

Supercomputing has become a staple of science and the poster child for aggressive developments in silicon technology, energy efficiency and programming. In this series we examine the key components of supercomputing setups and the various advances – recent and past – that made headlines and delivered bigger and bigger machines. We also take a closer look at the future prospects of supercomputing, and the extent of its overlap with high throughput computing, in the context of main use cases ranging from oil exploration to market simulation. On the first day, we will focus on the history and theory of supercomputing, the top500 list and the hardware that makes supercomputers tick. Lecturer's short bio: Andrzej Nowak has 10 years of experience in computing technologies, primarily from CERN openlab and Intel. At CERN, he managed a research lab collaborating with Intel and was part of the openlab Chief Technology Office. Andrzej also worked closely and initiated projects with the private sector (e.g. HP an...

Supercomputing - Use Cases, Advances, The Future (2/2)

CERN Multimedia

CERN. Geneva

2017-01-01

Supercomputing has become a staple of science and the poster child for aggressive developments in silicon technology, energy efficiency and programming. In this series we examine the key components of supercomputing setups and the various advances – recent and past – that made headlines and delivered bigger and bigger machines. We also take a closer look at the future prospects of supercomputing, and the extent of its overlap with high throughput computing, in the context of main use cases ranging from oil exploration to market simulation. On the second day, we will focus on software and software paradigms driving supercomputers, workloads that need supercomputing treatment, advances in technology and possible future developments. Lecturer's short bio: Andrzej Nowak has 10 years of experience in computing technologies, primarily from CERN openlab and Intel. At CERN, he managed a research lab collaborating with Intel and was part of the openlab Chief Technology Office. Andrzej also worked closely and i...

Integration Of PanDA Workload Management System With Supercomputers for ATLAS and Data Intensive Science

Science.gov (United States)

Klimentov, A.; De, K.; Jha, S.; Maeno, T.; Nilsson, P.; Oleynik, D.; Panitkin, S.; Wells, J.; Wenaus, T.

2016-10-01

The.LHC, operating at CERN, is leading Big Data driven scientific explorations. Experiments at the LHC explore the fundamental nature of matter and the basic forces that shape our universe. ATLAS, one of the largest collaborations ever assembled in the sciences, is at the forefront of research at the LHC. To address an unprecedented multi-petabyte data processing challenge, the ATLAS experiment is relying on a heterogeneous distributed computational infrastructure. The ATLAS experiment uses PanDA (Production and Data Analysis) Workload Management System for managing the workflow for all data processing on over 150 data centers. Through PanDA, ATLAS physicists see a single computing facility that enables rapid scientific breakthroughs for the experiment, even though the data centers are physically scattered all over the world. While PanDA currently uses more than 250,000 cores with a peak performance of 0.3 petaFLOPS, LHC data taking runs require more resources than grid can possibly provide. To alleviate these challenges, LHC experiments are engaged in an ambitious program to expand the current computing model to include additional resources such as the opportunistic use of supercomputers. We will describe a project aimed at integration of PanDA WMS with supercomputers in United States, in particular with Titan supercomputer at Oak Ridge Leadership Computing Facility. Current approach utilizes modified PanDA pilot framework for job submission to the supercomputers batch queues and local data management, with light-weight MPI wrappers to run single threaded workloads in parallel on LCFs multi-core worker nodes. This implementation was tested with a variety of Monte-Carlo workloads on several supercomputing platforms for ALICE and ATLAS experiments and it is in full pro duction for the ATLAS since September 2015. We will present our current accomplishments with running PanDA at supercomputers and demonstrate our ability to use PanDA as a portal independent of the

Integration Of PanDA Workload Management System With Supercomputers for ATLAS and Data Intensive Science

International Nuclear Information System (INIS)

Klimentov, A; Maeno, T; Nilsson, P; Panitkin, S; Wenaus, T; De, K; Oleynik, D; Jha, S; Wells, J

2016-01-01

The.LHC, operating at CERN, is leading Big Data driven scientific explorations. Experiments at the LHC explore the fundamental nature of matter and the basic forces that shape our universe. ATLAS, one of the largest collaborations ever assembled in the sciences, is at the forefront of research at the LHC. To address an unprecedented multi-petabyte data processing challenge, the ATLAS experiment is relying on a heterogeneous distributed computational infrastructure. The ATLAS experiment uses PanDA (Production and Data Analysis) Workload Management System for managing the workflow for all data processing on over 150 data centers. Through PanDA, ATLAS physicists see a single computing facility that enables rapid scientific breakthroughs for the experiment, even though the data centers are physically scattered all over the world. While PanDA currently uses more than 250,000 cores with a peak performance of 0.3 petaFLOPS, LHC data taking runs require more resources than grid can possibly provide. To alleviate these challenges, LHC experiments are engaged in an ambitious program to expand the current computing model to include additional resources such as the opportunistic use of supercomputers. We will describe a project aimed at integration of PanDA WMS with supercomputers in United States, in particular with Titan supercomputer at Oak Ridge Leadership Computing Facility. Current approach utilizes modified PanDA pilot framework for job submission to the supercomputers batch queues and local data management, with light-weight MPI wrappers to run single threaded workloads in parallel on LCFs multi-core worker nodes. This implementation was tested with a variety of Monte-Carlo workloads on several supercomputing platforms for ALICE and ATLAS experiments and it is in full pro duction for the ATLAS since September 2015. We will present our current accomplishments with running PanDA at supercomputers and demonstrate our ability to use PanDA as a portal independent of the

Desktop supercomputer: what can it do?

Science.gov (United States)

Bogdanov, A.; Degtyarev, A.; Korkhov, V.

2017-12-01

The paper addresses the issues of solving complex problems that require using supercomputers or multiprocessor clusters available for most researchers nowadays. Efficient distribution of high performance computing resources according to actual application needs has been a major research topic since high-performance computing (HPC) technologies became widely introduced. At the same time, comfortable and transparent access to these resources was a key user requirement. In this paper we discuss approaches to build a virtual private supercomputer available at user's desktop: a virtual computing environment tailored specifically for a target user with a particular target application. We describe and evaluate possibilities to create the virtual supercomputer based on light-weight virtualization technologies, and analyze the efficiency of our approach compared to traditional methods of HPC resource management.

Adaptability of supercomputers to nuclear computations

International Nuclear Information System (INIS)

Asai, Kiyoshi; Ishiguro, Misako; Matsuura, Toshihiko.

1983-01-01

Recently in the field of scientific and technical calculation, the usefulness of supercomputers represented by CRAY-1 has been recognized, and they are utilized in various countries. The rapid computation of supercomputers is based on the function of vector computation. The authors investigated the adaptability to vector computation of about 40 typical atomic energy codes for the past six years. Based on the results of investigation, the adaptability of the function of vector computation that supercomputers have to atomic energy codes, the problem regarding the utilization and the future prospect are explained. The adaptability of individual calculation codes to vector computation is largely dependent on the algorithm and program structure used for the codes. The change to high speed by pipeline vector system, the investigation in the Japan Atomic Energy Research Institute and the results, and the examples of expressing the codes for atomic energy, environmental safety and nuclear fusion by vector are reported. The magnification of speed up for 40 examples was from 1.5 to 9.0. It can be said that the adaptability of supercomputers to atomic energy codes is fairly good. (Kako, I.)

Parallel-vector algorithms for particle simulations on shared-memory multiprocessors

International Nuclear Information System (INIS)

Nishiura, Daisuke; Sakaguchi, Hide

2011-01-01

Over the last few decades, the computational demands of massive particle-based simulations for both scientific and industrial purposes have been continuously increasing. Hence, considerable efforts are being made to develop parallel computing techniques on various platforms. In such simulations, particles freely move within a given space, and so on a distributed-memory system, load balancing, i.e., assigning an equal number of particles to each processor, is not guaranteed. However, shared-memory systems achieve better load balancing for particle models, but suffer from the intrinsic drawback of memory access competition, particularly during (1) paring of contact candidates from among neighboring particles and (2) force summation for each particle. Here, novel algorithms are proposed to overcome these two problems. For the first problem, the key is a pre-conditioning process during which particle labels are sorted by a cell label in the domain to which the particles belong. Then, a list of contact candidates is constructed by pairing the sorted particle labels. For the latter problem, a table comprising the list indexes of the contact candidate pairs is created and used to sum the contact forces acting on each particle for all contacts according to Newton's third law. With just these methods, memory access competition is avoided without additional redundant procedures. The parallel efficiency and compatibility of these two algorithms were evaluated in discrete element method (DEM) simulations on four types of shared-memory parallel computers: a multicore multiprocessor computer, scalar supercomputer, vector supercomputer, and graphics processing unit. The computational efficiency of a DEM code was found to be drastically improved with our algorithms on all but the scalar supercomputer. Thus, the developed parallel algorithms are useful on shared-memory parallel computers with sufficient memory bandwidth.

Speedup predictions on large scientific parallel programs

International Nuclear Information System (INIS)

Williams, E.; Bobrowicz, F.

1985-01-01

How much speedup can we expect for large scientific parallel programs running on supercomputers. For insight into this problem we extend the parallel processing environment currently existing on the Cray X-MP (a shared memory multiprocessor with at most four processors) to a simulated N-processor environment, where N greater than or equal to 1. Several large scientific parallel programs from Los Alamos National Laboratory were run in this simulated environment, and speedups were predicted. A speedup of 14.4 on 16 processors was measured for one of the three most used codes at the Laboratory

Desktop supercomputer: what can it do?

International Nuclear Information System (INIS)

Bogdanov, A.; Degtyarev, A.; Korkhov, V.

2017-01-01

The paper addresses the issues of solving complex problems that require using supercomputers or multiprocessor clusters available for most researchers nowadays. Efficient distribution of high performance computing resources according to actual application needs has been a major research topic since high-performance computing (HPC) technologies became widely introduced. At the same time, comfortable and transparent access to these resources was a key user requirement. In this paper we discuss approaches to build a virtual private supercomputer available at user's desktop: a virtual computing environment tailored specifically for a target user with a particular target application. We describe and evaluate possibilities to create the virtual supercomputer based on light-weight virtualization technologies, and analyze the efficiency of our approach compared to traditional methods of HPC resource management.

6th International Parallel Tools Workshop

CERN Document Server

Brinkmann, Steffen; Gracia, José; Resch, Michael; Nagel, Wolfgang

2013-01-01

The latest advances in the High Performance Computing hardware have significantly raised the level of available compute performance. At the same time, the growing hardware capabilities of modern supercomputing architectures have caused an increasing complexity of the parallel application development. Despite numerous efforts to improve and simplify parallel programming, there is still a lot of manual debugging and  tuning work required. This process  is supported by special software tools, facilitating debugging, performance analysis, and optimization and thus  making a major contribution to the development of  robust and efficient parallel software. This book introduces a selection of the tools, which were presented and discussed at the 6th International Parallel Tools Workshop, held in Stuttgart, Germany, 25-26 September 2012.

Parallel Computing Strategies for Irregular Algorithms

Science.gov (United States)

Biswas, Rupak; Oliker, Leonid; Shan, Hongzhang; Biegel, Bryan (Technical Monitor)

2002-01-01

Parallel computing promises several orders of magnitude increase in our ability to solve realistic computationally-intensive problems, but relies on their efficient mapping and execution on large-scale multiprocessor architectures. Unfortunately, many important applications are irregular and dynamic in nature, making their effective parallel implementation a daunting task. Moreover, with the proliferation of parallel architectures and programming paradigms, the typical scientist is faced with a plethora of questions that must be answered in order to obtain an acceptable parallel implementation of the solution algorithm. In this paper, we consider three representative irregular applications: unstructured remeshing, sparse matrix computations, and N-body problems, and parallelize them using various popular programming paradigms on a wide spectrum of computer platforms ranging from state-of-the-art supercomputers to PC clusters. We present the underlying problems, the solution algorithms, and the parallel implementation strategies. Smart load-balancing, partitioning, and ordering techniques are used to enhance parallel performance. Overall results demonstrate the complexity of efficiently parallelizing irregular algorithms.

Confrontation clause

Directory of Open Access Journals (Sweden)

Tkachuk Sviatoslav

2016-07-01

Full Text Available The Sixth Amendment to the United States Constitution enumerates a cluster of rights granted to criminal defendants and is designed to make criminal prosecutions more accurate, fair, and legitimate. The Confrontation Clause, which states that „In all criminal prosecutions, the accused shall enjoy the right…to be confronted with the witness against him” should not be underestimated. This article seeks to analyse the evolution of the Confrontation Clause and the extent of a defendant’s right to face-to-face confrontation. The article analyse the case Crawford v. Washington, which was a key shift in the Supreme Court’s Confrontation Clause jurisprudence.

Optimisation of a parallel ocean general circulation model

Science.gov (United States)

Beare, M. I.; Stevens, D. P.

1997-10-01

This paper presents the development of a general-purpose parallel ocean circulation model, for use on a wide range of computer platforms, from traditional scalar machines to workstation clusters and massively parallel processors. Parallelism is provided, as a modular option, via high-level message-passing routines, thus hiding the technical intricacies from the user. An initial implementation highlights that the parallel efficiency of the model is adversely affected by a number of factors, for which optimisations are discussed and implemented. The resulting ocean code is portable and, in particular, allows science to be achieved on local workstations that could otherwise only be undertaken on state-of-the-art supercomputers.

A user-friendly web portal for T-Coffee on supercomputers

Directory of Open Access Journals (Sweden)

Koetsier Jos

2011-05-01

Full Text Available Abstract Background Parallel T-Coffee (PTC was the first parallel implementation of the T-Coffee multiple sequence alignment tool. It is based on MPI and RMA mechanisms. Its purpose is to reduce the execution time of the large-scale sequence alignments. It can be run on distributed memory clusters allowing users to align data sets consisting of hundreds of proteins within a reasonable time. However, most of the potential users of this tool are not familiar with the use of grids or supercomputers. Results In this paper we show how PTC can be easily deployed and controlled on a super computer architecture using a web portal developed using Rapid. Rapid is a tool for efficiently generating standardized portlets for a wide range of applications and the approach described here is generic enough to be applied to other applications, or to deploy PTC on different HPC environments. Conclusions The PTC portal allows users to upload a large number of sequences to be aligned by the parallel version of TC that cannot be aligned by a single machine due to memory and execution time constraints. The web portal provides a user-friendly solution.

Partial Overhaul and Initial Parallel Optimization of KINETICS, a Coupled Dynamics and Chemistry Atmosphere Model

Science.gov (United States)

Nguyen, Howard; Willacy, Karen; Allen, Mark

2012-01-01

KINETICS is a coupled dynamics and chemistry atmosphere model that is data intensive and computationally demanding. The potential performance gain from using a supercomputer motivates the adaptation from a serial version to a parallelized one. Although the initial parallelization had been done, bottlenecks caused by an abundance of communication calls between processors led to an unfavorable drop in performance. Before starting on the parallel optimization process, a partial overhaul was required because a large emphasis was placed on streamlining the code for user convenience and revising the program to accommodate the new supercomputers at Caltech and JPL. After the first round of optimizations, the partial runtime was reduced by a factor of 23; however, performance gains are dependent on the size of the data, the number of processors requested, and the computer used.

Vector and parallel processors in computational science

International Nuclear Information System (INIS)

Duff, I.S.; Reid, J.K.

1985-01-01

This book presents the papers given at a conference which reviewed the new developments in parallel and vector processing. Topics considered at the conference included hardware (array processors, supercomputers), programming languages, software aids, numerical methods (e.g., Monte Carlo algorithms, iterative methods, finite elements, optimization), and applications (e.g., neutron transport theory, meteorology, image processing)

Parallel visualization on leadership computing resources

Energy Technology Data Exchange (ETDEWEB)

Peterka, T; Ross, R B [Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Shen, H-W [Department of Computer Science and Engineering, Ohio State University, Columbus, OH 43210 (United States); Ma, K-L [Department of Computer Science, University of California at Davis, Davis, CA 95616 (United States); Kendall, W [Department of Electrical Engineering and Computer Science, University of Tennessee at Knoxville, Knoxville, TN 37996 (United States); Yu, H, E-mail: tpeterka@mcs.anl.go [Sandia National Laboratories, California, Livermore, CA 94551 (United States)

2009-07-01

Changes are needed in the way that visualization is performed, if we expect the analysis of scientific data to be effective at the petascale and beyond. By using similar techniques as those used to parallelize simulations, such as parallel I/O, load balancing, and effective use of interprocess communication, the supercomputers that compute these datasets can also serve as analysis and visualization engines for them. Our team is assessing the feasibility of performing parallel scientific visualization on some of the most powerful computational resources of the U.S. Department of Energy's National Laboratories in order to pave the way for analyzing the next generation of computational results. This paper highlights some of the conclusions of that research.

Parallel visualization on leadership computing resources

International Nuclear Information System (INIS)

Peterka, T; Ross, R B; Shen, H-W; Ma, K-L; Kendall, W; Yu, H

2009-01-01

Changes are needed in the way that visualization is performed, if we expect the analysis of scientific data to be effective at the petascale and beyond. By using similar techniques as those used to parallelize simulations, such as parallel I/O, load balancing, and effective use of interprocess communication, the supercomputers that compute these datasets can also serve as analysis and visualization engines for them. Our team is assessing the feasibility of performing parallel scientific visualization on some of the most powerful computational resources of the U.S. Department of Energy's National Laboratories in order to pave the way for analyzing the next generation of computational results. This paper highlights some of the conclusions of that research.

TOP500 Supercomputers for November 2004

Energy Technology Data Exchange (ETDEWEB)

Strohmaier, Erich; Meuer, Hans W.; Dongarra, Jack; Simon, Horst D.

2004-11-08

24th Edition of TOP500 List of World's Fastest Supercomputers Released: DOE/IBM BlueGene/L and NASA/SGI's Columbia gain Top Positions MANNHEIM, Germany; KNOXVILLE, Tenn.; BERKELEY, Calif. In what has become a closely watched event in the world of high-performance computing, the 24th edition of the TOP500 list of the worlds fastest supercomputers was released today (November 8, 2004) at the SC2004 Conference in Pittsburgh, Pa.

TOP500 Supercomputers for June 2003

Energy Technology Data Exchange (ETDEWEB)

Strohmaier, Erich; Meuer, Hans W.; Dongarra, Jack; Simon, Horst D.

2003-06-23

21st Edition of TOP500 List of World's Fastest Supercomputers Released MANNHEIM, Germany; KNOXVILLE, Tenn.;&BERKELEY, Calif. In what has become a much-anticipated event in the world of high-performance computing, the 21st edition of the TOP500 list of the world's fastest supercomputers was released today (June 23, 2003). The Earth Simulator supercomputer built by NEC and installed last year at the Earth Simulator Center in Yokohama, Japan, with its Linpack benchmark performance of 35.86 Tflop/s (teraflops or trillions of calculations per second), retains the number one position. The number 2 position is held by the re-measured ASCI Q system at Los Alamos National Laboratory. With 13.88 Tflop/s, it is the second system ever to exceed the 10 Tflop/smark. ASCIQ was built by Hewlett-Packard and is based on the AlphaServerSC computer system.

TOP500 Supercomputers for June 2002

Energy Technology Data Exchange (ETDEWEB)

Strohmaier, Erich; Meuer, Hans W.; Dongarra, Jack; Simon, Horst D.

2002-06-20

19th Edition of TOP500 List of World's Fastest Supercomputers Released MANNHEIM, Germany; KNOXVILLE, Tenn.;&BERKELEY, Calif. In what has become a much-anticipated event in the world of high-performance computing, the 19th edition of the TOP500 list of the worlds fastest supercomputers was released today (June 20, 2002). The recently installed Earth Simulator supercomputer at the Earth Simulator Center in Yokohama, Japan, is as expected the clear new number 1. Its performance of 35.86 Tflop/s (trillions of calculations per second) running the Linpack benchmark is almost five times higher than the performance of the now No.2 IBM ASCI White system at Lawrence Livermore National Laboratory (7.2 Tflop/s). This powerful leap frogging to the top by a system so much faster than the previous top system is unparalleled in the history of the TOP500.

Status reports of supercomputing astrophysics in Japan

International Nuclear Information System (INIS)

Nakamura, Takashi; Nagasawa, Mikio

1990-01-01

The Workshop on Supercomputing Astrophysics was held at National Laboratory for High Energy Physics (KEK, Tsukuba) from August 31 to September 2, 1989. More than 40 participants of physicists, astronomers were attendant and discussed many topics in the informal atmosphere. The main purpose of this workshop was focused on the theoretical activities in computational astrophysics in Japan. It was also aimed to promote effective collaboration between the numerical experimentists working on supercomputing technique. The various subjects of the presented papers of hydrodynamics, plasma physics, gravitating systems, radiative transfer and general relativity are all stimulating. In fact, these numerical calculations become possible now in Japan owing to the power of Japanese supercomputer such as HITAC S820, Fujitsu VP400E and NEC SX-2. (J.P.N.)

Parallelization of the FLAPW method

Science.gov (United States)

Canning, A.; Mannstadt, W.; Freeman, A. J.

2000-08-01

The FLAPW (full-potential linearized-augmented plane-wave) method is one of the most accurate first-principles methods for determining structural, electronic and magnetic properties of crystals and surfaces. Until the present work, the FLAPW method has been limited to systems of less than about a hundred atoms due to the lack of an efficient parallel implementation to exploit the power and memory of parallel computers. In this work, we present an efficient parallelization of the method by division among the processors of the plane-wave components for each state. The code is also optimized for RISC (reduced instruction set computer) architectures, such as those found on most parallel computers, making full use of BLAS (basic linear algebra subprograms) wherever possible. Scaling results are presented for systems of up to 686 silicon atoms and 343 palladium atoms per unit cell, running on up to 512 processors on a CRAY T3E parallel supercomputer.

Comprehensive efficiency analysis of supercomputer resource usage based on system monitoring data

Science.gov (United States)

Mamaeva, A. A.; Shaykhislamov, D. I.; Voevodin, Vad V.; Zhumatiy, S. A.

2018-03-01

One of the main problems of modern supercomputers is the low efficiency of their usage, which leads to the significant idle time of computational resources, and, in turn, to the decrease in speed of scientific research. This paper presents three approaches to study the efficiency of supercomputer resource usage based on monitoring data analysis. The first approach performs an analysis of computing resource utilization statistics, which allows to identify different typical classes of programs, to explore the structure of the supercomputer job flow and to track overall trends in the supercomputer behavior. The second approach is aimed specifically at analyzing off-the-shelf software packages and libraries installed on the supercomputer, since efficiency of their usage is becoming an increasingly important factor for the efficient functioning of the entire supercomputer. Within the third approach, abnormal jobs – jobs with abnormally inefficient behavior that differs significantly from the standard behavior of the overall supercomputer job flow – are being detected. For each approach, the results obtained in practice in the Supercomputer Center of Moscow State University are demonstrated.

Time-dependent density-functional theory in massively parallel computer architectures: the OCTOPUS project.

Science.gov (United States)

Andrade, Xavier; Alberdi-Rodriguez, Joseba; Strubbe, David A; Oliveira, Micael J T; Nogueira, Fernando; Castro, Alberto; Muguerza, Javier; Arruabarrena, Agustin; Louie, Steven G; Aspuru-Guzik, Alán; Rubio, Angel; Marques, Miguel A L

2012-06-13

Octopus is a general-purpose density-functional theory (DFT) code, with a particular emphasis on the time-dependent version of DFT (TDDFT). In this paper we present the ongoing efforts to achieve the parallelization of octopus. We focus on the real-time variant of TDDFT, where the time-dependent Kohn-Sham equations are directly propagated in time. This approach has great potential for execution in massively parallel systems such as modern supercomputers with thousands of processors and graphics processing units (GPUs). For harvesting the potential of conventional supercomputers, the main strategy is a multi-level parallelization scheme that combines the inherent scalability of real-time TDDFT with a real-space grid domain-partitioning approach. A scalable Poisson solver is critical for the efficiency of this scheme. For GPUs, we show how using blocks of Kohn-Sham states provides the required level of data parallelism and that this strategy is also applicable for code optimization on standard processors. Our results show that real-time TDDFT, as implemented in octopus, can be the method of choice for studying the excited states of large molecular systems in modern parallel architectures.

Time-dependent density-functional theory in massively parallel computer architectures: the octopus project

Science.gov (United States)

Andrade, Xavier; Alberdi-Rodriguez, Joseba; Strubbe, David A.; Oliveira, Micael J. T.; Nogueira, Fernando; Castro, Alberto; Muguerza, Javier; Arruabarrena, Agustin; Louie, Steven G.; Aspuru-Guzik, Alán; Rubio, Angel; Marques, Miguel A. L.

2012-06-01

Octopus is a general-purpose density-functional theory (DFT) code, with a particular emphasis on the time-dependent version of DFT (TDDFT). In this paper we present the ongoing efforts to achieve the parallelization of octopus. We focus on the real-time variant of TDDFT, where the time-dependent Kohn-Sham equations are directly propagated in time. This approach has great potential for execution in massively parallel systems such as modern supercomputers with thousands of processors and graphics processing units (GPUs). For harvesting the potential of conventional supercomputers, the main strategy is a multi-level parallelization scheme that combines the inherent scalability of real-time TDDFT with a real-space grid domain-partitioning approach. A scalable Poisson solver is critical for the efficiency of this scheme. For GPUs, we show how using blocks of Kohn-Sham states provides the required level of data parallelism and that this strategy is also applicable for code optimization on standard processors. Our results show that real-time TDDFT, as implemented in octopus, can be the method of choice for studying the excited states of large molecular systems in modern parallel architectures.

Time-dependent density-functional theory in massively parallel computer architectures: the octopus project

International Nuclear Information System (INIS)

Andrade, Xavier; Aspuru-Guzik, Alán; Alberdi-Rodriguez, Joseba; Rubio, Angel; Strubbe, David A; Louie, Steven G; Oliveira, Micael J T; Nogueira, Fernando; Castro, Alberto; Muguerza, Javier; Arruabarrena, Agustin; Marques, Miguel A L

2012-01-01

Octopus is a general-purpose density-functional theory (DFT) code, with a particular emphasis on the time-dependent version of DFT (TDDFT). In this paper we present the ongoing efforts to achieve the parallelization of octopus. We focus on the real-time variant of TDDFT, where the time-dependent Kohn-Sham equations are directly propagated in time. This approach has great potential for execution in massively parallel systems such as modern supercomputers with thousands of processors and graphics processing units (GPUs). For harvesting the potential of conventional supercomputers, the main strategy is a multi-level parallelization scheme that combines the inherent scalability of real-time TDDFT with a real-space grid domain-partitioning approach. A scalable Poisson solver is critical for the efficiency of this scheme. For GPUs, we show how using blocks of Kohn-Sham states provides the required level of data parallelism and that this strategy is also applicable for code optimization on standard processors. Our results show that real-time TDDFT, as implemented in octopus, can be the method of choice for studying the excited states of large molecular systems in modern parallel architectures. (topical review)

The ETA10 supercomputer system

International Nuclear Information System (INIS)

Swanson, C.D.

1987-01-01

The ETA Systems, Inc. ETA 10 is a next-generation supercomputer featuring multiprocessing, a large hierarchical memory system, high performance input/output, and network support for both batch and interactive processing. Advanced technology used in the ETA 10 includes liquid nitrogen cooled CMOS logic with 20,000 gates per chip, a single printed circuit board for each CPU, and high density static and dynamics MOS memory chips. Software for the ETA 10 includes an underlying kernel that supports multiple user environments, a new ETA FORTRAN compiler with an advanced automatic vectorizer, a multitasking library and debugging tools. Possible developments for future supercomputers from ETA Systems are discussed. (orig.)

Optimisation of a parallel ocean general circulation model

Directory of Open Access Journals (Sweden)

M. I. Beare

1997-10-01

Full Text Available This paper presents the development of a general-purpose parallel ocean circulation model, for use on a wide range of computer platforms, from traditional scalar machines to workstation clusters and massively parallel processors. Parallelism is provided, as a modular option, via high-level message-passing routines, thus hiding the technical intricacies from the user. An initial implementation highlights that the parallel efficiency of the model is adversely affected by a number of factors, for which optimisations are discussed and implemented. The resulting ocean code is portable and, in particular, allows science to be achieved on local workstations that could otherwise only be undertaken on state-of-the-art supercomputers.

Optimisation of a parallel ocean general circulation model

Directory of Open Access Journals (Sweden)

M. I. Beare

Full Text Available This paper presents the development of a general-purpose parallel ocean circulation model, for use on a wide range of computer platforms, from traditional scalar machines to workstation clusters and massively parallel processors. Parallelism is provided, as a modular option, via high-level message-passing routines, thus hiding the technical intricacies from the user. An initial implementation highlights that the parallel efficiency of the model is adversely affected by a number of factors, for which optimisations are discussed and implemented. The resulting ocean code is portable and, in particular, allows science to be achieved on local workstations that could otherwise only be undertaken on state-of-the-art supercomputers.

Application of Raptor-M3G to reactor dosimetry problems on massively parallel architectures - 026

International Nuclear Information System (INIS)

Longoni, G.

2010-01-01

The solution of complex 3-D radiation transport problems requires significant resources both in terms of computation time and memory availability. Therefore, parallel algorithms and multi-processor architectures are required to solve efficiently large 3-D radiation transport problems. This paper presents the application of RAPTOR-M3G (Rapid Parallel Transport Of Radiation - Multiple 3D Geometries) to reactor dosimetry problems. RAPTOR-M3G is a newly developed parallel computer code designed to solve the discrete ordinates (SN) equations on multi-processor computer architectures. This paper presents the results for a reactor dosimetry problem using a 3-D model of a commercial 2-loop pressurized water reactor (PWR). The accuracy and performance of RAPTOR-M3G will be analyzed and the numerical results obtained from the calculation will be compared directly to measurements of the neutron field in the reactor cavity air gap. The parallel performance of RAPTOR-M3G on massively parallel architectures, where the number of computing nodes is in the order of hundreds, will be analyzed up to four hundred processors. The performance results will be presented based on two supercomputing architectures: the POPLE supercomputer operated by the Pittsburgh Supercomputing Center and the Westinghouse computer cluster. The Westinghouse computer cluster is equipped with a standard Ethernet network connection and an InfiniBand R interconnects capable of a bandwidth in excess of 20 GBit/sec. Therefore, the impact of the network architecture on RAPTOR-M3G performance will be analyzed as well. (authors)

Quantum Hamiltonian Physics with Supercomputers

International Nuclear Information System (INIS)

Vary, James P.

2014-01-01

The vision of solving the nuclear many-body problem in a Hamiltonian framework with fundamental interactions tied to QCD via Chiral Perturbation Theory is gaining support. The goals are to preserve the predictive power of the underlying theory, to test fundamental symmetries with the nucleus as laboratory and to develop new understandings of the full range of complex quantum phenomena. Advances in theoretical frameworks (renormalization and many-body methods) as well as in computational resources (new algorithms and leadership-class parallel computers) signal a new generation of theory and simulations that will yield profound insights into the origins of nuclear shell structure, collective phenomena and complex reaction dynamics. Fundamental discovery opportunities also exist in such areas as physics beyond the Standard Model of Elementary Particles, the transition between hadronic and quark–gluon dominated dynamics in nuclei and signals that characterize dark matter. I will review some recent achievements and present ambitious consensus plans along with their challenges for a coming decade of research that will build new links between theory, simulations and experiment. Opportunities for graduate students to embark upon careers in the fast developing field of supercomputer simulations is also discussed

Quantum Hamiltonian Physics with Supercomputers

Energy Technology Data Exchange (ETDEWEB)

Vary, James P.

2014-06-15

The vision of solving the nuclear many-body problem in a Hamiltonian framework with fundamental interactions tied to QCD via Chiral Perturbation Theory is gaining support. The goals are to preserve the predictive power of the underlying theory, to test fundamental symmetries with the nucleus as laboratory and to develop new understandings of the full range of complex quantum phenomena. Advances in theoretical frameworks (renormalization and many-body methods) as well as in computational resources (new algorithms and leadership-class parallel computers) signal a new generation of theory and simulations that will yield profound insights into the origins of nuclear shell structure, collective phenomena and complex reaction dynamics. Fundamental discovery opportunities also exist in such areas as physics beyond the Standard Model of Elementary Particles, the transition between hadronic and quark–gluon dominated dynamics in nuclei and signals that characterize dark matter. I will review some recent achievements and present ambitious consensus plans along with their challenges for a coming decade of research that will build new links between theory, simulations and experiment. Opportunities for graduate students to embark upon careers in the fast developing field of supercomputer simulations is also discussed.

On the adequacy of message-passing parallel supercomputers for solving neutron transport problems

International Nuclear Information System (INIS)

Azmy, Y.Y.

1990-01-01

A coarse-grained, static-scheduling parallelization of the standard iterative scheme used for solving the discrete-ordinates approximation of the neutron transport equation is described. The parallel algorithm is based on a decomposition of the angular domain along the discrete ordinates, thus naturally producing a set of completely uncoupled systems of equations in each iteration. Implementation of the parallel code on Intcl's iPSC/2 hypercube, and solutions to test problems are presented as evidence of the high speedup and efficiency of the parallel code. The performance of the parallel code on the iPSC/2 is analyzed, and a model for the CPU time as a function of the problem size (order of angular quadrature) and the number of participating processors is developed and validated against measured CPU times. The performance model is used to speculate on the potential of massively parallel computers for significantly speeding up real-life transport calculations at acceptable efficiencies. We conclude that parallel computers with a few hundred processors are capable of producing large speedups at very high efficiencies in very large three-dimensional problems. 10 refs., 8 figs

PFLOTRAN: Reactive Flow & Transport Code for Use on Laptops to Leadership-Class Supercomputers

Energy Technology Data Exchange (ETDEWEB)

Hammond, Glenn E.; Lichtner, Peter C.; Lu, Chuan; Mills, Richard T.

2012-04-18

PFLOTRAN, a next-generation reactive flow and transport code for modeling subsurface processes, has been designed from the ground up to run efficiently on machines ranging from leadership-class supercomputers to laptops. Based on an object-oriented design, the code is easily extensible to incorporate additional processes. It can interface seamlessly with Fortran 9X, C and C++ codes. Domain decomposition parallelism is employed, with the PETSc parallel framework used to manage parallel solvers, data structures and communication. Features of the code include a modular input file, implementation of high-performance I/O using parallel HDF5, ability to perform multiple realization simulations with multiple processors per realization in a seamless manner, and multiple modes for multiphase flow and multicomponent geochemical transport. Chemical reactions currently implemented in the code include homogeneous aqueous complexing reactions and heterogeneous mineral precipitation/dissolution, ion exchange, surface complexation and a multirate kinetic sorption model. PFLOTRAN has demonstrated petascale performance using 2{sup 17} processor cores with over 2 billion degrees of freedom. Accomplishments achieved to date include applications to the Hanford 300 Area and modeling CO{sub 2} sequestration in deep geologic formations.

LUCKY-TD code for solving the time-dependent transport equation with the use of parallel computations

Energy Technology Data Exchange (ETDEWEB)

Moryakov, A. V., E-mail: sailor@orc.ru [National Research Centre Kurchatov Institute (Russian Federation)

2016-12-15

An algorithm for solving the time-dependent transport equation in the P{sub m}S{sub n} group approximation with the use of parallel computations is presented. The algorithm is implemented in the LUCKY-TD code for supercomputers employing the MPI standard for the data exchange between parallel processes.

Earth and environmental science in the 1980's: Part 1: Environmental data systems, supercomputer facilities and networks

Science.gov (United States)

1986-01-01

Overview descriptions of on-line environmental data systems, supercomputer facilities, and networks are presented. Each description addresses the concepts of content, capability, and user access relevant to the point of view of potential utilization by the Earth and environmental science community. The information on similar systems or facilities is presented in parallel fashion to encourage and facilitate intercomparison. In addition, summary sheets are given for each description, and a summary table precedes each section.

Reactive flow simulations in complex geometries with high-performance supercomputing

International Nuclear Information System (INIS)

Rehm, W.; Gerndt, M.; Jahn, W.; Vogelsang, R.; Binninger, B.; Herrmann, M.; Olivier, H.; Weber, M.

2000-01-01

In this paper, we report on a modern field code cluster consisting of state-of-the-art reactive Navier-Stokes- and reactive Euler solvers that has been developed on vector- and parallel supercomputers at the research center Juelich. This field code cluster is used for hydrogen safety analyses of technical systems, for example, in the field of nuclear reactor safety and conventional hydrogen demonstration plants with fuel cells. Emphasis is put on the assessment of combustion loads, which could result from slow, fast or rapid flames, including transition from deflagration to detonation. As a sample of proof tests, the special tools have been tested for specific tasks, based on the comparison of experimental and numerical results, which are in reasonable agreement. (author)

Parallel/vector algorithms for the spherical SN transport theory method

International Nuclear Information System (INIS)

Haghighat, A.; Mattis, R.E.

1990-01-01

This paper discusses vector and parallel processing of a 1-D curvilinear (i.e. spherical) S N transport theory algorithm on the Cornell National SuperComputer Facility (CNSF) IBM 3090/600E. Two different vector algorithms were developed and parallelized based on angular decomposition. It is shown that significant speedups are attainable. For example, for problems with large granularity, using 4 processors, the parallel/vector algorithm achieves speedups (for wall-clock time) of more than 4.5 relative to the old serial/scalar algorithm. Furthermore, this work has demonstrated the existing potential for the development of faster processing vector and parallel algorithms for multidimensional curvilinear geometries. (author)

Parallelization of a numerical simulation code for isotropic turbulence

International Nuclear Information System (INIS)

Sato, Shigeru; Yokokawa, Mitsuo; Watanabe, Tadashi; Kaburaki, Hideo.

1996-03-01

A parallel pseudospectral code which solves the three-dimensional Navier-Stokes equation by direct numerical simulation is developed and execution time, parallelization efficiency, load balance and scalability are evaluated. A vector parallel supercomputer, Fujitsu VPP500 with up to 16 processors is used for this calculation for Fourier modes up to 256x256x256 using 16 processors. Good scalability for number of processors is achieved when number of Fourier mode is fixed. For small Fourier modes, calculation time of the program is proportional to NlogN which is ideal complexity of calculation for 3D-FFT on vector parallel processors. It is found that the calculation performance decreases as the increase of the Fourier modes. (author)

Applications of supercomputing and the utility industry: Calculation of power transfer capabilities

International Nuclear Information System (INIS)

Jensen, D.D.; Behling, S.R.; Betancourt, R.

1990-01-01

Numerical models and iterative simulation using supercomputers can furnish cost-effective answers to utility industry problems that are all but intractable using conventional computing equipment. An example of the use of supercomputers by the utility industry is the determination of power transfer capability limits for power transmission systems. This work has the goal of markedly reducing the run time of transient stability codes used to determine power distributions following major system disturbances. To date, run times of several hours on a conventional computer have been reduced to several minutes on state-of-the-art supercomputers, with further improvements anticipated to reduce run times to less than a minute. In spite of the potential advantages of supercomputers, few utilities have sufficient need for a dedicated in-house supercomputing capability. This problem is resolved using a supercomputer center serving a geographically distributed user base coupled via high speed communication networks

Supercomputers to transform Science

CERN Multimedia

2006-01-01

"New insights into the structure of space and time, climate modeling, and the design of novel drugs, are but a few of the many research areas that will be transforned by the installation of three supercomputers at the Unversity of Bristol." (1/2 page)

Convex unwraps its first grown-up supercomputer

Energy Technology Data Exchange (ETDEWEB)

Manuel, T.

1988-03-03

Convex Computer Corp.'s new supercomputer family is even more of an industry blockbuster than its first system. At a tenfold jump in performance, it's far from just an incremental upgrade over its first minisupercomputer, the C-1. The heart of the new family, the new C-2 processor, churning at 50 million floating-point operations/s, spawns a group of systems whose performance could pass for some fancy supercomputers-namely those of the Cray Research Inc. family. When added to the C-1, Convex's five new supercomputers create the C series, a six-member product group offering a performance range from 20 to 200 Mflops. They mark an important transition for Convex from a one-product high-tech startup to a multinational company with a wide-ranging product line. It's a tough transition but the Richardson, Texas, company seems to be doing it. The extended product line propels Convex into the upper end of the minisupercomputer class and nudges it into the low end of the big supercomputers. It positions Convex in an uncrowded segment of the market in the $500,000 to $1 million range offering 50 to 200 Mflops of performance. The company is making this move because the minisuper area, which it pioneered, quickly became crowded with new vendors, causing prices and gross margins to drop drastically.

PENTACLE: Parallelized particle-particle particle-tree code for planet formation

Science.gov (United States)

Iwasawa, Masaki; Oshino, Shoichi; Fujii, Michiko S.; Hori, Yasunori

2017-10-01

We have newly developed a parallelized particle-particle particle-tree code for planet formation, PENTACLE, which is a parallelized hybrid N-body integrator executed on a CPU-based (super)computer. PENTACLE uses a fourth-order Hermite algorithm to calculate gravitational interactions between particles within a cut-off radius and a Barnes-Hut tree method for gravity from particles beyond. It also implements an open-source library designed for full automatic parallelization of particle simulations, FDPS (Framework for Developing Particle Simulator), to parallelize a Barnes-Hut tree algorithm for a memory-distributed supercomputer. These allow us to handle 1-10 million particles in a high-resolution N-body simulation on CPU clusters for collisional dynamics, including physical collisions in a planetesimal disc. In this paper, we show the performance and the accuracy of PENTACLE in terms of \\tilde{R}_cut and a time-step Δt. It turns out that the accuracy of a hybrid N-body simulation is controlled through Δ t / \\tilde{R}_cut and Δ t / \\tilde{R}_cut ˜ 0.1 is necessary to simulate accurately the accretion process of a planet for ≥106 yr. For all those interested in large-scale particle simulations, PENTACLE, customized for planet formation, will be freely available from https://github.com/PENTACLE-Team/PENTACLE under the MIT licence.

Parallel science and engineering applications the Charm++ approach

CERN Document Server

Kale, Laxmikant V

2016-01-01

Developed in the context of science and engineering applications, with each abstraction motivated by and further honed by specific application needs, Charm++ is a production-quality system that runs on almost all parallel computers available. Parallel Science and Engineering Applications: The Charm++ Approach surveys a diverse and scalable collection of science and engineering applications, most of which are used regularly on supercomputers by scientists to further their research. After a brief introduction to Charm++, the book presents several parallel CSE codes written in the Charm++ model, along with their underlying scientific and numerical formulations, explaining their parallelization strategies and parallel performance. These chapters demonstrate the versatility of Charm++ and its utility for a wide variety of applications, including molecular dynamics, cosmology, quantum chemistry, fracture simulations, agent-based simulations, and weather modeling. The book is intended for a wide audience of people i...

A supercomputing application for reactors core design and optimization

International Nuclear Information System (INIS)

Hourcade, Edouard; Gaudier, Fabrice; Arnaud, Gilles; Funtowiez, David; Ammar, Karim

2010-01-01

Advanced nuclear reactor designs are often intuition-driven processes where designers first develop or use simplified simulation tools for each physical phenomenon involved. Through the project development, complexity in each discipline increases and implementation of chaining/coupling capabilities adapted to supercomputing optimization process are often postponed to a further step so that task gets increasingly challenging. In the context of renewal in reactor designs, project of first realization are often run in parallel with advanced design although very dependant on final options. As a consequence, the development of tools to globally assess/optimize reactor core features, with the on-going design methods accuracy, is needed. This should be possible within reasonable simulation time and without advanced computer skills needed at project management scale. Also, these tools should be ready to easily cope with modeling progresses in each discipline through project life-time. An early stage development of multi-physics package adapted to supercomputing is presented. The URANIE platform, developed at CEA and based on the Data Analysis Framework ROOT, is very well adapted to this approach. It allows diversified sampling techniques (SRS, LHS, qMC), fitting tools (neuronal networks...) and optimization techniques (genetic algorithm). Also data-base management and visualization are made very easy. In this paper, we'll present the various implementing steps of this core physics tool where neutronics, thermo-hydraulics, and fuel mechanics codes are run simultaneously. A relevant example of optimization of nuclear reactor safety characteristics will be presented. Also, flexibility of URANIE tool will be illustrated with the presentation of several approaches to improve Pareto front quality. (author)

The ETA systems plans for supercomputers

International Nuclear Information System (INIS)

Swanson, C.D.

1987-01-01

The ETA Systems, is a class VII supercomputer featuring multiprocessing, a large hierarchical memory system, high performance input/output, and network support for both batch and interactive processing. Advanced technology used in the ETA 10 includes liquid nitrogen cooled CMOS logic with 20,000 gates per chip, a single printed circuit board for each CPU, and high density static and dynamic MOS memory chips. Software for the ETA 10 includes an underlying kernel that supports multiple user environments, a new ETA FORTRAN compiler with an advanced automatic vectorizer, a multitasking library and debugging tools. Possible developments for future supercomputers from ETA Systems are discussed

Integration of PanDA workload management system with Titan supercomputer at OLCF

Science.gov (United States)

De, K.; Klimentov, A.; Oleynik, D.; Panitkin, S.; Petrosyan, A.; Schovancova, J.; Vaniachine, A.; Wenaus, T.

2015-12-01

The PanDA (Production and Distributed Analysis) workload management system (WMS) was developed to meet the scale and complexity of LHC distributed computing for the ATLAS experiment. While PanDA currently distributes jobs to more than 100,000 cores at well over 100 Grid sites, the future LHC data taking runs will require more resources than Grid computing can possibly provide. To alleviate these challenges, ATLAS is engaged in an ambitious program to expand the current computing model to include additional resources such as the opportunistic use of supercomputers. We will describe a project aimed at integration of PanDA WMS with Titan supercomputer at Oak Ridge Leadership Computing Facility (OLCF). The current approach utilizes a modified PanDA pilot framework for job submission to Titan's batch queues and local data management, with light-weight MPI wrappers to run single threaded workloads in parallel on Titan's multicore worker nodes. It also gives PanDA new capability to collect, in real time, information about unused worker nodes on Titan, which allows precise definition of the size and duration of jobs submitted to Titan according to available free resources. This capability significantly reduces PanDA job wait time while improving Titan's utilization efficiency. This implementation was tested with a variety of Monte-Carlo workloads on Titan and is being tested on several other supercomputing platforms. Notice: This manuscript has been authored, by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.

Streaming Parallel GPU Acceleration of Large-Scale filter-based Spiking Neural Networks

NARCIS (Netherlands)

L.P. Slazynski (Leszek); S.M. Bohte (Sander)

2012-01-01

htmlabstractThe arrival of graphics processing (GPU) cards suitable for massively parallel computing promises a↵ordable large-scale neural network simulation previously only available at supercomputing facil- ities. While the raw numbers suggest that GPUs may outperform CPUs by at least an order of

Automatic discovery of the communication network topology for building a supercomputer model

Science.gov (United States)

Sobolev, Sergey; Stefanov, Konstantin; Voevodin, Vadim

2016-10-01

The Research Computing Center of Lomonosov Moscow State University is developing the Octotron software suite for automatic monitoring and mitigation of emergency situations in supercomputers so as to maximize hardware reliability. The suite is based on a software model of the supercomputer. The model uses a graph to describe the computing system components and their interconnections. One of the most complex components of a supercomputer that needs to be included in the model is its communication network. This work describes the proposed approach for automatically discovering the Ethernet communication network topology in a supercomputer and its description in terms of the Octotron model. This suite automatically detects computing nodes and switches, collects information about them and identifies their interconnections. The application of this approach is demonstrated on the "Lomonosov" and "Lomonosov-2" supercomputers.

PNNL supercomputer to become largest computing resource on the Grid

CERN Multimedia

2002-01-01

Hewlett Packard announced that the US DOE Pacific Northwest National Laboratory will connect a 9.3-teraflop HP supercomputer to the DOE Science Grid. This will be the largest supercomputer attached to a computer grid anywhere in the world (1 page).

Parallel computing of a climate model on the dawn 1000 by domain decomposition method

Science.gov (United States)

Bi, Xunqiang

1997-12-01

In this paper the parallel computing of a grid-point nine-level atmospheric general circulation model on the Dawn 1000 is introduced. The model was developed by the Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS). The Dawn 1000 is a MIMD massive parallel computer made by National Research Center for Intelligent Computer (NCIC), CAS. A two-dimensional domain decomposition method is adopted to perform the parallel computing. The potential ways to increase the speed-up ratio and exploit more resources of future massively parallel supercomputation are also discussed.

SiGN-SSM: open source parallel software for estimating gene networks with state space models.

Science.gov (United States)

Tamada, Yoshinori; Yamaguchi, Rui; Imoto, Seiya; Hirose, Osamu; Yoshida, Ryo; Nagasaki, Masao; Miyano, Satoru

2011-04-15

SiGN-SSM is an open-source gene network estimation software able to run in parallel on PCs and massively parallel supercomputers. The software estimates a state space model (SSM), that is a statistical dynamic model suitable for analyzing short time and/or replicated time series gene expression profiles. SiGN-SSM implements a novel parameter constraint effective to stabilize the estimated models. Also, by using a supercomputer, it is able to determine the gene network structure by a statistical permutation test in a practical time. SiGN-SSM is applicable not only to analyzing temporal regulatory dependencies between genes, but also to extracting the differentially regulated genes from time series expression profiles. SiGN-SSM is distributed under GNU Affero General Public Licence (GNU AGPL) version 3 and can be downloaded at http://sign.hgc.jp/signssm/. The pre-compiled binaries for some architectures are available in addition to the source code. The pre-installed binaries are also available on the Human Genome Center supercomputer system. The online manual and the supplementary information of SiGN-SSM is available on our web site. tamada@ims.u-tokyo.ac.jp.

Implementation, capabilities, and benchmarking of Shift, a massively parallel Monte Carlo radiation transport code

International Nuclear Information System (INIS)

Pandya, Tara M.; Johnson, Seth R.; Evans, Thomas M.; Davidson, Gregory G.; Hamilton, Steven P.; Godfrey, Andrew T.

2015-01-01

This paper discusses the implementation, capabilities, and validation of Shift, a massively parallel Monte Carlo radiation transport package developed and maintained at Oak Ridge National Laboratory. It has been developed to scale well from laptop to small computing clusters to advanced supercomputers. Special features of Shift include hybrid capabilities for variance reduction such as CADIS and FW-CADIS, and advanced parallel decomposition and tally methods optimized for scalability on supercomputing architectures. Shift has been validated and verified against various reactor physics benchmarks and compares well to other state-of-the-art Monte Carlo radiation transport codes such as MCNP5, CE KENO-VI, and OpenMC. Some specific benchmarks used for verification and validation include the CASL VERA criticality test suite and several Westinghouse AP1000 ® problems. These benchmark and scaling studies show promising results

Performance Analysis and Scaling Behavior of the Terrestrial Systems Modeling Platform TerrSysMP in Large-Scale Supercomputing Environments

Science.gov (United States)

Kollet, S. J.; Goergen, K.; Gasper, F.; Shresta, P.; Sulis, M.; Rihani, J.; Simmer, C.; Vereecken, H.

2013-12-01

In studies of the terrestrial hydrologic, energy and biogeochemical cycles, integrated multi-physics simulation platforms take a central role in characterizing non-linear interactions, variances and uncertainties of system states and fluxes in reciprocity with observations. Recently developed integrated simulation platforms attempt to honor the complexity of the terrestrial system across multiple time and space scales from the deeper subsurface including groundwater dynamics into the atmosphere. Technically, this requires the coupling of atmospheric, land surface, and subsurface-surface flow models in supercomputing environments, while ensuring a high-degree of efficiency in the utilization of e.g., standard Linux clusters and massively parallel resources. A systematic performance analysis including profiling and tracing in such an application is crucial in the understanding of the runtime behavior, to identify optimum model settings, and is an efficient way to distinguish potential parallel deficiencies. On sophisticated leadership-class supercomputers, such as the 28-rack 5.9 petaFLOP IBM Blue Gene/Q 'JUQUEEN' of the Jülich Supercomputing Centre (JSC), this is a challenging task, but even more so important, when complex coupled component models are to be analysed. Here we want to present our experience from coupling, application tuning (e.g. 5-times speedup through compiler optimizations), parallel scaling and performance monitoring of the parallel Terrestrial Systems Modeling Platform TerrSysMP. The modeling platform consists of the weather prediction system COSMO of the German Weather Service; the Community Land Model, CLM of NCAR; and the variably saturated surface-subsurface flow code ParFlow. The model system relies on the Multiple Program Multiple Data (MPMD) execution model where the external Ocean-Atmosphere-Sea-Ice-Soil coupler (OASIS3) links the component models. TerrSysMP has been instrumented with the performance analysis tool Scalasca and analyzed

SUPERCOMPUTER SIMULATION OF CRITICAL PHENOMENA IN COMPLEX SOCIAL SYSTEMS

Directory of Open Access Journals (Sweden)

Petrus M.A. Sloot

2014-09-01

Full Text Available The paper describes a problem of computer simulation of critical phenomena in complex social systems on a petascale computing systems in frames of complex networks approach. The three-layer system of nested models of complex networks is proposed including aggregated analytical model to identify critical phenomena, detailed model of individualized network dynamics and model to adjust a topological structure of a complex network. The scalable parallel algorithm covering all layers of complex networks simulation is proposed. Performance of the algorithm is studied on different supercomputing systems. The issues of software and information infrastructure of complex networks simulation are discussed including organization of distributed calculations, crawling the data in social networks and results visualization. The applications of developed methods and technologies are considered including simulation of criminal networks disruption, fast rumors spreading in social networks, evolution of financial networks and epidemics spreading.

Dust modelling and forecasting in the Barcelona Supercomputing Center: Activities and developments

Energy Technology Data Exchange (ETDEWEB)

Perez, C; Baldasano, J M; Jimenez-Guerrero, P; Jorba, O; Haustein, K; Basart, S [Earth Sciences Department. Barcelona Supercomputing Center. Barcelona (Spain); Cuevas, E [Izanaa Atmospheric Research Center. Agencia Estatal de Meteorologia, Tenerife (Spain); Nickovic, S [Atmospheric Research and Environment Branch, World Meteorological Organization, Geneva (Switzerland)], E-mail: carlos.perez@bsc.es

2009-03-01

The Barcelona Supercomputing Center (BSC) is the National Supercomputer Facility in Spain, hosting MareNostrum, one of the most powerful Supercomputers in Europe. The Earth Sciences Department of BSC operates daily regional dust and air quality forecasts and conducts intensive modelling research for short-term operational prediction. This contribution summarizes the latest developments and current activities in the field of sand and dust storm modelling and forecasting.

Dust modelling and forecasting in the Barcelona Supercomputing Center: Activities and developments

International Nuclear Information System (INIS)

Perez, C; Baldasano, J M; Jimenez-Guerrero, P; Jorba, O; Haustein, K; Basart, S; Cuevas, E; Nickovic, S

2009-01-01

The Barcelona Supercomputing Center (BSC) is the National Supercomputer Facility in Spain, hosting MareNostrum, one of the most powerful Supercomputers in Europe. The Earth Sciences Department of BSC operates daily regional dust and air quality forecasts and conducts intensive modelling research for short-term operational prediction. This contribution summarizes the latest developments and current activities in the field of sand and dust storm modelling and forecasting.

Parallelization for X-ray crystal structural analysis program

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Hiroshi [Japan Atomic Energy Research Inst., Tokyo (Japan); Minami, Masayuki; Yamamoto, Akiji

1997-10-01

In this report we study vectorization and parallelization for X-ray crystal structural analysis program. The target machine is NEC SX-4 which is a distributed/shared memory type vector parallel supercomputer. X-ray crystal structural analysis is surveyed, and a new multi-dimensional discrete Fourier transform method is proposed. The new method is designed to have a very long vector length, so that it enables to obtain the 12.0 times higher performance result that the original code. Besides the above-mentioned vectorization, the parallelization by micro-task functions on SX-4 reaches 13.7 times acceleration in the part of multi-dimensional discrete Fourier transform with 14 CPUs, and 3.0 times acceleration in the whole program. Totally 35.9 times acceleration to the original 1CPU scalar version is achieved with vectorization and parallelization on SX-4. (author)

Development of a parallelization method for KENO V.a

International Nuclear Information System (INIS)

Basoglu, B.; Bentley, C.; Dunn, M.

1995-01-01

The KENO V.a codes is a widely used Monte carlo codes that is part of the SCALE modular codes system for performing standardized computer analysis of nuclear systems for licensing evaluation. In the past few years, attempts have been made to speed up KENO V.a using new generation computers. In this paper we report on the initial development of a parallel version of KENO V.a for the Kendall Square Research supercomputer (KSRI) at ORNL. Investigations thus far have shown that the parallel code provides accurate results with significantly reduced computation times relative to the conventional KENO V.a code

Parallelism in computations in quantum and statistical mechanics

International Nuclear Information System (INIS)

Clementi, E.; Corongiu, G.; Detrich, J.H.

1985-01-01

Often very fundamental biochemical and biophysical problems defy simulations because of limitations in today's computers. We present and discuss a distributed system composed of two IBM 4341 s and/or an IBM 4381 as front-end processors and ten FPS-164 attached array processors. This parallel system - called LCAP - has presently a peak performance of about 110 Mflops; extensions to higher performance are discussed. Presently, the system applications use a modified version of VM/SP as the operating system: description of the modifications is given. Three applications programs have been migrated from sequential to parallel: a molecular quantum mechanical, a Metropolis-Monte Carlo and a molecular dynamics program. Descriptions of the parallel codes are briefly outlined. Use of these parallel codes has already opened up new capabilities for our research. The very positive performance comparisons with today's supercomputers allow us to conclude that parallel computers and programming, of the type we have considered, represent a pragmatic answer to many computationally intensive problems. (orig.)

ATLAS FTK a - very complex - custom parallel supercomputer

CERN Document Server

Kimura, Naoki; The ATLAS collaboration

2016-01-01

In the ever increasing pile-up LHC environment advanced techniques of analysing the data are implemented in order to increase the rate of relevant physics processes with respect to background processes. The Fast TracKer (FTK) is a track finding implementation at hardware level that is designed to deliver full-scan tracks with $p_{T}$ above 1GeV to the ATLAS trigger system for every L1 accept (at a maximum rate of 100kHz). In order to achieve this performance a highly parallel system was designed and now it is under installation in ATLAS. In the beginning of 2016 it will provide tracks for the trigger system in a region covering the central part of the ATLAS detector, and during the year it's coverage will be extended to the full detector coverage. The system relies on matching hits coming from the silicon tracking detectors against 1 billion patterns stored in specially designed ASICS chips (Associative memory - AM06). In a first stage coarse resolution hits are matched against the patterns and the accepted h...

Impact analysis on a massively parallel computer

International Nuclear Information System (INIS)

Zacharia, T.; Aramayo, G.A.

1994-01-01

Advanced mathematical techniques and computer simulation play a major role in evaluating and enhancing the design of beverage cans, industrial, and transportation containers for improved performance. Numerical models are used to evaluate the impact requirements of containers used by the Department of Energy (DOE) for transporting radioactive materials. Many of these models are highly compute-intensive. An analysis may require several hours of computational time on current supercomputers despite the simplicity of the models being studied. As computer simulations and materials databases grow in complexity, massively parallel computers have become important tools. Massively parallel computational research at the Oak Ridge National Laboratory (ORNL) and its application to the impact analysis of shipping containers is briefly described in this paper

NASA Advanced Supercomputing Facility Expansion

Science.gov (United States)

Thigpen, William W.

2017-01-01

The NASA Advanced Supercomputing (NAS) Division enables advances in high-end computing technologies and in modeling and simulation methods to tackle some of the toughest science and engineering challenges facing NASA today. The name "NAS" has long been associated with leadership and innovation throughout the high-end computing (HEC) community. We play a significant role in shaping HEC standards and paradigms, and provide leadership in the areas of large-scale InfiniBand fabrics, Lustre open-source filesystems, and hyperwall technologies. We provide an integrated high-end computing environment to accelerate NASA missions and make revolutionary advances in science. Pleiades, a petaflop-scale supercomputer, is used by scientists throughout the U.S. to support NASA missions, and is ranked among the most powerful systems in the world. One of our key focus areas is in modeling and simulation to support NASA's real-world engineering applications and make fundamental advances in modeling and simulation methods.

ATLAS Software Installation on Supercomputers

CERN Document Server

Undrus, Alexander; The ATLAS collaboration

2018-01-01

PowerPC and high performance computers (HPC) are important resources for computing in the ATLAS experiment. The future LHC data processing will require more resources than Grid computing, currently using approximately 100,000 cores at well over 100 sites, can provide. Supercomputers are extremely powerful as they use resources of hundreds of thousands CPUs joined together. However their architectures have different instruction sets. ATLAS binary software distributions for x86 chipsets do not fit these architectures, as emulation of these chipsets results in huge performance loss. This presentation describes the methodology of ATLAS software installation from source code on supercomputers. The installation procedure includes downloading the ATLAS code base as well as the source of about 50 external packages, such as ROOT and Geant4, followed by compilation, and rigorous unit and integration testing. The presentation reports the application of this procedure at Titan HPC and Summit PowerPC at Oak Ridge Computin...

Highly parallel machines and future of scientific computing

International Nuclear Information System (INIS)

Singh, G.S.

1992-01-01

Computing requirement of large scale scientific computing has always been ahead of what state of the art hardware could supply in the form of supercomputers of the day. And for any single processor system the limit to increase in the computing power was realized a few years back itself. Now with the advent of parallel computing systems the availability of machines with the required computing power seems a reality. In this paper the author tries to visualize the future large scale scientific computing in the penultimate decade of the present century. The author summarized trends in parallel computers and emphasize the need for a better programming environment and software tools for optimal performance. The author concludes this paper with critique on parallel architectures, software tools and algorithms. (author). 10 refs., 2 tabs

Supercomputers and quantum field theory

International Nuclear Information System (INIS)

Creutz, M.

1985-01-01

A review is given of why recent simulations of lattice gauge theories have resulted in substantial demands from particle theorists for supercomputer time. These calculations have yielded first principle results on non-perturbative aspects of the strong interactions. An algorithm for simulating dynamical quark fields is discussed. 14 refs

Communication Characterization and Optimization of Applications Using Topology-Aware Task Mapping on Large Supercomputers

Energy Technology Data Exchange (ETDEWEB)

Sreepathi, Sarat [ORNL; D' Azevedo, Eduardo [ORNL; Philip, Bobby [ORNL; Worley, Patrick H [ORNL

2016-01-01

On large supercomputers, the job scheduling systems may assign a non-contiguous node allocation for user applications depending on available resources. With parallel applications using MPI (Message Passing Interface), the default process ordering does not take into account the actual physical node layout available to the application. This contributes to non-locality in terms of physical network topology and impacts communication performance of the application. In order to mitigate such performance penalties, this work describes techniques to identify suitable task mapping that takes the layout of the allocated nodes as well as the application's communication behavior into account. During the first phase of this research, we instrumented and collected performance data to characterize communication behavior of critical US DOE (United States - Department of Energy) applications using an augmented version of the mpiP tool. Subsequently, we developed several reordering methods (spectral bisection, neighbor join tree etc.) to combine node layout and application communication data for optimized task placement. We developed a tool called mpiAproxy to facilitate detailed evaluation of the various reordering algorithms without requiring full application executions. This work presents a comprehensive performance evaluation (14,000 experiments) of the various task mapping techniques in lowering communication costs on Titan, the leadership class supercomputer at Oak Ridge National Laboratory.

Computational fluid dynamics: complex flows requiring supercomputers. January 1975-July 1988 (Citations from the INSPEC: Information Services for the Physics and Engineering Communities data base). Report for January 1975-July 1988

International Nuclear Information System (INIS)

1988-08-01

This bibliography contains citations concerning computational fluid dynamics (CFD), a new method in computational science to perform complex flow simulations in three dimensions. Applications include aerodynamic design and analysis for aircraft, rockets, and missiles, and automobiles; heat-transfer studies; and combustion processes. Included are references to supercomputers, array processors, and parallel processors where needed for complete, integrated design. Also included are software packages and grid-generation techniques required to apply CFD numerical solutions. Numerical methods for fluid dynamics, not requiring supercomputers, are found in a separate published search. (Contains 83 citations fully indexed and including a title list.)

High temporal resolution mapping of seismic noise sources using heterogeneous supercomputers

Science.gov (United States)

Gokhberg, Alexey; Ermert, Laura; Paitz, Patrick; Fichtner, Andreas

2017-04-01

Time- and space-dependent distribution of seismic noise sources is becoming a key ingredient of modern real-time monitoring of various geo-systems. Significant interest in seismic noise source maps with high temporal resolution (days) is expected to come from a number of domains, including natural resources exploration, analysis of active earthquake fault zones and volcanoes, as well as geothermal and hydrocarbon reservoir monitoring. Currently, knowledge of noise sources is insufficient for high-resolution subsurface monitoring applications. Near-real-time seismic data, as well as advanced imaging methods to constrain seismic noise sources have recently become available. These methods are based on the massive cross-correlation of seismic noise records from all available seismic stations in the region of interest and are therefore very computationally intensive. Heterogeneous massively parallel supercomputing systems introduced in the recent years combine conventional multi-core CPU with GPU accelerators and provide an opportunity for manifold increase and computing performance. Therefore, these systems represent an efficient platform for implementation of a noise source mapping solution. We present the first results of an ongoing research project conducted in collaboration with the Swiss National Supercomputing Centre (CSCS). The project aims at building a service that provides seismic noise source maps for Central Europe with high temporal resolution (days to few weeks depending on frequency and data availability). The service is hosted on the CSCS computing infrastructure; all computationally intensive processing is performed on the massively parallel heterogeneous supercomputer "Piz Daint". The solution architecture is based on the Application-as-a-Service concept in order to provide the interested external researchers the regular access to the noise source maps. The solution architecture includes the following sub-systems: (1) data acquisition responsible for

Parallel implementation of the PHOENIX generalized stellar atmosphere program. II. Wavelength parallelization

International Nuclear Information System (INIS)

Baron, E.; Hauschildt, Peter H.

1998-01-01

We describe an important addition to the parallel implementation of our generalized nonlocal thermodynamic equilibrium (NLTE) stellar atmosphere and radiative transfer computer program PHOENIX. In a previous paper in this series we described data and task parallel algorithms we have developed for radiative transfer, spectral line opacity, and NLTE opacity and rate calculations. These algorithms divided the work spatially or by spectral lines, that is, distributing the radial zones, individual spectral lines, or characteristic rays among different processors and employ, in addition, task parallelism for logically independent functions (such as atomic and molecular line opacities). For finite, monotonic velocity fields, the radiative transfer equation is an initial value problem in wavelength, and hence each wavelength point depends upon the previous one. However, for sophisticated NLTE models of both static and moving atmospheres needed to accurately describe, e.g., novae and supernovae, the number of wavelength points is very large (200,000 - 300,000) and hence parallelization over wavelength can lead both to considerable speedup in calculation time and the ability to make use of the aggregate memory available on massively parallel supercomputers. Here, we describe an implementation of a pipelined design for the wavelength parallelization of PHOENIX, where the necessary data from the processor working on a previous wavelength point is sent to the processor working on the succeeding wavelength point as soon as it is known. Our implementation uses a MIMD design based on a relatively small number of standard message passing interface (MPI) library calls and is fully portable between serial and parallel computers. copyright 1998 The American Astronomical Society

DVS-SOFTWARE: An Effective Tool for Applying Highly Parallelized Hardware To Computational Geophysics

Science.gov (United States)

Herrera, I.; Herrera, G. S.

2015-12-01

Most geophysical systems are macroscopic physical systems. The behavior prediction of such systems is carried out by means of computational models whose basic models are partial differential equations (PDEs) [1]. Due to the enormous size of the discretized version of such PDEs it is necessary to apply highly parallelized super-computers. For them, at present, the most efficient software is based on non-overlapping domain decomposition methods (DDM). However, a limiting feature of the present state-of-the-art techniques is due to the kind of discretizations used in them. Recently, I. Herrera and co-workers using 'non-overlapping discretizations' have produced the DVS-Software which overcomes this limitation [2]. The DVS-software can be applied to a great variety of geophysical problems and achieves very high parallel efficiencies (90%, or so [3]). It is therefore very suitable for effectively applying the most advanced parallel supercomputers available at present. In a parallel talk, in this AGU Fall Meeting, Graciela Herrera Z. will present how this software is being applied to advance MOD-FLOW. Key Words: Parallel Software for Geophysics, High Performance Computing, HPC, Parallel Computing, Domain Decomposition Methods (DDM)REFERENCES [1]. Herrera Ismael and George F. Pinder, Mathematical Modelling in Science and Engineering: An axiomatic approach", John Wiley, 243p., 2012. [2]. Herrera, I., de la Cruz L.M. and Rosas-Medina A. "Non Overlapping Discretization Methods for Partial, Differential Equations". NUMER METH PART D E, 30: 1427-1454, 2014, DOI 10.1002/num 21852. (Open source) [3]. Herrera, I., & Contreras Iván "An Innovative Tool for Effectively Applying Highly Parallelized Software To Problems of Elasticity". Geofísica Internacional, 2015 (In press)

Parallel plasma fluid turbulence calculations

International Nuclear Information System (INIS)

Leboeuf, J.N.; Carreras, B.A.; Charlton, L.A.; Drake, J.B.; Lynch, V.E.; Newman, D.E.; Sidikman, K.L.; Spong, D.A.

1994-01-01

The study of plasma turbulence and transport is a complex problem of critical importance for fusion-relevant plasmas. To this day, the fluid treatment of plasma dynamics is the best approach to realistic physics at the high resolution required for certain experimentally relevant calculations. Core and edge turbulence in a magnetic fusion device have been modeled using state-of-the-art, nonlinear, three-dimensional, initial-value fluid and gyrofluid codes. Parallel implementation of these models on diverse platforms--vector parallel (National Energy Research Supercomputer Center's CRAY Y-MP C90), massively parallel (Intel Paragon XP/S 35), and serial parallel (clusters of high-performance workstations using the Parallel Virtual Machine protocol)--offers a variety of paths to high resolution and significant improvements in real-time efficiency, each with its own advantages. The largest and most efficient calculations have been performed at the 200 Mword memory limit on the C90 in dedicated mode, where an overlap of 12 to 13 out of a maximum of 16 processors has been achieved with a gyrofluid model of core fluctuations. The richness of the physics captured by these calculations is commensurate with the increased resolution and efficiency and is limited only by the ingenuity brought to the analysis of the massive amounts of data generated

Compiler and Runtime Support for Programming in Adaptive Parallel Environments

Science.gov (United States)

1998-10-15

noother job is waiting for resources, and use a smaller number of processors when other jobs needresources. Setia et al. [15, 20] have shown that such...15] Vijay K. Naik, Sanjeev Setia , and Mark Squillante. Performance analysis of job scheduling policiesin parallel supercomputing environments. In...on networks ofheterogeneous workstations. Technical Report CSE-94-012, Oregon Graduate Institute of Scienceand Technology, 1994.[20] Sanjeev Setia

Alleviating Search Uncertainty through Concept Associations: Automatic Indexing, Co-Occurrence Analysis, and Parallel Computing.

Science.gov (United States)

Chen, Hsinchun; Martinez, Joanne; Kirchhoff, Amy; Ng, Tobun D.; Schatz, Bruce R.

1998-01-01

Grounded on object filtering, automatic indexing, and co-occurrence analysis, an experiment was performed using a parallel supercomputer to analyze over 400,000 abstracts in an INSPEC computer engineering collection. A user evaluation revealed that system-generated thesauri were better than the human-generated INSPEC subject thesaurus in concept…

Vectorization and parallelization of a production reactor assembly code

International Nuclear Information System (INIS)

Vujic, J.L.; Martin, W.R.; Michigan Univ., Ann Arbor, MI

1991-01-01

In order to use efficiently the new features of supercomputers, production codes, usually written 10 -20 years ago, must be tailored for modern computer architectures. We have chosen to optimize the CPM-2 code, a production reactor assembly code based on the collision probability transport method. Substantial speedup in the execution times was obtained with the parallel/vector version of the CPM-2 code. In addition, we have developed a new transfer probability method, which removes some of the modelling limitations of the collision probability method encoded in the CPM-2 code, and can fully utilize the parallel/vector architecture of a multiprocessor IBM 3090. (author)

Vectorization and parallelization of a production reactor assembly code

International Nuclear Information System (INIS)

Vujic, J.L.; Martin, W.R.

1991-01-01

In order to efficiently use new features of supercomputers, production codes, usually written 10 - 20 years ago, must be tailored for modern computer architectures. We have chosen to optimize the CPM-2 code, a production reactor assembly code based on the collision probability transport method. Substantial speedups in the execution times were obtained with the parallel/vector version of the CPM-2 code. In addition, we have developed a new transfer probability method, which removes some of the modelling limitations of the collision probability method encoded in the CPM-2 code, and can fully utilize parallel/vector architecture of a multiprocessor IBM 3090. (author)

A parallel finite-difference method for computational aerodynamics

International Nuclear Information System (INIS)

Swisshelm, J.M.

1989-01-01

A finite-difference scheme for solving complex three-dimensional aerodynamic flow on parallel-processing supercomputers is presented. The method consists of a basic flow solver with multigrid convergence acceleration, embedded grid refinements, and a zonal equation scheme. Multitasking and vectorization have been incorporated into the algorithm. Results obtained include multiprocessed flow simulations from the Cray X-MP and Cray-2. Speedups as high as 3.3 for the two-dimensional case and 3.5 for segments of the three-dimensional case have been achieved on the Cray-2. The entire solver attained a factor of 2.7 improvement over its unitasked version on the Cray-2. The performance of the parallel algorithm on each machine is analyzed. 14 refs

Benchmarking Further Single Board Computers for Building a Mini Supercomputer for Simulation of Telecommunication Systems

Directory of Open Access Journals (Sweden)

Gábor Lencse

2016-01-01

Full Text Available Parallel Discrete Event Simulation (PDES with the conservative synchronization method can be efficiently used for the performance analysis of telecommunication systems because of their good lookahead properties. For PDES, a cost effective execution platform may be built by using single board computers (SBCs, which offer relatively high computation capacity compared to their price or power consumption and especially to the space they take up. A benchmarking method is proposed and its operation is demonstrated by benchmarking ten different SBCs, namely Banana Pi, Beaglebone Black, Cubieboard2, Odroid-C1+, Odroid-U3+, Odroid-XU3 Lite, Orange Pi Plus, Radxa Rock Lite, Raspberry Pi Model B+, and Raspberry Pi 2 Model B+. Their benchmarking results are compared to find out which one should be used for building a mini supercomputer for parallel discrete-event simulation of telecommunication systems. The SBCs are also used to build a heterogeneous cluster and the performance of the cluster is tested, too.

Progress on H5Part: A Portable High Performance Parallel Data Interface for Electromagnetics Simulations

International Nuclear Information System (INIS)

Adelmann, Andreas; Gsell, Achim; Oswald, Benedikt; Schietinger, Thomas; Bethel, Wes; Shalf, John; Siegerist, Cristina; Stockinger, Kurt

2007-01-01

Significant problems facing all experimental and computational sciences arise from growing data size and complexity. Common to all these problems is the need to perform efficient data I/O on diverse computer architectures. In our scientific application, the largest parallel particle simulations generate vast quantities of six-dimensional data. Such a simulation run produces data for an aggregate data size up to several TB per run. Motivated by the need to address data I/O and access challenges, we have implemented H5Part, an open source data I/O API that simplifies the use of the Hierarchical Data Format v5 library (HDF5). HDF5 is an industry standard for high performance, cross-platform data storage and retrieval that runs on all contemporary architectures from large parallel supercomputers to laptops. H5Part, which is oriented to the needs of the particle physics and cosmology communities, provides support for parallel storage and retrieval of particles, structured and in the future unstructured meshes. In this paper, we describe recent work focusing on I/O support for particles and structured meshes and provide data showing performance on modern supercomputer architectures like the IBM POWER 5

Mistral Supercomputer Job History Analysis

OpenAIRE

Zasadziński, Michał; Muntés-Mulero, Victor; Solé, Marc; Ludwig, Thomas

2018-01-01

In this technical report, we show insights and results of operational data analysis from petascale supercomputer Mistral, which is ranked as 42nd most powerful in the world as of January 2018. Data sources include hardware monitoring data, job scheduler history, topology, and hardware information. We explore job state sequences, spatial distribution, and electric power patterns.

Interactive real-time nuclear plant simulations on a UNIX based supercomputer

International Nuclear Information System (INIS)

Behling, S.R.

1990-01-01

Interactive real-time nuclear plant simulations are critically important to train nuclear power plant engineers and operators. In addition, real-time simulations can be used to test the validity and timing of plant technical specifications and operational procedures. To accurately and confidently simulate a nuclear power plant transient in real-time, sufficient computer resources must be available. Since some important transients cannot be simulated using preprogrammed responses or non-physical models, commonly used simulation techniques may not be adequate. However, the power of a supercomputer allows one to accurately calculate the behavior of nuclear power plants even during very complex transients. Many of these transients can be calculated in real-time or quicker on the fastest supercomputers. The concept of running interactive real-time nuclear power plant transients on a supercomputer has been tested. This paper describes the architecture of the simulation program, the techniques used to establish real-time synchronization, and other issues related to the use of supercomputers in a new and potentially very important area. (author)

A universe model confronted to observations

International Nuclear Information System (INIS)

Souriau, J.M.

1982-09-01

Present work is a detailed study of a Universe model elaborated in several steps, and some of its consequences. Absence zone in quasar spatial distribution is first described; demonstration is made it is sufficient to determine a cosmological model. Each following paragraph is concerned with a type of observation, which is confronted with the model. Universe age and density, redshift-luminosity relation for galaxies and quasars, diameter-redshift relation for radiosources, radiation isotropy at 3 0 K, matter-antimatter contact zone physics. An eventual stratification of universe parallel to this zone is more peculiarly studied; absorption lines in quasar spectra are in way interpreted, just as local super-cluster and local group of galaxies, galaxy HI region orientation, and at last neighbouring galaxy kinematics [fr

Flux-Level Transit Injection Experiments with NASA Pleiades Supercomputer

Science.gov (United States)

Li, Jie; Burke, Christopher J.; Catanzarite, Joseph; Seader, Shawn; Haas, Michael R.; Batalha, Natalie; Henze, Christopher; Christiansen, Jessie; Kepler Project, NASA Advanced Supercomputing Division

2016-06-01

Flux-Level Transit Injection (FLTI) experiments are executed with NASA's Pleiades supercomputer for the Kepler Mission. The latest release (9.3, January 2016) of the Kepler Science Operations Center Pipeline is used in the FLTI experiments. Their purpose is to validate the Analytic Completeness Model (ACM), which can be computed for all Kepler target stars, thereby enabling exoplanet occurrence rate studies. Pleiades, a facility of NASA's Advanced Supercomputing Division, is one of the world's most powerful supercomputers and represents NASA's state-of-the-art technology. We discuss the details of implementing the FLTI experiments on the Pleiades supercomputer. For example, taking into account that ~16 injections are generated by one core of the Pleiades processors in an hour, the “shallow” FLTI experiment, in which ~2000 injections are required per target star, can be done for 16% of all Kepler target stars in about 200 hours. Stripping down the transit search to bare bones, i.e. only searching adjacent high/low periods at high/low pulse durations, makes the computationally intensive FLTI experiments affordable. The design of the FLTI experiments and the analysis of the resulting data are presented in “Validating an Analytic Completeness Model for Kepler Target Stars Based on Flux-level Transit Injection Experiments” by Catanzarite et al. (#2494058).Kepler was selected as the 10th mission of the Discovery Program. Funding for the Kepler Mission has been provided by the NASA Science Mission Directorate.

Who confronts prejudice?: the role of implicit theories in the motivation to confront prejudice.

Science.gov (United States)

Rattan, Aneeta; Dweck, Carol S

2010-07-01

Despite the possible costs, confronting prejudice can have important benefits, ranging from the well-being of the target of prejudice to social change. What, then, motivates targets of prejudice to confront people who express explicit bias? In three studies, we tested the hypothesis that targets who hold an incremental theory of personality (i.e., the belief that people can change) are more likely to confront prejudice than targets who hold an entity theory of personality (i.e., the belief that people have fixed traits). In Study 1, targets' beliefs about the malleability of personality predicted whether they spontaneously confronted an individual who expressed bias. In Study 2, targets who held more of an incremental theory reported that they would be more likely to confront prejudice and less likely to withdraw from future interactions with an individual who expressed prejudice. In Study 3, we manipulated implicit theories and replicated these findings. By highlighting the central role that implicit theories of personality play in targets' motivation to confront prejudice, this research has important implications for intergroup relations and social change.

Storage-Intensive Supercomputing Benchmark Study

Energy Technology Data Exchange (ETDEWEB)

Cohen, J; Dossa, D; Gokhale, M; Hysom, D; May, J; Pearce, R; Yoo, A

2007-10-30

Critical data science applications requiring frequent access to storage perform poorly on today's computing architectures. This project addresses efficient computation of data-intensive problems in national security and basic science by exploring, advancing, and applying a new form of computing called storage-intensive supercomputing (SISC). Our goal is to enable applications that simply cannot run on current systems, and, for a broad range of data-intensive problems, to deliver an order of magnitude improvement in price/performance over today's data-intensive architectures. This technical report documents much of the work done under LDRD 07-ERD-063 Storage Intensive Supercomputing during the period 05/07-09/07. The following chapters describe: (1) a new file I/O monitoring tool iotrace developed to capture the dynamic I/O profiles of Linux processes; (2) an out-of-core graph benchmark for level-set expansion of scale-free graphs; (3) an entity extraction benchmark consisting of a pipeline of eight components; and (4) an image resampling benchmark drawn from the SWarp program in the LSST data processing pipeline. The performance of the graph and entity extraction benchmarks was measured in three different scenarios: data sets residing on the NFS file server and accessed over the network; data sets stored on local disk; and data sets stored on the Fusion I/O parallel NAND Flash array. The image resampling benchmark compared performance of software-only to GPU-accelerated. In addition to the work reported here, an additional text processing application was developed that used an FPGA to accelerate n-gram profiling for language classification. The n-gram application will be presented at SC07 at the High Performance Reconfigurable Computing Technologies and Applications Workshop. The graph and entity extraction benchmarks were run on a Supermicro server housing the NAND Flash 40GB parallel disk array, the Fusion-io. The Fusion system specs are as follows

Extracting the Textual and Temporal Structure of Supercomputing Logs

Energy Technology Data Exchange (ETDEWEB)

Jain, S; Singh, I; Chandra, A; Zhang, Z; Bronevetsky, G

2009-05-26

Supercomputers are prone to frequent faults that adversely affect their performance, reliability and functionality. System logs collected on these systems are a valuable resource of information about their operational status and health. However, their massive size, complexity, and lack of standard format makes it difficult to automatically extract information that can be used to improve system management. In this work we propose a novel method to succinctly represent the contents of supercomputing logs, by using textual clustering to automatically find the syntactic structures of log messages. This information is used to automatically classify messages into semantic groups via an online clustering algorithm. Further, we describe a methodology for using the temporal proximity between groups of log messages to identify correlated events in the system. We apply our proposed methods to two large, publicly available supercomputing logs and show that our technique features nearly perfect accuracy for online log-classification and extracts meaningful structural and temporal message patterns that can be used to improve the accuracy of other log analysis techniques.

GROMACS: High performance molecular simulations through multi-level parallelism from laptops to supercomputers

Directory of Open Access Journals (Sweden)

Mark James Abraham

2015-09-01

Full Text Available GROMACS is one of the most widely used open-source and free software codes in chemistry, used primarily for dynamical simulations of biomolecules. It provides a rich set of calculation types, preparation and analysis tools. Several advanced techniques for free-energy calculations are supported. In version 5, it reaches new performance heights, through several new and enhanced parallelization algorithms. These work on every level; SIMD registers inside cores, multithreading, heterogeneous CPU–GPU acceleration, state-of-the-art 3D domain decomposition, and ensemble-level parallelization through built-in replica exchange and the separate Copernicus framework. The latest best-in-class compressed trajectory storage format is supported.

Introduction to Reconfigurable Supercomputing

CERN Document Server

Lanzagorta, Marco; Rosenberg, Robert

2010-01-01

This book covers technologies, applications, tools, languages, procedures, advantages, and disadvantages of reconfigurable supercomputing using Field Programmable Gate Arrays (FPGAs). The target audience is the community of users of High Performance Computers (HPe who may benefit from porting their applications into a reconfigurable environment. As such, this book is intended to guide the HPC user through the many algorithmic considerations, hardware alternatives, usability issues, programming languages, and design tools that need to be understood before embarking on the creation of reconfigur

Sieving for pseudosquares and pseudocubes in parallel using doubly-focused enumeration and wheel datastructures

OpenAIRE

Sorenson, Jonathan P.

2010-01-01

We extend the known tables of pseudosquares and pseudocubes, discuss the implications of these new data on the conjectured distribution of pseudosquares and pseudocubes, and present the details of the algorithm used to do this work. Our algorithm is based on the space-saving wheel data structure combined with doubly-focused enumeration, run in parallel on a cluster supercomputer.

SUPERCOMPUTERS FOR AIDING ECONOMIC PROCESSES WITH REFERENCE TO THE FINANCIAL SECTOR

Directory of Open Access Journals (Sweden)

Jerzy Balicki

2014-12-01

Full Text Available The article discusses the use of supercomputers to support business processes with particular emphasis on the financial sector. A reference was made to the selected projects that support economic development. In particular, we propose the use of supercomputers to perform artificial intel-ligence methods in banking. The proposed methods combined with modern technology enables a significant increase in the competitiveness of enterprises and banks by adding new functionality.

Three-dimensional kinetic simulations of whistler turbulence in solar wind on parallel supercomputers

Science.gov (United States)

Chang, Ouliang

The objective of this dissertation is to study the physics of whistler turbulence evolution and its role in energy transport and dissipation in the solar wind plasmas through computational and theoretical investigations. This dissertation presents the first fully three-dimensional (3D) particle-in-cell (PIC) simulations of whistler turbulence forward cascade in a homogeneous, collisionless plasma with a uniform background magnetic field B o, and the first 3D PIC simulation of whistler turbulence with both forward and inverse cascades. Such computationally demanding research is made possible through the use of massively parallel, high performance electromagnetic PIC simulations on state-of-the-art supercomputers. Simulations are carried out to study characteristic properties of whistler turbulence under variable solar wind fluctuation amplitude (epsilon e) and electron beta (betae), relative contributions to energy dissipation and electron heating in whistler turbulence from the quasilinear scenario and the intermittency scenario, and whistler turbulence preferential cascading direction and wavevector anisotropy. The 3D simulations of whistler turbulence exhibit a forward cascade of fluctuations into broadband, anisotropic, turbulent spectrum at shorter wavelengths with wavevectors preferentially quasi-perpendicular to B o. The overall electron heating yields T ∥ > T⊥ for all epsilone and betae values, indicating the primary linear wave-particle interaction is Landau damping. But linear wave-particle interactions play a minor role in shaping the wavevector spectrum, whereas nonlinear wave-wave interactions are overall stronger and faster processes, and ultimately determine the wavevector anisotropy. Simulated magnetic energy spectra as function of wavenumber show a spectral break to steeper slopes, which scales as k⊥lambda e ≃ 1 independent of betae values, where lambdae is electron inertial length, qualitatively similar to solar wind observations. Specific

Games Based Study of Nonblind Confrontation

Directory of Open Access Journals (Sweden)

Yixian Yang

2017-01-01

Full Text Available Security confrontation is the second cornerstone of the General Theory of Security. And it can be divided into two categories: blind confrontation and nonblind confrontation between attackers and defenders. In this paper, we study the nonblind confrontation by some well-known games. We show the probability of winning and losing between the attackers and defenders from the perspective of channel capacity. We establish channel models and find that the attacker or the defender wining one time is equivalent to one bit transmitted successfully in the channel. This paper also gives unified solutions for all the nonblind confrontations.

BCYCLIC: A parallel block tridiagonal matrix cyclic solver

Science.gov (United States)

Hirshman, S. P.; Perumalla, K. S.; Lynch, V. E.; Sanchez, R.

2010-09-01

A block tridiagonal matrix is factored with minimal fill-in using a cyclic reduction algorithm that is easily parallelized. Storage of the factored blocks allows the application of the inverse to multiple right-hand sides which may not be known at factorization time. Scalability with the number of block rows is achieved with cyclic reduction, while scalability with the block size is achieved using multithreaded routines (OpenMP, GotoBLAS) for block matrix manipulation. This dual scalability is a noteworthy feature of this new solver, as well as its ability to efficiently handle arbitrary (non-powers-of-2) block row and processor numbers. Comparison with a state-of-the art parallel sparse solver is presented. It is expected that this new solver will allow many physical applications to optimally use the parallel resources on current supercomputers. Example usage of the solver in magneto-hydrodynamic (MHD), three-dimensional equilibrium solvers for high-temperature fusion plasmas is cited.

A tool for simulating parallel branch-and-bound methods

Science.gov (United States)

Golubeva, Yana; Orlov, Yury; Posypkin, Mikhail

2016-01-01

The Branch-and-Bound method is known as one of the most powerful but very resource consuming global optimization methods. Parallel and distributed computing can efficiently cope with this issue. The major difficulty in parallel B&B method is the need for dynamic load redistribution. Therefore design and study of load balancing algorithms is a separate and very important research topic. This paper presents a tool for simulating parallel Branchand-Bound method. The simulator allows one to run load balancing algorithms with various numbers of processors, sizes of the search tree, the characteristics of the supercomputer's interconnect thereby fostering deep study of load distribution strategies. The process of resolution of the optimization problem by B&B method is replaced by a stochastic branching process. Data exchanges are modeled using the concept of logical time. The user friendly graphical interface to the simulator provides efficient visualization and convenient performance analysis.

Unique Methodologies for Nano/Micro Manufacturing Job Training Via Desktop Supercomputer Modeling and Simulation

Energy Technology Data Exchange (ETDEWEB)

Kimball, Clyde [Northern Illinois Univ., DeKalb, IL (United States); Karonis, Nicholas [Northern Illinois Univ., DeKalb, IL (United States); Lurio, Laurence [Northern Illinois Univ., DeKalb, IL (United States); Piot, Philippe [Northern Illinois Univ., DeKalb, IL (United States); Xiao, Zhili [Northern Illinois Univ., DeKalb, IL (United States); Glatz, Andreas [Northern Illinois Univ., DeKalb, IL (United States); Pohlman, Nicholas [Northern Illinois Univ., DeKalb, IL (United States); Hou, Minmei [Northern Illinois Univ., DeKalb, IL (United States); Demir, Veysel [Northern Illinois Univ., DeKalb, IL (United States); Song, Jie [Northern Illinois Univ., DeKalb, IL (United States); Duffin, Kirk [Northern Illinois Univ., DeKalb, IL (United States); Johns, Mitrick [Northern Illinois Univ., DeKalb, IL (United States); Sims, Thomas [Northern Illinois Univ., DeKalb, IL (United States); Yin, Yanbin [Northern Illinois Univ., DeKalb, IL (United States)

2012-11-21

This project establishes an initiative in high speed (Teraflop)/large-memory desktop supercomputing for modeling and simulation of dynamic processes important for energy and industrial applications. It provides a training ground for employment of current students in an emerging field with skills necessary to access the large supercomputing systems now present at DOE laboratories. It also provides a foundation for NIU faculty to quantum leap beyond their current small cluster facilities. The funding extends faculty and student capability to a new level of analytic skills with concomitant publication avenues. The components of the Hewlett Packard computer obtained by the DOE funds create a hybrid combination of a Graphics Processing System (12 GPU/Teraflops) and a Beowulf CPU system (144 CPU), the first expandable via the NIU GAEA system to ~60 Teraflops integrated with a 720 CPU Beowulf system. The software is based on access to the NVIDIA/CUDA library and the ability through MATLAB multiple licenses to create additional local programs. A number of existing programs are being transferred to the CPU Beowulf Cluster. Since the expertise necessary to create the parallel processing applications has recently been obtained at NIU, this effort for software development is in an early stage. The educational program has been initiated via formal tutorials and classroom curricula designed for the coming year. Specifically, the cost focus was on hardware acquisitions and appointment of graduate students for a wide range of applications in engineering, physics and computer science.

QCD on the BlueGene/L Supercomputer

International Nuclear Information System (INIS)

Bhanot, G.; Chen, D.; Gara, A.; Sexton, J.; Vranas, P.

2005-01-01

In June 2004 QCD was simulated for the first time at sustained speed exceeding 1 TeraFlops in the BlueGene/L supercomputer at the IBM T.J. Watson Research Lab. The implementation and performance of QCD in the BlueGene/L is presented

QCD on the BlueGene/L Supercomputer

Science.gov (United States)

Bhanot, G.; Chen, D.; Gara, A.; Sexton, J.; Vranas, P.

2005-03-01

In June 2004 QCD was simulated for the first time at sustained speed exceeding 1 TeraFlops in the BlueGene/L supercomputer at the IBM T.J. Watson Research Lab. The implementation and performance of QCD in the BlueGene/L is presented.

Graphics supercomputer for computational fluid dynamics research

Science.gov (United States)

Liaw, Goang S.

1994-11-01

The objective of this project is to purchase a state-of-the-art graphics supercomputer to improve the Computational Fluid Dynamics (CFD) research capability at Alabama A & M University (AAMU) and to support the Air Force research projects. A cutting-edge graphics supercomputer system, Onyx VTX, from Silicon Graphics Computer Systems (SGI), was purchased and installed. Other equipment including a desktop personal computer, PC-486 DX2 with a built-in 10-BaseT Ethernet card, a 10-BaseT hub, an Apple Laser Printer Select 360, and a notebook computer from Zenith were also purchased. A reading room has been converted to a research computer lab by adding some furniture and an air conditioning unit in order to provide an appropriate working environments for researchers and the purchase equipment. All the purchased equipment were successfully installed and are fully functional. Several research projects, including two existing Air Force projects, are being performed using these facilities.

A workbench for tera-flop supercomputing

International Nuclear Information System (INIS)

Resch, M.M.; Kuester, U.; Mueller, M.S.; Lang, U.

2003-01-01

Supercomputers currently reach a peak performance in the range of TFlop/s. With but one exception - the Japanese Earth Simulator - none of these systems has so far been able to also show a level of sustained performance for a variety of applications that comes close to the peak performance. Sustained TFlop/s are therefore rarely seen. The reasons are manifold and are well known: Bandwidth and latency both for main memory and for the internal network are the key internal technical problems. Cache hierarchies with large caches can bring relief but are no remedy to the problem. However, there are not only technical problems that inhibit the full exploitation by scientists of the potential of modern supercomputers. More and more organizational issues come to the forefront. This paper shows the approach of the High Performance Computing Center Stuttgart (HLRS) to deliver a sustained performance of TFlop/s for a wide range of applications from a large group of users spread over Germany. The core of the concept is the role of the data. Around this we design a simulation workbench that hides the complexity of interacting computers, networks and file systems from the user. (authors)

User's Guide for TOUGH2-MP - A Massively Parallel Version of the TOUGH2 Code

International Nuclear Information System (INIS)

Earth Sciences Division; Zhang, Keni; Zhang, Keni; Wu, Yu-Shu; Pruess, Karsten

2008-01-01

TOUGH2-MP is a massively parallel (MP) version of the TOUGH2 code, designed for computationally efficient parallel simulation of isothermal and nonisothermal flows of multicomponent, multiphase fluids in one, two, and three-dimensional porous and fractured media. In recent years, computational requirements have become increasingly intensive in large or highly nonlinear problems for applications in areas such as radioactive waste disposal, CO2 geological sequestration, environmental assessment and remediation, reservoir engineering, and groundwater hydrology. The primary objective of developing the parallel-simulation capability is to significantly improve the computational performance of the TOUGH2 family of codes. The particular goal for the parallel simulator is to achieve orders-of-magnitude improvement in computational time for models with ever-increasing complexity. TOUGH2-MP is designed to perform parallel simulation on multi-CPU computational platforms. An earlier version of TOUGH2-MP (V1.0) was based on the TOUGH2 Version 1.4 with EOS3, EOS9, and T2R3D modules, a software previously qualified for applications in the Yucca Mountain project, and was designed for execution on CRAY T3E and IBM SP supercomputers. The current version of TOUGH2-MP (V2.0) includes all fluid property modules of the standard version TOUGH2 V2.0. It provides computationally efficient capabilities using supercomputers, Linux clusters, or multi-core PCs, and also offers many user-friendly features. The parallel simulator inherits all process capabilities from V2.0 together with additional capabilities for handling fractured media from V1.4. This report provides a quick starting guide on how to set up and run the TOUGH2-MP program for users with a basic knowledge of running the (standard) version TOUGH2 code. The report also gives a brief technical description of the code, including a discussion of parallel methodology, code structure, as well as mathematical and numerical methods used

Integration of Titan supercomputer at OLCF with ATLAS Production System

Science.gov (United States)

Barreiro Megino, F.; De, K.; Jha, S.; Klimentov, A.; Maeno, T.; Nilsson, P.; Oleynik, D.; Padolski, S.; Panitkin, S.; Wells, J.; Wenaus, T.; ATLAS Collaboration

2017-10-01

The PanDA (Production and Distributed Analysis) workload management system was developed to meet the scale and complexity of distributed computing for the ATLAS experiment. PanDA managed resources are distributed worldwide, on hundreds of computing sites, with thousands of physicists accessing hundreds of Petabytes of data and the rate of data processing already exceeds Exabyte per year. While PanDA currently uses more than 200,000 cores at well over 100 Grid sites, future LHC data taking runs will require more resources than Grid computing can possibly provide. Additional computing and storage resources are required. Therefore ATLAS is engaged in an ambitious program to expand the current computing model to include additional resources such as the opportunistic use of supercomputers. In this paper we will describe a project aimed at integration of ATLAS Production System with Titan supercomputer at Oak Ridge Leadership Computing Facility (OLCF). Current approach utilizes modified PanDA Pilot framework for job submission to Titan’s batch queues and local data management, with lightweight MPI wrappers to run single node workloads in parallel on Titan’s multi-core worker nodes. It provides for running of standard ATLAS production jobs on unused resources (backfill) on Titan. The system already allowed ATLAS to collect on Titan millions of core-hours per month, execute hundreds of thousands jobs, while simultaneously improving Titans utilization efficiency. We will discuss the details of the implementation, current experience with running the system, as well as future plans aimed at improvements in scalability and efficiency. Notice: This manuscript has been authored, by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to

KfK-seminar series on supercomputing und visualization from May till September 1992

International Nuclear Information System (INIS)

Hohenhinnebusch, W.

1993-05-01

During the period of may 1992 to september 1992 a series of seminars was held at KfK on several topics of supercomputing in different fields of application. The aim was to demonstrate the importance of supercomputing and visualization in numerical simulations of complex physical and technical phenomena. This report contains the collection of all submitted seminar papers. (orig./HP) [de

Development of a high performance eigensolver on the peta-scale next generation supercomputer system

International Nuclear Information System (INIS)

Imamura, Toshiyuki; Yamada, Susumu; Machida, Masahiko

2010-01-01

For the present supercomputer systems, a multicore and multisocket processors are necessary to build a system, and choice of interconnection is essential. In addition, for effective development of a new code, high performance, scalable, and reliable numerical software is one of the key items. ScaLAPACK and PETSc are well-known software on distributed memory parallel computer systems. It is needless to say that highly tuned software towards new architecture like many-core processors must be chosen for real computation. In this study, we present a high-performance and high-scalable eigenvalue solver towards the next-generation supercomputer system, so called 'K-computer' system. We have developed two versions, the standard version (eigen s) and enhanced performance version (eigen sx), which are developed on the T2K cluster system housed at University of Tokyo. Eigen s employs the conventional algorithms; Householder tridiagonalization, divide and conquer (DC) algorithm, and Householder back-transformation. They are carefully implemented with blocking technique and flexible two-dimensional data-distribution to reduce the overhead of memory traffic and data transfer, respectively. Eigen s performs excellently on the T2K system with 4096 cores (theoretical peak is 37.6 TFLOPS), and it shows fine performance 3.0 TFLOPS with a two hundred thousand dimensional matrix. The enhanced version, eigen sx, uses more advanced algorithms; the narrow-band reduction algorithm, DC for band matrices, and the block Householder back-transformation with WY-representation. Even though this version is still on a test stage, it shows 4.7 TFLOPS with the same dimensional matrix on eigen s. (author)

Performance studies of the parallel VIM code

International Nuclear Information System (INIS)

Shi, B.; Blomquist, R.N.

1996-01-01

In this paper, the authors evaluate the performance of the parallel version of the VIM Monte Carlo code on the IBM SPx at the High Performance Computing Research Facility at ANL. Three test problems with contrasting computational characteristics were used to assess effects in performance. A statistical method for estimating the inefficiencies due to load imbalance and communication is also introduced. VIM is a large scale continuous energy Monte Carlo radiation transport program and was parallelized using history partitioning, the master/worker approach, and p4 message passing library. Dynamic load balancing is accomplished when the master processor assigns chunks of histories to workers that have completed a previously assigned task, accommodating variations in the lengths of histories, processor speeds, and worker loads. At the end of each batch (generation), the fission sites and tallies are sent from each worker to the master process, contributing to the parallel inefficiency. All communications are between master and workers, and are serial. The SPx is a scalable 128-node parallel supercomputer with high-performance Omega switches of 63 microsec latency and 35 MBytes/sec bandwidth. For uniform and reproducible performance, they used only the 120 identical regular processors (IBM RS/6000) and excluded the remaining eight planet nodes, which may be loaded by other's jobs

A compositional reservoir simulator on distributed memory parallel computers

International Nuclear Information System (INIS)

Rame, M.; Delshad, M.

1995-01-01

This paper presents the application of distributed memory parallel computes to field scale reservoir simulations using a parallel version of UTCHEM, The University of Texas Chemical Flooding Simulator. The model is a general purpose highly vectorized chemical compositional simulator that can simulate a wide range of displacement processes at both field and laboratory scales. The original simulator was modified to run on both distributed memory parallel machines (Intel iPSC/960 and Delta, Connection Machine 5, Kendall Square 1 and 2, and CRAY T3D) and a cluster of workstations. A domain decomposition approach has been taken towards parallelization of the code. A portion of the discrete reservoir model is assigned to each processor by a set-up routine that attempts a data layout as even as possible from the load-balance standpoint. Each of these subdomains is extended so that data can be shared between adjacent processors for stencil computation. The added routines that make parallel execution possible are written in a modular fashion that makes the porting to new parallel platforms straight forward. Results of the distributed memory computing performance of Parallel simulator are presented for field scale applications such as tracer flood and polymer flood. A comparison of the wall-clock times for same problems on a vector supercomputer is also presented

Monte Carlo simulations of quantum systems on massively parallel supercomputers

International Nuclear Information System (INIS)

Ding, H.Q.

1993-01-01

A large class of quantum physics applications uses operator representations that are discrete integers by nature. This class includes magnetic properties of solids, interacting bosons modeling superfluids and Cooper pairs in superconductors, and Hubbard models for strongly correlated electrons systems. This kind of application typically uses integer data representations and the resulting algorithms are dominated entirely by integer operations. The authors implemented an efficient algorithm for one such application on the Intel Touchstone Delta and iPSC/860. The algorithm uses a multispin coding technique which allows significant data compactification and efficient vectorization of Monte Carlo updates. The algorithm regularly switches between two data decompositions, corresponding naturally to different Monte Carlo updating processes and observable measurements such that only nearest-neighbor communications are needed within a given decomposition. On 128 nodes of Intel Delta, this algorithm updates 183 million spins per second (compared to 21 million on CM-2 and 6.2 million on a Cray Y-MP). A systematic performance analysis shows a better than 90% efficiency in the parallel implementation

Parallel Evolutionary Optimization for Neuromorphic Network Training

Energy Technology Data Exchange (ETDEWEB)

Schuman, Catherine D [ORNL; Disney, Adam [University of Tennessee (UT); Singh, Susheela [North Carolina State University (NCSU), Raleigh; Bruer, Grant [University of Tennessee (UT); Mitchell, John Parker [University of Tennessee (UT); Klibisz, Aleksander [University of Tennessee (UT); Plank, James [University of Tennessee (UT)

2016-01-01

One of the key impediments to the success of current neuromorphic computing architectures is the issue of how best to program them. Evolutionary optimization (EO) is one promising programming technique; in particular, its wide applicability makes it especially attractive for neuromorphic architectures, which can have many different characteristics. In this paper, we explore different facets of EO on a spiking neuromorphic computing model called DANNA. We focus on the performance of EO in the design of our DANNA simulator, and on how to structure EO on both multicore and massively parallel computing systems. We evaluate how our parallel methods impact the performance of EO on Titan, the U.S.'s largest open science supercomputer, and BOB, a Beowulf-style cluster of Raspberry Pi's. We also focus on how to improve the EO by evaluating commonality in higher performing neural networks, and present the result of a study that evaluates the EO performed by Titan.

Application of Supercomputer Technologies for Simulation Of Socio-Economic Systems

Directory of Open Access Journals (Sweden)

Vladimir Valentinovich Okrepilov

2015-06-01

Full Text Available To date, an extensive experience has been accumulated in investigation of problems related to quality, assessment of management systems, modeling of economic system sustainability. The performed studies have created a basis for development of a new research area — Economics of Quality. Its tools allow to use opportunities of model simulation for construction of the mathematical models adequately reflecting the role of quality in natural, technical, social regularities of functioning of the complex socio-economic systems. Extensive application and development of models, and also system modeling with use of supercomputer technologies, on our deep belief, will bring the conducted research of socio-economic systems to essentially new level. Moreover, the current scientific research makes a significant contribution to model simulation of multi-agent social systems and that is not less important, it belongs to the priority areas in development of science and technology in our country. This article is devoted to the questions of supercomputer technologies application in public sciences, first of all, — regarding technical realization of the large-scale agent-focused models (AFM. The essence of this tool is that owing to the power computer increase it has become possible to describe the behavior of many separate fragments of a difficult system, as socio-economic systems are. The article also deals with the experience of foreign scientists and practicians in launching the AFM on supercomputers, and also the example of AFM developed in CEMI RAS, stages and methods of effective calculating kernel display of multi-agent system on architecture of a modern supercomputer will be analyzed. The experiments on the basis of model simulation on forecasting the population of St. Petersburg according to three scenarios as one of the major factors influencing the development of socio-economic system and quality of life of the population are presented in the

A hybrid method for the parallel computation of Green's functions

DEFF Research Database (Denmark)

Petersen, Dan Erik; Li, Song; Stokbro, Kurt

2009-01-01

of the large number of times this calculation needs to be performed, this is computationally very expensive even on supercomputers. The classical approach is based on recurrence formulas which cannot be efficiently parallelized. This practically prevents the solution of large problems with hundreds...... of thousands of atoms. We propose new recurrences for a general class of sparse matrices to calculate Green's and lesser Green's function matrices which extend formulas derived by Takahashi and others. We show that these recurrences may lead to a dramatically reduced computational cost because they only...... require computing a small number of entries of the inverse matrix. Then. we propose a parallelization strategy for block tridiagonal matrices which involves a combination of Schur complement calculations and cyclic reduction. It achieves good scalability even on problems of modest size....

Centralized supercomputer support for magnetic fusion energy research

International Nuclear Information System (INIS)

Fuss, D.; Tull, G.G.

1984-01-01

High-speed computers with large memories are vital to magnetic fusion energy research. Magnetohydrodynamic (MHD), transport, equilibrium, Vlasov, particle, and Fokker-Planck codes that model plasma behavior play an important role in designing experimental hardware and interpreting the resulting data, as well as in advancing plasma theory itself. The size, architecture, and software of supercomputers to run these codes are often the crucial constraints on the benefits such computational modeling can provide. Hence, vector computers such as the CRAY-1 offer a valuable research resource. To meet the computational needs of the fusion program, the National Magnetic Fusion Energy Computer Center (NMFECC) was established in 1974 at the Lawrence Livermore National Laboratory. Supercomputers at the central computing facility are linked to smaller computer centers at each of the major fusion laboratories by a satellite communication network. In addition to providing large-scale computing, the NMFECC environment stimulates collaboration and the sharing of computer codes and data among the many fusion researchers in a cost-effective manner

The four-meter confrontation visual field test.

OpenAIRE

Kodsi, S R; Younge, B R

1992-01-01

The 4-m confrontation visual field test has been successfully used at the Mayo Clinic for many years in addition to the standard 0.5-m confrontation visual field test. The 4-m confrontation visual field test is a test of macular function and can identify small central or paracentral scotomas that the examiner may not find when the patient is tested only at 0.5 m. Also, macular sparing in homonymous hemianopias and quadrantanopias may be identified with the 4-m confrontation visual field test....

Performance Characteristics of Hybrid MPI/OpenMP Scientific Applications on a Large-Scale Multithreaded BlueGene/Q Supercomputer

KAUST Repository

Wu, Xingfu; Taylor, Valerie

2013-01-01

In this paper, we investigate the performance characteristics of five hybrid MPI/OpenMP scientific applications (two NAS Parallel benchmarks Multi-Zone SP-MZ and BT-MZ, an earthquake simulation PEQdyna, an aerospace application PMLB and a 3D particle-in-cell application GTC) on a large-scale multithreaded Blue Gene/Q supercomputer at Argonne National laboratory, and quantify the performance gap resulting from using different number of threads per node. We use performance tools and MPI profile and trace libraries available on the supercomputer to analyze and compare the performance of these hybrid scientific applications with increasing the number OpenMP threads per node, and find that increasing the number of threads to some extent saturates or worsens performance of these hybrid applications. For the strong-scaling hybrid scientific applications such as SP-MZ, BT-MZ, PEQdyna and PLMB, using 32 threads per node results in much better application efficiency than using 64 threads per node, and as increasing the number of threads per node, the FPU (Floating Point Unit) percentage decreases, and the MPI percentage (except PMLB) and IPC (Instructions per cycle) per core (except BT-MZ) increase. For the weak-scaling hybrid scientific application such as GTC, the performance trend (relative speedup) is very similar with increasing number of threads per node no matter how many nodes (32, 128, 512) are used. © 2013 IEEE.

Performance Characteristics of Hybrid MPI/OpenMP Scientific Applications on a Large-Scale Multithreaded BlueGene/Q Supercomputer

KAUST Repository

Wu, Xingfu

2013-07-01

In this paper, we investigate the performance characteristics of five hybrid MPI/OpenMP scientific applications (two NAS Parallel benchmarks Multi-Zone SP-MZ and BT-MZ, an earthquake simulation PEQdyna, an aerospace application PMLB and a 3D particle-in-cell application GTC) on a large-scale multithreaded Blue Gene/Q supercomputer at Argonne National laboratory, and quantify the performance gap resulting from using different number of threads per node. We use performance tools and MPI profile and trace libraries available on the supercomputer to analyze and compare the performance of these hybrid scientific applications with increasing the number OpenMP threads per node, and find that increasing the number of threads to some extent saturates or worsens performance of these hybrid applications. For the strong-scaling hybrid scientific applications such as SP-MZ, BT-MZ, PEQdyna and PLMB, using 32 threads per node results in much better application efficiency than using 64 threads per node, and as increasing the number of threads per node, the FPU (Floating Point Unit) percentage decreases, and the MPI percentage (except PMLB) and IPC (Instructions per cycle) per core (except BT-MZ) increase. For the weak-scaling hybrid scientific application such as GTC, the performance trend (relative speedup) is very similar with increasing number of threads per node no matter how many nodes (32, 128, 512) are used. © 2013 IEEE.

High Temporal Resolution Mapping of Seismic Noise Sources Using Heterogeneous Supercomputers

Science.gov (United States)

Paitz, P.; Gokhberg, A.; Ermert, L. A.; Fichtner, A.

2017-12-01

The time- and space-dependent distribution of seismic noise sources is becoming a key ingredient of modern real-time monitoring of various geo-systems like earthquake fault zones, volcanoes, geothermal and hydrocarbon reservoirs. We present results of an ongoing research project conducted in collaboration with the Swiss National Supercomputing Centre (CSCS). The project aims at building a service providing seismic noise source maps for Central Europe with high temporal resolution. We use source imaging methods based on the cross-correlation of seismic noise records from all seismic stations available in the region of interest. The service is hosted on the CSCS computing infrastructure; all computationally intensive processing is performed on the massively parallel heterogeneous supercomputer "Piz Daint". The solution architecture is based on the Application-as-a-Service concept to provide the interested researchers worldwide with regular access to the noise source maps. The solution architecture includes the following sub-systems: (1) data acquisition responsible for collecting, on a periodic basis, raw seismic records from the European seismic networks, (2) high-performance noise source mapping application responsible for the generation of source maps using cross-correlation of seismic records, (3) back-end infrastructure for the coordination of various tasks and computations, (4) front-end Web interface providing the service to the end-users and (5) data repository. The noise source mapping itself rests on the measurement of logarithmic amplitude ratios in suitably pre-processed noise correlations, and the use of simplified sensitivity kernels. During the implementation we addressed various challenges, in particular, selection of data sources and transfer protocols, automation and monitoring of daily data downloads, ensuring the required data processing performance, design of a general service-oriented architecture for coordination of various sub-systems, and

Fiscal 2000 report on advanced parallelized compiler technology. Outlines; 2000 nendo advanced heiretsuka compiler gijutsu hokokusho (Gaiyo hen)

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Research and development was carried out concerning the automatic parallelized compiler technology which improves on the practical performance, cost/performance ratio, and ease of operation of the multiprocessor system now used for constructing supercomputers and expected to provide a fundamental architecture for microprocessors for the 21st century. Efforts were made to develop an automatic multigrain parallelization technology for extracting multigrain as parallelized from a program and for making full use of the same and a parallelizing tuning technology for accelerating parallelization by feeding back to the compiler the dynamic information and user knowledge to be acquired during execution. Moreover, a benchmark program was selected and studies were made to set execution rules and evaluation indexes for the establishment of technologies for subjectively evaluating the performance of parallelizing compilers for the existing commercial parallel processing computers, which was achieved through the implementation and evaluation of the 'Advanced parallelizing compiler technology research and development project.' (NEDO)

Performance modeling of hybrid MPI/OpenMP scientific applications on large-scale multicore supercomputers

KAUST Repository

Wu, Xingfu; Taylor, Valerie

2013-01-01

In this paper, we present a performance modeling framework based on memory bandwidth contention time and a parameterized communication model to predict the performance of OpenMP, MPI and hybrid applications with weak scaling on three large-scale multicore supercomputers: IBM POWER4, POWER5+ and BlueGene/P, and analyze the performance of these MPI, OpenMP and hybrid applications. We use STREAM memory benchmarks and Intel's MPI benchmarks to provide initial performance analysis and model validation of MPI and OpenMP applications on these multicore supercomputers because the measured sustained memory bandwidth can provide insight into the memory bandwidth that a system should sustain on scientific applications with the same amount of workload per core. In addition to using these benchmarks, we also use a weak-scaling hybrid MPI/OpenMP large-scale scientific application: Gyrokinetic Toroidal Code (GTC) in magnetic fusion to validate our performance model of the hybrid application on these multicore supercomputers. The validation results for our performance modeling method show less than 7.77% error rate in predicting the performance of hybrid MPI/OpenMP GTC on up to 512 cores on these multicore supercomputers. © 2013 Elsevier Inc.

Performance modeling of hybrid MPI/OpenMP scientific applications on large-scale multicore supercomputers

KAUST Repository

Wu, Xingfu

2013-12-01

In this paper, we present a performance modeling framework based on memory bandwidth contention time and a parameterized communication model to predict the performance of OpenMP, MPI and hybrid applications with weak scaling on three large-scale multicore supercomputers: IBM POWER4, POWER5+ and BlueGene/P, and analyze the performance of these MPI, OpenMP and hybrid applications. We use STREAM memory benchmarks and Intel\\'s MPI benchmarks to provide initial performance analysis and model validation of MPI and OpenMP applications on these multicore supercomputers because the measured sustained memory bandwidth can provide insight into the memory bandwidth that a system should sustain on scientific applications with the same amount of workload per core. In addition to using these benchmarks, we also use a weak-scaling hybrid MPI/OpenMP large-scale scientific application: Gyrokinetic Toroidal Code (GTC) in magnetic fusion to validate our performance model of the hybrid application on these multicore supercomputers. The validation results for our performance modeling method show less than 7.77% error rate in predicting the performance of hybrid MPI/OpenMP GTC on up to 512 cores on these multicore supercomputers. © 2013 Elsevier Inc.

Guide to dataflow supercomputing basic concepts, case studies, and a detailed example

CERN Document Server

Milutinovic, Veljko; Trifunovic, Nemanja; Giorgi, Roberto

2015-01-01

This unique text/reference describes an exciting and novel approach to supercomputing in the DataFlow paradigm. The major advantages and applications of this approach are clearly described, and a detailed explanation of the programming model is provided using simple yet effective examples. The work is developed from a series of lecture courses taught by the authors in more than 40 universities across more than 20 countries, and from research carried out by Maxeler Technologies, Inc. Topics and features: presents a thorough introduction to DataFlow supercomputing for big data problems; revie

Parallelized implicit propagators for the finite-difference Schrödinger equation

Science.gov (United States)

Parker, Jonathan; Taylor, K. T.

1995-08-01

We describe the application of block Gauss-Seidel and block Jacobi iterative methods to the design of implicit propagators for finite-difference models of the time-dependent Schrödinger equation. The block-wise iterative methods discussed here are mixed direct-iterative methods for solving simultaneous equations, in the sense that direct methods (e.g. LU decomposition) are used to invert certain block sub-matrices, and iterative methods are used to complete the solution. We describe parallel variants of the basic algorithm that are well suited to the medium- to coarse-grained parallelism of work-station clusters, and MIMD supercomputers, and we show that under a wide range of conditions, fine-grained parallelism of the computation can be achieved. Numerical tests are conducted on a typical one-electron atom Hamiltonian. The methods converge robustly to machine precision (15 significant figures), in some cases in as few as 6 or 7 iterations. The rate of convergence is nearly independent of the finite-difference grid-point separations.

The Parallel System for Integrating Impact Models and Sectors (pSIMS)

Science.gov (United States)

Elliott, Joshua; Kelly, David; Chryssanthacopoulos, James; Glotter, Michael; Jhunjhnuwala, Kanika; Best, Neil; Wilde, Michael; Foster, Ian

2014-01-01

We present a framework for massively parallel climate impact simulations: the parallel System for Integrating Impact Models and Sectors (pSIMS). This framework comprises a) tools for ingesting and converting large amounts of data to a versatile datatype based on a common geospatial grid; b) tools for translating this datatype into custom formats for site-based models; c) a scalable parallel framework for performing large ensemble simulations, using any one of a number of different impacts models, on clusters, supercomputers, distributed grids, or clouds; d) tools and data standards for reformatting outputs to common datatypes for analysis and visualization; and e) methodologies for aggregating these datatypes to arbitrary spatial scales such as administrative and environmental demarcations. By automating many time-consuming and error-prone aspects of large-scale climate impacts studies, pSIMS accelerates computational research, encourages model intercomparison, and enhances reproducibility of simulation results. We present the pSIMS design and use example assessments to demonstrate its multi-model, multi-scale, and multi-sector versatility.

Homemade Buckeye-Pi: A Learning Many-Node Platform for High-Performance Parallel Computing

Science.gov (United States)

Amooie, M. A.; Moortgat, J.

2017-12-01

We report on the "Buckeye-Pi" cluster, the supercomputer developed in The Ohio State University School of Earth Sciences from 128 inexpensive Raspberry Pi (RPi) 3 Model B single-board computers. Each RPi is equipped with fast Quad Core 1.2GHz ARMv8 64bit processor, 1GB of RAM, and 32GB microSD card for local storage. Therefore, the cluster has a total RAM of 128GB that is distributed on the individual nodes and a flash capacity of 4TB with 512 processors, while it benefits from low power consumption, easy portability, and low total cost. The cluster uses the Message Passing Interface protocol to manage the communications between each node. These features render our platform the most powerful RPi supercomputer to date and suitable for educational applications in high-performance-computing (HPC) and handling of large datasets. In particular, we use the Buckeye-Pi to implement optimized parallel codes in our in-house simulator for subsurface media flows with the goal of achieving a massively-parallelized scalable code. We present benchmarking results for the computational performance across various number of RPi nodes. We believe our project could inspire scientists and students to consider the proposed unconventional cluster architecture as a mainstream and a feasible learning platform for challenging engineering and scientific problems.

Parallel file system performances in fusion data storage

International Nuclear Information System (INIS)

Iannone, F.; Podda, S.; Bracco, G.; Manduchi, G.; Maslennikov, A.; Migliori, S.; Wolkersdorfer, K.

2012-01-01

High I/O flow rates, up to 10 GB/s, are required in large fusion Tokamak experiments like ITER where hundreds of nodes store simultaneously large amounts of data acquired during the plasma discharges. Typical network topologies such as linear arrays (systolic), rings, meshes (2-D arrays), tori (3-D arrays), trees, butterfly, hypercube in combination with high speed data transports like Infiniband or 10G-Ethernet, are the main areas in which the effort to overcome the so-called parallel I/O bottlenecks is most focused. The high I/O flow rates were modelled in an emulated testbed based on the parallel file systems such as Lustre and GPFS, commonly used in High Performance Computing. The test runs on High Performance Computing–For Fusion (8640 cores) and ENEA CRESCO (3392 cores) supercomputers. Message Passing Interface based applications were developed to emulate parallel I/O on Lustre and GPFS using data archival and access solutions like MDSPLUS and Universal Access Layer. These methods of data storage organization are widely diffused in nuclear fusion experiments and are being developed within the EFDA Integrated Tokamak Modelling – Task Force; the authors tried to evaluate their behaviour in a realistic emulation setup.

Parallel file system performances in fusion data storage

Energy Technology Data Exchange (ETDEWEB)

Iannone, F., E-mail: francesco.iannone@enea.it [Associazione EURATOM-ENEA sulla Fusione, C.R.ENEA Frascati, via E.Fermi, 45 - 00044 Frascati, Rome (Italy); Podda, S.; Bracco, G. [ENEA Information Communication Tecnologies, Lungotevere Thaon di Revel, 76 - 00196 Rome (Italy); Manduchi, G. [Associazione EURATOM-ENEA sulla Fusione, Consorzio RFX, Corso Stati Uniti, 4 - 35127 Padua (Italy); Maslennikov, A. [CASPUR Inter-University Consortium for the Application of Super-Computing for Research, via dei Tizii, 6b - 00185 Rome (Italy); Migliori, S. [ENEA Information Communication Tecnologies, Lungotevere Thaon di Revel, 76 - 00196 Rome (Italy); Wolkersdorfer, K. [Juelich Supercomputing Centre-FZJ, D-52425 Juelich (Germany)

2012-12-15

High I/O flow rates, up to 10 GB/s, are required in large fusion Tokamak experiments like ITER where hundreds of nodes store simultaneously large amounts of data acquired during the plasma discharges. Typical network topologies such as linear arrays (systolic), rings, meshes (2-D arrays), tori (3-D arrays), trees, butterfly, hypercube in combination with high speed data transports like Infiniband or 10G-Ethernet, are the main areas in which the effort to overcome the so-called parallel I/O bottlenecks is most focused. The high I/O flow rates were modelled in an emulated testbed based on the parallel file systems such as Lustre and GPFS, commonly used in High Performance Computing. The test runs on High Performance Computing-For Fusion (8640 cores) and ENEA CRESCO (3392 cores) supercomputers. Message Passing Interface based applications were developed to emulate parallel I/O on Lustre and GPFS using data archival and access solutions like MDSPLUS and Universal Access Layer. These methods of data storage organization are widely diffused in nuclear fusion experiments and are being developed within the EFDA Integrated Tokamak Modelling - Task Force; the authors tried to evaluate their behaviour in a realistic emulation setup.

The island dynamics model on parallel quadtree grids

Science.gov (United States)

Mistani, Pouria; Guittet, Arthur; Bochkov, Daniil; Schneider, Joshua; Margetis, Dionisios; Ratsch, Christian; Gibou, Frederic

2018-05-01

We introduce an approach for simulating epitaxial growth by use of an island dynamics model on a forest of quadtree grids, and in a parallel environment. To this end, we use a parallel framework introduced in the context of the level-set method. This framework utilizes: discretizations that achieve a second-order accurate level-set method on non-graded adaptive Cartesian grids for solving the associated free boundary value problem for surface diffusion; and an established library for the partitioning of the grid. We consider the cases with: irreversible aggregation, which amounts to applying Dirichlet boundary conditions at the island boundary; and an asymmetric (Ehrlich-Schwoebel) energy barrier for attachment/detachment of atoms at the island boundary, which entails the use of a Robin boundary condition. We provide the scaling analyses performed on the Stampede supercomputer and numerical examples that illustrate the capability of our methodology to efficiently simulate different aspects of epitaxial growth. The combination of adaptivity and parallelism in our approach enables simulations that are several orders of magnitude faster than those reported in the recent literature and, thus, provides a viable framework for the systematic study of mound formation on crystal surfaces.

Enabling Diverse Software Stacks on Supercomputers using High Performance Virtual Clusters.

Energy Technology Data Exchange (ETDEWEB)

Younge, Andrew J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pedretti, Kevin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grant, Ryan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brightwell, Ron [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-05-01

While large-scale simulations have been the hallmark of the High Performance Computing (HPC) community for decades, Large Scale Data Analytics (LSDA) workloads are gaining attention within the scientific community not only as a processing component to large HPC simulations, but also as standalone scientific tools for knowledge discovery. With the path towards Exascale, new HPC runtime systems are also emerging in a way that differs from classical distributed com- puting models. However, system software for such capabilities on the latest extreme-scale DOE supercomputing needs to be enhanced to more appropriately support these types of emerging soft- ware ecosystems. In this paper, we propose the use of Virtual Clusters on advanced supercomputing resources to enable systems to support not only HPC workloads, but also emerging big data stacks. Specifi- cally, we have deployed the KVM hypervisor within Cray's Compute Node Linux on a XC-series supercomputer testbed. We also use libvirt and QEMU to manage and provision VMs directly on compute nodes, leveraging Ethernet-over-Aries network emulation. To our knowledge, this is the first known use of KVM on a true MPP supercomputer. We investigate the overhead our solution using HPC benchmarks, both evaluating single-node performance as well as weak scaling of a 32-node virtual cluster. Overall, we find single node performance of our solution using KVM on a Cray is very efficient with near-native performance. However overhead increases by up to 20% as virtual cluster size increases, due to limitations of the Ethernet-over-Aries bridged network. Furthermore, we deploy Apache Spark with large data analysis workloads in a Virtual Cluster, ef- fectively demonstrating how diverse software ecosystems can be supported by High Performance Virtual Clusters.

Cellular-automata supercomputers for fluid-dynamics modeling

International Nuclear Information System (INIS)

Margolus, N.; Toffoli, T.; Vichniac, G.

1986-01-01

We report recent developments in the modeling of fluid dynamics, and give experimental results (including dynamical exponents) obtained using cellular automata machines. Because of their locality and uniformity, cellular automata lend themselves to an extremely efficient physical realization; with a suitable architecture, an amount of hardware resources comparable to that of a home computer can achieve (in the simulation of cellular automata) the performance of a conventional supercomputer

Load-balancing techniques for a parallel electromagnetic particle-in-cell code

Energy Technology Data Exchange (ETDEWEB)

PLIMPTON,STEVEN J.; SEIDEL,DAVID B.; PASIK,MICHAEL F.; COATS,REBECCA S.

2000-01-01

QUICKSILVER is a 3-d electromagnetic particle-in-cell simulation code developed and used at Sandia to model relativistic charged particle transport. It models the time-response of electromagnetic fields and low-density-plasmas in a self-consistent manner: the fields push the plasma particles and the plasma current modifies the fields. Through an LDRD project a new parallel version of QUICKSILVER was created to enable large-scale plasma simulations to be run on massively-parallel distributed-memory supercomputers with thousands of processors, such as the Intel Tflops and DEC CPlant machines at Sandia. The new parallel code implements nearly all the features of the original serial QUICKSILVER and can be run on any platform which supports the message-passing interface (MPI) standard as well as on single-processor workstations. This report describes basic strategies useful for parallelizing and load-balancing particle-in-cell codes, outlines the parallel algorithms used in this implementation, and provides a summary of the modifications made to QUICKSILVER. It also highlights a series of benchmark simulations which have been run with the new code that illustrate its performance and parallel efficiency. These calculations have up to a billion grid cells and particles and were run on thousands of processors. This report also serves as a user manual for people wishing to run parallel QUICKSILVER.

Load-balancing techniques for a parallel electromagnetic particle-in-cell code

International Nuclear Information System (INIS)

Plimpton, Steven J.; Seidel, David B.; Pasik, Michael F.; Coats, Rebecca S.

2000-01-01

QUICKSILVER is a 3-d electromagnetic particle-in-cell simulation code developed and used at Sandia to model relativistic charged particle transport. It models the time-response of electromagnetic fields and low-density-plasmas in a self-consistent manner: the fields push the plasma particles and the plasma current modifies the fields. Through an LDRD project a new parallel version of QUICKSILVER was created to enable large-scale plasma simulations to be run on massively-parallel distributed-memory supercomputers with thousands of processors, such as the Intel Tflops and DEC CPlant machines at Sandia. The new parallel code implements nearly all the features of the original serial QUICKSILVER and can be run on any platform which supports the message-passing interface (MPI) standard as well as on single-processor workstations. This report describes basic strategies useful for parallelizing and load-balancing particle-in-cell codes, outlines the parallel algorithms used in this implementation, and provides a summary of the modifications made to QUICKSILVER. It also highlights a series of benchmark simulations which have been run with the new code that illustrate its performance and parallel efficiency. These calculations have up to a billion grid cells and particles and were run on thousands of processors. This report also serves as a user manual for people wishing to run parallel QUICKSILVER

The TeraGyroid Experiment – Supercomputing 2003

Directory of Open Access Journals (Sweden)

R.J. Blake

2005-01-01

Full Text Available Amphiphiles are molecules with hydrophobic tails and hydrophilic heads. When dispersed in solvents, they self assemble into complex mesophases including the beautiful cubic gyroid phase. The goal of the TeraGyroid experiment was to study defect pathways and dynamics in these gyroids. The UK's supercomputing and USA's TeraGrid facilities were coupled together, through a dedicated high-speed network, into a single computational Grid for research work that peaked around the Supercomputing 2003 conference. The gyroids were modeled using lattice Boltzmann methods with parameter spaces explored using many 1283 and 3grid point simulations, this data being used to inform the world's largest three-dimensional time dependent simulation with 10243-grid points. The experiment generated some 2 TBytes of useful data. In terms of Grid technology the project demonstrated the migration of simulations (using Globus middleware to and fro across the Atlantic exploiting the availability of resources. Integration of the systems accelerated the time to insight. Distributed visualisation of the output datasets enabled the parameter space of the interactions within the complex fluid to be explored from a number of sites, informed by discourse over the Access Grid. The project was sponsored by EPSRC (UK and NSF (USA with trans-Atlantic optical bandwidth provided by British Telecommunications.

Confronting Stereotypes

Science.gov (United States)

Buswell, Carol

2011-01-01

People confront stereotypes every day, both in and out of the classroom. Some ideas have been carried in the collective memory and classroom textbooks for so long they are generally recognized as fact. Many are constantly being reinforced by personal experiences, family discussions, and Hollywood productions as well. The distinct advantage to…

Efficient development of memory bounded geo-applications to scale on modern supercomputers

Science.gov (United States)

Räss, Ludovic; Omlin, Samuel; Licul, Aleksandar; Podladchikov, Yuri; Herman, Frédéric

2016-04-01

Numerical modeling is an actual key tool in the area of geosciences. The current challenge is to solve problems that are multi-physics and for which the length scale and the place of occurrence might not be known in advance. Also, the spatial extend of the investigated domain might strongly vary in size, ranging from millimeters for reactive transport to kilometers for glacier erosion dynamics. An efficient way to proceed is to develop simple but robust algorithms that perform well and scale on modern supercomputers and permit therefore very high-resolution simulations. We propose an efficient approach to solve memory bounded real-world applications on modern supercomputers architectures. We optimize the software to run on our newly acquired state-of-the-art GPU cluster "octopus". Our approach shows promising preliminary results on important geodynamical and geomechanical problematics: we have developed a Stokes solver for glacier flow and a poromechanical solver including complex rheologies for nonlinear waves in stressed rocks porous rocks. We solve the system of partial differential equations on a regular Cartesian grid and use an iterative finite difference scheme with preconditioning of the residuals. The MPI communication happens only locally (point-to-point); this method is known to scale linearly by construction. The "octopus" GPU cluster, which we use for the computations, has been designed to achieve maximal data transfer throughput at minimal hardware cost. It is composed of twenty compute nodes, each hosting four Nvidia Titan X GPU accelerators. These high-density nodes are interconnected with a parallel (dual-rail) FDR InfiniBand network. Our efforts show promising preliminary results for the different physics investigated. The glacier flow solver achieves good accuracy in the relevant benchmarks and the coupled poromechanical solver permits to explain previously unresolvable focused fluid flow as a natural outcome of the porosity setup. In both cases

Analyzing the Interplay of Failures and Workload on a Leadership-Class Supercomputer

Energy Technology Data Exchange (ETDEWEB)

Meneses, Esteban [University of Pittsburgh; Ni, Xiang [University of Illinois at Urbana-Champaign; Jones, Terry R [ORNL; Maxwell, Don E [ORNL

2015-01-01

The unprecedented computational power of cur- rent supercomputers now makes possible the exploration of complex problems in many scientific fields, from genomic analysis to computational fluid dynamics. Modern machines are powerful because they are massive: they assemble millions of cores and a huge quantity of disks, cards, routers, and other components. But it is precisely the size of these machines that glooms the future of supercomputing. A system that comprises many components has a high chance to fail, and fail often. In order to make the next generation of supercomputers usable, it is imperative to use some type of fault tolerance platform to run applications on large machines. Most fault tolerance strategies can be optimized for the peculiarities of each system and boost efficacy by keeping the system productive. In this paper, we aim to understand how failure characterization can improve resilience in several layers of the software stack: applications, runtime systems, and job schedulers. We examine the Titan supercomputer, one of the fastest systems in the world. We analyze a full year of Titan in production and distill the failure patterns of the machine. By looking into Titan s log files and using the criteria of experts, we provide a detailed description of the types of failures. In addition, we inspect the job submission files and describe how the system is used. Using those two sources, we cross correlate failures in the machine to executing jobs and provide a picture of how failures affect the user experience. We believe such characterization is fundamental in developing appropriate fault tolerance solutions for Cray systems similar to Titan.

Parallel Optimization of Polynomials for Large-scale Problems in Stability and Control

Science.gov (United States)

Kamyar, Reza

In this thesis, we focus on some of the NP-hard problems in control theory. Thanks to the converse Lyapunov theory, these problems can often be modeled as optimization over polynomials. To avoid the problem of intractability, we establish a trade off between accuracy and complexity. In particular, we develop a sequence of tractable optimization problems --- in the form of Linear Programs (LPs) and/or Semi-Definite Programs (SDPs) --- whose solutions converge to the exact solution of the NP-hard problem. However, the computational and memory complexity of these LPs and SDPs grow exponentially with the progress of the sequence - meaning that improving the accuracy of the solutions requires solving SDPs with tens of thousands of decision variables and constraints. Setting up and solving such problems is a significant challenge. The existing optimization algorithms and software are only designed to use desktop computers or small cluster computers --- machines which do not have sufficient memory for solving such large SDPs. Moreover, the speed-up of these algorithms does not scale beyond dozens of processors. This in fact is the reason we seek parallel algorithms for setting-up and solving large SDPs on large cluster- and/or super-computers. We propose parallel algorithms for stability analysis of two classes of systems: 1) Linear systems with a large number of uncertain parameters; 2) Nonlinear systems defined by polynomial vector fields. First, we develop a distributed parallel algorithm which applies Polya's and/or Handelman's theorems to some variants of parameter-dependent Lyapunov inequalities with parameters defined over the standard simplex. The result is a sequence of SDPs which possess a block-diagonal structure. We then develop a parallel SDP solver which exploits this structure in order to map the computation, memory and communication to a distributed parallel environment. Numerical tests on a supercomputer demonstrate the ability of the algorithm to

369 TFlop/s molecular dynamics simulations on the Roadrunner general-purpose heterogeneous supercomputer

Energy Technology Data Exchange (ETDEWEB)

Swaminarayan, Sriram [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory; Kadau, Kai [Los Alamos National Laboratory; Fossum, Gordon C [IBM CORPORATION

2008-01-01

The authors present timing and performance numbers for a short-range parallel molecular dynamics (MD) code, SPaSM, that has been rewritten for the heterogeneous Roadrunner supercomputer. Each Roadrunner compute node consists of two AMD Opteron dual-core microprocessors and four PowerXCell 8i enhanced Cell microprocessors, so that there are four MPI ranks per node, each with one Opteron and one Cell. The interatomic forces are computed on the Cells (each with one PPU and eight SPU cores), while the Opterons are used to direct inter-rank communication and perform I/O-heavy periodic analysis, visualization, and checkpointing tasks. The performance measured for our initial implementation of a standard Lennard-Jones pair potential benchmark reached a peak of 369 Tflop/s double-precision floating-point performance on the full Roadrunner system (27.7% of peak), corresponding to 124 MFlop/Watt/s at a price of approximately 3.69 MFlops/dollar. They demonstrate an initial target application, the jetting and ejection of material from a shocked surface.

Contribution to the algorithmic and efficient programming of new parallel architectures including accelerators for neutron physics and shielding computations

International Nuclear Information System (INIS)

Dubois, J.

2011-01-01

In science, simulation is a key process for research or validation. Modern computer technology allows faster numerical experiments, which are cheaper than real models. In the field of neutron simulation, the calculation of eigenvalues is one of the key challenges. The complexity of these problems is such that a lot of computing power may be necessary. The work of this thesis is first the evaluation of new computing hardware such as graphics card or massively multi-core chips, and their application to eigenvalue problems for neutron simulation. Then, in order to address the massive parallelism of supercomputers national, we also study the use of asynchronous hybrid methods for solving eigenvalue problems with this very high level of parallelism. Then we experiment the work of this research on several national supercomputers such as the Titane hybrid machine of the Computing Center, Research and Technology (CCRT), the Curie machine of the Very Large Computing Centre (TGCC), currently being installed, and the Hopper machine at the Lawrence Berkeley National Laboratory (LBNL). We also do our experiments on local workstations to illustrate the interest of this research in an everyday use with local computing resources. (author) [fr

MADmap: A Massively Parallel Maximum-Likelihood Cosmic Microwave Background Map-Maker

Energy Technology Data Exchange (ETDEWEB)

Cantalupo, Christopher; Borrill, Julian; Jaffe, Andrew; Kisner, Theodore; Stompor, Radoslaw

2009-06-09

MADmap is a software application used to produce maximum-likelihood images of the sky from time-ordered data which include correlated noise, such as those gathered by Cosmic Microwave Background (CMB) experiments. It works efficiently on platforms ranging from small workstations to the most massively parallel supercomputers. Map-making is a critical step in the analysis of all CMB data sets, and the maximum-likelihood approach is the most accurate and widely applicable algorithm; however, it is a computationally challenging task. This challenge will only increase with the next generation of ground-based, balloon-borne and satellite CMB polarization experiments. The faintness of the B-mode signal that these experiments seek to measure requires them to gather enormous data sets. MADmap is already being run on up to O(1011) time samples, O(108) pixels and O(104) cores, with ongoing work to scale to the next generation of data sets and supercomputers. We describe MADmap's algorithm based around a preconditioned conjugate gradient solver, fast Fourier transforms and sparse matrix operations. We highlight MADmap's ability to address problems typically encountered in the analysis of realistic CMB data sets and describe its application to simulations of the Planck and EBEX experiments. The massively parallel and distributed implementation is detailed and scaling complexities are given for the resources required. MADmap is capable of analysing the largest data sets now being collected on computing resources currently available, and we argue that, given Moore's Law, MADmap will be capable of reducing the most massive projected data sets.

Parallel solutions of the two-group neutron diffusion equations

International Nuclear Information System (INIS)

Zee, K.S.; Turinsky, P.J.

1987-01-01

Recent efforts to adapt various numerical solution algorithms to parallel computer architectures have addressed the possibility of substantially reducing the running time of few-group neutron diffusion calculations. The authors have developed an efficient iterative parallel algorithm and an associated computer code for the rapid solution of the finite difference method representation of the two-group neutron diffusion equations on the CRAY X/MP-48 supercomputer having multi-CPUs and vector pipelines. For realistic simulation of light water reactor cores, the code employees a macroscopic depletion model with trace capability for selected fission product transients and critical boron. In addition to this, moderator and fuel temperature feedback models are also incorporated into the code. The validity of the physics models used in the code were benchmarked against qualified codes and proved accurate. This work is an extension of previous work in that various feedback effects are accounted for in the system; the entire code is structured to accommodate extensive vectorization; and an additional parallelism by multitasking is achieved not only for the solution of the matrix equations associated with the inner iterations but also for the other segments of the code, e.g., outer iterations

Role of supercomputers in magnetic fusion and energy research programs

International Nuclear Information System (INIS)

Killeen, J.

1985-06-01

The importance of computer modeling in magnetic fusion (MFE) and energy research (ER) programs is discussed. The need for the most advanced supercomputers is described, and the role of the National Magnetic Fusion Energy Computer Center in meeting these needs is explained

Supercomputer and cluster performance modeling and analysis efforts:2004-2006.

Energy Technology Data Exchange (ETDEWEB)

Sturtevant, Judith E.; Ganti, Anand; Meyer, Harold (Hal) Edward; Stevenson, Joel O.; Benner, Robert E., Jr. (.,; .); Goudy, Susan Phelps; Doerfler, Douglas W.; Domino, Stefan Paul; Taylor, Mark A.; Malins, Robert Joseph; Scott, Ryan T.; Barnette, Daniel Wayne; Rajan, Mahesh; Ang, James Alfred; Black, Amalia Rebecca; Laub, Thomas William; Vaughan, Courtenay Thomas; Franke, Brian Claude

2007-02-01

This report describes efforts by the Performance Modeling and Analysis Team to investigate performance characteristics of Sandia's engineering and scientific applications on the ASC capability and advanced architecture supercomputers, and Sandia's capacity Linux clusters. Efforts to model various aspects of these computers are also discussed. The goals of these efforts are to quantify and compare Sandia's supercomputer and cluster performance characteristics; to reveal strengths and weaknesses in such systems; and to predict performance characteristics of, and provide guidelines for, future acquisitions and follow-on systems. Described herein are the results obtained from running benchmarks and applications to extract performance characteristics and comparisons, as well as modeling efforts, obtained during the time period 2004-2006. The format of the report, with hypertext links to numerous additional documents, purposefully minimizes the document size needed to disseminate the extensive results from our research.

A Computational Fluid Dynamics Algorithm on a Massively Parallel Computer

Science.gov (United States)

Jespersen, Dennis C.; Levit, Creon

1989-01-01

The discipline of computational fluid dynamics is demanding ever-increasing computational power to deal with complex fluid flow problems. We investigate the performance of a finite-difference computational fluid dynamics algorithm on a massively parallel computer, the Connection Machine. Of special interest is an implicit time-stepping algorithm; to obtain maximum performance from the Connection Machine, it is necessary to use a nonstandard algorithm to solve the linear systems that arise in the implicit algorithm. We find that the Connection Machine ran achieve very high computation rates on both explicit and implicit algorithms. The performance of the Connection Machine puts it in the same class as today's most powerful conventional supercomputers.

Algorithm for solving the linear Cauchy problem for large systems of ordinary differential equations with the use of parallel computations

Energy Technology Data Exchange (ETDEWEB)

Moryakov, A. V., E-mail: sailor@orc.ru [National Research Centre Kurchatov Institute (Russian Federation)

2016-12-15

An algorithm for solving the linear Cauchy problem for large systems of ordinary differential equations is presented. The algorithm for systems of first-order differential equations is implemented in the EDELWEISS code with the possibility of parallel computations on supercomputers employing the MPI (Message Passing Interface) standard for the data exchange between parallel processes. The solution is represented by a series of orthogonal polynomials on the interval [0, 1]. The algorithm is characterized by simplicity and the possibility to solve nonlinear problems with a correction of the operator in accordance with the solution obtained in the previous iterative process.

Toward a Proof of Concept Cloud Framework for Physics Applications on Blue Gene Supercomputers

International Nuclear Information System (INIS)

Dreher, Patrick; Scullin, William; Vouk, Mladen

2015-01-01

Traditional high performance supercomputers are capable of delivering large sustained state-of-the-art computational resources to physics applications over extended periods of time using batch processing mode operating environments. However, today there is an increasing demand for more complex workflows that involve large fluctuations in the levels of HPC physics computational requirements during the simulations. Some of the workflow components may also require a richer set of operating system features and schedulers than normally found in a batch oriented HPC environment. This paper reports on progress toward a proof of concept design that implements a cloud framework onto BG/P and BG/Q platforms at the Argonne Leadership Computing Facility. The BG/P implementation utilizes the Kittyhawk utility and the BG/Q platform uses an experimental heterogeneous FusedOS operating system environment. Both platforms use the Virtual Computing Laboratory as the cloud computing system embedded within the supercomputer. This proof of concept design allows a cloud to be configured so that it can capitalize on the specialized infrastructure capabilities of a supercomputer and the flexible cloud configurations without resorting to virtualization. Initial testing of the proof of concept system is done using the lattice QCD MILC code. These types of user reconfigurable environments have the potential to deliver experimental schedulers and operating systems within a working HPC environment for physics computations that may be different from the native OS and schedulers on production HPC supercomputers. (paper)

Problem solving in nuclear engineering using supercomputers

International Nuclear Information System (INIS)

Schmidt, F.; Scheuermann, W.; Schatz, A.

1987-01-01

The availability of supercomputers enables the engineer to formulate new strategies for problem solving. One such strategy is the Integrated Planning and Simulation System (IPSS). With the integrated systems, simulation models with greater consistency and good agreement with actual plant data can be effectively realized. In the present work some of the basic ideas of IPSS are described as well as some of the conditions necessary to build such systems. Hardware and software characteristics as realized are outlined. (orig.) [de

A Massively Parallel Solver for the Mechanical Harmonic Analysis of Accelerator Cavities

International Nuclear Information System (INIS)

2015-01-01

ACE3P is a 3D massively parallel simulation suite that developed at SLAC National Accelerator Laboratory that can perform coupled electromagnetic, thermal and mechanical study. Effectively utilizing supercomputer resources, ACE3P has become a key simulation tool for particle accelerator R and D. A new frequency domain solver to perform mechanical harmonic response analysis of accelerator components is developed within the existing parallel framework. This solver is designed to determine the frequency response of the mechanical system to external harmonic excitations for time-efficient accurate analysis of the large-scale problems. Coupled with the ACE3P electromagnetic modules, this capability complements a set of multi-physics tools for a comprehensive study of microphonics in superconducting accelerating cavities in order to understand the RF response and feedback requirements for the operational reliability of a particle accelerator. (auth)

The strategy of parallel approaches in projects with unforeseeable uncertainty: the Manhattan case in retrospect

OpenAIRE

Sylvain Lenfle

2011-01-01

International audience; This paper discusses the literature on the management of projects with unforeseeable uncertainty. Recent work demonstrates that, when confronted with unforeseeable uncertainties, managers can adopt either a learning, trial-and-error-based strategy, or a parallel approach. In the latter, different solutions are developed in parallel and the best one is chosen when enough information becomes available. Studying the case of the Manhattan Project, which historically exempl...

Evolution of a minimal parallel programming model

International Nuclear Information System (INIS)

Lusk, Ewing; Butler, Ralph; Pieper, Steven C.

2017-01-01

Here, we take a historical approach to our presentation of self-scheduled task parallelism, a programming model with its origins in early irregular and nondeterministic computations encountered in automated theorem proving and logic programming. We show how an extremely simple task model has evolved into a system, asynchronous dynamic load balancing (ADLB), and a scalable implementation capable of supporting sophisticated applications on today’s (and tomorrow’s) largest supercomputers; and we illustrate the use of ADLB with a Green’s function Monte Carlo application, a modern, mature nuclear physics code in production use. Our lesson is that by surrendering a certain amount of generality and thus applicability, a minimal programming model (in terms of its basic concepts and the size of its application programmer interface) can achieve extreme scalability without introducing complexity.

Highly efficient parallel direct solver for solving dense complex matrix equations from method of moments

Directory of Open Access Journals (Sweden)

Yan Chen

2017-03-01

Full Text Available Based on the vectorised and cache optimised kernel, a parallel lower upper decomposition with a novel communication avoiding pivoting scheme is developed to solve dense complex matrix equations generated by the method of moments. The fine-grain data rearrangement and assembler instructions are adopted to reduce memory accessing times and improve CPU cache utilisation, which also facilitate vectorisation of the code. Through grouping processes in a binary tree, a parallel pivoting scheme is designed to optimise the communication pattern and thus reduces the solving time of the proposed solver. Two large electromagnetic radiation problems are solved on two supercomputers, respectively, and the numerical results demonstrate that the proposed method outperforms those in open source and commercial libraries.

Integration of Titan supercomputer at OLCF with ATLAS Production System

CERN Document Server

AUTHOR|(SzGeCERN)643806; The ATLAS collaboration; De, Kaushik; Klimentov, Alexei; Nilsson, Paul; Oleynik, Danila; Padolski, Siarhei; Panitkin, Sergey; Wenaus, Torre

2017-01-01

The PanDA (Production and Distributed Analysis) workload management system was developed to meet the scale and complexity of distributed computing for the ATLAS experiment. PanDA managed resources are distributed worldwide, on hundreds of computing sites, with thousands of physicists accessing hundreds of Petabytes of data and the rate of data processing already exceeds Exabyte per year. While PanDA currently uses more than 200,000 cores at well over 100 Grid sites, future LHC data taking runs will require more resources than Grid computing can possibly provide. Additional computing and storage resources are required. Therefore ATLAS is engaged in an ambitious program to expand the current computing model to include additional resources such as the opportunistic use of supercomputers. In this paper we will describe a project aimed at integration of ATLAS Production System with Titan supercomputer at Oak Ridge Leadership Computing Facility (OLCF). Current approach utilizes modified PanDA Pilot framework for jo...

Integration of Titan supercomputer at OLCF with ATLAS production system

CERN Document Server

Panitkin, Sergey; The ATLAS collaboration

2016-01-01

The PanDA (Production and Distributed Analysis) workload management system was developed to meet the scale and complexity of distributed computing for the ATLAS experiment. PanDA managed resources are distributed worldwide, on hundreds of computing sites, with thousands of physicists accessing hundreds of Petabytes of data and the rate of data processing already exceeds Exabyte per year. While PanDA currently uses more than 200,000 cores at well over 100 Grid sites, future LHC data taking runs will require more resources than Grid computing can possibly provide. Additional computing and storage resources are required. Therefore ATLAS is engaged in an ambitious program to expand the current computing model to include additional resources such as the opportunistic use of supercomputers. In this talk we will describe a project aimed at integration of ATLAS Production System with Titan supercomputer at Oak Ridge Leadership Computing Facility (OLCF). Current approach utilizes modified PanDA Pilot framework for job...

Evaluating the networking characteristics of the Cray XC-40 Intel Knights Landing-based Cori supercomputer at NERSC

Energy Technology Data Exchange (ETDEWEB)

Doerfler, Douglas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Austin, Brian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cook, Brandon [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Deslippe, Jack [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kandalla, Krishna [Cray Inc, Bloomington, MN (United States); Mendygral, Peter [Cray Inc, Bloomington, MN (United States)

2017-09-12

There are many potential issues associated with deploying the Intel Xeon Phi™ (code named Knights Landing [KNL]) manycore processor in a large-scale supercomputer. One in particular is the ability to fully utilize the high-speed communications network, given that the serial performance of a Xeon Phi TM core is a fraction of a Xeon®core. In this paper, we take a look at the trade-offs associated with allocating enough cores to fully utilize the Aries high-speed network versus cores dedicated to computation, e.g., the trade-off between MPI and OpenMP. In addition, we evaluate new features of Cray MPI in support of KNL, such as internode optimizations. We also evaluate one-sided programming models such as Unified Parallel C. We quantify the impact of the above trade-offs and features using a suite of National Energy Research Scientific Computing Center applications.

Exploring Shared-Memory Optimizations for an Unstructured Mesh CFD Application on Modern Parallel Systems

KAUST Repository

Mudigere, Dheevatsa

2015-05-01

In this work, we revisit the 1999 Gordon Bell Prize winning PETSc-FUN3D aerodynamics code, extending it with highly-tuned shared-memory parallelization and detailed performance analysis on modern highly parallel architectures. An unstructured-grid implicit flow solver, which forms the backbone of computational aerodynamics, poses particular challenges due to its large irregular working sets, unstructured memory accesses, and variable/limited amount of parallelism. This code, based on a domain decomposition approach, exposes tradeoffs between the number of threads assigned to each MPI-rank sub domain, and the total number of domains. By applying several algorithm- and architecture-aware optimization techniques for unstructured grids, we show a 6.9X speed-up in performance on a single-node Intel® XeonTM1 E5 2690 v2 processor relative to the out-of-the-box compilation. Our scaling studies on TACC Stampede supercomputer show that our optimizations continue to provide performance benefits over baseline implementation as we scale up to 256 nodes.

28 CFR 552.23 - Confrontation avoidance procedures.

Science.gov (United States)

2010-07-01

... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Confrontation avoidance procedures. 552... MANAGEMENT CUSTODY Use of Force and Application of Restraints on Inmates § 552.23 Confrontation avoidance... information about the inmate and the immediate situation. Based on their assessment of that information, they...

Performance assessment of the SIMFAP parallel cluster at IFIN-HH Bucharest

International Nuclear Information System (INIS)

Adam, Gh.; Adam, S.; Ayriyan, A.; Dushanov, E.; Hayryan, E.; Korenkov, V.; Lutsenko, A.; Mitsyn, V.; Sapozhnikova, T.; Sapozhnikov, A; Streltsova, O.; Buzatu, F.; Dulea, M.; Vasile, I.; Sima, A.; Visan, C.; Busa, J.; Pokorny, I.

2008-01-01

Performance assessment and case study outputs of the parallel SIMFAP cluster at IFIN-HH Bucharest point to its effective and reliable operation. A comparison with results on the supercomputing system in LIT-JINR Dubna adds insight on resource allocation for problem solving by parallel computing. The solution of models asking for very large numbers of knots in the discretization mesh needs the migration to high performance computing based on parallel cluster architectures. The acquisition of ready-to-use parallel computing facilities being beyond limited budgetary resources, the solution at IFIN-HH was to buy the hardware and the inter-processor network, and to implement by own efforts the open software concerning both the operating system and the parallel computing standard. The present paper provides a report demonstrating the successful solution of these tasks. The implementation of the well-known HPL (High Performance LINPACK) Benchmark points to the effective and reliable operation of the cluster. The comparison of HPL outputs obtained on parallel clusters of different magnitudes shows that there is an optimum range of the order N of the linear algebraic system over which a given parallel cluster provides optimum parallel solutions. For the SIMFAP cluster, this range can be inferred to correspond to about 1 to 2 x 10 4 linear algebraic equations. For an algorithm of polynomial complexity N α the task sharing among p processors within a parallel solution mainly follows an (N/p)α behaviour under peak performance achievement. Thus, while the problem complexity remains the same, a substantial decrease of the coefficient of the leading order of the polynomial complexity is achieved. (authors)

Accurate reaction-diffusion operator splitting on tetrahedral meshes for parallel stochastic molecular simulations

Energy Technology Data Exchange (ETDEWEB)

Hepburn, I.; De Schutter, E., E-mail: erik@oist.jp [Computational Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495 (Japan); Theoretical Neurobiology & Neuroengineering, University of Antwerp, Antwerp 2610 (Belgium); Chen, W. [Computational Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495 (Japan)

2016-08-07

Spatial stochastic molecular simulations in biology are limited by the intense computation required to track molecules in space either in a discrete time or discrete space framework, which has led to the development of parallel methods that can take advantage of the power of modern supercomputers in recent years. We systematically test suggested components of stochastic reaction-diffusion operator splitting in the literature and discuss their effects on accuracy. We introduce an operator splitting implementation for irregular meshes that enhances accuracy with minimal performance cost. We test a range of models in small-scale MPI simulations from simple diffusion models to realistic biological models and find that multi-dimensional geometry partitioning is an important consideration for optimum performance. We demonstrate performance gains of 1-3 orders of magnitude in the parallel implementation, with peak performance strongly dependent on model specification.

Novel Supercomputing Approaches for High Performance Linear Algebra Using FPGAs, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Supercomputing plays a major role in many areas of science and engineering, and it has had tremendous impact for decades in areas such as aerospace, defense, energy,...

When Do We Confront? Perceptions of Costs and Benefits Predict Confronting Discrimination on Behalf of the Self and Others

Science.gov (United States)

Good, Jessica J.; Moss-Racusin, Corinne A.; Sanchez, Diana T.

2012-01-01

Across two studies, we tested whether perceived social costs and benefits of confrontation would similarly predict confronting discrimination both when it was experienced and when it was observed as directed at others. Female undergraduate participants were asked to recall past experiences and observations of sexism, as well as their confronting…

BSMBench: a flexible and scalable supercomputer benchmark from computational particle physics

CERN Document Server

Bennett, Ed; Del Debbio, Luigi; Jordan, Kirk; Patella, Agostino; Pica, Claudio; Rago, Antonio

2016-01-01

Benchmarking plays a central role in the evaluation of High Performance Computing architectures. Several benchmarks have been designed that allow users to stress various components of supercomputers. In order for the figures they provide to be useful, benchmarks need to be representative of the most common real-world scenarios. In this work, we introduce BSMBench, a benchmarking suite derived from Monte Carlo code used in computational particle physics. The advantage of this suite (which can be freely downloaded from http://www.bsmbench.org/) over others is the capacity to vary the relative importance of computation and communication. This enables the tests to simulate various practical situations. To showcase BSMBench, we perform a wide range of tests on various architectures, from desktop computers to state-of-the-art supercomputers, and discuss the corresponding results. Possible future directions of development of the benchmark are also outlined.

Parallelization of the Coupled Earthquake Model

Science.gov (United States)

Block, Gary; Li, P. Peggy; Song, Yuhe T.

2007-01-01

This Web-based tsunami simulation system allows users to remotely run a model on JPL s supercomputers for a given undersea earthquake. At the time of this reporting, predicting tsunamis on the Internet has never happened before. This new code directly couples the earthquake model and the ocean model on parallel computers and improves simulation speed. Seismometers can only detect information from earthquakes; they cannot detect whether or not a tsunami may occur as a result of the earthquake. When earthquake-tsunami models are coupled with the improved computational speed of modern, high-performance computers and constrained by remotely sensed data, they are able to provide early warnings for those coastal regions at risk. The software is capable of testing NASA s satellite observations of tsunamis. It has been successfully tested for several historical tsunamis, has passed all alpha and beta testing, and is well documented for users.

High performance computing of density matrix renormalization group method for 2-dimensional model. Parallelization strategy toward peta computing

International Nuclear Information System (INIS)

Yamada, Susumu; Igarashi, Ryo; Machida, Masahiko; Imamura, Toshiyuki; Okumura, Masahiko; Onishi, Hiroaki

2010-01-01

We parallelize the density matrix renormalization group (DMRG) method, which is a ground-state solver for one-dimensional quantum lattice systems. The parallelization allows us to extend the applicable range of the DMRG to n-leg ladders i.e., quasi two-dimension cases. Such an extension is regarded to bring about several breakthroughs in e.g., quantum-physics, chemistry, and nano-engineering. However, the straightforward parallelization requires all-to-all communications between all processes which are unsuitable for multi-core systems, which is a mainstream of current parallel computers. Therefore, we optimize the all-to-all communications by the following two steps. The first one is the elimination of the communications between all processes by only rearranging data distribution with the communication data amount kept. The second one is the avoidance of the communication conflict by rescheduling the calculation and the communication. We evaluate the performance of the DMRG method on multi-core supercomputers and confirm that our two-steps tuning is quite effective. (author)

Intelligent Personal Supercomputer for Solving Scientific and Technical Problems

Directory of Open Access Journals (Sweden)

Khimich, O.M.

2016-09-01

Full Text Available New domestic intellіgent personal supercomputer of hybrid architecture Inparkom_pg for the mathematical modeling of processes in the defense industry, engineering, construction, etc. was developed. Intelligent software for the automatic research and tasks of computational mathematics with approximate data of different structures was designed. Applied software to provide mathematical modeling problems in construction, welding and filtration processes was implemented.

Supercomputers and the future of computational atomic scattering physics

International Nuclear Information System (INIS)

Younger, S.M.

1989-01-01

The advent of the supercomputer has opened new vistas for the computational atomic physicist. Problems of hitherto unparalleled complexity are now being examined using these new machines, and important connections with other fields of physics are being established. This talk briefly reviews some of the most important trends in computational scattering physics and suggests some exciting possibilities for the future. 7 refs., 2 figs

Proton decay: Numerical simulations confront grand unification

International Nuclear Information System (INIS)

Brower, R.C.; Maturana, G.; Giles, R.C.; Moriarty, K.J.M.; Samuel, S.

1985-01-01

The Grand Unified Theories of the electromagnetic, weak and strong interactions constitute a far reaching attempt to synthesize our knowledge of theoretical particle physics into a consistent and compelling whole. Unfortunately, many quantitative predictions of such unified theories are sensitive to the analytically intractible effects of the strong subnuclear theory (Quantum Chromodynamics or QCD). The consequence is that even ambitious experimental programs exploring weak and super-weak interaction effects often fail to give definitive theoretical tests. This paper describes large-scale calculations on a supercomputer which can help to overcome this gap between theoretical predictions and experimental results. Our focus here is on proton decay, though the methods described are useful for many weak processes. The basic algorithms for the numerical simulation of QCD are well known. We will discuss the advantages and challenges of applying these methods to weak transitions. The algorithms require a very large data base with regular data flow and are natural candidates for vectorization. Also, 32-bit floating point arithmetic is adequate. Thus they are most naturally approached using a supercomputer alone or in combination with a dedicated special purpose processor. (orig.)

3-D electromagnetic plasma particle simulations on the Intel Delta parallel computer

International Nuclear Information System (INIS)

Wang, J.; Liewer, P.C.

1994-01-01

A three-dimensional electromagnetic PIC code has been developed on the 512 node Intel Touchstone Delta MIMD parallel computer. This code is based on the General Concurrent PIC algorithm which uses a domain decomposition to divide the computation among the processors. The 3D simulation domain can be partitioned into 1-, 2-, or 3-dimensional sub-domains. Particles must be exchanged between processors as they move among the subdomains. The Intel Delta allows one to use this code for very-large-scale simulations (i.e. over 10 8 particles and 10 6 grid cells). The parallel efficiency of this code is measured, and the overall code performance on the Delta is compared with that on Cray supercomputers. It is shown that their code runs with a high parallel efficiency of ≥ 95% for large size problems. The particle push time achieved is 115 nsecs/particle/time step for 162 million particles on 512 nodes. Comparing with the performance on a single processor Cray C90, this represents a factor of 58 speedup. The code uses a finite-difference leap frog method for field solve which is significantly more efficient than fast fourier transforms on parallel computers. The performance of this code on the 128 node Cray T3D will also be discussed

Mathematical methods and supercomputing in nuclear applications. Proceedings. Vol. 2

International Nuclear Information System (INIS)

Kuesters, H.; Stein, E.; Werner, W.

1993-04-01

All papers of the two volumes are separately indexed in the data base. Main topics are: Progress in advanced numerical techniques, fluid mechanics, on-line systems, artificial intelligence applications, nodal methods reactor kinetics, reactor design, supercomputer architecture, probabilistic estimation of risk assessment, methods in transport theory, advances in Monte Carlo techniques, and man-machine interface. (orig.)

Mathematical methods and supercomputing in nuclear applications. Proceedings. Vol. 1

International Nuclear Information System (INIS)

Kuesters, H.; Stein, E.; Werner, W.

1993-04-01

All papers of the two volumes are separately indexed in the data base. Main topics are: Progress in advanced numerical techniques, fluid mechanics, on-line systems, artificial intelligence applications, nodal methods reactor kinetics, reactor design, supercomputer architecture, probabilistic estimation of risk assessment, methods in transport theory, advances in Monte Carlo techniques, and man-machine interface. (orig.)

Wastewater Use in Irrigated Agriculture : Confronting the Livelihood ...

International Development Research Centre (IDRC) Digital Library (Canada)

Wastewater Use in Irrigated Agriculture : Confronting the Livelihood and Environmental Realities. Couverture du livre Wastewater Use in Irrigated Agriculture: Confronting the Livelihood and Environmental Realities. Directeur(s) : Christopher Scott, Naser I. Faruqui et Liqa Raschid. Maison(s) d'édition : CABI, IWMI, CRDI.

Supercomputer debugging workshop `92

Energy Technology Data Exchange (ETDEWEB)

Brown, J.S.

1993-02-01

This report contains papers or viewgraphs on the following topics: The ABCs of Debugging in the 1990s; Cray Computer Corporation; Thinking Machines Corporation; Cray Research, Incorporated; Sun Microsystems, Inc; Kendall Square Research; The Effects of Register Allocation and Instruction Scheduling on Symbolic Debugging; Debugging Optimized Code: Currency Determination with Data Flow; A Debugging Tool for Parallel and Distributed Programs; Analyzing Traces of Parallel Programs Containing Semaphore Synchronization; Compile-time Support for Efficient Data Race Detection in Shared-Memory Parallel Programs; Direct Manipulation Techniques for Parallel Debuggers; Transparent Observation of XENOOPS Objects; A Parallel Software Monitor for Debugging and Performance Tools on Distributed Memory Multicomputers; Profiling Performance of Inter-Processor Communications in an iWarp Torus; The Application of Code Instrumentation Technology in the Los Alamos Debugger; and CXdb: The Road to Remote Debugging.

Efficient parallel simulation of CO2 geologic sequestration in saline aquifers

International Nuclear Information System (INIS)

Zhang, Keni; Doughty, Christine; Wu, Yu-Shu; Pruess, Karsten

2007-01-01

An efficient parallel simulator for large-scale, long-term CO2 geologic sequestration in saline aquifers has been developed. The parallel simulator is a three-dimensional, fully implicit model that solves large, sparse linear systems arising from discretization of the partial differential equations for mass and energy balance in porous and fractured media. The simulator is based on the ECO2N module of the TOUGH2code and inherits all the process capabilities of the single-CPU TOUGH2code, including a comprehensive description of the thermodynamics and thermophysical properties of H2O-NaCl- CO2 mixtures, modeling single and/or two-phase isothermal or non-isothermal flow processes, two-phase mixtures, fluid phases appearing or disappearing, as well as salt precipitation or dissolution. The new parallel simulator uses MPI for parallel implementation, the METIS software package for simulation domain partitioning, and the iterative parallel linear solver package Aztec for solving linear equations by multiple processors. In addition, the parallel simulator has been implemented with an efficient communication scheme. Test examples show that a linear or super-linear speedup can be obtained on Linux clusters as well as on supercomputers. Because of the significant improvement in both simulation time and memory requirement, the new simulator provides a powerful tool for tackling larger scale and more complex problems than can be solved by single-CPU codes. A high-resolution simulation example is presented that models buoyant convection, induced by a small increase in brine density caused by dissolution of CO2

Grid-based Parallel Data Streaming Implemented for the Gyrokinetic Toroidal Code

International Nuclear Information System (INIS)

Klasky, S.; Ethier, S.; Lin, Z.; Martins, K.; McCune, D.; Samtaney, R.

2003-01-01

We have developed a threaded parallel data streaming approach using Globus to transfer multi-terabyte simulation data from a remote supercomputer to the scientist's home analysis/visualization cluster, as the simulation executes, with negligible overhead. Data transfer experiments show that this concurrent data transfer approach is more favorable compared with writing to local disk and then transferring this data to be post-processed. The present approach is conducive to using the grid to pipeline the simulation with post-processing and visualization. We have applied this method to the Gyrokinetic Toroidal Code (GTC), a 3-dimensional particle-in-cell code used to study microturbulence in magnetic confinement fusion from first principles plasma theory

Personal Supercomputing for Monte Carlo Simulation Using a GPU

Energy Technology Data Exchange (ETDEWEB)

Oh, Jae-Yong; Koo, Yang-Hyun; Lee, Byung-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2008-05-15

Since the usability, accessibility, and maintenance of a personal computer (PC) are very good, a PC is a useful computer simulation tool for researchers. It has enough calculation power to simulate a small scale system with the improved performance of a PC's CPU. However, if a system is large or long time scale, we need a cluster computer or supercomputer. Recently great changes have occurred in the PC calculation environment. A graphic process unit (GPU) on a graphic card, only used to calculate display data, has a superior calculation capability to a PC's CPU. This GPU calculation performance is a match for the supercomputer in 2000. Although it has such a great calculation potential, it is not easy to program a simulation code for GPU due to difficult programming techniques for converting a calculation matrix to a 3D rendering image using graphic APIs. In 2006, NVIDIA provided the Software Development Kit (SDK) for the programming environment for NVIDIA's graphic cards, which is called the Compute Unified Device Architecture (CUDA). It makes the programming on the GPU easy without knowledge of the graphic APIs. This paper describes the basic architectures of NVIDIA's GPU and CUDA, and carries out a performance benchmark for the Monte Carlo simulation.

Personal Supercomputing for Monte Carlo Simulation Using a GPU

International Nuclear Information System (INIS)

Oh, Jae-Yong; Koo, Yang-Hyun; Lee, Byung-Ho

2008-01-01

Since the usability, accessibility, and maintenance of a personal computer (PC) are very good, a PC is a useful computer simulation tool for researchers. It has enough calculation power to simulate a small scale system with the improved performance of a PC's CPU. However, if a system is large or long time scale, we need a cluster computer or supercomputer. Recently great changes have occurred in the PC calculation environment. A graphic process unit (GPU) on a graphic card, only used to calculate display data, has a superior calculation capability to a PC's CPU. This GPU calculation performance is a match for the supercomputer in 2000. Although it has such a great calculation potential, it is not easy to program a simulation code for GPU due to difficult programming techniques for converting a calculation matrix to a 3D rendering image using graphic APIs. In 2006, NVIDIA provided the Software Development Kit (SDK) for the programming environment for NVIDIA's graphic cards, which is called the Compute Unified Device Architecture (CUDA). It makes the programming on the GPU easy without knowledge of the graphic APIs. This paper describes the basic architectures of NVIDIA's GPU and CUDA, and carries out a performance benchmark for the Monte Carlo simulation

A hybrid method for the parallel computation of Green's functions

International Nuclear Information System (INIS)

Petersen, Dan Erik; Li Song; Stokbro, Kurt; Sorensen, Hans Henrik B.; Hansen, Per Christian; Skelboe, Stig; Darve, Eric

2009-01-01

Quantum transport models for nanodevices using the non-equilibrium Green's function method require the repeated calculation of the block tridiagonal part of the Green's and lesser Green's function matrices. This problem is related to the calculation of the inverse of a sparse matrix. Because of the large number of times this calculation needs to be performed, this is computationally very expensive even on supercomputers. The classical approach is based on recurrence formulas which cannot be efficiently parallelized. This practically prevents the solution of large problems with hundreds of thousands of atoms. We propose new recurrences for a general class of sparse matrices to calculate Green's and lesser Green's function matrices which extend formulas derived by Takahashi and others. We show that these recurrences may lead to a dramatically reduced computational cost because they only require computing a small number of entries of the inverse matrix. Then, we propose a parallelization strategy for block tridiagonal matrices which involves a combination of Schur complement calculations and cyclic reduction. It achieves good scalability even on problems of modest size.

Recognizing, Confronting, and Eliminating Workplace Bullying.

Science.gov (United States)

Berry, Peggy Ann; Gillespie, Gordon L; Fisher, Bonnie S; Gormley, Denise K

2016-07-01

Workplace bullying (WPB) behaviors negatively affect nurse productivity, satisfaction, and retention, and hinder safe patient care. The purpose of this article is to define WPB, differentiate between incivility and WPB, and recommend actions to prevent WPB behaviors. Informed occupational and environmental health nurses and nurse leaders must recognize, confront, and eliminate WPB in their facilities and organizations. Recognizing, confronting, and eliminating WPB behaviors in health care is a crucial first step toward sustained improvements in patient care quality and the health and safety of health care employees. © 2016 The Author(s).

Confronting new technological challenges in HEP

International Nuclear Information System (INIS)

Savoy-Navarro, Aurore

2000-01-01

The new technological challenges that will have to be confronted in HEP are mainly due to the new physics issues. What is beyond the standard model? That is the question. This review will first list the physics demands in order to explore this unknown world. It will then show with appropriate examples, how the new physics will require confronting new technological challenges in: designing new accelerators, developing new detectors, designing new front-end readout systems and using the new software and hardware tools for the online readout and DAQ systems

A comprehensive study of MPI parallelism in three-dimensional discrete element method (DEM) simulation of complex-shaped granular particles

Science.gov (United States)

Yan, Beichuan; Regueiro, Richard A.

2018-02-01

A three-dimensional (3D) DEM code for simulating complex-shaped granular particles is parallelized using message-passing interface (MPI). The concepts of link-block, ghost/border layer, and migration layer are put forward for design of the parallel algorithm, and theoretical scalability function of 3-D DEM scalability and memory usage is derived. Many performance-critical implementation details are managed optimally to achieve high performance and scalability, such as: minimizing communication overhead, maintaining dynamic load balance, handling particle migrations across block borders, transmitting C++ dynamic objects of particles between MPI processes efficiently, eliminating redundant contact information between adjacent MPI processes. The code executes on multiple US Department of Defense (DoD) supercomputers and tests up to 2048 compute nodes for simulating 10 million three-axis ellipsoidal particles. Performance analyses of the code including speedup, efficiency, scalability, and granularity across five orders of magnitude of simulation scale (number of particles) are provided, and they demonstrate high speedup and excellent scalability. It is also discovered that communication time is a decreasing function of the number of compute nodes in strong scaling measurements. The code's capability of simulating a large number of complex-shaped particles on modern supercomputers will be of value in both laboratory studies on micromechanical properties of granular materials and many realistic engineering applications involving granular materials.

Massively parallel simulations of strong electronic correlations: Realistic Coulomb vertex and multiplet effects

Science.gov (United States)

Baumgärtel, M.; Ghanem, K.; Kiani, A.; Koch, E.; Pavarini, E.; Sims, H.; Zhang, G.

2017-07-01

We discuss the efficient implementation of general impurity solvers for dynamical mean-field theory. We show that both Lanczos and quantum Monte Carlo in different flavors (Hirsch-Fye, continuous-time hybridization- and interaction-expansion) exhibit excellent scaling on massively parallel supercomputers. We apply these algorithms to simulate realistic model Hamiltonians including the full Coulomb vertex, crystal-field splitting, and spin-orbit interaction. We discuss how to remove the sign problem in the presence of non-diagonal crystal-field and hybridization matrices. We show how to extract the physically observable quantities from imaginary time data, in particular correlation functions and susceptibilities. Finally, we present benchmarks and applications for representative correlated systems.

Self-Confrontation of Teachers.

Science.gov (United States)

Schmuck, Richard A.

Simply presenting teachers with information about discrepancies between their ideal and their actual classroom performances does not, in itself, lead to constructive change. In part, this is because teachers confronted with such discrepancies experience dissonance which often gives rise to anxiety. This paper discusses the psychological processes…

Confronting quasi-exponential inflation with WMAP seven

International Nuclear Information System (INIS)

Pal, Barun Kumar; Pal, Supratik; Basu, B.

2012-01-01

We confront quasi-exponential models of inflation with WMAP seven years dataset using Hamilton Jacobi formalism. With a phenomenological Hubble parameter, representing quasi exponential inflation, we develop the formalism and subject the analysis to confrontation with WMAP seven using the publicly available code CAMB. The observable parameters are found to fair extremely well with WMAP seven. We also obtain a ratio of tensor to scalar amplitudes which may be detectable in PLANCK

Computational Science with the Titan Supercomputer: Early Outcomes and Lessons Learned

Science.gov (United States)

Wells, Jack

2014-03-01

Modeling and simulation with petascale computing has supercharged the process of innovation and understanding, dramatically accelerating time-to-insight and time-to-discovery. This presentation will focus on early outcomes from the Titan supercomputer at the Oak Ridge National Laboratory. Titan has over 18,000 hybrid compute nodes consisting of both CPUs and GPUs. In this presentation, I will discuss the lessons we have learned in deploying Titan and preparing applications to move from conventional CPU architectures to a hybrid machine. I will present early results of materials applications running on Titan and the implications for the research community as we prepare for exascale supercomputer in the next decade. Lastly, I will provide an overview of user programs at the Oak Ridge Leadership Computing Facility with specific information how researchers may apply for allocations of computing resources. This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725.

H5Part A Portable High Performance Parallel Data Interface for Particle Simulations

CERN Document Server

Adelmann, Andreas; Shalf, John M; Siegerist, Cristina

2005-01-01

Largest parallel particle simulations, in six dimensional phase space generate wast amont of data. It is also desirable to share data and data analysis tools such as ParViT (Particle Visualization Toolkit) among other groups who are working on particle-based accelerator simulations. We define a very simple file schema built on top of HDF5 (Hierarchical Data Format version 5) as well as an API that simplifies the reading/writing of the data to the HDF5 file format. HDF5 offers a self-describing machine-independent binary file format that supports scalable parallel I/O performance for MPI codes on a variety of supercomputing systems and works equally well on laptop computers. The API is available for C, C++, and Fortran codes. The file format will enable disparate research groups with very different simulation implementations to share data transparently and share data analysis tools. For instance, the common file format will enable groups that depend on completely different simulation implementations to share c...

Visualizing Network Traffic to Understand the Performance of Massively Parallel Simulations

KAUST Repository

Landge, A. G.

2012-12-01

The performance of massively parallel applications is often heavily impacted by the cost of communication among compute nodes. However, determining how to best use the network is a formidable task, made challenging by the ever increasing size and complexity of modern supercomputers. This paper applies visualization techniques to aid parallel application developers in understanding the network activity by enabling a detailed exploration of the flow of packets through the hardware interconnect. In order to visualize this large and complex data, we employ two linked views of the hardware network. The first is a 2D view, that represents the network structure as one of several simplified planar projections. This view is designed to allow a user to easily identify trends and patterns in the network traffic. The second is a 3D view that augments the 2D view by preserving the physical network topology and providing a context that is familiar to the application developers. Using the massively parallel multi-physics code pF3D as a case study, we demonstrate that our tool provides valuable insight that we use to explain and optimize pF3D-s performance on an IBM Blue Gene/P system. © 1995-2012 IEEE.

Computational fluid dynamics research at the United Technologies Research Center requiring supercomputers

Science.gov (United States)

Landgrebe, Anton J.

1987-01-01

An overview of research activities at the United Technologies Research Center (UTRC) in the area of Computational Fluid Dynamics (CFD) is presented. The requirement and use of various levels of computers, including supercomputers, for the CFD activities is described. Examples of CFD directed toward applications to helicopters, turbomachinery, heat exchangers, and the National Aerospace Plane are included. Helicopter rotor codes for the prediction of rotor and fuselage flow fields and airloads were developed with emphasis on rotor wake modeling. Airflow and airload predictions and comparisons with experimental data are presented. Examples are presented of recent parabolized Navier-Stokes and full Navier-Stokes solutions for hypersonic shock-wave/boundary layer interaction, and hydrogen/air supersonic combustion. In addition, other examples of CFD efforts in turbomachinery Navier-Stokes methodology and separated flow modeling are presented. A brief discussion of the 3-tier scientific computing environment is also presented, in which the researcher has access to workstations, mid-size computers, and supercomputers.

An efficient parallel algorithm: Poststack and prestack Kirchhoff 3D depth migration using flexi-depth iterations

Science.gov (United States)

Rastogi, Richa; Srivastava, Abhishek; Khonde, Kiran; Sirasala, Kirannmayi M.; Londhe, Ashutosh; Chavhan, Hitesh

2015-07-01

This paper presents an efficient parallel 3D Kirchhoff depth migration algorithm suitable for current class of multicore architecture. The fundamental Kirchhoff depth migration algorithm exhibits inherent parallelism however, when it comes to 3D data migration, as the data size increases the resource requirement of the algorithm also increases. This challenges its practical implementation even on current generation high performance computing systems. Therefore a smart parallelization approach is essential to handle 3D data for migration. The most compute intensive part of Kirchhoff depth migration algorithm is the calculation of traveltime tables due to its resource requirements such as memory/storage and I/O. In the current research work, we target this area and develop a competent parallel algorithm for post and prestack 3D Kirchhoff depth migration, using hybrid MPI+OpenMP programming techniques. We introduce a concept of flexi-depth iterations while depth migrating data in parallel imaging space, using optimized traveltime table computations. This concept provides flexibility to the algorithm by migrating data in a number of depth iterations, which depends upon the available node memory and the size of data to be migrated during runtime. Furthermore, it minimizes the requirements of storage, I/O and inter-node communication, thus making it advantageous over the conventional parallelization approaches. The developed parallel algorithm is demonstrated and analysed on Yuva II, a PARAM series of supercomputers. Optimization, performance and scalability experiment results along with the migration outcome show the effectiveness of the parallel algorithm.

Space-charge-dominated beam dynamics simulations using the massively parallel processors (MPPs) of the Cray T3D

International Nuclear Information System (INIS)

Liu, H.

1996-01-01

Computer simulations using the multi-particle code PARMELA with a three-dimensional point-by-point space charge algorithm have turned out to be very helpful in supporting injector commissioning and operations at Thomas Jefferson National Accelerator Facility (Jefferson Lab, formerly called CEBAF). However, this algorithm, which defines a typical N 2 problem in CPU time scaling, is very time-consuming when N, the number of macro-particles, is large. Therefore, it is attractive to use massively parallel processors (MPPs) to speed up the simulations. Motivated by this, the authors modified the space charge subroutine for using the MPPs of the Cray T3D. The techniques used to parallelize and optimize the code on the T3D are discussed in this paper. The performance of the code on the T3D is examined in comparison with a Parallel Vector Processing supercomputer of the Cray C90 and an HP 735/15 high-end workstation

Confronting Ambiguity in Science

Science.gov (United States)

Emery, Katherine; Harlow, Danielle; Whitmer, Ali; Gaines, Steven

2015-01-01

People are regularly confronted with environmental and science-related issues presented to them in newspapers, on television, or even in their own doctor's office. Often the information they use to inform their decisions on matters of science may be ambiguous and contradictory. This article presents an activity that investigates how students deal…

Some computational challenges of developing efficient parallel algorithms for data-dependent computations in thermal-hydraulics supercomputer applications

International Nuclear Information System (INIS)

Woodruff, S.B.

1992-01-01

The Transient Reactor Analysis Code (TRAC), which features a two- fluid treatment of thermal-hydraulics, is designed to model transients in water reactors and related facilities. One of the major computational costs associated with TRAC and similar codes is calculating constitutive coefficients. Although the formulations for these coefficients are local the costs are flow-regime- or data-dependent; i.e., the computations needed for a given spatial node often vary widely as a function of time. Consequently, poor load balancing will degrade efficiency on either vector or data parallel architectures when the data are organized according to spatial location. Unfortunately, a general automatic solution to the load-balancing problem associated with data-dependent computations is not yet available for massively parallel architectures. This document discusses why developers algorithms, such as a neural net representation, that do not exhibit algorithms, such as a neural net representation, that do not exhibit load-balancing problems

Programs Lucky and LuckyC - 3D parallel transport codes for the multi-group transport equation solution for XYZ geometry by Pm Sn method

International Nuclear Information System (INIS)

Moriakov, A.; Vasyukhno, V.; Netecha, M.; Khacheresov, G.

2003-01-01

Powerful supercomputers are available today. MBC-1000M is one of Russian supercomputers that may be used by distant way access. Programs LUCKY and LUCKY C were created to work for multi-processors systems. These programs have algorithms created especially for these computers and used MPI (message passing interface) service for exchanges between processors. LUCKY may resolved shielding tasks by multigroup discreet ordinate method. LUCKY C may resolve critical tasks by same method. Only XYZ orthogonal geometry is available. Under little space steps to approximate discreet operator this geometry may be used as universal one to describe complex geometrical structures. Cross section libraries are used up to P8 approximation by Legendre polynomials for nuclear data in GIT format. Programming language is Fortran-90. 'Vector' processors may be used that lets get a time profit up to 30 times. But unfortunately MBC-1000M has not these processors. Nevertheless sufficient value for efficiency of parallel calculations was obtained under 'space' (LUCKY) and 'space and energy' (LUCKY C ) paralleling. AUTOCAD program is used to control geometry after a treatment of input data. Programs have powerful geometry module, it is a beautiful tool to achieve any geometry. Output results may be processed by graphic programs on personal computer. (authors)

A supercomputer for parallel data analysis

International Nuclear Information System (INIS)

Kolpakov, I.F.; Senner, A.E.; Smirnov, V.A.

1987-01-01

The project of a powerful multiprocessor system is proposed. The main purpose of the project is to develop a low cost computer system with a processing rate of a few tens of millions of operations per second. The system solves many problems of data analysis from high-energy physics spectrometers. It includes about 70 MOTOROLA-68020 based powerful slave microprocessor boards liaisoned through the VME crates to a host VAX micro computer. Each single microprocessor board performs the same algorithm requiring large computing time. The host computer distributes data over the microprocessor board, collects and combines obtained results. The architecture of the system easily allows one to use it in the real time mode

HPL and STREAM Benchmarks on SANAM Supercomputer

KAUST Repository

Bin Sulaiman, Riman A.

2017-01-01

SANAM supercomputer was jointly built by KACST and FIAS in 2012 ranking second that year in the Green500 list with a power efficiency of 2.3 GFLOPS/W (Rohr et al., 2014). It is a heterogeneous accelerator-based HPC system that has 300 compute nodes. Each node includes two Intel Xeon E5?2650 CPUs, two AMD FirePro S10000 dual GPUs and 128 GiB of main memory. In this work, the seven benchmarks of HPCC were installed and configured to reassess the performance of SANAM, as part of an unpublished master thesis, after it was reassembled in the Kingdom of Saudi Arabia. We present here detailed results of HPL and STREAM benchmarks.

HPL and STREAM Benchmarks on SANAM Supercomputer

KAUST Repository

Bin Sulaiman, Riman A.

2017-03-13

SANAM supercomputer was jointly built by KACST and FIAS in 2012 ranking second that year in the Green500 list with a power efficiency of 2.3 GFLOPS/W (Rohr et al., 2014). It is a heterogeneous accelerator-based HPC system that has 300 compute nodes. Each node includes two Intel Xeon E5?2650 CPUs, two AMD FirePro S10000 dual GPUs and 128 GiB of main memory. In this work, the seven benchmarks of HPCC were installed and configured to reassess the performance of SANAM, as part of an unpublished master thesis, after it was reassembled in the Kingdom of Saudi Arabia. We present here detailed results of HPL and STREAM benchmarks.

GPAW - massively parallel electronic structure calculations with Python-based software

DEFF Research Database (Denmark)

Enkovaara, Jussi; Romero, Nichols A.; Shende, Sameer

2011-01-01

of the productivity enhancing features together with a good numerical performance. We have used this approach in implementing an electronic structure simulation software GPAW using the combination of Python and C programming languages. While the chosen approach works well in standard workstations and Unix...... popular choice. While dynamic, interpreted languages, such as Python, can increase the effciency of programmer, they cannot compete directly with the raw performance of compiled languages. However, by using an interpreted language together with a compiled language, it is possible to have most...... environments, massively parallel supercomputing systems can present some challenges in porting, debugging and profiling the software. In this paper we describe some details of the implementation and discuss the advantages and challenges of the combined Python/C approach. We show that despite the challenges...

Parallel time domain solvers for electrically large transient scattering problems

KAUST Repository

Liu, Yang

2014-09-26

Marching on in time (MOT)-based integral equation solvers represent an increasingly appealing avenue for analyzing transient electromagnetic interactions with large and complex structures. MOT integral equation solvers for analyzing electromagnetic scattering from perfect electrically conducting objects are obtained by enforcing electric field boundary conditions and implicitly time advance electric surface current densities by iteratively solving sparse systems of equations at all time steps. Contrary to finite difference and element competitors, these solvers apply to nonlinear and multi-scale structures comprising geometrically intricate and deep sub-wavelength features residing atop electrically large platforms. Moreover, they are high-order accurate, stable in the low- and high-frequency limits, and applicable to conducting and penetrable structures represented by highly irregular meshes. This presentation reviews some recent advances in the parallel implementations of time domain integral equation solvers, specifically those that leverage multilevel plane-wave time-domain algorithm (PWTD) on modern manycore computer architectures including graphics processing units (GPUs) and distributed memory supercomputers. The GPU-based implementation achieves at least one order of magnitude speedups compared to serial implementations while the distributed parallel implementation are highly scalable to thousands of compute-nodes. A distributed parallel PWTD kernel has been adopted to solve time domain surface/volume integral equations (TDSIE/TDVIE) for analyzing transient scattering from large and complex-shaped perfectly electrically conducting (PEC)/dielectric objects involving ten million/tens of millions of spatial unknowns.

Confronting an Augmented Reality

Science.gov (United States)

Munnerley, Danny; Bacon, Matt; Wilson, Anna; Steele, James; Hedberg, John; Fitzgerald, Robert

2012-01-01

How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself ? In this article, we seek to initiate a discussion that focuses on these questions, and…

Confronting an augmented reality

Directory of Open Access Journals (Sweden)

John Hedberg

2012-08-01

Full Text Available How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself? In this article, we seek to initiate a discussion that focuses on these questions, and suggest that they be used as drivers for research into effective educational applications of augmented reality. We discuss how multi-modal, sensorial augmentation of reality links to existing theories of education and learning, focusing on ideas of cognitive dissonance and the confrontation of new realities implied by exposure to new and varied perspectives. We also discuss connections with broader debates brought on by the social and cultural changes wrought by the increased digitalisation of our lives, especially the concept of the extended mind. Rather than offer a prescription for augmentation, our intention is to throw open debate and to provoke deep thinking about what interacting with and creating an augmented reality might mean for both teacher and learner.

Numerical methods and parallel algorithms for fast transient strongly coupled fluid-structure dynamics

International Nuclear Information System (INIS)

Faucher, V.

2014-01-01

This HDR is dedicated to the research in the framework of fast transient dynamics for industrial fluid-structure systems carried in the Laboratory of Dynamic Studies from CEA, implementing new numerical methods for the modelling of complex systems and the parallel solution of large coupled problems on supercomputers. One key issue for the proposed approaches is the limitation to its minimum of the number of non-physical parameters, to cope with constraints arising from the area of usage of the concepts: safety for both nuclear applications (CEA, EDF) and aeronautics (ONERA), protection of the citizen (EC/JRC) in particular. Kinematic constraints strongly coupling structures (namely through unilateral contact) or fluid and structures (with both conformant or non-conformant meshes depending on the geometrical situation) are handled through exact methods including Lagrange Multipliers, with consequences on the solution strategy to be dealt with. This latter aspect makes EPX, the simulation code where the methods are integrated, a singular tool in the community of fast transient dynamics software. The document mainly relies on a description of the modelling needs for industrial fast transient scenarios, for nuclear applications in particular, and the proposed solutions built in the framework of the collaboration between CEA, EDF (via the LaMSID laboratory) and the LaMCoS laboratory from INSA Lyon. The main considered examples are the tearing of the fluid-filled tank after impact, the Code Disruptive Accident for a Generation IV reactor or the ruin of reinforced concrete structures under impact. Innovative models and parallel algorithms are thus proposed, allowing to carry out with robustness and performance the corresponding simulations on supercomputers made of interconnected multi-core nodes, with a strict preservation of the quality of the physical solution. This was particularly the main point of the ANR RePDyn project (2010-2013), with CEA as the pilot. (author

To Confront Versus not to Confront: Women’s Perception of Sexual Harassment

Directory of Open Access Journals (Sweden)

María del Carmen Herrera

2017-05-01

Full Text Available Current research has postulated that sexual harassment is one of the most serious social problems. Perceptions of sexual harassment vary according to some factors: gender, context, and perceiver’s ideology. The strategies most commonly used by women to cope with harassment range from avoiding or ignoring the harasser to confronting the harasser or reporting the incident. The aim of this study was to explore women’s perception of sexual harassment, and to assess the implications of different victim responses to harassment. A total of 138 women were administered a questionnaire where the type of harassment, and victim response were manipulated. Moreover, the influence of ideological variables (i.e. ambivalent sexism and the acceptance of myths of sexual harassment on perception was assessed. Results show perception of sexual harassment was lower in gender harassment than in unwanted sexual attention and participants believed women who confronted their harasser would be evaluated negatively by men. Furthermore, effects of ideology on perception of harassment were found. The results underscore the complexities involved in defining certain behaviours as harassment, and the implications of different victim responses to harassment.

Supercomputing Centers and Electricity Service Providers

DEFF Research Database (Denmark)

Patki, Tapasya; Bates, Natalie; Ghatikar, Girish

2016-01-01

from a detailed, quantitative survey-based analysis and compare the perspectives of the European grid and SCs to the ones of the United States (US). We then show that contrary to the expectation, SCs in the US are more open toward cooperating and developing demand-management strategies with their ESPs......Supercomputing Centers (SCs) have high and variable power demands, which increase the challenges of the Electricity Service Providers (ESPs) with regards to efficient electricity distribution and reliable grid operation. High penetration of renewable energy generation further exacerbates...... this problem. In order to develop a symbiotic relationship between the SCs and their ESPs and to support effective power management at all levels, it is critical to understand and analyze how the existing relationships were formed and how these are expected to evolve. In this paper, we first present results...

Supercomputer debugging workshop '92

Energy Technology Data Exchange (ETDEWEB)

Brown, J.S.

1993-01-01

This report contains papers or viewgraphs on the following topics: The ABCs of Debugging in the 1990s; Cray Computer Corporation; Thinking Machines Corporation; Cray Research, Incorporated; Sun Microsystems, Inc; Kendall Square Research; The Effects of Register Allocation and Instruction Scheduling on Symbolic Debugging; Debugging Optimized Code: Currency Determination with Data Flow; A Debugging Tool for Parallel and Distributed Programs; Analyzing Traces of Parallel Programs Containing Semaphore Synchronization; Compile-time Support for Efficient Data Race Detection in Shared-Memory Parallel Programs; Direct Manipulation Techniques for Parallel Debuggers; Transparent Observation of XENOOPS Objects; A Parallel Software Monitor for Debugging and Performance Tools on Distributed Memory Multicomputers; Profiling Performance of Inter-Processor Communications in an iWarp Torus; The Application of Code Instrumentation Technology in the Los Alamos Debugger; and CXdb: The Road to Remote Debugging.

Optimization of sparse matrix-vector multiplication on emerging multicore platforms

Energy Technology Data Exchange (ETDEWEB)

Williams, Samuel [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Oliker, Leonid [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Vuduc, Richard [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shalf, John [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yelick, Katherine [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Demmel, James [Univ. of California, Berkeley, CA (United States)

2007-01-01

We are witnessing a dramatic change in computer architecture due to the multicore paradigm shift, as every electronic device from cell phones to supercomputers confronts parallelism of unprecedented scale. To fully unleash the potential of these systems, the HPC community must develop multicore specific optimization methodologies for important scientific computations. In this work, we examine sparse matrix-vector multiply (SpMV) - one of the most heavily used kernels in scientific computing - across a broad spectrum of multicore designs. Our experimental platform includes the homogeneous AMD dual-core and Intel quad-core designs, the heterogeneous STI Cell, as well as the first scientific study of the highly multithreaded Sun Niagara2. We present several optimization strategies especially effective for the multicore environment, and demonstrate significant performance improvements compared to existing state-of-the-art serial and parallel SpMV implementations. Additionally, we present key insights into the architectural tradeoffs of leading multicore design strategies, in the context of demanding memory-bound numerical algorithms.

Massively parallel electrical conductivity imaging of the subsurface: Applications to hydrocarbon exploration

Science.gov (United States)

Newman, Gregory A.; Commer, Michael

2009-07-01

Three-dimensional (3D) geophysical imaging is now receiving considerable attention for electrical conductivity mapping of potential offshore oil and gas reservoirs. The imaging technology employs controlled source electromagnetic (CSEM) and magnetotelluric (MT) fields and treats geological media exhibiting transverse anisotropy. Moreover when combined with established seismic methods, direct imaging of reservoir fluids is possible. Because of the size of the 3D conductivity imaging problem, strategies are required exploiting computational parallelism and optimal meshing. The algorithm thus developed has been shown to scale to tens of thousands of processors. In one imaging experiment, 32,768 tasks/processors on the IBM Watson Research Blue Gene/L supercomputer were successfully utilized. Over a 24 hour period we were able to image a large scale field data set that previously required over four months of processing time on distributed clusters based on Intel or AMD processors utilizing 1024 tasks on an InfiniBand fabric. Electrical conductivity imaging using massively parallel computational resources produces results that cannot be obtained otherwise and are consistent with timeframes required for practical exploration problems.

Massively parallel electrical conductivity imaging of the subsurface: Applications to hydrocarbon exploration

International Nuclear Information System (INIS)

Newman, Gregory A; Commer, Michael

2009-01-01

Three-dimensional (3D) geophysical imaging is now receiving considerable attention for electrical conductivity mapping of potential offshore oil and gas reservoirs. The imaging technology employs controlled source electromagnetic (CSEM) and magnetotelluric (MT) fields and treats geological media exhibiting transverse anisotropy. Moreover when combined with established seismic methods, direct imaging of reservoir fluids is possible. Because of the size of the 3D conductivity imaging problem, strategies are required exploiting computational parallelism and optimal meshing. The algorithm thus developed has been shown to scale to tens of thousands of processors. In one imaging experiment, 32,768 tasks/processors on the IBM Watson Research Blue Gene/L supercomputer were successfully utilized. Over a 24 hour period we were able to image a large scale field data set that previously required over four months of processing time on distributed clusters based on Intel or AMD processors utilizing 1024 tasks on an InfiniBand fabric. Electrical conductivity imaging using massively parallel computational resources produces results that cannot be obtained otherwise and are consistent with timeframes required for practical exploration problems.

Building more powerful less expensive supercomputers using Processing-In-Memory (PIM) LDRD final report.

Energy Technology Data Exchange (ETDEWEB)

Murphy, Richard C.

2009-09-01

This report details the accomplishments of the 'Building More Powerful Less Expensive Supercomputers Using Processing-In-Memory (PIM)' LDRD ('PIM LDRD', number 105809) for FY07-FY09. Latency dominates all levels of supercomputer design. Within a node, increasing memory latency, relative to processor cycle time, limits CPU performance. Between nodes, the same increase in relative latency impacts scalability. Processing-In-Memory (PIM) is an architecture that directly addresses this problem using enhanced chip fabrication technology and machine organization. PIMs combine high-speed logic and dense, low-latency, high-bandwidth DRAM, and lightweight threads that tolerate latency by performing useful work during memory transactions. This work examines the potential of PIM-based architectures to support mission critical Sandia applications and an emerging class of more data intensive informatics applications. This work has resulted in a stronger architecture/implementation collaboration between 1400 and 1700. Additionally, key technology components have impacted vendor roadmaps, and we are in the process of pursuing these new collaborations. This work has the potential to impact future supercomputer design and construction, reducing power and increasing performance. This final report is organized as follow: this summary chapter discusses the impact of the project (Section 1), provides an enumeration of publications and other public discussion of the work (Section 1), and concludes with a discussion of future work and impact from the project (Section 1). The appendix contains reprints of the refereed publications resulting from this work.

Supercomputers and the mathematical modeling of high complexity problems

International Nuclear Information System (INIS)

Belotserkovskii, Oleg M

2010-01-01

This paper is a review of many works carried out by members of our scientific school in past years. The general principles of constructing numerical algorithms for high-performance computers are described. Several techniques are highlighted and these are based on the method of splitting with respect to physical processes and are widely used in computing nonlinear multidimensional processes in fluid dynamics, in studies of turbulence and hydrodynamic instabilities and in medicine and other natural sciences. The advances and developments related to the new generation of high-performance supercomputing in Russia are presented.

The Vatican & Population Growth Control: Why an American Confrontation?

Science.gov (United States)

Mumford, Stephen D.

1983-01-01

The Vatican, because of its position on population growth, threatens the security of all nations. Catholic countries with right-wing dictatorships cannot confront the Vatican on family planning and survive. U.S. Catholics must confront the Vatican on this issue. American lay Catholics must break the American church away from the Vatican control.…

Race: A scalable and elastic parallel system for discovering repeats in very long sequences

KAUST Repository

Mansour, Essam

2013-08-26

A wide range of applications, including bioinformatics, time series, and log analysis, depend on the identification of repetitions in very long sequences. The problem of finding maximal pairs subsumes most important types of repetition-finding tasks. Existing solutions require both the input sequence and its index (typically an order of magnitude larger than the input) to fit in memory. Moreover, they are serial algorithms with long execution time. Therefore, they are limited to small datasets, despite the fact that modern applications demand orders of magnitude longer sequences. In this paper we present RACE, a parallel system for finding maximal pairs in very long sequences. RACE supports parallel execution on stand-alone multicore systems, in addition to scaling to thousands of nodes on clusters or supercomputers. RACE does not require the input or the index to fit in memory; therefore, it supports very long sequences with limited memory. Moreover, it uses a novel array representation that allows for cache-efficient implementation. RACE is particularly suitable for the cloud (e.g., Amazon EC2) because, based on availability, it can scale elastically to more or fewer machines during its execution. Since scaling out introduces overheads, mainly due to load imbalance, we propose a cost model to estimate the expected speedup, based on statistics gathered through sampling. The model allows the user to select the appropriate combination of cloud resources based on the provider\\'s prices and the required deadline. We conducted extensive experimental evaluation with large real datasets and large computing infrastructures. In contrast to existing methods, RACE can handle the entire human genome on a typical desktop computer with 16GB RAM. Moreover, for a problem that takes 10 hours of serial execution, RACE finishes in 28 seconds using 2,048 nodes on an IBM BlueGene/P supercomputer.

The Pawsey Supercomputer geothermal cooling project

Science.gov (United States)

Regenauer-Lieb, K.; Horowitz, F.; Western Australian Geothermal Centre Of Excellence, T.

2010-12-01

The Australian Government has funded the Pawsey supercomputer in Perth, Western Australia, providing computational infrastructure intended to support the future operations of the Australian Square Kilometre Array radiotelescope and to boost next-generation computational geosciences in Australia. Supplementary funds have been directed to the development of a geothermal exploration well to research the potential for direct heat use applications at the Pawsey Centre site. Cooling the Pawsey supercomputer may be achieved by geothermal heat exchange rather than by conventional electrical power cooling, thus reducing the carbon footprint of the Pawsey Centre and demonstrating an innovative green technology that is widely applicable in industry and urban centres across the world. The exploration well is scheduled to be completed in 2013, with drilling due to commence in the third quarter of 2011. One year is allocated to finalizing the design of the exploration, monitoring and research well. Success in the geothermal exploration and research program will result in an industrial-scale geothermal cooling facility at the Pawsey Centre, and will provide a world-class student training environment in geothermal energy systems. A similar system is partially funded and in advanced planning to provide base-load air-conditioning for the main campus of the University of Western Australia. Both systems are expected to draw ~80-95 degrees C water from aquifers lying between 2000 and 3000 meters depth from naturally permeable rocks of the Perth sedimentary basin. The geothermal water will be run through absorption chilling devices, which only require heat (as opposed to mechanical work) to power a chilled water stream adequate to meet the cooling requirements. Once the heat has been removed from the geothermal water, licensing issues require the water to be re-injected back into the aquifer system. These systems are intended to demonstrate the feasibility of powering large-scale air

Fast Simulation of Large-Scale Floods Based on GPU Parallel Computing

Directory of Open Access Journals (Sweden)

Qiang Liu

2018-05-01

Full Text Available Computing speed is a significant issue of large-scale flood simulations for real-time response to disaster prevention and mitigation. Even today, most of the large-scale flood simulations are generally run on supercomputers due to the massive amounts of data and computations necessary. In this work, a two-dimensional shallow water model based on an unstructured Godunov-type finite volume scheme was proposed for flood simulation. To realize a fast simulation of large-scale floods on a personal computer, a Graphics Processing Unit (GPU-based, high-performance computing method using the OpenACC application was adopted to parallelize the shallow water model. An unstructured data management method was presented to control the data transportation between the GPU and CPU (Central Processing Unit with minimum overhead, and then both computation and data were offloaded from the CPU to the GPU, which exploited the computational capability of the GPU as much as possible. The parallel model was validated using various benchmarks and real-world case studies. The results demonstrate that speed-ups of up to one order of magnitude can be achieved in comparison with the serial model. The proposed parallel model provides a fast and reliable tool with which to quickly assess flood hazards in large-scale areas and, thus, has a bright application prospect for dynamic inundation risk identification and disaster assessment.

Parallel Performance Optimizations on Unstructured Mesh-based Simulations

Energy Technology Data Exchange (ETDEWEB)

Sarje, Abhinav; Song, Sukhyun; Jacobsen, Douglas; Huck, Kevin; Hollingsworth, Jeffrey; Malony, Allen; Williams, Samuel; Oliker, Leonid

2015-01-01

© The Authors. Published by Elsevier B.V. This paper addresses two key parallelization challenges the unstructured mesh-based ocean modeling code, MPAS-Ocean, which uses a mesh based on Voronoi tessellations: (1) load imbalance across processes, and (2) unstructured data access patterns, that inhibit intra- and inter-node performance. Our work analyzes the load imbalance due to naive partitioning of the mesh, and develops methods to generate mesh partitioning with better load balance and reduced communication. Furthermore, we present methods that minimize both inter- and intranode data movement and maximize data reuse. Our techniques include predictive ordering of data elements for higher cache efficiency, as well as communication reduction approaches. We present detailed performance data when running on thousands of cores using the Cray XC30 supercomputer and show that our optimization strategies can exceed the original performance by over 2×. Additionally, many of these solutions can be broadly applied to a wide variety of unstructured grid-based computations.

Heat dissipation computations of a HVDC ground electrode using a supercomputer

International Nuclear Information System (INIS)

Greiss, H.; Mukhedkar, D.; Lagace, P.J.

1990-01-01

This paper reports on the temperature, of soil surrounding a High Voltage Direct Current (HVDC) toroidal ground electrode of practical dimensions, in both homogeneous and non-homogeneous soils that was computed at incremental points in time using finite difference methods on a supercomputer. Curves of the response were computed and plotted at several locations within the soil in the vicinity of the ground electrode for various values of the soil parameters

Argonne National Lab deploys Force10 networks' massively dense ethernet switch for supercomputing cluster

CERN Multimedia

2003-01-01

"Force10 Networks, Inc. today announced that Argonne National Laboratory (Argonne, IL) has successfully deployed Force10 E-Series switch/routers to connect to the TeraGrid, the world's largest supercomputing grid, sponsored by the National Science Foundation (NSF)" (1/2 page).

Parallel Dynamic Analysis of a Large-Scale Water Conveyance Tunnel under Seismic Excitation Using ALE Finite-Element Method

Directory of Open Access Journals (Sweden)

Xiaoqing Wang

2016-01-01

Full Text Available Parallel analyses about the dynamic responses of a large-scale water conveyance tunnel under seismic excitation are presented in this paper. A full three-dimensional numerical model considering the water-tunnel-soil coupling is established and adopted to investigate the tunnel’s dynamic responses. The movement and sloshing of the internal water are simulated using the multi-material Arbitrary Lagrangian Eulerian (ALE method. Nonlinear fluid–structure interaction (FSI between tunnel and inner water is treated by using the penalty method. Nonlinear soil-structure interaction (SSI between soil and tunnel is dealt with by using the surface to surface contact algorithm. To overcome computing power limitations and to deal with such a large-scale calculation, a parallel algorithm based on the modified recursive coordinate bisection (MRCB considering the balance of SSI and FSI loads is proposed and used. The whole simulation is accomplished on Dawning 5000 A using the proposed MRCB based parallel algorithm optimized to run on supercomputers. The simulation model and the proposed approaches are validated by comparison with the added mass method. Dynamic responses of the tunnel are analyzed and the parallelism is discussed. Besides, factors affecting the dynamic responses are investigated. Better speedup and parallel efficiency show the scalability of the parallel method and the analysis results can be used to aid in the design of water conveyance tunnels.

A PARALLEL MONTE CARLO CODE FOR SIMULATING COLLISIONAL N-BODY SYSTEMS

International Nuclear Information System (INIS)

Pattabiraman, Bharath; Umbreit, Stefan; Liao, Wei-keng; Choudhary, Alok; Kalogera, Vassiliki; Memik, Gokhan; Rasio, Frederic A.

2013-01-01

We present a new parallel code for computing the dynamical evolution of collisional N-body systems with up to N ∼ 10 7 particles. Our code is based on the Hénon Monte Carlo method for solving the Fokker-Planck equation, and makes assumptions of spherical symmetry and dynamical equilibrium. The principal algorithmic developments involve optimizing data structures and the introduction of a parallel random number generation scheme as well as a parallel sorting algorithm required to find nearest neighbors for interactions and to compute the gravitational potential. The new algorithms we introduce along with our choice of decomposition scheme minimize communication costs and ensure optimal distribution of data and workload among the processing units. Our implementation uses the Message Passing Interface library for communication, which makes it portable to many different supercomputing architectures. We validate the code by calculating the evolution of clusters with initial Plummer distribution functions up to core collapse with the number of stars, N, spanning three orders of magnitude from 10 5 to 10 7 . We find that our results are in good agreement with self-similar core-collapse solutions, and the core-collapse times generally agree with expectations from the literature. Also, we observe good total energy conservation, within ∼ 5 , 128 for N = 10 6 and 256 for N = 10 7 . The runtime reaches saturation with the addition of processors beyond these limits, which is a characteristic of the parallel sorting algorithm. The resulting maximum speedups we achieve are approximately 60×, 100×, and 220×, respectively.

Nuclear Terrorism and its Confrontation

International Nuclear Information System (INIS)

Al Barody, M.M.

2006-01-01

The whole world first knew nuclear terrorism during the second world war through the use of excessive violence that to terror exercised by one country against another, as was carried out by USA when it exploded two nuclear bombs over Hiroshima and Nagasaki t the end of the war. there are numerous types of nuclear terrorism that can be performed by individuals or organized groups for achieving political or social objectives. the definition of the term t errorism i s correlated with u sing means capable of creating a case of public dnger . that property exists in all types of direct or indirect nuclear terrorism . the present study is divided into two chapters. Chapter one deals with nuclear terrorism and consists of two sections , the first deals with the identification of the nature of nuclear terrorism an the second deals with organize nuclear terrorism on the international level. Chapter two deals with the confrontation of nuclear terrorism in two sections. the first deals with the role of the state in combating against nuclear terrorism nd the second deals with combating against nuclear terrorism on the international level. while internally it is confronted through promulgation of legislations that deal with the protection against nuclear terrorism as well as the national legal instruments for protection of nuclear materials and installation and combating illicit trafficking of nuclear materials, confrontation of nuclear terrorism on the international level is carried out through the promulgation of international convention such as that on suppression of actions of nuclear terrorism which shall be opened for signature on sept.14 -2005 according to the recommendation the general assembly of the united nations in its 59 t h session

A concurrent visualization system for large-scale unsteady simulations. Parallel vector performance on an NEC SX-4

International Nuclear Information System (INIS)

Takei, Toshifumi; Doi, Shun; Matsumoto, Hideki; Muramatsu, Kazuhiro

2000-01-01

We have developed a concurrent visualization system RVSLIB (Real-time Visual Simulation Library). This paper shows the effectiveness of the system when it is applied to large-scale unsteady simulations, for which the conventional post-processing approach may no longer work, on high-performance parallel vector supercomputers. The system performs almost all of the visualization tasks on a computation server and uses compressed visualized image data for efficient communication between the server and the user terminal. We have introduced several techniques, including vectorization and parallelization, into the system to minimize the computational costs of the visualization tools. The performance of RVSLIB was evaluated by using an actual CFD code on an NEC SX-4. The computational time increase due to the concurrent visualization was at most 3% for a smaller (1.6 million) grid and less than 1% for a larger (6.2 million) one. (author)

Parallel processing at the SSC: The fact and the fiction

International Nuclear Information System (INIS)

Bourianoff, G.; Cole, B.

1991-10-01

Accurately modelling the behavior of particles circulating in accelerators is a computationally demanding task. The particle tracking code currently in use at SSC is based upon a ''thin element'' analysis (TEAPOT). In this model each magnet in the lattice is described by a thin element at which the particle experiences an impulsive kick. Each kick requires approximately 200 floating point operations (''FLOP''). For the SSC collider lattice consisting of 10 4 elements, performing a tracking of study for a set of 100 particles for 10 7 turns would require 2 x 10 15 FLOPS. Even on a machine capable of 100 MFLOP/sec (MFLOPS), this would require 2 x 10 7 seconds, and many such runs are necessary. It should be noted that the accuracy with which the kicks are to be calculated is important: the large number of iterations involved will magnify the effects of small errors. The inability of current computational resources to effectively perform the full calculation motivates the migration of this calculation to the most powerful computers available. A survey of the current research into new technologies for superconducting reveals that the supercomputers of the future will be parallel in nature. Further, numerous such machines exist today, and are being used to solve other difficult problems. Thus it seems clear that it is not early to begin developing the capability to develop tracking codes for parallel architectures. This report discusses implementing parallel processing on the SCC

To Confront Versus not to Confront: Women’s Perception of Sexual Harassment

OpenAIRE

María del Carmen Herrera; Antonio Herrera; Francisca Expósito

2017-01-01

Current research has postulated that sexual harassment is one of the most serious social problems. Perceptions of sexual harassment vary according to some factors: gender, context, and perceiver’s ideology. The strategies most commonly used by women to cope with harassment range from avoiding or ignoring the harasser to confronting the harasser or reporting the incident. The aim of this study was to explore women’s perception of sexual harassment, and to assess the implications of different v...

Performance Evaluation of Supercomputers using HPCC and IMB Benchmarks

Science.gov (United States)

Saini, Subhash; Ciotti, Robert; Gunney, Brian T. N.; Spelce, Thomas E.; Koniges, Alice; Dossa, Don; Adamidis, Panagiotis; Rabenseifner, Rolf; Tiyyagura, Sunil R.; Mueller, Matthias;

High performance shallow water kernels for parallel overland flow simulations based on FullSWOF2D

KAUST Repository

Wittmann, Roland

2017-01-25

We describe code optimization and parallelization procedures applied to the sequential overland flow solver FullSWOF2D. Major difficulties when simulating overland flows comprise dealing with high resolution datasets of large scale areas which either cannot be computed on a single node either due to limited amount of memory or due to too many (time step) iterations resulting from the CFL condition. We address these issues in terms of two major contributions. First, we demonstrate a generic step-by-step transformation of the second order finite volume scheme in FullSWOF2D towards MPI parallelization. Second, the computational kernels are optimized by the use of templates and a portable vectorization approach. We discuss the load imbalance of the flux computation due to dry and wet cells and propose a solution using an efficient cell counting approach. Finally, scalability results are shown for different test scenarios along with a flood simulation benchmark using the Shaheen II supercomputer.

An Interface for Biomedical Big Data Processing on the Tianhe-2 Supercomputer.

Science.gov (United States)

Yang, Xi; Wu, Chengkun; Lu, Kai; Fang, Lin; Zhang, Yong; Li, Shengkang; Guo, Guixin; Du, YunFei

2017-12-01

Big data, cloud computing, and high-performance computing (HPC) are at the verge of convergence. Cloud computing is already playing an active part in big data processing with the help of big data frameworks like Hadoop and Spark. The recent upsurge of high-performance computing in China provides extra possibilities and capacity to address the challenges associated with big data. In this paper, we propose Orion-a big data interface on the Tianhe-2 supercomputer-to enable big data applications to run on Tianhe-2 via a single command or a shell script. Orion supports multiple users, and each user can launch multiple tasks. It minimizes the effort needed to initiate big data applications on the Tianhe-2 supercomputer via automated configuration. Orion follows the "allocate-when-needed" paradigm, and it avoids the idle occupation of computational resources. We tested the utility and performance of Orion using a big genomic dataset and achieved a satisfactory performance on Tianhe-2 with very few modifications to existing applications that were implemented in Hadoop/Spark. In summary, Orion provides a practical and economical interface for big data processing on Tianhe-2.

Confronting Perpetrators of Prejudice: The Inhibitory Effects of Social Costs

Science.gov (United States)

Shelton, J. Nicole; Stewart, Rebecca E.

2004-01-01

The purpose of this research is to investigate the extent to which social costs influence whether or not targets of prejudice confront individuals who behave in a prejudiced manner during interpersonal interactions. Consistent with our predictions, we found that although women believe they will confront perpetrators of prejudice regardless of the…

CHILD WITNESSES AND THE CONFRONTATION CLAUSE.

Science.gov (United States)

Lyon, Thomas D; Dente, Julia A

2012-01-01

After the Supreme Court's ruling in Crawford v. Washington that a criminal defendant's right to confront the witnesses against him is violated by the admission of testimonial hearsay that has not been cross-examined, lower courts have overturned convictions in which hearsay from children was admitted after child witnesses were either unwilling or unable to testify. A review of social scientific evidence regarding the dynamics of child sexual abuse suggests a means for facilitating the fair receipt of children's evidence. Courts should hold that defendants have forfeited their confrontation rights if they exploited a child's vulnerabilities such that they could reasonably anticipate that the child would be unavailable to testify. Exploitation includes choosing victims on the basis of their filial dependency, their vulnerability, or their immaturity, as well as taking actions that create or accentuate those vulnerabilities.

ERA: Efficient serial and parallel suffix tree construction for very long strings

KAUST Repository

Mansour, Essam

2011-09-01

The suffix tree is a data structure for indexing strings. It is used in a variety of applications such as bioinformatics, time series analysis, clustering, text editing and data compression. However, when the string and the resulting suffix tree are too large to fit into the main memory, most existing construction algorithms become very inefficient. This paper presents a disk-based suffix tree construction method, called Elastic Range (ERa), which works efficiently with very long strings that are much larger than the available memory. ERa partitions the tree construction process horizontally and vertically and minimizes I/Os by dynamically adjusting the horizontal partitions independently for each vertical partition, based on the evolving shape of the tree and the available memory. Where appropriate, ERa also groups vertical partitions together to amortize the I/O cost. We developed a serial version; a parallel version for shared-memory and shared-disk multi-core systems; and a parallel version for shared-nothing architectures. ERa indexes the entire human genome in 19 minutes on an ordinary desktop computer. For comparison, the fastest existing method needs 15 minutes using 1024 CPUs on an IBM BlueGene supercomputer.

Analysis of Parallel Algorithms on SMP Node and Cluster of Workstations Using Parallel Programming Models with New Tile-based Method for Large Biological Datasets.

Science.gov (United States)

Shrimankar, D D; Sathe, S R

2016-01-01

Sequence alignment is an important tool for describing the relationships between DNA sequences. Many sequence alignment algorithms exist, differing in efficiency, in their models of the sequences, and in the relationship between sequences. The focus of this study is to obtain an optimal alignment between two sequences of biological data, particularly DNA sequences. The algorithm is discussed with particular emphasis on time, speedup, and efficiency optimizations. Parallel programming presents a number of critical challenges to application developers. Today's supercomputer often consists of clusters of SMP nodes. Programming paradigms such as OpenMP and MPI are used to write parallel codes for such architectures. However, the OpenMP programs cannot be scaled for more than a single SMP node. However, programs written in MPI can have more than single SMP nodes. But such a programming paradigm has an overhead of internode communication. In this work, we explore the tradeoffs between using OpenMP and MPI. We demonstrate that the communication overhead incurs significantly even in OpenMP loop execution and increases with the number of cores participating. We also demonstrate a communication model to approximate the overhead from communication in OpenMP loops. Our results are astonishing and interesting to a large variety of input data files. We have developed our own load balancing and cache optimization technique for message passing model. Our experimental results show that our own developed techniques give optimum performance of our parallel algorithm for various sizes of input parameter, such as sequence size and tile size, on a wide variety of multicore architectures.

Analysis of Parallel Algorithms on SMP Node and Cluster of Workstations Using Parallel Programming Models with New Tile-based Method for Large Biological Datasets

Science.gov (United States)

Shrimankar, D. D.; Sathe, S. R.

2016-01-01

Sequence alignment is an important tool for describing the relationships between DNA sequences. Many sequence alignment algorithms exist, differing in efficiency, in their models of the sequences, and in the relationship between sequences. The focus of this study is to obtain an optimal alignment between two sequences of biological data, particularly DNA sequences. The algorithm is discussed with particular emphasis on time, speedup, and efficiency optimizations. Parallel programming presents a number of critical challenges to application developers. Today’s supercomputer often consists of clusters of SMP nodes. Programming paradigms such as OpenMP and MPI are used to write parallel codes for such architectures. However, the OpenMP programs cannot be scaled for more than a single SMP node. However, programs written in MPI can have more than single SMP nodes. But such a programming paradigm has an overhead of internode communication. In this work, we explore the tradeoffs between using OpenMP and MPI. We demonstrate that the communication overhead incurs significantly even in OpenMP loop execution and increases with the number of cores participating. We also demonstrate a communication model to approximate the overhead from communication in OpenMP loops. Our results are astonishing and interesting to a large variety of input data files. We have developed our own load balancing and cache optimization technique for message passing model. Our experimental results show that our own developed techniques give optimum performance of our parallel algorithm for various sizes of input parameter, such as sequence size and tile size, on a wide variety of multicore architectures. PMID:27932868

Coherent 40 Gb/s SP-16QAM and 80 Gb/s PDM-16QAM in an Optimal Supercomputer Optical Switch Fabric

DEFF Research Database (Denmark)

Karinou, Fotini; Borkowski, Robert; Zibar, Darko

2013-01-01

We demonstrate, for the first time, the feasibility of using 40 Gb/s SP-16QAM and 80 Gb/s PDM-16QAM in an optimized cell switching supercomputer optical interconnect architecture based on semiconductor optical amplifiers as ON/OFF gates.......We demonstrate, for the first time, the feasibility of using 40 Gb/s SP-16QAM and 80 Gb/s PDM-16QAM in an optimized cell switching supercomputer optical interconnect architecture based on semiconductor optical amplifiers as ON/OFF gates....

Confronting New Demands : Inclusive Growth, Inclusive Trade ...

International Development Research Centre (IDRC) Digital Library (Canada)

Confronting New Demands : Inclusive Growth, Inclusive Trade. Policymakers, businesspeople and civil society advocates need evidence-based research to react ... understood implications, such as labour standards and intellectual property; ...

Cooperative visualization and simulation in a supercomputer environment

International Nuclear Information System (INIS)

Ruehle, R.; Lang, U.; Wierse, A.

1993-01-01

The article takes a closer look on the requirements being imposed by the idea to integrate all the components into a homogeneous software environment. To this end several methods for the distribtuion of applications in dependence of certain problem types are discussed. The currently available methods at the University of Stuttgart Computer Center for the distribution of applications are further explained. Finally the aims and characteristics of a European sponsored project, called PAGEIN, are explained, which fits perfectly into the line of developments at RUS. The aim of the project is to experiment with future cooperative working modes of aerospace scientists in a high speed distributed supercomputing environment. Project results will have an impact on the development of real future scientific application environments. (orig./DG)

Goal preference shapes confrontations of sexism.

Science.gov (United States)

Mallett, Robyn K; Melchiori, Kala J

2014-05-01

Although most women assume they would confront sexism, assertive responses are rare. We test whether women's preference for respect or liking during interpersonal interactions explains this surprising tendency. Women report preferring respect relative to liking after being asked sexist, compared with inappropriate, questions during a virtual job interview (Study 1, n = 149). Women's responses to sexism increase in assertiveness along with their preference for being respected, and a respect-preference mediates the relation between the type of questions and response assertiveness (Studies 1 and 2). In Study 2 (n = 105), women's responses to sexist questions are more assertive when the sense of belonging is enhanced with a belonging manipulation. Moreover, preference for respect mediates the effect of the type of questions on response assertiveness, but only when belonging needs are met. Thus the likelihood of confrontation depends on the goal to be respected outweighing the goal to be liked.

Macroeconomic Issues Confronting the Next President.

Science.gov (United States)

Solow, Robert M.

1988-01-01

Identifies economic issues that confronted the United States in the late 1980's and discusses how the president might deal with them. Highlights the following issues: recession, rising price levels, the budget deficit, international trade imbalance, and revival of U.S. long-term growth. (GEA)

Fear appeals and confronting information campaigns. [Previously: Fear-based information campaigns.

NARCIS (Netherlands)

2007-01-01

Fear appeals or confronting information campaigns confront people in an often hard and sometimes even shocking way with the consequences of risky behaviour. This can have a positive impact on the attitudes and behavioural intentions of the target group, but only if key conditions are met. Those

La Grippe and World War I: conflict participation and pandemic confrontation.

Science.gov (United States)

Steele, B J; Collins, C D

2009-01-01

This paper assesses whether a nation-state's participation in conflict influences its ability to confront global pandemic or disease. Two alternative hypotheses are proposed. First, increased levels of conflict participation lead to increased abilities of states to confront pandemics. A second and alternative hypothesis is that increased conflict participation decreases the ability of states to confront pandemics. The hypotheses are tested through the ultimate case of war and pandemic: the 1918 Influenza pandemic (Spanish Flu or 'La Grippe') that killed 20-100 million people worldwide. Using simple correlation and case illustrations, we test these hypotheses with special focus upon the ability of the participant countries to confront the pandemic. The findings suggest, in a limited and varied fashion, that while neutral countries enjoyed the lowest levels of pandemic deaths, of the participant countries greater levels of conflict participation correlate with lower levels of pandemic deaths. The paper concludes with some propositions regarding the relationship between the current 'war on terror' and prospective pandemics such as avian flu.

GPU: the biggest key processor for AI and parallel processing

Science.gov (United States)

Baji, Toru

2017-07-01

Two types of processors exist in the market. One is the conventional CPU and the other is Graphic Processor Unit (GPU). Typical CPU is composed of 1 to 8 cores while GPU has thousands of cores. CPU is good for sequential processing, while GPU is good to accelerate software with heavy parallel executions. GPU was initially dedicated for 3D graphics. However from 2006, when GPU started to apply general-purpose cores, it was noticed that this architecture can be used as a general purpose massive-parallel processor. NVIDIA developed a software framework Compute Unified Device Architecture (CUDA) that make it possible to easily program the GPU for these application. With CUDA, GPU started to be used in workstations and supercomputers widely. Recently two key technologies are highlighted in the industry. The Artificial Intelligence (AI) and Autonomous Driving Cars. AI requires a massive parallel operation to train many-layers of neural networks. With CPU alone, it was impossible to finish the training in a practical time. The latest multi-GPU system with P100 makes it possible to finish the training in a few hours. For the autonomous driving cars, TOPS class of performance is required to implement perception, localization, path planning processing and again SoC with integrated GPU will play a key role there. In this paper, the evolution of the GPU which is one of the biggest commercial devices requiring state-of-the-art fabrication technology will be introduced. Also overview of the GPU demanding key application like the ones described above will be introduced.

Exascale Data Analysis

CERN Multimedia

CERN. Geneva; Fitch, Blake

2011-01-01

Traditionaly, the primary role of supercomputers was to create data, primarily for simulation applications. Due to usage and technology trends, supercomputers are increasingly also used for data analysis. Some of this data is from simulations, but there is also a rapidly increasingly amount of real-world science and business data to be analyzed. We briefly overview Blue Gene and other current supercomputer architectures. We outline future architectures, up to the Exascale supercomputers expected in the 2020 time frame. We focus on the data analysis challenges and opportunites, especially those concerning Flash and other up-and-coming storage class memory. About the speakers Blake G. Fitch has been with IBM Research, Yorktown Heights, NY since 1987, mainly pursuing interests in parallel systems. He joined the Scalable Parallel Systems Group in 1990, contributing to research and development that culminated in the IBM scalable parallel system (SP*) product. His research interests have focused on applicatio...

Parallel and orthogonal stimulus in ultradiluted neural networks

International Nuclear Information System (INIS)

Sobral, G. A. Jr.; Vieira, V. M.; Lyra, M. L.; Silva, C. R. da

2006-01-01

Extending a model due to Derrida, Gardner, and Zippelius, we have studied the recognition ability of an extreme and asymmetrically diluted version of the Hopfield model for associative memory by including the effect of a stimulus in the dynamics of the system. We obtain exact results for the dynamic evolution of the average network superposition. The stimulus field was considered as proportional to the overlapping of the state of the system with a particular stimulated pattern. Two situations were analyzed, namely, the external stimulus acting on the initialization pattern (parallel stimulus) and the external stimulus acting on a pattern orthogonal to the initialization one (orthogonal stimulus). In both cases, we obtained the complete phase diagram in the parameter space composed of the stimulus field, thermal noise, and network capacity. Our results show that the system improves its recognition ability for parallel stimulus. For orthogonal stimulus two recognition phases emerge with the system locking at the initialization or stimulated pattern. We confront our analytical results with numerical simulations for the noiseless case T=0

Feynman diagrams sampling for quantum field theories on the QPACE 2 supercomputer

Energy Technology Data Exchange (ETDEWEB)

Rappl, Florian

2016-08-01

This work discusses the application of Feynman diagram sampling in quantum field theories. The method uses a computer simulation to sample the diagrammatic space obtained in a series expansion. For running large physical simulations powerful computers are obligatory, effectively splitting the thesis in two parts. The first part deals with the method of Feynman diagram sampling. Here the theoretical background of the method itself is discussed. Additionally, important statistical concepts and the theory of the strong force, quantum chromodynamics, are introduced. This sets the context of the simulations. We create and evaluate a variety of models to estimate the applicability of diagrammatic methods. The method is then applied to sample the perturbative expansion of the vertex correction. In the end we obtain the value for the anomalous magnetic moment of the electron. The second part looks at the QPACE 2 supercomputer. This includes a short introduction to supercomputers in general, as well as a closer look at the architecture and the cooling system of QPACE 2. Guiding benchmarks of the InfiniBand network are presented. At the core of this part, a collection of best practices and useful programming concepts are outlined, which enables the development of efficient, yet easily portable, applications for the QPACE 2 system.

Use of high performance networks and supercomputers for real-time flight simulation

Science.gov (United States)

Cleveland, Jeff I., II

1993-01-01

In order to meet the stringent time-critical requirements for real-time man-in-the-loop flight simulation, computer processing operations must be consistent in processing time and be completed in as short a time as possible. These operations include simulation mathematical model computation and data input/output to the simulators. In 1986, in response to increased demands for flight simulation performance, NASA's Langley Research Center (LaRC), working with the contractor, developed extensions to the Computer Automated Measurement and Control (CAMAC) technology which resulted in a factor of ten increase in the effective bandwidth and reduced latency of modules necessary for simulator communication. This technology extension is being used by more than 80 leading technological developers in the United States, Canada, and Europe. Included among the commercial applications are nuclear process control, power grid analysis, process monitoring, real-time simulation, and radar data acquisition. Personnel at LaRC are completing the development of the use of supercomputers for mathematical model computation to support real-time flight simulation. This includes the development of a real-time operating system and development of specialized software and hardware for the simulator network. This paper describes the data acquisition technology and the development of supercomputing for flight simulation.

Federal Market Information Technology in the Post Flash Crash Era: Roles for Supercomputing

Energy Technology Data Exchange (ETDEWEB)

Bethel, E. Wes; Leinweber, David; Ruebel, Oliver; Wu, Kesheng

2011-09-16

This paper describes collaborative work between active traders, regulators, economists, and supercomputing researchers to replicate and extend investigations of the Flash Crash and other market anomalies in a National Laboratory HPC environment. Our work suggests that supercomputing tools and methods will be valuable to market regulators in achieving the goal of market safety, stability, and security. Research results using high frequency data and analytics are described, and directions for future development are discussed. Currently the key mechanism for preventing catastrophic market action are “circuit breakers.” We believe a more graduated approach, similar to the “yellow light” approach in motorsports to slow down traffic, might be a better way to achieve the same goal. To enable this objective, we study a number of indicators that could foresee hazards in market conditions and explore options to confirm such predictions. Our tests confirm that Volume Synchronized Probability of Informed Trading (VPIN) and a version of volume Herfindahl-Hirschman Index (HHI) for measuring market fragmentation can indeed give strong signals ahead of the Flash Crash event on May 6 2010. This is a preliminary step toward a full-fledged early-warning system for unusual market conditions.

An overview of the activities of the OECD/NEA Task Force on adapting computer codes in nuclear applications to parallel architectures

Energy Technology Data Exchange (ETDEWEB)

Kirk, B.L. [Oak Ridge National Lab., TN (United States); Sartori, E. [OCDE/OECD NEA Data Bank, Issy-les-Moulineaux (France); Viedma, L.G. de [Consejo de Seguridad Nuclear, Madrid (Spain)

1997-06-01

Subsequent to the introduction of High Performance Computing in the developed countries, the Organization for Economic Cooperation and Development/Nuclear Energy Agency (OECD/NEA) created the Task Force on Adapting Computer Codes in Nuclear Applications to Parallel Architectures (under the guidance of the Nuclear Science Committee`s Working Party on Advanced Computing) to study the growth area in supercomputing and its applicability to the nuclear community`s computer codes. The result has been four years of investigation for the Task Force in different subject fields - deterministic and Monte Carlo radiation transport, computational mechanics and fluid dynamics, nuclear safety, atmospheric models and waste management.

An overview of the activities of the OECD/NEA Task Force on adapting computer codes in nuclear applications to parallel architectures

International Nuclear Information System (INIS)

Kirk, B.L.; Sartori, E.; Viedma, L.G. de

1997-01-01

Subsequent to the introduction of High Performance Computing in the developed countries, the Organization for Economic Cooperation and Development/Nuclear Energy Agency (OECD/NEA) created the Task Force on Adapting Computer Codes in Nuclear Applications to Parallel Architectures (under the guidance of the Nuclear Science Committee's Working Party on Advanced Computing) to study the growth area in supercomputing and its applicability to the nuclear community's computer codes. The result has been four years of investigation for the Task Force in different subject fields - deterministic and Monte Carlo radiation transport, computational mechanics and fluid dynamics, nuclear safety, atmospheric models and waste management

Development of a Cloud Resolving Model for Heterogeneous Supercomputers

Science.gov (United States)

Sreepathi, S.; Norman, M. R.; Pal, A.; Hannah, W.; Ponder, C.

2017-12-01

A cloud resolving climate model is needed to reduce major systematic errors in climate simulations due to structural uncertainty in numerical treatments of convection - such as convective storm systems. This research describes the porting effort to enable SAM (System for Atmosphere Modeling) cloud resolving model on heterogeneous supercomputers using GPUs (Graphical Processing Units). We have isolated a standalone configuration of SAM that is targeted to be integrated into the DOE ACME (Accelerated Climate Modeling for Energy) Earth System model. We have identified key computational kernels from the model and offloaded them to a GPU using the OpenACC programming model. Furthermore, we are investigating various optimization strategies intended to enhance GPU utilization including loop fusion/fission, coalesced data access and loop refactoring to a higher abstraction level. We will present early performance results, lessons learned as well as optimization strategies. The computational platform used in this study is the Summitdev system, an early testbed that is one generation removed from Summit, the next leadership class supercomputer at Oak Ridge National Laboratory. The system contains 54 nodes wherein each node has 2 IBM POWER8 CPUs and 4 NVIDIA Tesla P100 GPUs. This work is part of a larger project, ACME-MMF component of the U.S. Department of Energy(DOE) Exascale Computing Project. The ACME-MMF approach addresses structural uncertainty in cloud processes by replacing traditional parameterizations with cloud resolving "superparameterization" within each grid cell of global climate model. Super-parameterization dramatically increases arithmetic intensity, making the MMF approach an ideal strategy to achieve good performance on emerging exascale computing architectures. The goal of the project is to integrate superparameterization into ACME, and explore its full potential to scientifically and computationally advance climate simulation and prediction.

Parallelization of a beam dynamics code and first large scale radio frequency quadrupole simulations

Directory of Open Access Journals (Sweden)

J. Xu

2007-01-01

Full Text Available The design and operation support of hadron (proton and heavy-ion linear accelerators require substantial use of beam dynamics simulation tools. The beam dynamics code TRACK has been originally developed at Argonne National Laboratory (ANL to fulfill the special requirements of the rare isotope accelerator (RIA accelerator systems. From the beginning, the code has been developed to make it useful in the three stages of a linear accelerator project, namely, the design, commissioning, and operation of the machine. To realize this concept, the code has unique features such as end-to-end simulations from the ion source to the final beam destination and automatic procedures for tuning of a multiple charge state heavy-ion beam. The TRACK code has become a general beam dynamics code for hadron linacs and has found wide applications worldwide. Until recently, the code has remained serial except for a simple parallelization used for the simulation of multiple seeds to study the machine errors. To speed up computation, the TRACK Poisson solver has been parallelized. This paper discusses different parallel models for solving the Poisson equation with the primary goal to extend the scalability of the code onto 1024 and more processors of the new generation of supercomputers known as BlueGene (BG/L. Domain decomposition techniques have been adapted and incorporated into the parallel version of the TRACK code. To demonstrate the new capabilities of the parallelized TRACK code, the dynamics of a 45 mA proton beam represented by 10^{8} particles has been simulated through the 325 MHz radio frequency quadrupole and initial accelerator section of the proposed FNAL proton driver. The results show the benefits and advantages of large-scale parallel computing in beam dynamics simulations.

Parallel spatial direct numerical simulations on the Intel iPSC/860 hypercube

Science.gov (United States)

Joslin, Ronald D.; Zubair, Mohammad

1993-01-01

The implementation and performance of a parallel spatial direct numerical simulation (PSDNS) approach on the Intel iPSC/860 hypercube is documented. The direct numerical simulation approach is used to compute spatially evolving disturbances associated with the laminar-to-turbulent transition in boundary-layer flows. The feasibility of using the PSDNS on the hypercube to perform transition studies is examined. The results indicate that the direct numerical simulation approach can effectively be parallelized on a distributed-memory parallel machine. By increasing the number of processors nearly ideal linear speedups are achieved with nonoptimized routines; slower than linear speedups are achieved with optimized (machine dependent library) routines. This slower than linear speedup results because the Fast Fourier Transform (FFT) routine dominates the computational cost and because the routine indicates less than ideal speedups. However with the machine-dependent routines the total computational cost decreases by a factor of 4 to 5 compared with standard FORTRAN routines. The computational cost increases linearly with spanwise wall-normal and streamwise grid refinements. The hypercube with 32 processors was estimated to require approximately twice the amount of Cray supercomputer single processor time to complete a comparable simulation; however it is estimated that a subgrid-scale model which reduces the required number of grid points and becomes a large-eddy simulation (PSLES) would reduce the computational cost and memory requirements by a factor of 10 over the PSDNS. This PSLES implementation would enable transition simulations on the hypercube at a reasonable computational cost.

Optimization of Sparse Matrix-Vector Multiplication on Emerging Multicore Platforms

Energy Technology Data Exchange (ETDEWEB)

Williams, Samuel; Oliker, Leonid; Vuduc, Richard; Shalf, John; Yelick, Katherine; Demmel, James

2008-10-16

We are witnessing a dramatic change in computer architecture due to the multicore paradigm shift, as every electronic device from cell phones to supercomputers confronts parallelism of unprecedented scale. To fully unleash the potential of these systems, the HPC community must develop multicore specific-optimization methodologies for important scientific computations. In this work, we examine sparse matrix-vector multiply (SpMV) - one of the most heavily used kernels in scientific computing - across a broad spectrum of multicore designs. Our experimental platform includes the homogeneous AMD quad-core, AMD dual-core, and Intel quad-core designs, the heterogeneous STI Cell, as well as one of the first scientific studies of the highly multithreaded Sun Victoria Falls (a Niagara2 SMP). We present several optimization strategies especially effective for the multicore environment, and demonstrate significant performance improvements compared to existing state-of-the-art serial and parallel SpMV implementations. Additionally, we present key insights into the architectural trade-offs of leading multicore design strategies, in the context of demanding memory-bound numerical algorithms.

Frequently updated noise threat maps created with use of supercomputing grid

Directory of Open Access Journals (Sweden)

Szczodrak Maciej

2014-09-01

Full Text Available An innovative supercomputing grid services devoted to noise threat evaluation were presented. The services described in this paper concern two issues, first is related to the noise mapping, while the second one focuses on assessment of the noise dose and its influence on the human hearing system. The discussed serviceswere developed within the PL-Grid Plus Infrastructure which accumulates Polish academic supercomputer centers. Selected experimental results achieved by the usage of the services proposed were presented. The assessment of the environmental noise threats includes creation of the noise maps using either ofline or online data, acquired through a grid of the monitoring stations. A concept of estimation of the source model parameters based on the measured sound level for the purpose of creating frequently updated noise maps was presented. Connecting the noise mapping grid service with a distributed sensor network enables to automatically update noise maps for a specified time period. Moreover, a unique attribute of the developed software is the estimation of the auditory effects evoked by the exposure to noise. The estimation method uses a modified psychoacoustic model of hearing and is based on the calculated noise level values and on the given exposure period. Potential use scenarios of the grid services for research or educational purpose were introduced. Presentation of the results of predicted hearing threshold shift caused by exposure to excessive noise can raise the public awareness of the noise threats.

Scalable geocomputation: evolving an environmental model building platform from single-core to supercomputers

Science.gov (United States)

Schmitz, Oliver; de Jong, Kor; Karssenberg, Derek

2017-04-01

There is an increasing demand to run environmental models on a big scale: simulations over large areas at high resolution. The heterogeneity of available computing hardware such as multi-core CPUs, GPUs or supercomputer potentially provides significant computing power to fulfil this demand. However, this requires detailed knowledge of the underlying hardware, parallel algorithm design and the implementation thereof in an efficient system programming language. Domain scientists such as hydrologists or ecologists often lack this specific software engineering knowledge, their emphasis is (and should be) on exploratory building and analysis of simulation models. As a result, models constructed by domain specialists mostly do not take full advantage of the available hardware. A promising solution is to separate the model building activity from software engineering by offering domain specialists a model building framework with pre-programmed building blocks that they combine to construct a model. The model building framework, consequently, needs to have built-in capabilities to make full usage of the available hardware. Developing such a framework providing understandable code for domain scientists and being runtime efficient at the same time poses several challenges on developers of such a framework. For example, optimisations can be performed on individual operations or the whole model, or tasks need to be generated for a well-balanced execution without explicitly knowing the complexity of the domain problem provided by the modeller. Ideally, a modelling framework supports the optimal use of available hardware whichsoever combination of model building blocks scientists use. We demonstrate our ongoing work on developing parallel algorithms for spatio-temporal modelling and demonstrate 1) PCRaster, an environmental software framework (http://www.pcraster.eu) providing spatio-temporal model building blocks and 2) parallelisation of about 50 of these building blocks using

Modeling of fatigue crack induced nonlinear ultrasonics using a highly parallelized explicit local interaction simulation approach

Science.gov (United States)

Shen, Yanfeng; Cesnik, Carlos E. S.

2016-04-01

This paper presents a parallelized modeling technique for the efficient simulation of nonlinear ultrasonics introduced by the wave interaction with fatigue cracks. The elastodynamic wave equations with contact effects are formulated using an explicit Local Interaction Simulation Approach (LISA). The LISA formulation is extended to capture the contact-impact phenomena during the wave damage interaction based on the penalty method. A Coulomb friction model is integrated into the computation procedure to capture the stick-slip contact shear motion. The LISA procedure is coded using the Compute Unified Device Architecture (CUDA), which enables the highly parallelized supercomputing on powerful graphic cards. Both the explicit contact formulation and the parallel feature facilitates LISA's superb computational efficiency over the conventional finite element method (FEM). The theoretical formulations based on the penalty method is introduced and a guideline for the proper choice of the contact stiffness is given. The convergence behavior of the solution under various contact stiffness values is examined. A numerical benchmark problem is used to investigate the new LISA formulation and results are compared with a conventional contact finite element solution. Various nonlinear ultrasonic phenomena are successfully captured using this contact LISA formulation, including the generation of nonlinear higher harmonic responses. Nonlinear mode conversion of guided waves at fatigue cracks is also studied.

Parallel Computation of RCS of Electrically Large Platform with Coatings Modeled with NURBS Surfaces

Directory of Open Access Journals (Sweden)

Ying Yan

2012-01-01

Full Text Available The significance of Radar Cross Section (RCS in the military applications makes its prediction an important problem. This paper uses large-scale parallel Physical Optics (PO to realize the fast computation of RCS to electrically large targets, which are modeled by Non-Uniform Rational B-Spline (NURBS surfaces and coated with dielectric materials. Some numerical examples are presented to validate this paper’s method. In addition, 1024 CPUs are used in Shanghai Supercomputer Center (SSC to perform the simulation of a model with the maximum electrical size 1966.7 λ for the first time in China. From which, it can be found that this paper’s method can greatly speed the calculation and is capable of solving the real-life problem of RCS prediction.

Methodologies and Tools for Tuning Parallel Programs: 80% Art, 20% Science, and 10% Luck

Science.gov (United States)

Yan, Jerry C.; Bailey, David (Technical Monitor)

1996-01-01

The need for computing power has forced a migration from serial computation on a single processor to parallel processing on multiprocessors. However, without effective means to monitor (and analyze) program execution, tuning the performance of parallel programs becomes exponentially difficult as program complexity and machine size increase. In the past few years, the ubiquitous introduction of performance tuning tools from various supercomputer vendors (Intel's ParAide, TMC's PRISM, CRI's Apprentice, and Convex's CXtrace) seems to indicate the maturity of performance instrumentation/monitor/tuning technologies and vendors'/customers' recognition of their importance. However, a few important questions remain: What kind of performance bottlenecks can these tools detect (or correct)? How time consuming is the performance tuning process? What are some important technical issues that remain to be tackled in this area? This workshop reviews the fundamental concepts involved in analyzing and improving the performance of parallel and heterogeneous message-passing programs. Several alternative strategies will be contrasted, and for each we will describe how currently available tuning tools (e.g. AIMS, ParAide, PRISM, Apprentice, CXtrace, ATExpert, Pablo, IPS-2) can be used to facilitate the process. We will characterize the effectiveness of the tools and methodologies based on actual user experiences at NASA Ames Research Center. Finally, we will discuss their limitations and outline recent approaches taken by vendors and the research community to address them.

A PARALLEL MONTE CARLO CODE FOR SIMULATING COLLISIONAL N-BODY SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

Pattabiraman, Bharath; Umbreit, Stefan; Liao, Wei-keng; Choudhary, Alok; Kalogera, Vassiliki; Memik, Gokhan; Rasio, Frederic A., E-mail: bharath@u.northwestern.edu [Center for Interdisciplinary Exploration and Research in Astrophysics, Northwestern University, Evanston, IL (United States)

2013-02-15

We present a new parallel code for computing the dynamical evolution of collisional N-body systems with up to N {approx} 10{sup 7} particles. Our code is based on the Henon Monte Carlo method for solving the Fokker-Planck equation, and makes assumptions of spherical symmetry and dynamical equilibrium. The principal algorithmic developments involve optimizing data structures and the introduction of a parallel random number generation scheme as well as a parallel sorting algorithm required to find nearest neighbors for interactions and to compute the gravitational potential. The new algorithms we introduce along with our choice of decomposition scheme minimize communication costs and ensure optimal distribution of data and workload among the processing units. Our implementation uses the Message Passing Interface library for communication, which makes it portable to many different supercomputing architectures. We validate the code by calculating the evolution of clusters with initial Plummer distribution functions up to core collapse with the number of stars, N, spanning three orders of magnitude from 10{sup 5} to 10{sup 7}. We find that our results are in good agreement with self-similar core-collapse solutions, and the core-collapse times generally agree with expectations from the literature. Also, we observe good total energy conservation, within {approx}< 0.04% throughout all simulations. We analyze the performance of the code, and demonstrate near-linear scaling of the runtime with the number of processors up to 64 processors for N = 10{sup 5}, 128 for N = 10{sup 6} and 256 for N = 10{sup 7}. The runtime reaches saturation with the addition of processors beyond these limits, which is a characteristic of the parallel sorting algorithm. The resulting maximum speedups we achieve are approximately 60 Multiplication-Sign , 100 Multiplication-Sign , and 220 Multiplication-Sign , respectively.

Stop Harassment! Men’s reactions to victims’ confrontation

Directory of Open Access Journals (Sweden)

M. Carmen Herrera

2014-07-01

Full Text Available Sexual harassment is one of the most widespread forms of gender violence. Perceptions of sexual harassment depend on gender, context, the perceivers’ ideology, and a host of other factors. Research has underscored the importance of coping strategies in raising a victim’s self-confidence by making her feel that she plays an active role in overcoming her own problems. The aim of this study was to assess the men’s perceptions of sexual harassment in relation to different victim responses. The study involved 101 men who were administered a questionnaire focusing on two of the most frequent types of harassment (gender harassment vs. unwanted sexual attention and victim response (confrontation vs. non confrontation, both of which were manipulated. Moreover, the influences of ideological variables, ambivalent sexism, and the acceptance of myths of sexual harassment on perception were also assessed. The results highlight the complexities involved in recognizing certain behaviors as harassment and the implications of different victim responses to incidents of harassment. As the coping strategies used by women to confront harassment entail drawbacks that pose problems or hinder them, the design and implementation of prevention and/or education programs should strive to raise awareness among men and women to further their understanding of this construct.

Parallel photonic information processing at gigabyte per second data rates using transient states

Science.gov (United States)

Brunner, Daniel; Soriano, Miguel C.; Mirasso, Claudio R.; Fischer, Ingo

2013-01-01

The increasing demands on information processing require novel computational concepts and true parallelism. Nevertheless, hardware realizations of unconventional computing approaches never exceeded a marginal existence. While the application of optics in super-computing receives reawakened interest, new concepts, partly neuro-inspired, are being considered and developed. Here we experimentally demonstrate the potential of a simple photonic architecture to process information at unprecedented data rates, implementing a learning-based approach. A semiconductor laser subject to delayed self-feedback and optical data injection is employed to solve computationally hard tasks. We demonstrate simultaneous spoken digit and speaker recognition and chaotic time-series prediction at data rates beyond 1Gbyte/s. We identify all digits with very low classification errors and perform chaotic time-series prediction with 10% error. Our approach bridges the areas of photonic information processing, cognitive and information science.

The Frontiers of Observational Cosmology and the Confrontation with Theory

International Nuclear Information System (INIS)

Longair, Malcolm

2011-01-01

The current state of observational cosmology and the confrontation with theory is presented. The review is divided into the following sections: - Basic observations on which the models are based. - Testing the basic assumptions made in the construction of the standard cosmological models. - Structure formation in the standard models; - Observational tests of the standard models - the confrontation with observation; - Basic problems and approaches to their solution; - Future challenges - the ESA EUCLID mission is given as an example.

Simulation of x-rays in refractive structure by the Monte Carlo method using the supercomputer SKIF

International Nuclear Information System (INIS)

Yaskevich, Yu.R.; Kravchenko, O.I.; Soroka, I.I.; Chembrovskij, A.G.; Kolesnik, A.S.; Serikova, N.V.; Petrov, P.V.; Kol'chevskij, N.N.

2013-01-01

Software 'Xray-SKIF' for the simulation of the X-rays in refractive structures by the Monte-Carlo method using the supercomputer SKIF BSU are developed. The program generates a large number of rays propagated from a source to the refractive structure. The ray trajectory under assumption of geometrical optics is calculated. Absorption is calculated for each ray inside of refractive structure. Dynamic arrays are used for results of calculation rays parameters, its restore the X-ray field distributions very fast at different position of detector. It was found that increasing the number of processors leads to proportional decreasing of calculation time: simulation of 10 8 X-rays using supercomputer with the number of processors from 1 to 30 run-times equal 3 hours and 6 minutes, respectively. 10 9 X-rays are calculated by software 'Xray-SKIF' which allows to reconstruct the X-ray field after refractive structure with a special resolution of 1 micron. (authors)

A 3D gyrokinetic particle-in-cell simulation of fusion plasma microturbulence on parallel computers

Science.gov (United States)

Williams, T. J.

1992-12-01

One of the grand challenge problems now supported by HPCC is the Numerical Tokamak Project. A goal of this project is the study of low-frequency micro-instabilities in tokamak plasmas, which are believed to cause energy loss via turbulent thermal transport across the magnetic field lines. An important tool in this study is gyrokinetic particle-in-cell (PIC) simulation. Gyrokinetic, as opposed to fully-kinetic, methods are particularly well suited to the task because they are optimized to study the frequency and wavelength domain of the microinstabilities. Furthermore, many researchers now employ low-noise delta(f) methods to greatly reduce statistical noise by modelling only the perturbation of the gyrokinetic distribution function from a fixed background, not the entire distribution function. In spite of the increased efficiency of these improved algorithms over conventional PIC algorithms, gyrokinetic PIC simulations of tokamak micro-turbulence are still highly demanding of computer power--even fully-vectorized codes on vector supercomputers. For this reason, we have worked for several years to redevelop these codes on massively parallel computers. We have developed 3D gyrokinetic PIC simulation codes for SIMD and MIMD parallel processors, using control-parallel, data-parallel, and domain-decomposition message-passing (DDMP) programming paradigms. This poster summarizes our earlier work on codes for the Connection Machine and BBN TC2000 and our development of a generic DDMP code for distributed-memory parallel machines. We discuss the memory-access issues which are of key importance in writing parallel PIC codes, with special emphasis on issues peculiar to gyrokinetic PIC. We outline the domain decompositions in our new DDMP code and discuss the interplay of different domain decompositions suited for the particle-pushing and field-solution components of the PIC algorithm.

Some computational challenges of developing efficient parallel algorithms for data-dependent computations in thermal-hydraulics supercomputer applications

International Nuclear Information System (INIS)

Woodruff, S.B.

1994-01-01

The Transient Reactor Analysis Code (TRAC), which features a two-fluid treatment of thermal-hydraulics, is designed to model transients in water reactors and related facilities. One of the major computational costs associated with TRAC and similar codes is calculating constitutive coefficients. Although the formulations for these coefficients are local, the costs are flow-regime- or data-dependent; i.e., the computations needed for a given spatial node often vary widely as a function of time. Consequently, a fixed, uniform assignment of nodes to prallel processors will result in degraded computational efficiency due to the poor load balancing. A standard method for treating data-dependent models on vector architectures has been to use gather operations (or indirect adressing) to sort the nodes into subsets that (temporarily) share a common computational model. However, this method is not effective on distributed memory data parallel architectures, where indirect adressing involves expensive communication overhead. Another serious problem with this method involves software engineering challenges in the areas of maintainability and extensibility. For example, an implementation that was hand-tuned to achieve good computational efficiency would have to be rewritten whenever the decision tree governing the sorting was modified. Using an example based on the calculation of the wall-to-liquid and wall-to-vapor heat-transfer coefficients for three nonboiling flow regimes, we describe how the use of the Fortran 90 WHERE construct and automatic inlining of functions can be used to ameliorate this problem while improving both efficiency and software engineering. Unfortunately, a general automatic solution to the load-balancing problem associated with data-dependent computations is not yet available for massively parallel architectures. We discuss why developers should either wait for such solutions or consider alternative numerical algorithms, such as a neural network

Parallel family trees for transfer matrices in the Potts model

Science.gov (United States)

Navarro, Cristobal A.; Canfora, Fabrizio; Hitschfeld, Nancy; Navarro, Gonzalo

2015-02-01

scenario it was in the range p ∈ [ 8 , 10 ] . Because of the parallel capabilities of the algorithm, a large-scale execution of the parallel family trees strategy in a supercomputer could contribute to the study of wider strip lattices.

Implementation of a 3D plasma particle-in-cell code on a MIMD parallel computer

International Nuclear Information System (INIS)

Liewer, P.C.; Lyster, P.; Wang, J.

1993-01-01

A three-dimensional plasma particle-in-cell (PIC) code has been implemented on the Intel Delta MIMD parallel supercomputer using the General Concurrent PIC algorithm. The GCPIC algorithm uses a domain decomposition to divide the computation among the processors: A processor is assigned a subdomain and all the particles in it. Particles must be exchanged between processors as they move. Results are presented comparing the efficiency for 1-, 2- and 3-dimensional partitions of the three dimensional domain. This algorithm has been found to be very efficient even when a large fraction (e.g. 30%) of the particles must be exchanged at every time step. On the 512-node Intel Delta, up to 125 million particles have been pushed with an electrostatic push time of under 500 nsec/particle/time step

Distributed Memory Parallel Computing with SEAWAT

Science.gov (United States)

Verkaik, J.; Huizer, S.; van Engelen, J.; Oude Essink, G.; Ram, R.; Vuik, K.

2017-12-01

Fresh groundwater reserves in coastal aquifers are threatened by sea-level rise, extreme weather conditions, increasing urbanization and associated groundwater extraction rates. To counteract these threats, accurate high-resolution numerical models are required to optimize the management of these precious reserves. The major model drawbacks are long run times and large memory requirements, limiting the predictive power of these models. Distributed memory parallel computing is an efficient technique for reducing run times and memory requirements, where the problem is divided over multiple processor cores. A new Parallel Krylov Solver (PKS) for SEAWAT is presented. PKS has recently been applied to MODFLOW and includes Conjugate Gradient (CG) and Biconjugate Gradient Stabilized (BiCGSTAB) linear accelerators. Both accelerators are preconditioned by an overlapping additive Schwarz preconditioner in a way that: a) subdomains are partitioned using Recursive Coordinate Bisection (RCB) load balancing, b) each subdomain uses local memory only and communicates with other subdomains by Message Passing Interface (MPI) within the linear accelerator, c) it is fully integrated in SEAWAT. Within SEAWAT, the PKS-CG solver replaces the Preconditioned Conjugate Gradient (PCG) solver for solving the variable-density groundwater flow equation and the PKS-BiCGSTAB solver replaces the Generalized Conjugate Gradient (GCG) solver for solving the advection-diffusion equation. PKS supports the third-order Total Variation Diminishing (TVD) scheme for computing advection. Benchmarks were performed on the Dutch national supercomputer (https://userinfo.surfsara.nl/systems/cartesius) using up to 128 cores, for a synthetic 3D Henry model (100 million cells) and the real-life Sand Engine model ( 10 million cells). The Sand Engine model was used to investigate the potential effect of the long-term morphological evolution of a large sand replenishment and climate change on fresh groundwater resources

Asynchronous Task-Based Parallelization of Algebraic Multigrid

KAUST Repository

AlOnazi, Amani A.

2017-06-23

As processor clock rates become more dynamic and workloads become more adaptive, the vulnerability to global synchronization that already complicates programming for performance in today\\'s petascale environment will be exacerbated. Algebraic multigrid (AMG), the solver of choice in many large-scale PDE-based simulations, scales well in the weak sense, with fixed problem size per node, on tightly coupled systems when loads are well balanced and core performance is reliable. However, its strong scaling to many cores within a node is challenging. Reducing synchronization and increasing concurrency are vital adaptations of AMG to hybrid architectures. Recent communication-reducing improvements to classical additive AMG by Vassilevski and Yang improve concurrency and increase communication-computation overlap, while retaining convergence properties close to those of standard multiplicative AMG, but remain bulk synchronous.We extend the Vassilevski and Yang additive AMG to asynchronous task-based parallelism using a hybrid MPI+OmpSs (from the Barcelona Supercomputer Center) within a node, along with MPI for internode communications. We implement a tiling approach to decompose the grid hierarchy into parallel units within task containers. We compare against the MPI-only BoomerAMG and the Auxiliary-space Maxwell Solver (AMS) in the hypre library for the 3D Laplacian operator and the electromagnetic diffusion, respectively. In time to solution for a full solve an MPI-OmpSs hybrid improves over an all-MPI approach in strong scaling at full core count (32 threads per single Haswell node of the Cray XC40) and maintains this per node advantage as both weak scale to thousands of cores, with MPI between nodes.

Confronting the neoliberal and libertarian reconceptualisations of ...

African Journals Online (AJOL)

Confronting this phenomenon, this paper reviews neoliberal and libertarian understandings of educational equality and democratic education and interrogates the rationale for the justification of markets in education. In the process, I criticise the notion of possessive individualism as a principle of democratic education on the ...

When do high and low status group members support confrontation? The role of perceived pervasiveness of prejudice.

Science.gov (United States)

Kahn, Kimberly Barsamian; Barreto, Manuela; Kaiser, Cheryl R; Rego, Marco Silva

2016-03-01

This paper examines how perceived pervasiveness of prejudice differentially affects high and low status group members' support for a low status group member who confronts. In Experiment 1 (N = 228), men and women read a text describing sexism as rare or as pervasive and subsequently indicated their support for a woman who confronted or did not confront a sexist remark. Experiment 2 (N = 324) specified the underlying process using a self-affirmation manipulation. Results show that men were more supportive of confrontation when sexism was perceived to be rare than when it was pervasive. By contrast, women tended to prefer confrontation when sexism was pervasive relative to when it was rare. Personal self-affirmation decreased men's and increased women's support for confrontation when prejudice was rare, suggesting that men's and women's support for confrontation when prejudice is rare is driven by personal impression management considerations. Implications for understanding how members of low and high status groups respond to prejudice are discussed. © 2015 The British Psychological Society.

Perceiving and Confronting Sexism: The Causal Role of Gender Identity Salience.

Science.gov (United States)

Wang, Katie; Dovidio, John F

2017-03-01

Although many researchers have explored the relations among gender identification, discriminatory attributions, and intentions to challenge discrimination, few have examined the causal impact of gender identity salience on women's actual responses to a sexist encounter. In the current study, we addressed this question by experimentally manipulating the salience of gender identity and assessing its impact on women's decision to confront a sexist comment in a simulated online interaction. Female participants ( N = 114) were randomly assigned to complete a short measure of either personal or collective self-esteem, which was designed to increase the salience of personal versus gender identity. They were then given the opportunity to confront a male interaction partner who expressed sexist views. Compared to those who were primed to focus on their personal identity, participants who were primed to focus on their gender identity perceived the interaction partner's remarks as more sexist and were more likely to engage in confrontation. By highlighting the powerful role of subtle contextual cues in shaping women's perceptions of, and responses to, sexism, our findings have important implications for the understanding of gender identity salience as an antecedent of prejudice confrontation. Online slides for instructors who want to use this article for teaching are available on PWQ's website at http://journals.sagepub.com/page/pwq/suppl/index.

3D multiphysics modeling of superconducting cavities with a massively parallel simulation suite

Directory of Open Access Journals (Sweden)

Oleksiy Kononenko

2017-10-01

Full Text Available Radiofrequency cavities based on superconducting technology are widely used in particle accelerators for various applications. The cavities usually have high quality factors and hence narrow bandwidths, so the field stability is sensitive to detuning from the Lorentz force and external loads, including vibrations and helium pressure variations. If not properly controlled, the detuning can result in a serious performance degradation of a superconducting accelerator, so an understanding of the underlying detuning mechanisms can be very helpful. Recent advances in the simulation suite ace3p have enabled realistic multiphysics characterization of such complex accelerator systems on supercomputers. In this paper, we present the new capabilities in ace3p for large-scale 3D multiphysics modeling of superconducting cavities, in particular, a parallel eigensolver for determining mechanical resonances, a parallel harmonic response solver to calculate the response of a cavity to external vibrations, and a numerical procedure to decompose mechanical loads, such as from the Lorentz force or piezoactuators, into the corresponding mechanical modes. These capabilities have been used to do an extensive rf-mechanical analysis of dressed TESLA-type superconducting cavities. The simulation results and their implications for the operational stability of the Linac Coherent Light Source-II are discussed.

Comparison of 250 MHz R10K Origin 2000 and 400 MHz Origin 2000 Using NAS Parallel Benchmarks

Science.gov (United States)

Turney, Raymond D.; Thigpen, William W. (Technical Monitor)

2001-01-01

This report describes results of benchmark tests on Steger, a 250 MHz Origin 2000 system with R10K processors, currently installed at the NASA Ames National Advanced Supercomputing (NAS) facility. For comparison purposes, the tests were also run on Lomax, a 400 MHz Origin 2000 with R12K processors. The BT, LU, and SP application benchmarks in the NAS Parallel Benchmark Suite and the kernel benchmark FT were chosen to measure system performance. Having been written to measure performance on Computational Fluid Dynamics applications, these benchmarks are assumed appropriate to represent the NAS workload. Since the NAS runs both message passing (MPI) and shared-memory, compiler directive type codes, both MPI and OpenMP versions of the benchmarks were used. The MPI versions used were the latest official release of the NAS Parallel Benchmarks, version 2.3. The OpenMP versions used were PBN3b2, a beta version that is in the process of being released. NPB 2.3 and PBN3b2 are technically different benchmarks, and NPB results are not directly comparable to PBN results.

Confronting as autonomy promotion: Speaking up against discrimination and psychological well-being in racial minorities.

Science.gov (United States)

Sanchez, Diana T; Himmelstein, Mary S; Young, Danielle M; Albuja, Analia F; Garcia, Julie A

2016-09-01

Few studies have considered confrontation in the context of coping with discriminatory experiences. These studies test for the first time whether confronting racial discrimination is associated with greater psychological well-being and physical health through the promotion of autonomy. In two separate samples of racial minorities who had experienced racial discrimination, confrontation was associated with greater psychological well-being, and this relationship was mediated by autonomy promotion. These findings did not extend to physical health symptoms. These studies provide preliminary evidence that confrontation may aid in the process of regaining autonomy after experiencing discrimination and therefore promote well-being. © The Author(s) 2015.

GRADSPMHD: A parallel MHD code based on the SPH formalism

Science.gov (United States)

Vanaverbeke, S.; Keppens, R.; Poedts, S.

2014-03-01

We present GRADSPMHD, a completely Lagrangian parallel magnetohydrodynamics code based on the SPH formalism. The implementation of the equations of SPMHD in the “GRAD-h” formalism assembles known results, including the derivation of the discretized MHD equations from a variational principle, the inclusion of time-dependent artificial viscosity, resistivity and conductivity terms, as well as the inclusion of a mixed hyperbolic/parabolic correction scheme for satisfying the ∇ṡB→ constraint on the magnetic field. The code uses a tree-based formalism for neighbor finding and can optionally use the tree code for computing the self-gravity of the plasma. The structure of the code closely follows the framework of our parallel GRADSPH FORTRAN 90 code which we added previously to the CPC program library. We demonstrate the capabilities of GRADSPMHD by running 1, 2, and 3 dimensional standard benchmark tests and we find good agreement with previous work done by other researchers. The code is also applied to the problem of simulating the magnetorotational instability in 2.5D shearing box tests as well as in global simulations of magnetized accretion disks. We find good agreement with available results on this subject in the literature. Finally, we discuss the performance of the code on a parallel supercomputer with distributed memory architecture. Catalogue identifier: AERP_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AERP_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 620503 No. of bytes in distributed program, including test data, etc.: 19837671 Distribution format: tar.gz Programming language: FORTRAN 90/MPI. Computer: HPC cluster. Operating system: Unix. Has the code been vectorized or parallelized?: Yes, parallelized using MPI. RAM: ˜30 MB for a

Fear appeals and confronting information campaigns. [Previously: Fear-based information campaigns.

OpenAIRE

2007-01-01

Fear appeals or confronting information campaigns confront people in an often hard and sometimes even shocking way with the consequences of risky behaviour. This can have a positive impact on the attitudes and behavioural intentions of the target group, but only if key conditions are met. Those conditions are that the information does not only evoke fear, but also informs the target group individuals of their personal risk and provides them with feasible and effective behavioural alternatives...

Plasma turbulence calculations on supercomputers

International Nuclear Information System (INIS)

Carreras, B.A.; Charlton, L.A.; Dominguez, N.; Drake, J.B.; Garcia, L.; Leboeuf, J.N.; Lee, D.K.; Lynch, V.E.; Sidikman, K.

1991-01-01

Although the single-particle picture of magnetic confinement is helpful in understanding some basic physics of plasma confinement, it does not give a full description. Collective effects dominate plasma behavior. Any analysis of plasma confinement requires a self-consistent treatment of the particles and fields. The general picture is further complicated because the plasma, in general, is turbulent. The study of fluid turbulence is a rather complex field by itself. In addition to the difficulties of classical fluid turbulence, plasma turbulence studies face the problems caused by the induced magnetic turbulence, which couples field by itself. In addition to the difficulties of classical fluid turbulence, plasma turbulence studies face the problems caused by the induced magnetic turbulence, which couples back to the fluid. Since the fluid is not a perfect conductor, this turbulence can lead to changes in the topology of the magnetic field structure, causing the magnetic field lines to wander radially. Because the plasma fluid flows along field lines, they carry the particles with them, and this enhances the losses caused by collisions. The changes in topology are critical for the plasma confinement. The study of plasma turbulence and the concomitant transport is a challenging problem. Because of the importance of solving the plasma turbulence problem for controlled thermonuclear research, the high complexity of the problem, and the necessity of attacking the problem with supercomputers, the study of plasma turbulence in magnetic confinement devices is a Grand Challenge problem

Parallel Adjective High-Order CFD Simulations Characterizing SOFIA Cavity Acoustics

Science.gov (United States)

Barad, Michael F.; Brehm, Christoph; Kiris, Cetin C.; Biswas, Rupak

2016-01-01

This paper presents large-scale MPI-parallel computational uid dynamics simulations for the Stratospheric Observatory for Infrared Astronomy (SOFIA). SOFIA is an airborne, 2.5-meter infrared telescope mounted in an open cavity in the aft fuselage of a Boeing 747SP. These simulations focus on how the unsteady ow eld inside and over the cavity interferes with the optical path and mounting structure of the telescope. A temporally fourth-order accurate Runge-Kutta, and spatially fth-order accurate WENO- 5Z scheme was used to perform implicit large eddy simulations. An immersed boundary method provides automated gridding for complex geometries and natural coupling to a block-structured Cartesian adaptive mesh re nement framework. Strong scaling studies using NASA's Pleiades supercomputer with up to 32k CPU cores and 4 billion compu- tational cells shows excellent scaling. Dynamic load balancing based on execution time on individual AMR blocks addresses irregular numerical cost associated with blocks con- taining boundaries. Limits to scaling beyond 32k cores are identi ed, and targeted code optimizations are discussed.

Perceiving and Confronting Sexism: The Causal Role of Gender Identity Salience

Science.gov (United States)

Wang, Katie; Dovidio, John F.

2017-01-01

Although many researchers have explored the relations among gender identification, discriminatory attributions, and intentions to challenge discrimination, few have examined the causal impact of gender identity salience on women’s actual responses to a sexist encounter. In the current study, we addressed this question by experimentally manipulating the salience of gender identity and assessing its impact on women’s decision to confront a sexist comment in a simulated online interaction. Female participants (N = 114) were randomly assigned to complete a short measure of either personal or collective self-esteem, which was designed to increase the salience of personal versus gender identity. They were then given the opportunity to confront a male interaction partner who expressed sexist views. Compared to those who were primed to focus on their personal identity, participants who were primed to focus on their gender identity perceived the interaction partner’s remarks as more sexist and were more likely to engage in confrontation. By highlighting the powerful role of subtle contextual cues in shaping women’s perceptions of, and responses to, sexism, our findings have important implications for the understanding of gender identity salience as an antecedent of prejudice confrontation. Online slides for instructors who want to use this article for teaching are available on PWQ’s website at http://journals.sagepub.com/page/pwq/suppl/index. PMID:29051685

Challenges confronting health care workers in government's ARV ...

African Journals Online (AJOL)

Challenges confronting health care workers in government's ARV rollout: rights and responsibilities. ... Potchefstroom Electronic Law Journal/Potchefstroomse Elektroniese Regsblad ... Unless the rights of HCWs are recognised and their needs adequately addressed, the best laid plans of government will be at risk.

MANAGERIAL PROBLEMS CONFRONTED BY EXECUTIVE CHEFS IN HOTELS

Directory of Open Access Journals (Sweden)

Kemal BIRDIR

2014-07-01

Full Text Available The study was conducted to determine the managerial problems confronted by executive chefs working at 4 and 5-star hotels in Turkey. A survey developed by the researchers was employed as a data collection tool. Answers given by participants were analyzed using “T-test” and “ANOVA” analyses in order to determine whether there are significant differences of opinion on the subject (collated in answers to the survey questionnaire amongst executive chefs, based on answers given by them (expressed as average figures dependent upon such variables as their “Age”, “Gender”, “Educational Status” and “Star status of the hotel within which they worked.” The study results showed that the most important problem confronting executive chefs was “finding educated/trained kitchen personnel.” On the specific problem, “responsibility and authority is not clear within the kitchen,” there was a significant difference of opinion by the gender of the executive chefs. Moreover, there was a significant difference of opinion dependent upon the star status of the hotels within which the chefs worked on the problem of whether or not “the working hours of kitchen personnel were too long.” The findings suggest that there are important problems confronted by executive chefs. Moreover, male and female executive chefs have different opinions on the magnitudes of some specific problems. Whereas there are various reports and similar publications discussing problems faced by executive chefs, the present study is the first one in the literature that solely explore the managerial problems experienced at a kitchen context.

Parallel symbolic state-space exploration is difficult, but what is the alternative?

Directory of Open Access Journals (Sweden)

Gianfranco Ciardo

2009-12-01

Full Text Available State-space exploration is an essential step in many modeling and analysis problems. Its goal is to find the states reachable from the initial state of a discrete-state model described. The state space can used to answer important questions, e.g., "Is there a dead state?" and "Can N become negative?", or as a starting point for sophisticated investigations expressed in temporal logic. Unfortunately, the state space is often so large that ordinary explicit data structures and sequential algorithms cannot cope, prompting the exploration of (1 parallel approaches using multiple processors, from simple workstation networks to shared-memory supercomputers, to satisfy large memory and runtime requirements and (2 symbolic approaches using decision diagrams to encode the large structured sets and relations manipulated during state-space generation. Both approaches have merits and limitations. Parallel explicit state-space generation is challenging, but almost linear speedup can be achieved; however, the analysis is ultimately limited by the memory and processors available. Symbolic methods are a heuristic that can efficiently encode many, but not all, functions over a structured and exponentially large domain; here the pitfalls are subtler: their performance varies widely depending on the class of decision diagram chosen, the state variable order, and obscure algorithmic parameters. As symbolic approaches are often much more efficient than explicit ones for many practical models, we argue for the need to parallelize symbolic state-space generation algorithms, so that we can realize the advantage of both approaches. This is a challenging endeavor, as the most efficient symbolic algorithm, Saturation, is inherently sequential. We conclude by discussing challenges, efforts, and promising directions toward this goal.

Parallel Earthquake Simulations on Large-Scale Multicore Supercomputers

KAUST Repository

Wu, Xingfu

2011-01-01

Earthquakes are one of the most destructive natural hazards on our planet Earth. Hugh earthquakes striking offshore may cause devastating tsunamis, as evidenced by the 11 March 2011 Japan (moment magnitude Mw9.0) and the 26 December 2004 Sumatra (Mw9.1) earthquakes. Earthquake prediction (in terms of the precise time, place, and magnitude of a coming earthquake) is arguably unfeasible in the foreseeable future. To mitigate seismic hazards from future earthquakes in earthquake-prone areas, such as California and Japan, scientists have been using numerical simulations to study earthquake rupture propagation along faults and seismic wave propagation in the surrounding media on ever-advancing modern computers over past several decades. In particular, ground motion simulations for past and future (possible) significant earthquakes have been performed to understand factors that affect ground shaking in populated areas, and to provide ground shaking characteristics and synthetic seismograms for emergency preparation and design of earthquake-resistant structures. These simulation results can guide the development of more rational seismic provisions for leading to safer, more efficient, and economical50pt]Please provide V. Taylor author e-mail ID. structures in earthquake-prone regions.

Parallel Earthquake Simulations on Large-Scale Multicore Supercomputers

KAUST Repository

Wu, Xingfu; Duan, Benchun; Taylor, Valerie

2011-01-01

, such as California and Japan, scientists have been using numerical simulations to study earthquake rupture propagation along faults and seismic wave propagation in the surrounding media on ever-advancing modern computers over past several decades. In particular

Performance and scalability analysis of teraflop-scale parallel architectures using multidimensional wavefront applications

International Nuclear Information System (INIS)

Hoisie, A.; Lubeck, O.; Wasserman, H.

1998-01-01

The authors develop a model for the parallel performance of algorithms that consist of concurrent, two-dimensional wavefronts implemented in a message passing environment. The model, based on a LogGP machine parameterization, combines the separate contributions of computation and communication wavefronts. They validate the model on three important supercomputer systems, on up to 500 processors. They use data from a deterministic particle transport application taken from the ASCI workload, although the model is general to any wavefront algorithm implemented on a 2-D processor domain. They also use the validated model to make estimates of performance and scalability of wavefront algorithms on 100-TFLOPS computer systems expected to be in existence within the next decade as part of the ASCI program and elsewhere. In this context, they analyze two problem sizes. The model shows that on the largest such problem (1 billion cells), inter-processor communication performance is not the bottleneck. Single-node efficiency is the dominant factor

Harnessing Petaflop-Scale Multi-Core Supercomputing for Problems in Space Science

Science.gov (United States)

Albright, B. J.; Yin, L.; Bowers, K. J.; Daughton, W.; Bergen, B.; Kwan, T. J.

2008-12-01

The particle-in-cell kinetic plasma code VPIC has been migrated successfully to the world's fastest supercomputer, Roadrunner, a hybrid multi-core platform built by IBM for the Los Alamos National Laboratory. How this was achieved will be described and examples of state-of-the-art calculations in space science, in particular, the study of magnetic reconnection, will be presented. With VPIC on Roadrunner, we have performed, for the first time, plasma PIC calculations with over one trillion particles, >100× larger than calculations considered "heroic" by community standards. This allows examination of physics at unprecedented scale and fidelity. Roadrunner is an example of an emerging paradigm in supercomputing: the trend toward multi-core systems with deep hierarchies and where memory bandwidth optimization is vital to achieving high performance. Getting VPIC to perform well on such systems is a formidable challenge: the core algorithm is memory bandwidth limited with low compute-to-data ratio and requires random access to memory in its inner loop. That we were able to get VPIC to perform and scale well, achieving >0.374 Pflop/s and linear weak scaling on real physics problems on up to the full 12240-core Roadrunner machine, bodes well for harnessing these machines for our community's needs in the future. Many of the design considerations encountered commute to other multi-core and accelerated (e.g., via GPU) platforms and we modified VPIC with flexibility in mind. These will be summarized and strategies for how one might adapt a code for such platforms will be shared. Work performed under the auspices of the U.S. DOE by the LANS LLC Los Alamos National Laboratory. Dr. Bowers is a LANL Guest Scientist; he is presently at D. E. Shaw Research LLC, 120 W 45th Street, 39th Floor, New York, NY 10036.

Evaluation of existing and proposed computer architectures for future ground-based systems

Science.gov (United States)

Schulbach, C.

1985-01-01

Parallel processing architectures and techniques used in current supercomputers are described and projections are made of future advances. Presently, the von Neumann sequential processing pattern has been accelerated by having separate I/O processors, interleaved memories, wide memories, independent functional units and pipelining. Recent supercomputers have featured single-input, multiple data stream architectures, which have different processors for performing various operations (vector or pipeline processors). Multiple input, multiple data stream machines have also been developed. Data flow techniques, wherein program instructions are activated only when data are available, are expected to play a large role in future supercomputers, along with increased parallel processor arrays. The enhanced operational speeds are essential for adequately treating data from future spacecraft remote sensing instruments such as the Thematic Mapper.

Confronting Violence, Improving Women's Lives Special Display Opens at NLM | NIH MedlinePlus the Magazine

Science.gov (United States)

... of this page please turn JavaScript on. Confronting Violence, Improving Women's Lives Special Display Opens at NLM ... Medicine Division. Photo Courtesy of Lisa Helfert Confronting Violence, Improving Women's Lives is on display in the ...

Use of QUADRICS supercomputer as embedded simulator in emergency management systems

International Nuclear Information System (INIS)

Bove, R.; Di Costanzo, G.; Ziparo, A.

1996-07-01

The experience related to the implementation of a MRBT, atmospheric spreading model with a short duration releasing, are reported. This model was implemented on a QUADRICS-Q1 supercomputer. First is reported a description of the MRBT model. It is an analytical model to study the speadings of light gases realised in the atmosphere cause incidental releasing. The solution of diffusion equation is Gaussian like. It yield the concentration of pollutant substance released. The concentration is function of space and time. Thus the QUADRICS architecture is introduced. And the implementation of the model is described. At the end it will be consider the integration of the QUADRICS-based model as simulator in a emergency management system

Navigating between Dialogue and Confrontation

DEFF Research Database (Denmark)

Thuesen, Frederik

2011-01-01

such as human rights and ethnic discrimination, issues that may involve strong emotions. Drawing inspiration from a qualitative methodology focusing on resistance and power, the article argues that in such situations the interviewer needs to integrate both dialogic and agonistic interview methodologies through...... phronesis, Aristotle’s concept of practical rationality. A phronetic approach, involving reflections on the link between reason and emotions, is well suited for handling both dialogue and confrontation in the interview process. Empirically, the paper draws on interviews with representatives of trade unions...... and employer organizations on the subject of human rights and ethnic discrimination in the Danish labor market....

Lectures in Supercomputational Neurosciences Dynamics in Complex Brain Networks

CERN Document Server

Graben, Peter beim; Thiel, Marco; Kurths, Jürgen

2008-01-01

Computational Neuroscience is a burgeoning field of research where only the combined effort of neuroscientists, biologists, psychologists, physicists, mathematicians, computer scientists, engineers and other specialists, e.g. from linguistics and medicine, seem to be able to expand the limits of our knowledge. The present volume is an introduction, largely from the physicists' perspective, to the subject matter with in-depth contributions by system neuroscientists. A conceptual model for complex networks of neurons is introduced that incorporates many important features of the real brain, such as various types of neurons, various brain areas, inhibitory and excitatory coupling and the plasticity of the network. The computational implementation on supercomputers, which is introduced and discussed in detail in this book, will enable the readers to modify and adapt the algortihm for their own research. Worked-out examples of applications are presented for networks of Morris-Lecar neurons to model the cortical co...

Perceptions of racial confrontation: the role of color blindness and comment ambiguity.

Science.gov (United States)

Zou, Linda X; Dickter, Cheryl L

2013-01-01

Because of its emphasis on diminishing race and avoiding racial discourse, color-blind racial ideology has been suggested to have negative consequences for modern day race relations. The current research examined the influence of color blindness and the ambiguity of a prejudiced remark on perceptions of a racial minority group member who confronts the remark. One hundred thirteen White participants responded to a vignette depicting a White character making a prejudiced comment of variable ambiguity, after which a Black target character confronted the comment. Results demonstrated that the target confronter was perceived more negatively and as responding less appropriately by participants high in color blindness, and that this effect was particularly pronounced when participants responded to the ambiguous comment. Implications for the ways in which color blindness, as an accepted norm that is endorsed across legal and educational settings, can facilitate Whites' complicity in racial inequality are discussed.

Symbolic simulation of engineering systems on a supercomputer

International Nuclear Information System (INIS)

Ragheb, M.; Gvillo, D.; Makowitz, H.

1986-01-01

Model-Based Production-Rule systems for analysis are developed for the symbolic simulation of Complex Engineering systems on a CRAY X-MP Supercomputer. The Fault-Tree and Event-Tree Analysis methodologies from Systems-Analysis are used for problem representation and are coupled to the Rule-Based System Paradigm from Knowledge Engineering to provide modelling of engineering devices. Modelling is based on knowledge of the structure and function of the device rather than on human expertise alone. To implement the methodology, we developed a production-Rule Analysis System that uses both backward-chaining and forward-chaining: HAL-1986. The inference engine uses an Induction-Deduction-Oriented antecedent-consequent logic and is programmed in Portable Standard Lisp (PSL). The inference engine is general and can accommodate general modifications and additions to the knowledge base. The methodologies used will be demonstrated using a model for the identification of faults, and subsequent recovery from abnormal situations in Nuclear Reactor Safety Analysis. The use of the exposed methodologies for the prognostication of future device responses under operational and accident conditions using coupled symbolic and procedural programming is discussed

Assessment of Elderlies Sleep Disorders and Different Confronts Methods Among Them

Directory of Open Access Journals (Sweden)

Monir Nobahar

2007-07-01

Full Text Available Objectives: Sleep is one of the essential needs for human and every disorder in during of sleep causes psychological problem and decreased person>s ability. Although sleep disorders occur in every of ages. Elderly person usually has very problem for satisfied sleep. The aim of this study was to estimate prevalence of sleep disorders and confront methods of those in elderly persons in Semnan city. Methods & Materials: This is a descriptive analytical research. 200 elderly residents of Semnan were selected through rundomical sampling. Sleep disorders was assessment with questioner and interviewer that include of sleep disorders (Dissomnia, Parasomnia and confront methods (Behavioral, Cognitive, sleep hygiene and drug therapy. Results: Data indicated that prevalence of dissomnia was 67% and prevalence of insomnia was 61% that the most problem were in all stage of sleep (early, intermittent and end. Prevalence of Parasomnia was 29% that more of those (14% had night terror. In the part of confront methods of sleep disorders, 57% used of behavioral therapy. The most of that (25% were concentration of the limb before the sleep and 95.5% of them comprehension of cognitive methods. The most of that (26% were comprehension of effect of age on sleep. 100% of them orientation of sleep hygiene and the most of that (39% were orientation with 4 choose of sleep hygiene. 20% of them used of drug therapy. Conclusion: Finding above indicate that high prevalence of sleep disorders in elderly in Semnan, need supervised and widespread program for promoting awareness among population about sleep disorders and confront methods of those.

Confrontation Naming and Reading Abilities at Primary School: A Longitudinal Study

Directory of Open Access Journals (Sweden)

Chiara Luoni

2015-01-01

naming (i.e., the Boston Naming Test (BNT in a nonclinical sample of Italian primary school children was conducted (n=126, testing them at the end of each school year, to assess nonverbal intelligence, confrontation naming, and reading abilities. Results. Performance on the BNT emerged as a function of IQ and SES. Significant correlations between confrontation naming and reading abilities, especially comprehension, were found; BNT scores correlated better with reading fluency than with reading accuracy. Conclusions. The longitudinal data obtained in this study are discussed with regard to reading abilities, intelligence, age, gender, and socioeconomic status.

Parallel solution of the time-dependent Ginzburg-Landau equations and other experiences using BlockComm-Chameleon and PCN on the IBM SP, Intel iPSC/860, and clusters of workstations

International Nuclear Information System (INIS)

Coskun, E.

1995-09-01

Time-dependent Ginzburg-Landau (TDGL) equations are considered for modeling a thin-film finite size superconductor placed under magnetic field. The problem then leads to the use of so-called natural boundary conditions. Computational domain is partitioned into subdomains and bond variables are used in obtaining the corresponding discrete system of equations. An efficient time-differencing method based on the Forward Euler method is developed. Finally, a variable strength magnetic field resulting in a vortex motion in Type II High T c superconducting films is introduced. The authors tackled the problem using two different state-of-the-art parallel computing tools: BlockComm/Chameleon and PCN. They had access to two high-performance distributed memory supercomputers: the Intel iPSC/860 and IBM SP1. They also tested the codes using, as a parallel computing environment, a cluster of Sun Sparc workstations

Enabling parallel simulation of large-scale HPC network systems

International Nuclear Information System (INIS)

Mubarak, Misbah; Carothers, Christopher D.; Ross, Robert B.; Carns, Philip

2016-01-01

Here, with the increasing complexity of today’s high-performance computing (HPC) architectures, simulation has become an indispensable tool for exploring the design space of HPC systems—in particular, networks. In order to make effective design decisions, simulations of these systems must possess the following properties: (1) have high accuracy and fidelity, (2) produce results in a timely manner, and (3) be able to analyze a broad range of network workloads. Most state-of-the-art HPC network simulation frameworks, however, are constrained in one or more of these areas. In this work, we present a simulation framework for modeling two important classes of networks used in today’s IBM and Cray supercomputers: torus and dragonfly networks. We use the Co-Design of Multi-layer Exascale Storage Architecture (CODES) simulation framework to simulate these network topologies at a flit-level detail using the Rensselaer Optimistic Simulation System (ROSS) for parallel discrete-event simulation. Our simulation framework meets all the requirements of a practical network simulation and can assist network designers in design space exploration. First, it uses validated and detailed flit-level network models to provide an accurate and high-fidelity network simulation. Second, instead of relying on serial time-stepped or traditional conservative discrete-event simulations that limit simulation scalability and efficiency, we use the optimistic event-scheduling capability of ROSS to achieve efficient and scalable HPC network simulations on today’s high-performance cluster systems. Third, our models give network designers a choice in simulating a broad range of network workloads, including HPC application workloads using detailed network traces, an ability that is rarely offered in parallel with high-fidelity network simulations

Confronting Theoretical Predictions With Experimental Data; Fitting Strategy For Multi-Dimensional Distributions

Directory of Open Access Journals (Sweden)

Tomasz Przedziński

2015-01-01

Full Text Available After developing a Resonance Chiral Lagrangian (RχL model to describe hadronic τ lepton decays [18], the model was confronted with experimental data. This was accomplished using a fitting framework which was developed to take into account the complexity of the model and to ensure the numerical stability for the algorithms used in the fitting. Since the model used in the fit contained 15 parameters and there were only three 1-dimensional distributions available, we could expect multiple local minima or even whole regions of equal potential to appear. Our methods had to thoroughly explore the whole parameter space and ensure, as well as possible, that the result is a global minimum. This paper is focused on the technical aspects of the fitting strategy used. The first approach was based on re-weighting algorithm published in [17] and produced results in around two weeks. Later approach, with improved theoretical model and simple parallelization algorithm based on Inter-Process Communication (IPC methods of UNIX system, reduced computation time down to 2-3 days. Additional approximations were introduced to the model decreasing time to obtain the preliminary results down to 8 hours. This allowed to better validate the results leading to a more robust analysis published in [12].

GENESIS: a hybrid-parallel and multi-scale molecular dynamics simulator with enhanced sampling algorithms for biomolecular and cellular simulations.

Science.gov (United States)

Jung, Jaewoon; Mori, Takaharu; Kobayashi, Chigusa; Matsunaga, Yasuhiro; Yoda, Takao; Feig, Michael; Sugita, Yuji

2015-07-01

GENESIS (Generalized-Ensemble Simulation System) is a new software package for molecular dynamics (MD) simulations of macromolecules. It has two MD simulators, called ATDYN and SPDYN. ATDYN is parallelized based on an atomic decomposition algorithm for the simulations of all-atom force-field models as well as coarse-grained Go-like models. SPDYN is highly parallelized based on a domain decomposition scheme, allowing large-scale MD simulations on supercomputers. Hybrid schemes combining OpenMP and MPI are used in both simulators to target modern multicore computer architectures. Key advantages of GENESIS are (1) the highly parallel performance of SPDYN for very large biological systems consisting of more than one million atoms and (2) the availability of various REMD algorithms (T-REMD, REUS, multi-dimensional REMD for both all-atom and Go-like models under the NVT, NPT, NPAT, and NPγT ensembles). The former is achieved by a combination of the midpoint cell method and the efficient three-dimensional Fast Fourier Transform algorithm, where the domain decomposition space is shared in real-space and reciprocal-space calculations. Other features in SPDYN, such as avoiding concurrent memory access, reducing communication times, and usage of parallel input/output files, also contribute to the performance. We show the REMD simulation results of a mixed (POPC/DMPC) lipid bilayer as a real application using GENESIS. GENESIS is released as free software under the GPLv2 licence and can be easily modified for the development of new algorithms and molecular models. WIREs Comput Mol Sci 2015, 5:310-323. doi: 10.1002/wcms.1220.

Heterogeneous scalable framework for multiphase flows

Energy Technology Data Exchange (ETDEWEB)

Morris, Karla Vanessa [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2013-09-01

Two categories of challenges confront the developer of computational spray models: those related to the computation and those related to the physics. Regarding the computation, the trend towards heterogeneous, multi- and many-core platforms will require considerable re-engineering of codes written for the current supercomputing platforms. Regarding the physics, accurate methods for transferring mass, momentum and energy from the dispersed phase onto the carrier fluid grid have so far eluded modelers. Significant challenges also lie at the intersection between these two categories. To be competitive, any physics model must be expressible in a parallel algorithm that performs well on evolving computer platforms. This work created an application based on a software architecture where the physics and software concerns are separated in a way that adds flexibility to both. The develop spray-tracking package includes an application programming interface (API) that abstracts away the platform-dependent parallelization concerns, enabling the scientific programmer to write serial code that the API resolves into parallel processes and threads of execution. The project also developed the infrastructure required to provide similar APIs to other application. The API allow object-oriented Fortran applications direct interaction with Trilinos to support memory management of distributed objects in central processing units (CPU) and graphic processing units (GPU) nodes for applications using C++.

How to use MPI communication in highly parallel climate simulations more easily and more efficiently.

Science.gov (United States)

Behrens, Jörg; Hanke, Moritz; Jahns, Thomas

2014-05-01

In this talk we present a way to facilitate efficient use of MPI communication for developers of climate models. Exploitation of the performance potential of today's highly parallel supercomputers with real world simulations is a complex task. This is partly caused by the low level nature of the MPI communication library which is the dominant communication tool at least for inter-node communication. In order to manage the complexity of the task, climate simulations with non-trivial communication patterns often use an internal abstraction layer above MPI without exploiting the benefits of communication aggregation or MPI-datatypes. The solution for the complexity and performance problem we propose is the communication library YAXT. This library is built on top of MPI and takes high level descriptions of arbitrary domain decompositions and automatically derives an efficient collective data exchange. Several exchanges can be aggregated in order to reduce latency costs. Examples are given which demonstrate the simplicity and the performance gains for selected climate applications.

Education confronts the energy dilemma

Energy Technology Data Exchange (ETDEWEB)

None

1977-01-01

The conference was convened to present a role that America's schools could play in solving or coping with the energy crisis. Eleven sessions were conducted to fulfill this concern: Our Energy Crisis and Education: A Critical Assessment; The Energy Agenda at the Office of Education; Energy Resources: Scenarios for the Future; The Moral Dilemma of Energy Education; Constraints Influencing Education's Role; Energy Education: What's Been Done to Date; Practitioners Discuss Their Future Roles, Responsibilities; Politics of Energy Education; Confronting the Energy Dilemma; The Meaning of Scarcity; and The Impact of the Carter Energy Program on American Schools. Summary reports and reactions to the conference conclude the proceedings. (MCW)

Continuing to Confront COPD International Patient Survey : methods, COPD prevalence, and disease burden in 2012-2013

NARCIS (Netherlands)

Landis, Sarah H.; Muellerova, Hana; Mannino, David M.; Menezes, Ana M.; Han, MeiLan K.; van der Molen, Thys; Ichinose, Masakazu; Aisanov, Zaurbek; Oh, Yeon-Mok; Davis, Kourtney J.

2014-01-01

Purpose: The Continuing to Confront COPD International Patient Survey aimed to estimate the prevalence and burden of COPD globally and to update findings from the Confronting COPD International Survey conducted in 1999-2000. Materials and methods: Chronic obstructive pulmonary disease (COPD)

Confronting Female Genital Mutilation: The Role of Youth and ICTs ...

International Development Research Centre (IDRC) Digital Library (Canada)

2011-07-14

Jul 14, 2011 ... Book cover Confronting Female Genital Mutilation: The Role of ... of an innovative research and action project carried out by ENDA Tiers ... Congratulations to the first cohort of Women in Climate Change Science Fellows!

Faster Parallel Traversal of Scale Free Graphs at Extreme Scale with Vertex Delegates

KAUST Repository

Pearce, Roger

2014-11-01

© 2014 IEEE. At extreme scale, irregularities in the structure of scale-free graphs such as social network graphs limit our ability to analyze these important and growing datasets. A key challenge is the presence of high-degree vertices (hubs), that leads to parallel workload and storage imbalances. The imbalances occur because existing partitioning techniques are not able to effectively partition high-degree vertices. We present techniques to distribute storage, computation, and communication of hubs for extreme scale graphs in distributed memory supercomputers. To balance the hub processing workload, we distribute hub data structures and related computation among a set of delegates. The delegates coordinate using highly optimized, yet portable, asynchronous broadcast and reduction operations. We demonstrate scalability of our new algorithmic technique using Breadth-First Search (BFS), Single Source Shortest Path (SSSP), K-Core Decomposition, and Page-Rank on synthetically generated scale-free graphs. Our results show excellent scalability on large scale-free graphs up to 131K cores of the IBM BG/P, and outperform the best known Graph500 performance on BG/P Intrepid by 15%

Faster Parallel Traversal of Scale Free Graphs at Extreme Scale with Vertex Delegates

KAUST Repository

Pearce, Roger; Gokhale, Maya; Amato, Nancy M.

2014-01-01

© 2014 IEEE. At extreme scale, irregularities in the structure of scale-free graphs such as social network graphs limit our ability to analyze these important and growing datasets. A key challenge is the presence of high-degree vertices (hubs), that leads to parallel workload and storage imbalances. The imbalances occur because existing partitioning techniques are not able to effectively partition high-degree vertices. We present techniques to distribute storage, computation, and communication of hubs for extreme scale graphs in distributed memory supercomputers. To balance the hub processing workload, we distribute hub data structures and related computation among a set of delegates. The delegates coordinate using highly optimized, yet portable, asynchronous broadcast and reduction operations. We demonstrate scalability of our new algorithmic technique using Breadth-First Search (BFS), Single Source Shortest Path (SSSP), K-Core Decomposition, and Page-Rank on synthetically generated scale-free graphs. Our results show excellent scalability on large scale-free graphs up to 131K cores of the IBM BG/P, and outperform the best known Graph500 performance on BG/P Intrepid by 15%

Confronting tracker field quintessence with data

International Nuclear Information System (INIS)

Wang, Pao-Yu; Chen, Chien-Wen; Chen, Pisin

2012-01-01

We confront tracker field quintessence with observational data. The potentials considered in this paper include V(φ)∝φ −α , exp (M p /φ), exp (M p /φ)−1, exp (βM p /φ) and exp (γM p /φ)−1; while the data come from the latest SN Ia, CMB and BAO observations. Stringent parameter constraints are obtained. In comparison with the cosmological constant via information criteria, it is found that models with potentials exp (M p /φ), exp (M p /φ)−1 and exp (γM p /φ)−1 are not supported by the current data

Massively Parallel Polar Decomposition on Distributed-Memory Systems

KAUST Repository

Ltaief, Hatem

2018-01-01

We present a high-performance implementation of the Polar Decomposition (PD) on distributed-memory systems. Building upon on the QR-based Dynamically Weighted Halley (QDWH) algorithm, the key idea lies in finding the best rational approximation for the scalar sign function, which also corresponds to the polar factor for symmetric matrices, to further accelerate the QDWH convergence. Based on the Zolotarev rational functions—introduced by Zolotarev (ZOLO) in 1877— this new PD algorithm ZOLO-PD converges within two iterations even for ill-conditioned matrices, instead of the original six iterations needed for QDWH. ZOLO-PD uses the property of Zolotarev functions that optimality is maintained when two functions are composed in an appropriate manner. The resulting ZOLO-PD has a convergence rate up to seventeen, in contrast to the cubic convergence rate for QDWH. This comes at the price of higher arithmetic costs and memory footprint. These extra floating-point operations can, however, be processed in an embarrassingly parallel fashion. We demonstrate performance using up to 102, 400 cores on two supercomputers. We demonstrate that, in the presence of a large number of processing units, ZOLO-PD is able to outperform QDWH by up to 2.3X speedup, especially in situations where QDWH runs out of work, for instance, in the strong scaling mode of operation.

Sharing skills and knowledge to confront real-world problems | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

Sharing skills and knowledge to confront real-world problems ... because 1.3 billion people cannot read English, and only 163 million people (a fraction ... childhood obesity in urban areas, caused by increases in junk food and lack of exercise.

Watson will see you now: a supercomputer to help clinicians make informed treatment decisions.

Science.gov (United States)

Doyle-Lindrud, Susan

2015-02-01

IBM has collaborated with several cancer care providers to develop and train the IBM supercomputer Watson to help clinicians make informed treatment decisions. When a patient is seen in clinic, the oncologist can input all of the clinical information into the computer system. Watson will then review all of the data and recommend treatment options based on the latest evidence and guidelines. Once the oncologist makes the treatment decision, this information can be sent directly to the insurance company for approval. Watson has the ability to standardize care and accelerate the approval process, a benefit to the healthcare provider and the patient.

Affordable and accurate large-scale hybrid-functional calculations on GPU-accelerated supercomputers

Science.gov (United States)

Ratcliff, Laura E.; Degomme, A.; Flores-Livas, José A.; Goedecker, Stefan; Genovese, Luigi

2018-03-01

Performing high accuracy hybrid functional calculations for condensed matter systems containing a large number of atoms is at present computationally very demanding or even out of reach if high quality basis sets are used. We present a highly optimized multiple graphics processing unit implementation of the exact exchange operator which allows one to perform fast hybrid functional density-functional theory (DFT) calculations with systematic basis sets without additional approximations for up to a thousand atoms. With this method hybrid DFT calculations of high quality become accessible on state-of-the-art supercomputers within a time-to-solution that is of the same order of magnitude as traditional semilocal-GGA functionals. The method is implemented in a portable open-source library.

Thread-level parallelization and optimization of NWChem for the Intel MIC architecture

Energy Technology Data Exchange (ETDEWEB)

Shan, Hongzhang [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Williams, Samuel [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); de Jong, Wibe [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Oliker, Leonid [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2015-01-01

In the multicore era it was possible to exploit the increase in on-chip parallelism by simply running multiple MPI processes per chip. Unfortunately, manycore processors' greatly increased thread- and data-level parallelism coupled with a reduced memory capacity demand an altogether different approach. In this paper we explore augmenting two NWChem modules, triples correction of the CCSD(T) and Fock matrix construction, with OpenMP in order that they might run efficiently on future manycore architectures. As the next NERSC machine will be a self-hosted Intel MIC (Xeon Phi) based supercomputer, we leverage an existing MIC testbed at NERSC to evaluate our experiments. In order to proxy the fact that future MIC machines will not have a host processor, we run all of our experiments in native mode. We found that while straightforward application of OpenMP to the deep loop nests associated with the tensor contractions of CCSD(T) was sufficient in attaining high performance, significant e ort was required to safely and efeciently thread the TEXAS integral package when constructing the Fock matrix. Ultimately, our new MPI+OpenMP hybrid implementations attain up to 65× better performance for the triples part of the CCSD(T) due in large part to the fact that the limited on-card memory limits the existing MPI implementation to a single process per card. Additionally, we obtain up to 1.6× better performance on Fock matrix constructions when compared with the best MPI implementations running multiple processes per card.

Thread-Level Parallelization and Optimization of NWChem for the Intel MIC Architecture

Energy Technology Data Exchange (ETDEWEB)

Shan, Hongzhang; Williams, Samuel; Jong, Wibe de; Oliker, Leonid

2014-10-10

In the multicore era it was possible to exploit the increase in on-chip parallelism by simply running multiple MPI processes per chip. Unfortunately, manycore processors' greatly increased thread- and data-level parallelism coupled with a reduced memory capacity demand an altogether different approach. In this paper we explore augmenting two NWChem modules, triples correction of the CCSD(T) and Fock matrix construction, with OpenMP in order that they might run efficiently on future manycore architectures. As the next NERSC machine will be a self-hosted Intel MIC (Xeon Phi) based supercomputer, we leverage an existing MIC testbed at NERSC to evaluate our experiments. In order to proxy the fact that future MIC machines will not have a host processor, we run all of our experiments in tt native mode. We found that while straightforward application of OpenMP to the deep loop nests associated with the tensor contractions of CCSD(T) was sufficient in attaining high performance, significant effort was required to safely and efficiently thread the TEXAS integral package when constructing the Fock matrix. Ultimately, our new MPI OpenMP hybrid implementations attain up to 65x better performance for the triples part of the CCSD(T) due in large part to the fact that the limited on-card memory limits the existing MPI implementation to a single process per card. Additionally, we obtain up to 1.6x better performance on Fock matrix constructions when compared with the best MPI implementations running multiple processes per card.

Adventures in supercomputing: An innovative program for high school teachers

Energy Technology Data Exchange (ETDEWEB)

Oliver, C.E.; Hicks, H.R.; Summers, B.G. [Oak Ridge National Lab., TN (United States); Staten, D.G. [Wartburg Central High School, TN (United States)

1994-12-31

Within the realm of education, seldom does an innovative program become available with the potential to change an educator`s teaching methodology. Adventures in Supercomputing (AiS), sponsored by the U.S. Department of Energy (DOE), is such a program. It is a program for high school teachers that changes the teacher paradigm from a teacher-directed approach of teaching to a student-centered approach. {open_quotes}A student-centered classroom offers better opportunities for development of internal motivation, planning skills, goal setting and perseverance than does the traditional teacher-directed mode{close_quotes}. Not only is the process of teaching changed, but the cross-curricula integration within the AiS materials is remarkable. Written from a teacher`s perspective, this paper will describe the AiS program and its effects on teachers and students, primarily at Wartburg Central High School, in Wartburg, Tennessee. The AiS program in Tennessee is sponsored by Oak Ridge National Laboratory (ORNL).

A parallel domain decomposition-based implicit method for the Cahn-Hilliard-Cook phase-field equation in 3D

KAUST Repository

Zheng, Xiang

2015-03-01

We present a numerical algorithm for simulating the spinodal decomposition described by the three dimensional Cahn-Hilliard-Cook (CHC) equation, which is a fourth-order stochastic partial differential equation with a noise term. The equation is discretized in space and time based on a fully implicit, cell-centered finite difference scheme, with an adaptive time-stepping strategy designed to accelerate the progress to equilibrium. At each time step, a parallel Newton-Krylov-Schwarz algorithm is used to solve the nonlinear system. We discuss various numerical and computational challenges associated with the method. The numerical scheme is validated by a comparison with an explicit scheme of high accuracy (and unreasonably high cost). We present steady state solutions of the CHC equation in two and three dimensions. The effect of the thermal fluctuation on the spinodal decomposition process is studied. We show that the existence of the thermal fluctuation accelerates the spinodal decomposition process and that the final steady morphology is sensitive to the stochastic noise. We also show the evolution of the energies and statistical moments. In terms of the parallel performance, it is found that the implicit domain decomposition approach scales well on supercomputers with a large number of processors. © 2015 Elsevier Inc.

A parallel domain decomposition-based implicit method for the Cahn-Hilliard-Cook phase-field equation in 3D

Science.gov (United States)

Zheng, Xiang; Yang, Chao; Cai, Xiao-Chuan; Keyes, David

2015-03-01

We present a numerical algorithm for simulating the spinodal decomposition described by the three dimensional Cahn-Hilliard-Cook (CHC) equation, which is a fourth-order stochastic partial differential equation with a noise term. The equation is discretized in space and time based on a fully implicit, cell-centered finite difference scheme, with an adaptive time-stepping strategy designed to accelerate the progress to equilibrium. At each time step, a parallel Newton-Krylov-Schwarz algorithm is used to solve the nonlinear system. We discuss various numerical and computational challenges associated with the method. The numerical scheme is validated by a comparison with an explicit scheme of high accuracy (and unreasonably high cost). We present steady state solutions of the CHC equation in two and three dimensions. The effect of the thermal fluctuation on the spinodal decomposition process is studied. We show that the existence of the thermal fluctuation accelerates the spinodal decomposition process and that the final steady morphology is sensitive to the stochastic noise. We also show the evolution of the energies and statistical moments. In terms of the parallel performance, it is found that the implicit domain decomposition approach scales well on supercomputers with a large number of processors.

A parallel domain decomposition-based implicit method for the Cahn–Hilliard–Cook phase-field equation in 3D

International Nuclear Information System (INIS)

Zheng, Xiang; Yang, Chao; Cai, Xiao-Chuan; Keyes, David

2015-01-01

We present a numerical algorithm for simulating the spinodal decomposition described by the three dimensional Cahn–Hilliard–Cook (CHC) equation, which is a fourth-order stochastic partial differential equation with a noise term. The equation is discretized in space and time based on a fully implicit, cell-centered finite difference scheme, with an adaptive time-stepping strategy designed to accelerate the progress to equilibrium. At each time step, a parallel Newton–Krylov–Schwarz algorithm is used to solve the nonlinear system. We discuss various numerical and computational challenges associated with the method. The numerical scheme is validated by a comparison with an explicit scheme of high accuracy (and unreasonably high cost). We present steady state solutions of the CHC equation in two and three dimensions. The effect of the thermal fluctuation on the spinodal decomposition process is studied. We show that the existence of the thermal fluctuation accelerates the spinodal decomposition process and that the final steady morphology is sensitive to the stochastic noise. We also show the evolution of the energies and statistical moments. In terms of the parallel performance, it is found that the implicit domain decomposition approach scales well on supercomputers with a large number of processors

Re-inventing electromagnetics - Supercomputing solution of Maxwell's equations via direct time integration on space grids

International Nuclear Information System (INIS)

Taflove, A.

1992-01-01

This paper summarizes the present state and future directions of applying finite-difference and finite-volume time-domain techniques for Maxwell's equations on supercomputers to model complex electromagnetic wave interactions with structures. Applications so far have been dominated by radar cross section technology, but by no means are limited to this area. In fact, the gains we have made place us on the threshold of being able to make tremendous contributions to non-defense electronics and optical technology. Some of the most interesting research in these commercial areas is summarized. 47 refs

Parallel definition of tear film maps on distributed-memory clusters for the support of dry eye diagnosis.

Science.gov (United States)

González-Domínguez, Jorge; Remeseiro, Beatriz; Martín, María J

2017-02-01

The analysis of the interference patterns on the tear film lipid layer is a useful clinical test to diagnose dry eye syndrome. This task can be automated with a high degree of accuracy by means of the use of tear film maps. However, the time required by the existing applications to generate them prevents a wider acceptance of this method by medical experts. Multithreading has been previously successfully employed by the authors to accelerate the tear film map definition on multicore single-node machines. In this work, we propose a hybrid message-passing and multithreading parallel approach that further accelerates the generation of tear film maps by exploiting the computational capabilities of distributed-memory systems such as multicore clusters and supercomputers. The algorithm for drawing tear film maps is parallelized using Message Passing Interface (MPI) for inter-node communications and the multithreading support available in the C++11 standard for intra-node parallelization. The original algorithm is modified to reduce the communications and increase the scalability. The hybrid method has been tested on 32 nodes of an Intel cluster (with two 12-core Haswell 2680v3 processors per node) using 50 representative images. Results show that maximum runtime is reduced from almost two minutes using the previous only-multithreaded approach to less than ten seconds using the hybrid method. The hybrid MPI/multithreaded implementation can be used by medical experts to obtain tear film maps in only a few seconds, which will significantly accelerate and facilitate the diagnosis of the dry eye syndrome. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A Scheduling-Based Framework for Efficient Massively Parallel Execution, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The barrier to entry creating efficient, scalable applications for heterogeneous supercomputing environments is too high. EM Photonics has found that the majority of...

Parallel Block Structured Adaptive Mesh Refinement on Graphics Processing Units

Energy Technology Data Exchange (ETDEWEB)

Beckingsale, D. A. [Atomic Weapons Establishment (AWE), Aldermaston (United Kingdom); Gaudin, W. P. [Atomic Weapons Establishment (AWE), Aldermaston (United Kingdom); Hornung, R. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gunney, B. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gamblin, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Herdman, J. A. [Atomic Weapons Establishment (AWE), Aldermaston (United Kingdom); Jarvis, S. A. [Atomic Weapons Establishment (AWE), Aldermaston (United Kingdom)

2014-11-17

Block-structured adaptive mesh refinement is a technique that can be used when solving partial differential equations to reduce the number of zones necessary to achieve the required accuracy in areas of interest. These areas (shock fronts, material interfaces, etc.) are recursively covered with finer mesh patches that are grouped into a hierarchy of refinement levels. Despite the potential for large savings in computational requirements and memory usage without a corresponding reduction in accuracy, AMR adds overhead in managing the mesh hierarchy, adding complex communication and data movement requirements to a simulation. In this paper, we describe the design and implementation of a native GPU-based AMR library, including: the classes used to manage data on a mesh patch, the routines used for transferring data between GPUs on different nodes, and the data-parallel operators developed to coarsen and refine mesh data. We validate the performance and accuracy of our implementation using three test problems and two architectures: an eight-node cluster, and over four thousand nodes of Oak Ridge National Laboratory’s Titan supercomputer. Our GPU-based AMR hydrodynamics code performs up to 4.87× faster than the CPU-based implementation, and has been scaled to over four thousand GPUs using a combination of MPI and CUDA.

High performance parallel computing of flows in complex geometries: II. Applications

International Nuclear Information System (INIS)

Gourdain, N; Gicquel, L; Staffelbach, G; Vermorel, O; Duchaine, F; Boussuge, J-F; Poinsot, T

2009-01-01

Present regulations in terms of pollutant emissions, noise and economical constraints, require new approaches and designs in the fields of energy supply and transportation. It is now well established that the next breakthrough will come from a better understanding of unsteady flow effects and by considering the entire system and not only isolated components. However, these aspects are still not well taken into account by the numerical approaches or understood whatever the design stage considered. The main challenge is essentially due to the computational requirements inferred by such complex systems if it is to be simulated by use of supercomputers. This paper shows how new challenges can be addressed by using parallel computing platforms for distinct elements of a more complex systems as encountered in aeronautical applications. Based on numerical simulations performed with modern aerodynamic and reactive flow solvers, this work underlines the interest of high-performance computing for solving flow in complex industrial configurations such as aircrafts, combustion chambers and turbomachines. Performance indicators related to parallel computing efficiency are presented, showing that establishing fair criterions is a difficult task for complex industrial applications. Examples of numerical simulations performed in industrial systems are also described with a particular interest for the computational time and the potential design improvements obtained with high-fidelity and multi-physics computing methods. These simulations use either unsteady Reynolds-averaged Navier-Stokes methods or large eddy simulation and deal with turbulent unsteady flows, such as coupled flow phenomena (thermo-acoustic instabilities, buffet, etc). Some examples of the difficulties with grid generation and data analysis are also presented when dealing with these complex industrial applications.

Clinical confrontation results of diagnostics and treatment of skin cancer

International Nuclear Information System (INIS)

Zikiryakhodjaev, D.Z.; Sanginov, D.R.

2001-01-01

In this chapter of book authors investigated the clinical confrontation results of diagnostics and treatment of skin cancer. They noted that diagnostic of skin cancer have to foresee the determination morphologic implements and degree of malignancy tumorous process why in general depend prognosis of illness

Scalability of Parallel Spatial Direct Numerical Simulations on Intel Hypercube and IBM SP1 and SP2

Science.gov (United States)

Joslin, Ronald D.; Hanebutte, Ulf R.; Zubair, Mohammad

1995-01-01

The implementation and performance of a parallel spatial direct numerical simulation (PSDNS) approach on the Intel iPSC/860 hypercube and IBM SP1 and SP2 parallel computers is documented. Spatially evolving disturbances associated with the laminar-to-turbulent transition in boundary-layer flows are computed with the PSDNS code. The feasibility of using the PSDNS to perform transition studies on these computers is examined. The results indicate that PSDNS approach can effectively be parallelized on a distributed-memory parallel machine by remapping the distributed data structure during the course of the calculation. Scalability information is provided to estimate computational costs to match the actual costs relative to changes in the number of grid points. By increasing the number of processors, slower than linear speedups are achieved with optimized (machine-dependent library) routines. This slower than linear speedup results because the computational cost is dominated by FFT routine, which yields less than ideal speedups. By using appropriate compile options and optimized library routines on the SP1, the serial code achieves 52-56 M ops on a single node of the SP1 (45 percent of theoretical peak performance). The actual performance of the PSDNS code on the SP1 is evaluated with a "real world" simulation that consists of 1.7 million grid points. One time step of this simulation is calculated on eight nodes of the SP1 in the same time as required by a Cray Y/MP supercomputer. For the same simulation, 32-nodes of the SP1 and SP2 are required to reach the performance of a Cray C-90. A 32 node SP1 (SP2) configuration is 2.9 (4.6) times faster than a Cray Y/MP for this simulation, while the hypercube is roughly 2 times slower than the Y/MP for this application. KEY WORDS: Spatial direct numerical simulations; incompressible viscous flows; spectral methods; finite differences; parallel computing.

3D-radiative transfer in terrestrial atmosphere: An efficient parallel numerical procedure

Science.gov (United States)

Bass, L. P.; Germogenova, T. A.; Nikolaeva, O. V.; Kokhanovsky, A. A.; Kuznetsov, V. S.

2003-04-01

Light propagation and scattering in terrestrial atmosphere is usually studied in the framework of the 1D radiative transfer theory [1]. However, in reality particles (e.g., ice crystals, solid and liquid aerosols, cloud droplets) are randomly distributed in 3D space. In particular, their concentrations vary both in vertical and horizontal directions. Therefore, 3D effects influence modern cloud and aerosol retrieval procedures, which are currently based on the 1D radiative transfer theory. It should be pointed out that the standard radiative transfer equation allows to study these more complex situations as well [2]. In recent year the parallel version of the 2D and 3D RADUGA code has been developed. This version is successfully used in gammas and neutrons transport problems [3]. Applications of this code to radiative transfer in atmosphere problems are contained in [4]. Possibilities of code RADUGA are presented in [5]. The RADUGA code system is an universal solver of radiative transfer problems for complicated models, including 2D and 3D aerosol and cloud fields with arbitrary scattering anisotropy, light absorption, inhomogeneous underlying surface and topography. Both delta type and distributed light sources can be accounted for in the framework of the algorithm developed. The accurate numerical procedure is based on the new discrete ordinate SWDD scheme [6]. The algorithm is specifically designed for parallel supercomputers. The version RADUGA 5.1(P) can run on MBC1000M [7] (768 processors with 10 Gb of hard disc memory for each processor). The peak productivity is equal 1 Tfl. Corresponding scalar version RADUGA 5.1 is working on PC. As a first example of application of the algorithm developed, we have studied the shadowing effects of clouds on neighboring cloudless atmosphere, depending on the cloud optical thickness, surface albedo, and illumination conditions. This is of importance for modern satellite aerosol retrieval algorithms development. [1] Sobolev

Research center Juelich to install Germany's most powerful supercomputer new IBM System for science and research will achieve 5.8 trillion computations per second

CERN Multimedia

2002-01-01

"The Research Center Juelich, Germany, and IBM today announced that they have signed a contract for the delivery and installation of a new IBM supercomputer at the Central Institute for Applied Mathematics" (1/2 page).

Dark radiation confronting LHC in Z′ models

International Nuclear Information System (INIS)

Solaguren-Beascoa, A.; Gonzalez-Garcia, M.C.

2013-01-01

Recent cosmological data favour additional relativistic degrees of freedom beyond the three active neutrinos and photons, often referred to as “dark radiation”. Extensions of the SM involving TeV-scale Z ′ gauge bosons generically contain superweakly interacting light right-handed neutrinos which can constitute this dark radiation. In this Letter we confront the requirement on the parameters of the E 6 Z ′ models to account for the present evidence of dark radiation with the already existing constraints from searches for new neutral gauge bosons at LHC7

Confrontation and Alienation: Education's Flawed Response to Religious Textbook Objections.

Science.gov (United States)

Balajthy, Ernest

Recent controversies over textbooks illustrate objections held by Evangelicals to "secular humanism" in the schools. Educators automatically tend to assume that all religious objections to curricula are clear-cut attempts at censorship. This confrontational attitude on the part of educators can lead to alienation of minority religious…

Challenge, Confrontation, and Exhortation as Intentional Invitations by Professional Helpers.

Science.gov (United States)

Schmidt, John J.

1996-01-01

Examines intentional invitations that challenge, confront, exhort, and persuade people to change their behaviors. Assumes that the sender controls the "intention" and that the receiver determines the degree of "inviting." Suggests that elements of the invitational model serve as a framework to create acceptable inducements in…

A portable grid-enabled computing system for a nuclear material study

International Nuclear Information System (INIS)

Tsujita, Yuichi; Arima, Tatsumi; Takekawa, Takayuki; Suzuki, Yoshio

2010-01-01

We have built a portable grid-enabled computing system specialized for our molecular dynamics (MD) simulation program to study Pu material easily. Experimental approach to reveal properties of Pu materials is often accompanied by some difficulties such as radiotoxicity of actinides. Since a computational approach reveals new aspects to researchers without such radioactive facilities, we address an MD computation. In order to have more realistic results about e.g., melting point or thermal conductivity, we need a large scale of parallel computations. Most of application users who don't have supercomputers in their institutes should use a remote supercomputer. For such users, we have developed the portable and secured grid-enabled computing system to utilize a grid computing infrastructure provided by Information Technology Based Laboratory (ITBL). This system enables us to access remote supercomputers in the ITBL system seamlessly from a client PC through its graphical user interface (GUI). Typically it enables seamless file accesses on the GUI. Furthermore monitoring of standard output or standard error is available to see progress of an executed program. Since the system provides fruitful functionalities which are useful for parallel computing on a remote supercomputer, application users can concentrate on their researches. (author)

MEGADOCK 4.0: an ultra-high-performance protein-protein docking software for heterogeneous supercomputers.

Science.gov (United States)

Ohue, Masahito; Shimoda, Takehiro; Suzuki, Shuji; Matsuzaki, Yuri; Ishida, Takashi; Akiyama, Yutaka

2014-11-15

The application of protein-protein docking in large-scale interactome analysis is a major challenge in structural bioinformatics and requires huge computing resources. In this work, we present MEGADOCK 4.0, an FFT-based docking software that makes extensive use of recent heterogeneous supercomputers and shows powerful, scalable performance of >97% strong scaling. MEGADOCK 4.0 is written in C++ with OpenMPI and NVIDIA CUDA 5.0 (or later) and is freely available to all academic and non-profit users at: http://www.bi.cs.titech.ac.jp/megadock. akiyama@cs.titech.ac.jp Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press.

The effects of confrontation and avoidance coping in response to workplace incivility.

Science.gov (United States)

Hershcovis, M Sandy; Cameron, Ann-Frances; Gervais, Loie; Bozeman, Jennifer

2018-04-01

Workplace incivility has significant adverse consequences for targets. However, we know remarkably little about how targets of incivility cope and even less about which coping strategies are effective. Drawing on the coping process of the transactional model of stress, we examine confrontation as a form of problem-focused coping and avoidance as a form of emotion-focused coping in response to incivility. We examine the effects of these coping strategies on reoccurrence of incivility, incivility enacted by targets, psychological forgiveness, and emotional exhaustion. Focusing on the target's perspective of a series of uncivil interactions between a target and perpetrator, we conducted a 3-wave study of employees from various occupations. Employing the critical incident technique, participants reported on an incident of workplace incivility, and then answered a series of questions over 3 waves of data collection regarding their interactions with this perpetrator. Our findings suggest that confrontation and avoidance are ineffective in preventing reoccurrence of incivility. Avoidance can additionally lead to increased emotional exhaustion, target-enacted incivility, and lower psychological forgiveness. However, confrontation coping has promise with regards to eliciting positive outcomes such as psychological forgiveness that are beneficial to interpersonal workplace relationships. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Confronting quintessence models with recent high-redshift supernovae data

International Nuclear Information System (INIS)

Calvo, G. Barro; Maroto, A. L.

2006-01-01

We confront the predictions of different quintessence models with recent measurements of the luminosity distance from two sets of supernovae type Ia. In particular, we consider the 157 SNe Ia in the Gold dataset with z M -α and Ω M -w φ planes for the different models and compare their predictions with dark energy models with constant equation of state

The importance of confronting a colonial, patriarchal and racist past ...

African Journals Online (AJOL)

The importance of confronting a colonial, patriarchal and racist past in addressing post-apartheid sexual violence. ... It also needs to redress problems of social and economic inequality that exist in South Africa as hangovers from this country's colonial and apartheid-era past. Keywords: Zuma, rape, Kipling, colonialism, ...

Molecular simulation workflows as parallel algorithms: the execution engine of Copernicus, a distributed high-performance computing platform.

Science.gov (United States)

Pronk, Sander; Pouya, Iman; Lundborg, Magnus; Rotskoff, Grant; Wesén, Björn; Kasson, Peter M; Lindahl, Erik

2015-06-09

Computational chemistry and other simulation fields are critically dependent on computing resources, but few problems scale efficiently to the hundreds of thousands of processors available in current supercomputers-particularly for molecular dynamics. This has turned into a bottleneck as new hardware generations primarily provide more processing units rather than making individual units much faster, which simulation applications are addressing by increasingly focusing on sampling with algorithms such as free-energy perturbation, Markov state modeling, metadynamics, or milestoning. All these rely on combining results from multiple simulations into a single observation. They are potentially powerful approaches that aim to predict experimental observables directly, but this comes at the expense of added complexity in selecting sampling strategies and keeping track of dozens to thousands of simulations and their dependencies. Here, we describe how the distributed execution framework Copernicus allows the expression of such algorithms in generic workflows: dataflow programs. Because dataflow algorithms explicitly state dependencies of each constituent part, algorithms only need to be described on conceptual level, after which the execution is maximally parallel. The fully automated execution facilitates the optimization of these algorithms with adaptive sampling, where undersampled regions are automatically detected and targeted without user intervention. We show how several such algorithms can be formulated for computational chemistry problems, and how they are executed efficiently with many loosely coupled simulations using either distributed or parallel resources with Copernicus.

Parents’ experience confronting child burning situation

Directory of Open Access Journals (Sweden)

Valdira Vieira de Oliveira

2015-05-01

Full Text Available Objective: to understand experiences of parents in a child burning situation during the hospitalization process. Methods: phenomenological research in view of Martin Heidegger, held with seven assisting parents at a pediatrics unit of a general hospital in Montes Claros. The information was obtained by phenomenological interview, containing the question guide: “What does it mean to you being with a son who is suffering with burns?”. Results: during the experience, parents revealed anguish, fear, helplessness, concerns and expectations of “being-in-the-world”. Conclusion: respect, understanding and care from the health team were fundamental for the adaptation and the confrontation demanded by the consequent suffering of the event.

KNBD: A Remote Kernel Block Server for Linux

Science.gov (United States)

Becker, Jeff

1999-01-01

I am developing a prototype of a Linux remote disk block server whose purpose is to serve as a lower level component of a parallel file system. Parallel file systems are an important component of high performance supercomputers and clusters. Although supercomputer vendors such as SGI and IBM have their own custom solutions, there has been a void and hence a demand for such a system on Beowulf-type PC Clusters. Recently, the Parallel Virtual File System (PVFS) project at Clemson University has begun to address this need (1). Although their system provides much of the functionality of (and indeed was inspired by) the equivalent file systems in the commercial supercomputer market, their system is all in user-space. Migrating their 10 services to the kernel could provide a performance boost, by obviating the need for expensive system calls. Thanks to Pavel Machek, the Linux kernel has provided the network block device (2) with kernels 2.1.101 and later. You can configure this block device to redirect reads and writes to a remote machine's disk. This can be used as a building block for constructing a striped file system across several nodes.

Issues confronting women participation in the construction industry

OpenAIRE

Aulin, Radhlinah; Jingmond, Monika

2011-01-01

This paper raises the issues confronting the minority cohort’s participation in the construction industry. Women in construction are seen as the wrong gender to be around for the construction occupations require not only manual dexterity but physical strength. Currently, the industry is employing less than 10% of the female in the workforce with even lower participation in crafts and trade. This paper discussed about the current women participation in construction focusing on the European Uni...

Visualization system for grid environment in the nuclear field

International Nuclear Information System (INIS)

Suzuki, Yoshio; Matsumoto, Nobuko; Idomura, Yasuhiro; Tani, Masayuki

2006-01-01

An innovative scientific visualization system is needed to integratedly visualize large amount of data which are distributedly generated in remote locations as a result of a large-scale numerical simulation using a grid environment. One of the important functions in such a visualization system is a parallel visualization which enables to visualize data using multiple CPUs of a supercomputer. The other is a distributed visualization which enables to execute visualization processes using a local client computer and remote computers. We have developed a toolkit including these functions in cooperation with the commercial visualization software AVS/Express, called Parallel Support Toolkit (PST). PST can execute visualization processes with three kinds of parallelism (data parallelism, task parallelism and pipeline parallelism) using local and remote computers. We have evaluated PST for large amount of data generated by a nuclear fusion simulation. Here, two supercomputers Altix3700Bx2 and Prism installed in JAEA are used. From the evaluation, it can be seen that PST has a potential to efficiently visualize large amount of data in a grid environment. (author)

High-performance computing — an overview

Science.gov (United States)

Marksteiner, Peter

1996-08-01

An overview of high-performance computing (HPC) is given. Different types of computer architectures used in HPC are discussed: vector supercomputers, high-performance RISC processors, various parallel computers like symmetric multiprocessors, workstation clusters, massively parallel processors. Software tools and programming techniques used in HPC are reviewed: vectorizing compilers, optimization and vector tuning, optimization for RISC processors; parallel programming techniques like shared-memory parallelism, message passing and data parallelism; and numerical libraries.

ISP: an optimal out-of-core image-set processing streaming architecture for parallel heterogeneous systems.

Science.gov (United States)

Ha, Linh Khanh; Krüger, Jens; Dihl Comba, João Luiz; Silva, Cláudio T; Joshi, Sarang

2012-06-01

Image population analysis is the class of statistical methods that plays a central role in understanding the development, evolution, and disease of a population. However, these techniques often require excessive computational power and memory that are compounded with a large number of volumetric inputs. Restricted access to supercomputing power limits its influence in general research and practical applications. In this paper we introduce ISP, an Image-Set Processing streaming framework that harnesses the processing power of commodity heterogeneous CPU/GPU systems and attempts to solve this computational problem. In ISP, we introduce specially designed streaming algorithms and data structures that provide an optimal solution for out-of-core multiimage processing problems both in terms of memory usage and computational efficiency. ISP makes use of the asynchronous execution mechanism supported by parallel heterogeneous systems to efficiently hide the inherent latency of the processing pipeline of out-of-core approaches. Consequently, with computationally intensive problems, the ISP out-of-core solution can achieve the same performance as the in-core solution. We demonstrate the efficiency of the ISP framework on synthetic and real datasets.

Unraveling the age-productivity nexus : Confronting perceptions of employers and employees

NARCIS (Netherlands)

van Dalen, H.P.; Henkens, C.J.I.M.; Schippers, J.

2009-01-01

What determines the perceived productivity of young and older workers? In this study we present evidence for (Dutch) employers and employees. By confronting the perceptions of employers and employees some remarkable similarities and differences are revealed. It turns out that productivity

Unraveling the age-productivity nexus: confronting perceptions of employers and employees

NARCIS (Netherlands)

van Dalen, H.P.; Henkens, C.J.I.M.; Schippers, J.

2009-01-01

What determines the perceived productivity of young and older workers? In this study we present evidence for (Dutch) employers and employees. By confronting the perceptions of employers and employees some remarkable similarities and differences are revealed. It turns out that productivity

The GF11 supercomputer

International Nuclear Information System (INIS)

Beetem, J.; Weingarten, D.

1986-01-01

GF11 is a parallel computer currently under construction at the IBM Yorktown Research Center. The machine incorporates 576 floating-point processors arrangedin a modified SIMD architecture. Each has space for 2 Mbytes of memory and is capable of 20 Mflops, giving the total machine a peak of 1.125 Gbytes of memory and 11.52 Gflops. The floating-point processors are interconnected by a dynamically reconfigurable non-blocking switching network. At each machine cycle any of 1024 pre-selected permutations of data can be realized among the processors. The main intended application of GF11 is a class of calculations arising from quantum chromodynamics

The GF11 supercomputer

International Nuclear Information System (INIS)

Beetem, J.; Denneau, M.; Weingarten, D.

1985-01-01

GF11 is a parallel computer currently under construction at the IBM Yorktown Research Center. The machine incorporates 576 floating- point processors arranged in a modified SIMD architecture. Each has space for 2 Mbytes of memory and is capable of 20 Mflops, giving the total machine a peak of 1.125 Gbytes of memory and 11.52 Gflops. The floating-point processors are interconnected by a dynamically reconfigurable nonblocking switching network. At each machine cycle any of 1024 pre-selected permutations of data can be realized among the processors. The main intended application of GF11 is a class of calculations arising from quantum chromodynamics

Argonne Leadership Computing Facility 2011 annual report : Shaping future supercomputing.

Energy Technology Data Exchange (ETDEWEB)

Papka, M.; Messina, P.; Coffey, R.; Drugan, C. (LCF)

2012-08-16

The ALCF's Early Science Program aims to prepare key applications for the architecture and scale of Mira and to solidify libraries and infrastructure that will pave the way for other future production applications. Two billion core-hours have been allocated to 16 Early Science projects on Mira. The projects, in addition to promising delivery of exciting new science, are all based on state-of-the-art, petascale, parallel applications. The project teams, in collaboration with ALCF staff and IBM, have undertaken intensive efforts to adapt their software to take advantage of Mira's Blue Gene/Q architecture, which, in a number of ways, is a precursor to future high-performance-computing architecture. The Argonne Leadership Computing Facility (ALCF) enables transformative science that solves some of the most difficult challenges in biology, chemistry, energy, climate, materials, physics, and other scientific realms. Users partnering with ALCF staff have reached research milestones previously unattainable, due to the ALCF's world-class supercomputing resources and expertise in computation science. In 2011, the ALCF's commitment to providing outstanding science and leadership-class resources was honored with several prestigious awards. Research on multiscale brain blood flow simulations was named a Gordon Bell Prize finalist. Intrepid, the ALCF's BG/P system, ranked No. 1 on the Graph 500 list for the second consecutive year. The next-generation BG/Q prototype again topped the Green500 list. Skilled experts at the ALCF enable researchers to conduct breakthrough science on the Blue Gene system in key ways. The Catalyst Team matches project PIs with experienced computational scientists to maximize and accelerate research in their specific scientific domains. The Performance Engineering Team facilitates the effective use of applications on the Blue Gene system by assessing and improving the algorithms used by applications and the techniques used to

Predicting the severity of nuclear power plant transients using nearest neighbors modeling optimized by genetic algorithms on a parallel computer

International Nuclear Information System (INIS)

Lin, J.; Bartal, Y.; Uhrig, R.E.

1995-01-01

The importance of automatic diagnostic systems for nuclear power plants (NPPs) has been discussed in numerous studies, and various such systems have been proposed. None of those systems were designed to predict the severity of the diagnosed scenario. A classification and severity prediction system for NPP transients is developed. The system is based on nearest neighbors modeling, which is optimized using genetic algorithms. The optimization process is used to determine the most important variables for each of the transient types analyzed. An enhanced version of the genetic algorithms is used in which a local downhill search is performed to further increase the accuracy achieved. The genetic algorithms search was implemented on a massively parallel supercomputer, the KSR1-64, to perform the analysis in a reasonable time. The data for this study were supplied by the high-fidelity simulator of the San Onofre unit 1 pressurized water reactor

Understanding and Confronting Alcohol-Induced Risky Behavior among College Students

Science.gov (United States)

Dornier, Lucien J.; Fauquier, Katharine J.; Field, April R.; Budden, Michael C.

2010-01-01

Confronting alcohol abuse is a challenge for most higher education institutions. Each year, students are admitted to hospitals for issues arising from the misuse of alcohol. The deaths of some engaged in alcohol related activities is especially worrisome. Factors such as age and financial standing could impact the likelihood of abuse. So-called…

Finding Tropical Cyclones on a Cloud Computing Cluster: Using Parallel Virtualization for Large-Scale Climate Simulation Analysis

Energy Technology Data Exchange (ETDEWEB)

Hasenkamp, Daren; Sim, Alexander; Wehner, Michael; Wu, Kesheng

2010-09-30

Extensive computing power has been used to tackle issues such as climate changes, fusion energy, and other pressing scientific challenges. These computations produce a tremendous amount of data; however, many of the data analysis programs currently only run a single processor. In this work, we explore the possibility of using the emerging cloud computing platform to parallelize such sequential data analysis tasks. As a proof of concept, we wrap a program for analyzing trends of tropical cyclones in a set of virtual machines (VMs). This approach allows the user to keep their familiar data analysis environment in the VMs, while we provide the coordination and data transfer services to ensure the necessary input and output are directed to the desired locations. This work extensively exercises the networking capability of the cloud computing systems and has revealed a number of weaknesses in the current cloud system software. In our tests, we are able to scale the parallel data analysis job to a modest number of VMs and achieve a speedup that is comparable to running the same analysis task using MPI. However, compared to MPI based parallelization, the cloud-based approach has a number of advantages. The cloud-based approach is more flexible because the VMs can capture arbitrary software dependencies without requiring the user to rewrite their programs. The cloud-based approach is also more resilient to failure; as long as a single VM is running, it can make progress while as soon as one MPI node fails the whole analysis job fails. In short, this initial work demonstrates that a cloud computing system is a viable platform for distributed scientific data analyses traditionally conducted on dedicated supercomputing systems.

Finding Tropical Cyclones on a Cloud Computing Cluster: Using Parallel Virtualization for Large-Scale Climate Simulation Analysis

International Nuclear Information System (INIS)

Hasenkamp, Daren; Sim, Alexander; Wehner, Michael; Wu, Kesheng

2010-01-01

Extensive computing power has been used to tackle issues such as climate changes, fusion energy, and other pressing scientific challenges. These computations produce a tremendous amount of data; however, many of the data analysis programs currently only run a single processor. In this work, we explore the possibility of using the emerging cloud computing platform to parallelize such sequential data analysis tasks. As a proof of concept, we wrap a program for analyzing trends of tropical cyclones in a set of virtual machines (VMs). This approach allows the user to keep their familiar data analysis environment in the VMs, while we provide the coordination and data transfer services to ensure the necessary input and output are directed to the desired locations. This work extensively exercises the networking capability of the cloud computing systems and has revealed a number of weaknesses in the current cloud system software. In our tests, we are able to scale the parallel data analysis job to a modest number of VMs and achieve a speedup that is comparable to running the same analysis task using MPI. However, compared to MPI based parallelization, the cloud-based approach has a number of advantages. The cloud-based approach is more flexible because the VMs can capture arbitrary software dependencies without requiring the user to rewrite their programs. The cloud-based approach is also more resilient to failure; as long as a single VM is running, it can make progress while as soon as one MPI node fails the whole analysis job fails. In short, this initial work demonstrates that a cloud computing system is a viable platform for distributed scientific data analyses traditionally conducted on dedicated supercomputing systems.

Mathematical and numerical models to achieve high speed with special-purpose parallel processors

International Nuclear Information System (INIS)

Cheng, H.S.; Wulff, W.; Mallen, A.N.

1986-01-01

Historically, safety analyses and plant dynamic simulations have been and still are being carried out be means of detailed FORTRAN codes on expensive mainframe computers in time-consuming batch processing mode. These codes have grown to be so expensive to execute that their utilization depends increasingly on the availability of very expensive supercomputers. Thus, advanced technology for high-speed, low-cost, and accurate plant dynamic simulations is very much needed. Ideally, a low-cost facility based on a modern minicomputer can be dedicated to the staff of a power plant, which is easy and convenient to use, and which can simulate realistically plant transients at faster than real-time speeds. Such a simulation capability can enhance safety and plant utilization. One such simulation facility that has been developed is the Brookhaven National Laboratory (BNL) Plant Analyzer, currently set up for boiling water reactor plant simulations at up to seven times faster than real-time process speeds. The principal hardware components of the BNL Plant Analyzer are two units of special-purpose parallel processors, the AD10 of Applied Dynamics International and a PDP-11/34 host computer

Exploiting multi-scale parallelism for large scale numerical modelling of laser wakefield accelerators

International Nuclear Information System (INIS)

Fonseca, R A; Vieira, J; Silva, L O; Fiuza, F; Davidson, A; Tsung, F S; Mori, W B

2013-01-01

A new generation of laser wakefield accelerators (LWFA), supported by the extreme accelerating fields generated in the interaction of PW-Class lasers and underdense targets, promises the production of high quality electron beams in short distances for multiple applications. Achieving this goal will rely heavily on numerical modelling to further understand the underlying physics and identify optimal regimes, but large scale modelling of these scenarios is computationally heavy and requires the efficient use of state-of-the-art petascale supercomputing systems. We discuss the main difficulties involved in running these simulations and the new developments implemented in the OSIRIS framework to address these issues, ranging from multi-dimensional dynamic load balancing and hybrid distributed/shared memory parallelism to the vectorization of the PIC algorithm. We present the results of the OASCR Joule Metric program on the issue of large scale modelling of LWFA, demonstrating speedups of over 1 order of magnitude on the same hardware. Finally, scalability to over ∼10 6 cores and sustained performance over ∼2 P Flops is demonstrated, opening the way for large scale modelling of LWFA scenarios. (paper)

Wavelet transform-vector quantization compression of supercomputer ocean model simulation output

Energy Technology Data Exchange (ETDEWEB)

Bradley, J N; Brislawn, C M

1992-11-12

We describe a new procedure for efficient compression of digital information for storage and transmission purposes. The algorithm involves a discrete wavelet transform subband decomposition of the data set, followed by vector quantization of the wavelet transform coefficients using application-specific vector quantizers. The new vector quantizer design procedure optimizes the assignment of both memory resources and vector dimensions to the transform subbands by minimizing an exponential rate-distortion functional subject to constraints on both overall bit-rate and encoder complexity. The wavelet-vector quantization method, which originates in digital image compression. is applicable to the compression of other multidimensional data sets possessing some degree of smoothness. In this paper we discuss the use of this technique for compressing the output of supercomputer simulations of global climate models. The data presented here comes from Semtner-Chervin global ocean models run at the National Center for Atmospheric Research and at the Los Alamos Advanced Computing Laboratory.

[Meaning of family confrontation for nurses of intensive care units for adult people - Medellín 2013].

Science.gov (United States)

Montoya Tamayo, D P; Monsalve Ospina, T P; Forero Pulido, C

2015-01-01

To comprehend the meaning nurses give to family confrontation, from their experiences while patients are in adult intensive care units in Medellin 2013. A qualitative research study was carried out using a phenomenological approach and theoretical convenience sampling of subjects was used. Interviews with open questions were conducted with nurses that worked in different intensive care units in the city of Medellin, with more than one year of experience in these units. The information was coded and categorised to perform the analysis, and some concept maps were created for the final report. This study showed that nurses focus their care on the critical patient and not on the patient's family. They considered that there is family confrontation when its members comprehend the processes that are carried out in the intensive care unit, and can contribute to the patient's care, while if families do not have confrontations, it is because they do not understand the process, or feel desperate or are absent. The interventions that nurses consider must be done to help in the family confrontation are: information, interdisciplinary support, visits, and companionship. For the nurses, family confrontation means that family members understand, comprehend, accept, know, bear and go on with the situation; therefore, they can make good decisions regarding the patient's care in the adult intensive care units. Copyright © 2015 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

Parallel Programming with Intel Parallel Studio XE

CERN Document Server

Blair-Chappell , Stephen

2012-01-01

Optimize code for multi-core processors with Intel's Parallel Studio Parallel programming is rapidly becoming a "must-know" skill for developers. Yet, where to start? This teach-yourself tutorial is an ideal starting point for developers who already know Windows C and C++ and are eager to add parallelism to their code. With a focus on applying tools, techniques, and language extensions to implement parallelism, this essential resource teaches you how to write programs for multicore and leverage the power of multicore in your programs. Sharing hands-on case studies and real-world examples, the

The GF11 supercomputer

International Nuclear Information System (INIS)

Beetem, J.; Denneau, M.; Weingarten, D.

1985-01-01

GF11 is a parallel computer currently under construction at the Yorktown Research Center. The machine incorporates 576 floating-point processors arranged in a modified SIMD architecture. Each processor has space for 2 Mbytes of memory and is capable of 20 MFLOPS, giving the total machine a peak of 1.125 Gbytes of memory and 11.52 GFLOPS. The floating-point processors are interconnected by a dynamically reconfigurable non-blocking switching network. At each machine cycle any of 1024 pre-selected permutations of data can be realized among the processors. The main intended application of GF11 is a class of calculations arising from quantum chromodynamics, a proposed theory of the elementary particles which participate in nuclear interactions

Introducing heterogeneity in Monte Carlo models for risk assessments of high-level nuclear waste. A parallel implementation of the MLCRYSTAL code

Energy Technology Data Exchange (ETDEWEB)

Andersson, M.

1996-09-01

We have introduced heterogeneity to an existing model as a special feature and simultaneously extended the model from 1D to 3D. Briefly, the code generates stochastic fractures in a given geosphere. These fractures are connected in series to form one pathway for radionuclide transport from the repository to the biosphere. Rock heterogeneity is realized by simulating physical and chemical properties for each fracture, i.e. these properties vary along the transport pathway (which is an ensemble of all fractures serially connected). In this case, each Monte Carlo simulation involves a set of many thousands of realizations, one for each pathway. Each pathway can be formed by approx. 100 fractures. This means that for a Monte Carlo simulation of 1000 realizations, we need to perform a total of 100,000 simulations. Therefore the introduction of heterogeneity has increased the CPU demands by two orders of magnitude. To overcome the demand for CPU, the program, MLCRYSTAL, has been implemented in a parallel workstation environment using the MPI, Message Passing Interface, and later on ported to an IBM-SP2 parallel supercomputer. The program is presented here and a preliminary set of results is given with the conclusions that can be drawn. 3 refs, 12 figs.

Introducing heterogeneity in Monte Carlo models for risk assessments of high-level nuclear waste. A parallel implementation of the MLCRYSTAL code

International Nuclear Information System (INIS)

Andersson, M.

1996-09-01

We have introduced heterogeneity to an existing model as a special feature and simultaneously extended the model from 1D to 3D. Briefly, the code generates stochastic fractures in a given geosphere. These fractures are connected in series to form one pathway for radionuclide transport from the repository to the biosphere. Rock heterogeneity is realized by simulating physical and chemical properties for each fracture, i.e. these properties vary along the transport pathway (which is an ensemble of all fractures serially connected). In this case, each Monte Carlo simulation involves a set of many thousands of realizations, one for each pathway. Each pathway can be formed by approx. 100 fractures. This means that for a Monte Carlo simulation of 1000 realizations, we need to perform a total of 100,000 simulations. Therefore the introduction of heterogeneity has increased the CPU demands by two orders of magnitude. To overcome the demand for CPU, the program, MLCRYSTAL, has been implemented in a parallel workstation environment using the MPI, Message Passing Interface, and later on ported to an IBM-SP2 parallel supercomputer. The program is presented here and a preliminary set of results is given with the conclusions that can be drawn. 3 refs, 12 figs

Optimizing the Performance of Reactive Molecular Dynamics Simulations for Multi-core Architectures

Energy Technology Data Exchange (ETDEWEB)

Aktulga, Hasan Metin [Michigan State Univ., East Lansing, MI (United States); Coffman, Paul [Argonne National Lab. (ANL), Argonne, IL (United States); Shan, Tzu-Ray [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Knight, Chris [Argonne National Lab. (ANL), Argonne, IL (United States); Jiang, Wei [Argonne National Lab. (ANL), Argonne, IL (United States)

2015-12-01

Hybrid parallelism allows high performance computing applications to better leverage the increasing on-node parallelism of modern supercomputers. In this paper, we present a hybrid parallel implementation of the widely used LAMMPS/ReaxC package, where the construction of bonded and nonbonded lists and evaluation of complex ReaxFF interactions are implemented efficiently using OpenMP parallelism. Additionally, the performance of the QEq charge equilibration scheme is examined and a dual-solver is implemented. We present the performance of the resulting ReaxC-OMP package on a state-of-the-art multi-core architecture Mira, an IBM BlueGene/Q supercomputer. For system sizes ranging from 32 thousand to 16.6 million particles, speedups in the range of 1.5-4.5x are observed using the new ReaxC-OMP software. Sustained performance improvements have been observed for up to 262,144 cores (1,048,576 processes) of Mira with a weak scaling efficiency of 91.5% in larger simulations containing 16.6 million particles.

From experiment to design -- Fault characterization and detection in parallel computer systems using computational accelerators

Science.gov (United States)

Yim, Keun Soo

This dissertation summarizes experimental validation and co-design studies conducted to optimize the fault detection capabilities and overheads in hybrid computer systems (e.g., using CPUs and Graphics Processing Units, or GPUs), and consequently to improve the scalability of parallel computer systems using computational accelerators. The experimental validation studies were conducted to help us understand the failure characteristics of CPU-GPU hybrid computer systems under various types of hardware faults. The main characterization targets were faults that are difficult to detect and/or recover from, e.g., faults that cause long latency failures (Ch. 3), faults in dynamically allocated resources (Ch. 4), faults in GPUs (Ch. 5), faults in MPI programs (Ch. 6), and microarchitecture-level faults with specific timing features (Ch. 7). The co-design studies were based on the characterization results. One of the co-designed systems has a set of source-to-source translators that customize and strategically place error detectors in the source code of target GPU programs (Ch. 5). Another co-designed system uses an extension card to learn the normal behavioral and semantic execution patterns of message-passing processes executing on CPUs, and to detect abnormal behaviors of those parallel processes (Ch. 6). The third co-designed system is a co-processor that has a set of new instructions in order to support software-implemented fault detection techniques (Ch. 7). The work described in this dissertation gains more importance because heterogeneous processors have become an essential component of state-of-the-art supercomputers. GPUs were used in three of the five fastest supercomputers that were operating in 2011. Our work included comprehensive fault characterization studies in CPU-GPU hybrid computers. In CPUs, we monitored the target systems for a long period of time after injecting faults (a temporally comprehensive experiment), and injected faults into various types of

Research to application: Supercomputing trends for the 90's - Opportunities for interdisciplinary computations

International Nuclear Information System (INIS)

Shankar, V.

1991-01-01

The progression of supercomputing is reviewed from the point of view of computational fluid dynamics (CFD), and multidisciplinary problems impacting the design of advanced aerospace configurations are addressed. The application of full potential and Euler equations to transonic and supersonic problems in the 70s and early 80s is outlined, along with Navier-Stokes computations widespread during the late 80s and early 90s. Multidisciplinary computations currently in progress are discussed, including CFD and aeroelastic coupling for both static and dynamic flexible computations, CFD, aeroelastic, and controls coupling for flutter suppression and active control, and the development of a computational electromagnetics technology based on CFD methods. Attention is given to computational challenges standing in a way of the concept of establishing a computational environment including many technologies. 40 refs

Synergetic Paradigm of Geopolitical Confrontation in the Postmodern Era

Directory of Open Access Journals (Sweden)

Sergey N. Teplyakov

2014-01-01

Full Text Available The article analyzes current state and mechanisms of geopolitical struggle in postmodern information age that has come. The author judges from assumption that entirely new postmodern society appeared with expansion of information technology, accompanied by cardinal changes in mechanisms of political power. Information technologies have become one of the most important factors contributing to the transformation of modern society from industrial to informational (post-industrial. In modern conditions, ensuring national and global security is a comprehensive process that includes not only measures to ensure information and economic security individually, but also such an integrated component as providing both information and economic security. The author suggests that modem geopolitical confrontation is carried out based on the synergetic paradigm. The main tool is information and energy influence on enemy system weaknesses using information space control, organizing negative information campaigns and applying economic sanctions. If the main focus of geopolitical struggle in modern era was forced expansion of the territory, in information postmodern age control over economic and information space has become priority among forms of geopolitical struggle. Military expansion of modern era becomes substituted by information and economic expansionism of postmodern using synergetic paradigm of geopolitical confrontation in order to control and capture the opponent's political space.

Confronting the stigma of epilepsy

Directory of Open Access Journals (Sweden)

Sanjeev V Thomas

2011-01-01

Full Text Available Stigma and resultant psychosocial issues are major hurdles that people with epilepsy confront in their daily life. People with epilepsy, particularly women, living in economically weak countries are often ill equipped to handle the stigma that they experience at multiple levels. This paper offers a systematic review of the research on stigma from sociology and social psychology and details how stigma linked to epilepsy or similar conditions can result in stereotyping, prejudice and discrimination. We also briefly discuss the strategies that are most commonly utilized to mitigate stigma. Neurologists and other health care providers, social workers, support groups and policy makers working with epilepsy need to have a deep understanding of the social and cultural perceptions of epilepsy and the related stigma. It is necessary that societies establish unique determinants of stigma and set up appropriate strategies to mitigate stigma and facilitate the complete inclusion of people with epilepsy as well as mitigating any existing discrimination.

Fast methods for long-range interactions in complex systems. Lecture notes

Energy Technology Data Exchange (ETDEWEB)

Sutmann, Godehard; Gibbon, Paul; Lippert, Thomas (eds.)

2011-10-13

Parallel computing and computer simulations of complex particle systems including charges have an ever increasing impact in a broad range of fields in the physical sciences, e.g. in astrophysics, statistical physics, plasma physics, material sciences, physical chemistry, and biophysics. The present summer school, funded by the German Heraeus-Foundation, took place at the Juelich Supercomputing Centre from 6 - 10 September 2010. The focus was on providing an introduction and overview over different methods, algorithms and new trends for the computational treatment of long-range interactions in particle systems. The Lecture Notes contain an introduction into particle simulation, as well as five different fast methods, i.e. the Fast Multipole Method, Barnes-Hut Tree Method, Multigrid, FFT based methods, and Fast Summation using the non-equidistant FFT. In addition to introducing the methods, efficient parallelization of the methods is presented in detail. This publication was edited at the Juelich Supercomputing Centre (JSC) which is an integral part of the Institute for Advanced Simulation (IAS). The IAS combines the Juelich simulation sciences and the supercomputer facility in one organizational unit. It includes those parts of the scientific institutes at Forschungszentrum Juelich which use simulation on supercomputers as their main research methodology. (orig.)

Fast methods for long-range interactions in complex systems. Lecture notes

International Nuclear Information System (INIS)

Sutmann, Godehard; Gibbon, Paul; Lippert, Thomas

2011-01-01

Parallel computing and computer simulations of complex particle systems including charges have an ever increasing impact in a broad range of fields in the physical sciences, e.g. in astrophysics, statistical physics, plasma physics, material sciences, physical chemistry, and biophysics. The present summer school, funded by the German Heraeus-Foundation, took place at the Juelich Supercomputing Centre from 6 - 10 September 2010. The focus was on providing an introduction and overview over different methods, algorithms and new trends for the computational treatment of long-range interactions in particle systems. The Lecture Notes contain an introduction into particle simulation, as well as five different fast methods, i.e. the Fast Multipole Method, Barnes-Hut Tree Method, Multigrid, FFT based methods, and Fast Summation using the non-equidistant FFT. In addition to introducing the methods, efficient parallelization of the methods is presented in detail. This publication was edited at the Juelich Supercomputing Centre (JSC) which is an integral part of the Institute for Advanced Simulation (IAS). The IAS combines the Juelich simulation sciences and the supercomputer facility in one organizational unit. It includes those parts of the scientific institutes at Forschungszentrum Juelich which use simulation on supercomputers as their main research methodology. (orig.)

The future of Asian feminisms: confronting fundamentalisms, conflicts and neo-liberalism

NARCIS (Netherlands)

Katjasungkana, N.; Wieringa, S.E.

2012-01-01

This book on the future of Asian feminisms, confronting fundamentalisms, conflicts, and neo-liberalism is a critical contribution to the rising voices of Asian women’s studies scholars and activists. It is based on the ongoing research and advocacy work of the Kartini Asia Network, founded in 2003

Car2x with software defined networks, network functions virtualization and supercomputers technical and scientific preparations for the Amsterdam Arena telecoms fieldlab

NARCIS (Netherlands)

Meijer R.J.; Cushing R.; De Laat C.; Jackson P.; Klous S.; Koning R.; Makkes M.X.; Meerwijk A.

2015-01-01

In the invited talk 'Car2x with SDN, NFV and supercomputers' we report about how our past work with SDN [1, 2] allows the design of a smart mobility fieldlab in the huge parking lot the Amsterdam Arena. We explain how we can engineer and test software that handle the complex conditions of the Car2X

Advanced quadrature sets and acceleration and preconditioning techniques for the discrete ordinates method in parallel computing environments

Science.gov (United States)

Longoni, Gianluca

In the nuclear science and engineering field, radiation transport calculations play a key-role in the design and optimization of nuclear devices. The linear Boltzmann equation describes the angular, energy and spatial variations of the particle or radiation distribution. The discrete ordinates method (S N) is the most widely used technique for solving the linear Boltzmann equation. However, for realistic problems, the memory and computing time require the use of supercomputers. This research is devoted to the development of new formulations for the SN method, especially for highly angular dependent problems, in parallel environments. The present research work addresses two main issues affecting the accuracy and performance of SN transport theory methods: quadrature sets and acceleration techniques. New advanced quadrature techniques which allow for large numbers of angles with a capability for local angular refinement have been developed. These techniques have been integrated into the 3-D SN PENTRAN (Parallel Environment Neutral-particle TRANsport) code and applied to highly angular dependent problems, such as CT-Scan devices, that are widely used to obtain detailed 3-D images for industrial/medical applications. In addition, the accurate simulation of core physics and shielding problems with strong heterogeneities and transport effects requires the numerical solution of the transport equation. In general, the convergence rate of the solution methods for the transport equation is reduced for large problems with optically thick regions and scattering ratios approaching unity. To remedy this situation, new acceleration algorithms based on the Even-Parity Simplified SN (EP-SSN) method have been developed. A new stand-alone code system, PENSSn (Parallel Environment Neutral-particle Simplified SN), has been developed based on the EP-SSN method. The code is designed for parallel computing environments with spatial, angular and hybrid (spatial/angular) domain

Migration of vectorized iterative solvers to distributed memory architectures

Energy Technology Data Exchange (ETDEWEB)

Pommerell, C. [AT& T Bell Labs., Murray Hill, NJ (United States); Ruehl, R. [CSCS-ETH, Manno (Switzerland)

1994-12-31

Both necessity and opportunity motivate the use of high-performance computers for iterative linear solvers. Necessity results from the size of the problems being solved-smaller problems are often better handled by direct methods. Opportunity arises from the formulation of the iterative methods in terms of simple linear algebra operations, even if this {open_quote}natural{close_quotes} parallelism is not easy to exploit in irregularly structured sparse matrices and with good preconditioners. As a result, high-performance implementations of iterative solvers have attracted a lot of interest in recent years. Most efforts are geared to vectorize or parallelize the dominating operation-structured or unstructured sparse matrix-vector multiplication, or to increase locality and parallelism by reformulating the algorithm-reducing global synchronization in inner products or local data exchange in preconditioners. Target architectures for iterative solvers currently include mostly vector supercomputers and architectures with one or few optimized (e.g., super-scalar and/or super-pipelined RISC) processors and hierarchical memory systems. More recently, parallel computers with physically distributed memory and a better price/performance ratio have been offered by vendors as a very interesting alternative to vector supercomputers. However, programming comfort on such distributed memory parallel processors (DMPPs) still lags behind. Here the authors are concerned with iterative solvers and their changing computing environment. In particular, they are considering migration from traditional vector supercomputers to DMPPs. Application requirements force one to use flexible and portable libraries. They want to extend the portability of iterative solvers rather than reimplementing everything for each new machine, or even for each new architecture.

Social instigation and repeated aggressive confrontations in male Swiss mice: analysis of plasma corticosterone, CRF and BDNF levels in limbic brain areas

Directory of Open Access Journals (Sweden)

Paula Madeira Fortes

2017-06-01

Full Text Available Abstract Introduction: Agonistic behaviors help to ensure survival, provide advantage in competition, and communicate social status. The resident-intruder paradigm, an animal model based on male intraspecific confrontations, can be an ethologically relevant tool to investigate the neurobiology of aggressive behavior. Objectives: To examine behavioral and neurobiological mechanisms of aggressive behavior in male Swiss mice exposed to repeated confrontations in the resident intruder paradigm. Methods: Behavioral analysis was performed in association with measurements of plasma corticosterone of mice repeatedly exposed to a potential rival nearby, but inaccessible (social instigation, or to 10 sessions of social instigation followed by direct aggressive encounters. Moreover, corticotropin-releasing factor (CRF and brain-derived neurotrophic factor (BNDF were measured in the brain of these animals. Control mice were exposed to neither social instigation nor aggressive confrontations. Results: Mice exposed to aggressive confrontations exhibited a similar pattern of species-typical aggressive and non-aggressive behaviors on the first and the last session. Moreover, in contrast to social instigation only, repeated aggressive confrontations promoted an increase in plasma corticosterone. After 10 aggressive confrontation sessions, mice presented a non-significant trend toward reducing hippocampal levels of CRF, which inversely correlated with plasma corticosterone levels. Conversely, repeated sessions of social instigation or aggressive confrontation did not alter BDNF concentrations at the prefrontal cortex and hippocampus. Conclusion: Exposure to repeated episodes of aggressive encounters did not promote habituation over time. Additionally, CRF seems to be involved in physiological responses to social stressors.

Efficient multitasking of Choleski matrix factorization on CRAY supercomputers

Science.gov (United States)

Overman, Andrea L.; Poole, Eugene L.

1991-01-01

A Choleski method is described and used to solve linear systems of equations that arise in large scale structural analysis. The method uses a novel variable-band storage scheme and is structured to exploit fast local memory caches while minimizing data access delays between main memory and vector registers. Several parallel implementations of this method are described for the CRAY-2 and CRAY Y-MP computers demonstrating the use of microtasking and autotasking directives. A portable parallel language, FORCE, is used for comparison with the microtasked and autotasked implementations. Results are presented comparing the matrix factorization times for three representative structural analysis problems from runs made in both dedicated and multi-user modes on both computers. CPU and wall clock timings are given for the parallel implementations and are compared to single processor timings of the same algorithm.

DICE/ColDICE: 6D collisionless phase space hydrodynamics using a lagrangian tesselation

Science.gov (United States)

Sousbie, Thierry

2018-01-01

DICE is a C++ template library designed to solve collisionless fluid dynamics in 6D phase space using massively parallel supercomputers via an hybrid OpenMP/MPI parallelization. ColDICE, based on DICE, implements a cosmological and physical VLASOV-POISSON solver for cold systems such as dark matter (CDM) dynamics.

The Lived Experience of Iranian Women Confronting Breast Cancer Diagnosis

OpenAIRE

Esmat Mehrabi; Sepideh Hajian; Masoomeh Simbar; Mohammad Hoshyari; Farid Zayeri

2016-01-01

Introduction: The populations who survive from breast cancer are growing; nevertheless, they mostly encounter with many cancer related problems in their life, especially after early diagnosis and have to deal with these problems. Except for the disease entity, several socio-cultural factors may affect confronting this challenge among patients and the way they deal with. Present study was carried out to prepare clear understanding of Iranian women's...

Scheme with two large extra dimensions confronted with neutrino physics

International Nuclear Information System (INIS)

Maalampi, J.; Sipilaeinen, V.; Vilja, I.

2003-01-01

We investigate a particle physics model in a six-dimensional spacetime, where two extra dimensions form a torus. Particles with standard model charges are confined by interactions with a scalar field to four four-dimensional branes, two vortices accommodating ordinary type fermions and two antivortices accommodating mirror fermions. We investigate the phenomenological implications of this multibrane structure by confronting the model with neutrino physics data

Portable implementation model for CFD simulations. Application to hybrid CPU/GPU supercomputers

Science.gov (United States)

Oyarzun, Guillermo; Borrell, Ricard; Gorobets, Andrey; Oliva, Assensi

2017-10-01

Nowadays, high performance computing (HPC) systems experience a disruptive moment with a variety of novel architectures and frameworks, without any clarity of which one is going to prevail. In this context, the portability of codes across different architectures is of major importance. This paper presents a portable implementation model based on an algebraic operational approach for direct numerical simulation (DNS) and large eddy simulation (LES) of incompressible turbulent flows using unstructured hybrid meshes. The strategy proposed consists in representing the whole time-integration algorithm using only three basic algebraic operations: sparse matrix-vector product, a linear combination of vectors and dot product. The main idea is based on decomposing the nonlinear operators into a concatenation of two SpMV operations. This provides high modularity and portability. An exhaustive analysis of the proposed implementation for hybrid CPU/GPU supercomputers has been conducted with tests using up to 128 GPUs. The main objective consists in understanding the challenges of implementing CFD codes on new architectures.

Performance analysis of job scheduling policies in parallel supercomputing environments

Energy Technology Data Exchange (ETDEWEB)

Naik, V.K.; Squillante, M.S. [IBM T.J. Watson Research Center, Yorktown Heights, NY (United States); Setia, S.K. [George Mason Univ., Fairfax, VA (United States). Dept. of Computer Science

1993-12-31

In this paper the authors analyze three general classes of scheduling policies under a workload typical of largescale scientific computing. These policies differ in the manner in which processors are partitioned among the jobs as well as the way in which jobs are prioritized for execution on the partitions. Their results indicate that existing static schemes do not perform well under varying workloads. Adaptive policies tend to make better scheduling decisions, but their ability to adjust to workload changes is limited. Dynamic partitioning policies, on the other hand, yield the best performance and can be tuned to provide desired performance differences among jobs with varying resource demands.

Efficient implementation of multidimensional fast fourier transform on a distributed-memory parallel multi-node computer

Science.gov (United States)

Bhanot, Gyan V [Princeton, NJ; Chen, Dong [Croton-On-Hudson, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Steinmacher-Burow, Burkhard D [Mount Kisco, NY; Vranas, Pavlos M [Bedford Hills, NY

2012-01-10

The present in invention is directed to a method, system and program storage device for efficiently implementing a multidimensional Fast Fourier Transform (FFT) of a multidimensional array comprising a plurality of elements initially distributed in a multi-node computer system comprising a plurality of nodes in communication over a network, comprising: distributing the plurality of elements of the array in a first dimension across the plurality of nodes of the computer system over the network to facilitate a first one-dimensional FFT; performing the first one-dimensional FFT on the elements of the array distributed at each node in the first dimension; re-distributing the one-dimensional FFT-transformed elements at each node in a second dimension via "all-to-all" distribution in random order across other nodes of the computer system over the network; and performing a second one-dimensional FFT on elements of the array re-distributed at each node in the second dimension, wherein the random order facilitates efficient utilization of the network thereby efficiently implementing the multidimensional FFT. The "all-to-all" re-distribution of array elements is further efficiently implemented in applications other than the multidimensional FFT on the distributed-memory parallel supercomputer.

Scalable Parallel Methods for Analyzing Metagenomics Data at Extreme Scale

Energy Technology Data Exchange (ETDEWEB)

Daily, Jeffrey A. [Washington State Univ., Pullman, WA (United States)

2015-05-01

The field of bioinformatics and computational biology is currently experiencing a data revolution. The exciting prospect of making fundamental biological discoveries is fueling the rapid development and deployment of numerous cost-effective, high-throughput next-generation sequencing technologies. The result is that the DNA and protein sequence repositories are being bombarded with new sequence information. Databases are continuing to report a Moore’s law-like growth trajectory in their database sizes, roughly doubling every 18 months. In what seems to be a paradigm-shift, individual projects are now capable of generating billions of raw sequence data that need to be analyzed in the presence of already annotated sequence information. While it is clear that data-driven methods, such as sequencing homology detection, are becoming the mainstay in the field of computational life sciences, the algorithmic advancements essential for implementing complex data analytics at scale have mostly lagged behind. Sequence homology detection is central to a number of bioinformatics applications including genome sequencing and protein family characterization. Given millions of sequences, the goal is to identify all pairs of sequences that are highly similar (or “homologous”) on the basis of alignment criteria. While there are optimal alignment algorithms to compute pairwise homology, their deployment for large-scale is currently not feasible; instead, heuristic methods are used at the expense of quality. In this dissertation, we present the design and evaluation of a parallel implementation for conducting optimal homology detection on distributed memory supercomputers. Our approach uses a combination of techniques from asynchronous load balancing (viz. work stealing, dynamic task counters), data replication, and exact-matching filters to achieve homology detection at scale. Results for a collection of 2.56M sequences show parallel efficiencies of ~75-100% on up to 8K cores

Scalable Parallel Methods for Analyzing Metagenomics Data at Extreme Scale

International Nuclear Information System (INIS)

Daily, Jeffrey A.

2015-01-01

The field of bioinformatics and computational biology is currently experiencing a data revolution. The exciting prospect of making fundamental biological discoveries is fueling the rapid development and deployment of numerous cost-effective, high-throughput next-generation sequencing technologies. The result is that the DNA and protein sequence repositories are being bombarded with new sequence information. Databases are continuing to report a Moore's law-like growth trajectory in their database sizes, roughly doubling every 18 months. In what seems to be a paradigm-shift, individual projects are now capable of generating billions of raw sequence data that need to be analyzed in the presence of already annotated sequence information. While it is clear that data-driven methods, such as sequencing homology detection, are becoming the mainstay in the field of computational life sciences, the algorithmic advancements essential for implementing complex data analytics at scale have mostly lagged behind. Sequence homology detection is central to a number of bioinformatics applications including genome sequencing and protein family characterization. Given millions of sequences, the goal is to identify all pairs of sequences that are highly similar (or 'homologous') on the basis of alignment criteria. While there are optimal alignment algorithms to compute pairwise homology, their deployment for large-scale is currently not feasible; instead, heuristic methods are used at the expense of quality. In this dissertation, we present the design and evaluation of a parallel implementation for conducting optimal homology detection on distributed memory supercomputers. Our approach uses a combination of techniques from asynchronous load balancing (viz. work stealing, dynamic task counters), data replication, and exact-matching filters to achieve homology detection at scale. Results for a collection of 2.56M sequences show parallel efficiencies of ~75-100% on up to 8K

INFORMATIONAL CONFRONTATION BETWEEN THE RUSSIAN FEDERATION AND THE USA DURING THE “TULIP REVOLUTION” IN KYRGYZSTAN

Directory of Open Access Journals (Sweden)

Lina Yuryevna Medovkina

2017-10-01

Full Text Available In the present article the author considers the problem of informational confrontation between the Russian Federation and the USA during the “Tulip Revolution” of 2005 in Kyrgyzstan. Kyrgyzstan became the first post-socialist country in Central Asia where there had been a color revolution. It is noted that in 2004 the US State Department awarded grants to non-governmental organizations of Kyrgyzstan as help for the independent media and for dissemination of propaganda information. Financial and human resources provided by the United States gave the united Kyrgyz opposition enough financial and moral support to have the opportunity to go on the offensive on Russia in the information field. The confrontation in the information field of the Russian Federation and the United States during the “Tulip Revolution” was won by the West and lost by Russia, as their technology of counteraction to information influence were weak. The purpose of the research is the study of information confrontation between the Russian Federation and the USA during the “Tulip Revolution” of 2005 in Kyrgyzstan. Method or methodology of work. Content analysis, methods of organizing and synthesizing of information are used as methodological basis. The methodological approaches are presented by the system analysis of the considered phenomenon. The results of the study can be used as an objective confirmation of application of information confrontation methods in the conflict between states. Scope of application: state information policy.

EDF's experience with supercomputing and challenges ahead - towards multi-physics and multi-scale approaches

International Nuclear Information System (INIS)

Delbecq, J.M.; Banner, D.

2003-01-01

Nuclear power plants are a major asset of the EDF company. To remain so, in particular in a context of deregulation, competitiveness, safety and public acceptance are three conditions. These stakes apply both to existing plants and to future reactors. The purpose of the presentation is to explain how supercomputing can help EDF to satisfy these requirements. Three examples are described in detail: ensuring optimal use of nuclear fuel under wholly safe conditions, understanding and simulating the material deterioration mechanisms and moving forward with numerical simulation for the performance of EDF's activities. In conclusion, a broader vision of EDF long term R and D in the field of numerical simulation is given and especially of five challenges taken up by EDF together with its industrial and scientific partners. (author)

Practical parallel computing

CERN Document Server

Morse, H Stephen

1994-01-01

Practical Parallel Computing provides information pertinent to the fundamental aspects of high-performance parallel processing. This book discusses the development of parallel applications on a variety of equipment.Organized into three parts encompassing 12 chapters, this book begins with an overview of the technology trends that converge to favor massively parallel hardware over traditional mainframes and vector machines. This text then gives a tutorial introduction to parallel hardware architectures. Other chapters provide worked-out examples of programs using several parallel languages. Thi

Collaborating CPU and GPU for large-scale high-order CFD simulations with complex grids on the TianHe-1A supercomputer

Energy Technology Data Exchange (ETDEWEB)

Xu, Chuanfu, E-mail: xuchuanfu@nudt.edu.cn [College of Computer Science, National University of Defense Technology, Changsha 410073 (China); Deng, Xiaogang; Zhang, Lilun [College of Computer Science, National University of Defense Technology, Changsha 410073 (China); Fang, Jianbin [Parallel and Distributed Systems Group, Delft University of Technology, Delft 2628CD (Netherlands); Wang, Guangxue; Jiang, Yi [State Key Laboratory of Aerodynamics, P.O. Box 211, Mianyang 621000 (China); Cao, Wei; Che, Yonggang; Wang, Yongxian; Wang, Zhenghua; Liu, Wei; Cheng, Xinghua [College of Computer Science, National University of Defense Technology, Changsha 410073 (China)

2014-12-01

Programming and optimizing complex, real-world CFD codes on current many-core accelerated HPC systems is very challenging, especially when collaborating CPUs and accelerators to fully tap the potential of heterogeneous systems. In this paper, with a tri-level hybrid and heterogeneous programming model using MPI + OpenMP + CUDA, we port and optimize our high-order multi-block structured CFD software HOSTA on the GPU-accelerated TianHe-1A supercomputer. HOSTA adopts two self-developed high-order compact definite difference schemes WCNS and HDCS that can simulate flows with complex geometries. We present a dual-level parallelization scheme for efficient multi-block computation on GPUs and perform particular kernel optimizations for high-order CFD schemes. The GPU-only approach achieves a speedup of about 1.3 when comparing one Tesla M2050 GPU with two Xeon X5670 CPUs. To achieve a greater speedup, we collaborate CPU and GPU for HOSTA instead of using a naive GPU-only approach. We present a novel scheme to balance the loads between the store-poor GPU and the store-rich CPU. Taking CPU and GPU load balance into account, we improve the maximum simulation problem size per TianHe-1A node for HOSTA by 2.3×, meanwhile the collaborative approach can improve the performance by around 45% compared to the GPU-only approach. Further, to scale HOSTA on TianHe-1A, we propose a gather/scatter optimization to minimize PCI-e data transfer times for ghost and singularity data of 3D grid blocks, and overlap the collaborative computation and communication as far as possible using some advanced CUDA and MPI features. Scalability tests show that HOSTA can achieve a parallel efficiency of above 60% on 1024 TianHe-1A nodes. With our method, we have successfully simulated an EET high-lift airfoil configuration containing 800M cells and China's large civil airplane configuration containing 150M cells. To our best knowledge, those are the largest-scale CPU–GPU collaborative simulations

Collaborating CPU and GPU for large-scale high-order CFD simulations with complex grids on the TianHe-1A supercomputer

International Nuclear Information System (INIS)

Xu, Chuanfu; Deng, Xiaogang; Zhang, Lilun; Fang, Jianbin; Wang, Guangxue; Jiang, Yi; Cao, Wei; Che, Yonggang; Wang, Yongxian; Wang, Zhenghua; Liu, Wei; Cheng, Xinghua

2014-01-01

Programming and optimizing complex, real-world CFD codes on current many-core accelerated HPC systems is very challenging, especially when collaborating CPUs and accelerators to fully tap the potential of heterogeneous systems. In this paper, with a tri-level hybrid and heterogeneous programming model using MPI + OpenMP + CUDA, we port and optimize our high-order multi-block structured CFD software HOSTA on the GPU-accelerated TianHe-1A supercomputer. HOSTA adopts two self-developed high-order compact definite difference schemes WCNS and HDCS that can simulate flows with complex geometries. We present a dual-level parallelization scheme for efficient multi-block computation on GPUs and perform particular kernel optimizations for high-order CFD schemes. The GPU-only approach achieves a speedup of about 1.3 when comparing one Tesla M2050 GPU with two Xeon X5670 CPUs. To achieve a greater speedup, we collaborate CPU and GPU for HOSTA instead of using a naive GPU-only approach. We present a novel scheme to balance the loads between the store-poor GPU and the store-rich CPU. Taking CPU and GPU load balance into account, we improve the maximum simulation problem size per TianHe-1A node for HOSTA by 2.3×, meanwhile the collaborative approach can improve the performance by around 45% compared to the GPU-only approach. Further, to scale HOSTA on TianHe-1A, we propose a gather/scatter optimization to minimize PCI-e data transfer times for ghost and singularity data of 3D grid blocks, and overlap the collaborative computation and communication as far as possible using some advanced CUDA and MPI features. Scalability tests show that HOSTA can achieve a parallel efficiency of above 60% on 1024 TianHe-1A nodes. With our method, we have successfully simulated an EET high-lift airfoil configuration containing 800M cells and China's large civil airplane configuration containing 150M cells. To our best knowledge, those are the largest-scale CPU–GPU collaborative simulations

Parallel rendering

Science.gov (United States)

Crockett, Thomas W.

1995-01-01

This article provides a broad introduction to the subject of parallel rendering, encompassing both hardware and software systems. The focus is on the underlying concepts and the issues which arise in the design of parallel rendering algorithms and systems. We examine the different types of parallelism and how they can be applied in rendering applications. Concepts from parallel computing, such as data decomposition, task granularity, scalability, and load balancing, are considered in relation to the rendering problem. We also explore concepts from computer graphics, such as coherence and projection, which have a significant impact on the structure of parallel rendering algorithms. Our survey covers a number of practical considerations as well, including the choice of architectural platform, communication and memory requirements, and the problem of image assembly and display. We illustrate the discussion with numerous examples from the parallel rendering literature, representing most of the principal rendering methods currently used in computer graphics.

Differentiating between Confrontive and Coercive Kinds of Parental Power-Assertive Disciplinary Practices

Science.gov (United States)

Baumrind, Diana

2012-01-01

In this essay, I differentiate between coercive and confrontive kinds of power assertion to elucidate the significantly different effects on children's well-being of authoritarian and authoritative styles of parental authority. Although both parenting styles (in contrast to the permissive style) are equally demanding, forceful, and…

Parallel computations

CERN Document Server

1982-01-01

Parallel Computations focuses on parallel computation, with emphasis on algorithms used in a variety of numerical and physical applications and for many different types of parallel computers. Topics covered range from vectorization of fast Fourier transforms (FFTs) and of the incomplete Cholesky conjugate gradient (ICCG) algorithm on the Cray-1 to calculation of table lookups and piecewise functions. Single tridiagonal linear systems and vectorized computation of reactive flow are also discussed.Comprised of 13 chapters, this volume begins by classifying parallel computers and describing techn

SOFTWARE FOR SUPERCOMPUTER SKIF “ProLit-lC” and “ProNRS-lC” FOR FOUNDRY AND METALLURGICAL PRODUCTIONS

Directory of Open Access Journals (Sweden)

A. N. Chichko

2008-01-01

Full Text Available The data of modeling on supercomputer system SKIF of technological process of  molds filling by means of computer system 'ProLIT-lc', and also data of modeling of the steel pouring process by means ofTroNRS-lc'are presented. The influence of number of  processors of  multinuclear computer system SKIF on acceleration and time of  modeling of technological processes, connected with production of castings and slugs, is shown.

Palacios and Kitten : high performance operating systems for scalable virtualized and native supercomputing.

Energy Technology Data Exchange (ETDEWEB)

Widener, Patrick (University of New Mexico); Jaconette, Steven (Northwestern University); Bridges, Patrick G. (University of New Mexico); Xia, Lei (Northwestern University); Dinda, Peter (Northwestern University); Cui, Zheng.; Lange, John (Northwestern University); Hudson, Trammell B.; Levenhagen, Michael J.; Pedretti, Kevin Thomas Tauke; Brightwell, Ronald Brian

2009-09-01

Palacios and Kitten are new open source tools that enable applications, whether ported or not, to achieve scalable high performance on large machines. They provide a thin layer over the hardware to support both full-featured virtualized environments and native code bases. Kitten is an OS under development at Sandia that implements a lightweight kernel architecture to provide predictable behavior and increased flexibility on large machines, while also providing Linux binary compatibility. Palacios is a VMM that is under development at Northwestern University and the University of New Mexico. Palacios, which can be embedded into Kitten and other OSes, supports existing, unmodified applications and operating systems by using virtualization that leverages hardware technologies. We describe the design and implementation of both Kitten and Palacios. Our benchmarks show that they provide near native, scalable performance. Palacios and Kitten provide an incremental path to using supercomputer resources that is not performance-compromised.

Parallel sorting algorithms

CERN Document Server

Akl, Selim G

1985-01-01

Parallel Sorting Algorithms explains how to use parallel algorithms to sort a sequence of items on a variety of parallel computers. The book reviews the sorting problem, the parallel models of computation, parallel algorithms, and the lower bounds on the parallel sorting problems. The text also presents twenty different algorithms, such as linear arrays, mesh-connected computers, cube-connected computers. Another example where algorithm can be applied is on the shared-memory SIMD (single instruction stream multiple data stream) computers in which the whole sequence to be sorted can fit in the

MaMiCo: Transient multi-instance molecular-continuum flow simulation on supercomputers

Science.gov (United States)

Neumann, Philipp; Bian, Xin

2017-11-01

We present extensions of the macro-micro-coupling tool MaMiCo, which was designed to couple continuum fluid dynamics solvers with discrete particle dynamics. To enable local extraction of smooth flow field quantities especially on rather short time scales, sampling over an ensemble of molecular dynamics simulations is introduced. We provide details on these extensions including the transient coupling algorithm, open boundary forcing, and multi-instance sampling. Furthermore, we validate the coupling in Couette flow using different particle simulation software packages and particle models, i.e. molecular dynamics and dissipative particle dynamics. Finally, we demonstrate the parallel scalability of the molecular-continuum simulations by using up to 65 536 compute cores of the supercomputer Shaheen II located at KAUST. Program Files doi:http://dx.doi.org/10.17632/w7rgdrhb85.1 Licensing provisions: BSD 3-clause Programming language: C, C++ External routines/libraries: For compiling: SCons, MPI (optional) Subprograms used: ESPResSo, LAMMPS, ls1 mardyn, waLBerla For installation procedures of the MaMiCo interfaces, see the README files in the respective code directories located in coupling/interface/impl. Journal reference of previous version: P. Neumann, H. Flohr, R. Arora, P. Jarmatz, N. Tchipev, H.-J. Bungartz. MaMiCo: Software design for parallel molecular-continuum flow simulations, Computer Physics Communications 200: 324-335, 2016 Does the new version supersede the previous version?: Yes. The functionality of the previous version is completely retained in the new version. Nature of problem: Coupled molecular-continuum simulation for multi-resolution fluid dynamics: parts of the domain are resolved by molecular dynamics or another particle-based solver whereas large parts are covered by a mesh-based CFD solver, e.g. a lattice Boltzmann automaton. Solution method: We couple existing MD and CFD solvers via MaMiCo (macro-micro coupling tool). Data exchange and

A confrontation with reality - Proceedings of the 19th Association for Learning Technology Conference

NARCIS (Netherlands)

Hawkridge, David; Verjans, Steven; Wilson, Gail

2012-01-01

Hawkridge, D., Verjans, S., & Wilson, G. (Eds.) (2012). A confrontation with reality - Proceedings of the 19th Association for Learning Technology Conference (ALT-C 2012). September, 11-14, 2012, Manchester, UK.

Citizen-sensor-networks to confront government decision-makers: Two lessons from the Netherlands

NARCIS (Netherlands)

Carton, L.J.; Ache, P.M.

2017-01-01

This paper presents one emerging social-technical innovation: The evolution of citizen-sensor-networks where citizens organize themselves from the ‘bottom up’, for the sake of confronting governance officials with measured information about environmental qualities. We have observed how

The challenges that head nurses confront on financial management today: A qualitative study

Directory of Open Access Journals (Sweden)

Yang Bai, RN, BA

2017-04-01

Conclusions: The confusion confronted by head nurses in Changsha include three aspects: managerial roles, managerial training, and managerial tools. Cooperative management model, evidence-based management training, and data-driven tools will contribute to improving the financial management capacity of nurse managers.

PetClaw: Parallelization and Performance Optimization of a Python-Based Nonlinear Wave Propagation Solver Using PETSc

KAUST Repository

Alghamdi, Amal Mohammed

2012-04-01

Clawpack, a conservation laws package implemented in Fortran, and its Python-based version, PyClaw, are existing tools providing nonlinear wave propagation solvers that use state of the art finite volume methods. Simulations using those tools can have extensive computational requirements to provide accurate results. Therefore, a number of tools, such as BearClaw and MPIClaw, have been developed based on Clawpack to achieve significant speedup by exploiting parallel architectures. However, none of them has been shown to scale on a large number of cores. Furthermore, these tools, implemented in Fortran, achieve parallelization by inserting parallelization logic and MPI standard routines throughout the serial code in a non modular manner. Our contribution in this thesis research is three-fold. First, we demonstrate an advantageous use case of Python in implementing easy-to-use modular extensible scalable scientific software tools by developing an implementation of a parallelization framework, PetClaw, for PyClaw using the well-known Portable Extensible Toolkit for Scientific Computation, PETSc, through its Python wrapper petsc4py. Second, we demonstrate the possibility of getting acceptable Python code performance when compared to Fortran performance after introducing a number of serial optimizations to the Python code including integrating Clawpack Fortran kernels into PyClaw for low-level computationally intensive parts of the code. As a result of those optimizations, the Python overhead in PetClaw for a shallow water application is only 12 percent when compared to the corresponding Fortran Clawpack application. Third, we provide a demonstration of PetClaw scalability on up to the entirety of Shaheen; a 16-rack Blue Gene/P IBM supercomputer that comprises 65,536 cores and located at King Abdullah University of Science and Technology (KAUST). The PetClaw solver achieved above 0.98 weak scaling efficiency for an Euler application on the whole machine excluding the

Cache-aware data structure model for parallelism and dynamic load balancing

International Nuclear Information System (INIS)

Sridi, Marwa

2016-01-01

This PhD thesis is dedicated to the implementation of innovative parallel methods in the framework of fast transient fluid-structure dynamics. It improves existing methods within EUROPLEXUS software, in order to optimize the shared memory parallel strategy, complementary to the original distributed memory approach, brought together into a global hybrid strategy for clusters of multi-core nodes. Starting from a sound analysis of the state of the art concerning data structuring techniques correlated to the hierarchic memory organization of current multi-processor architectures, the proposed work introduces an approach suitable for an explicit time integration (i.e. with no linear system to solve at each step). A data structure of type 'Structure of arrays' is conserved for the global data storage, providing flexibility and efficiency for current operations on kinematics fields (displacement, velocity and acceleration). On the contrary, in the particular case of elementary operations (for internal forces generic computations, as well as fluxes computations between cell faces for fluid models), particularly time consuming but localized in the program, a temporary data structure of type 'Array of structures' is used instead, to force an efficient filling of the cache memory and increase the performance of the resolution, for both serial and shared memory parallel processing. Switching from the global structure to the temporary one is based on a cell grouping strategy, following classing cache-blocking principles but handling specifically for this work neighboring data necessary to the efficient treatment of ALE fluxes for cells on the group boundaries. The proposed approach is extensively tested, from the point of views of both the computation time and the access failures into cache memory, confronting the gains obtained within the elementary operations to the potential overhead generated by the data structure switch. Obtained results are very satisfactory, especially

Confronting hybrid inflation in supergravity with CMB data

International Nuclear Information System (INIS)

Jeannerot, Rachel; Postma, Marieke

2005-01-01

F-term GUT inflation coupled to N = 1 supergravity is confronted with CMB data. Corrections to the string mass-per-unit-length away from the Bogomolny limit are taken into account. We find that a superpotential coupling 10 -7 /N∼ -2 /N, with N the dimension of the Higgs-representation, is still compatible with the data. The parameter space is enlarged in warm inflation, as well as in the curvaton and inhomogeneous reheat scenario. F-strings formed at the end of P-term inflation are also considered. Because these strings satisfy the Bogomolny bound the bounds are stronger: the gauge coupling is constrained to the range 10 -7 -4

Confronting the Consequences of a Permanent Changing Environment

Directory of Open Access Journals (Sweden)

Raluca Ioana Vosloban

2013-05-01

Full Text Available Businesses and governments choose how they wish to deal with change. Whether this change is organizational, technological, political, financial etc or even individual pursuing actions as usual is likely to lead to a downward path. The authors of this paper are giving a set of tools for confronting and understanding the consequences of this era of permanent changes by building strengths and seeking opportunities within organizations (private or public and within family (including friends. The work environment and the personal life of the individual have a common point which is adaptability, coping efficiently with changes, a demanded ability of the 3rd millennium human being.

Efficient implementation of a multidimensional fast fourier transform on a distributed-memory parallel multi-node computer

Science.gov (United States)

Bhanot, Gyan V [Princeton, NJ; Chen, Dong [Croton-On-Hudson, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Steinmacher-Burow, Burkhard D [Mount Kisco, NY; Vranas, Pavlos M [Bedford Hills, NY

2008-01-01

The present in invention is directed to a method, system and program storage device for efficiently implementing a multidimensional Fast Fourier Transform (FFT) of a multidimensional array comprising a plurality of elements initially distributed in a multi-node computer system comprising a plurality of nodes in communication over a network, comprising: distributing the plurality of elements of the array in a first dimension across the plurality of nodes of the computer system over the network to facilitate a first one-dimensional FFT; performing the first one-dimensional FFT on the elements of the array distributed at each node in the first dimension; re-distributing the one-dimensional FFT-transformed elements at each node in a second dimension via "all-to-all" distribution in random order across other nodes of the computer system over the network; and performing a second one-dimensional FFT on elements of the array re-distributed at each node in the second dimension, wherein the random order facilitates efficient utilization of the network thereby efficiently implementing the multidimensional FFT. The "all-to-all" re-distribution of array elements is further efficiently implemented in applications other than the multidimensional FFT on the distributed-memory parallel supercomputer.

Scalability of DL_POLY on High Performance Computing Platform

CSIR Research Space (South Africa)

Mabakane, Mabule S

2017-12-01

Full Text Available stream_source_info Mabakanea_19979_2017.pdf.txt stream_content_type text/plain stream_size 33716 Content-Encoding UTF-8 stream_name Mabakanea_19979_2017.pdf.txt Content-Type text/plain; charset=UTF-8 SACJ 29(3) December... when using many processors within the compute nodes of the supercomputer. The type of the processors of compute nodes and their memory also play an important role in the overall performance of the parallel application running on a supercomputer. DL...

Parallel MR imaging.

Science.gov (United States)

Deshmane, Anagha; Gulani, Vikas; Griswold, Mark A; Seiberlich, Nicole

2012-07-01

Parallel imaging is a robust method for accelerating the acquisition of magnetic resonance imaging (MRI) data, and has made possible many new applications of MR imaging. Parallel imaging works by acquiring a reduced amount of k-space data with an array of receiver coils. These undersampled data can be acquired more quickly, but the undersampling leads to aliased images. One of several parallel imaging algorithms can then be used to reconstruct artifact-free images from either the aliased images (SENSE-type reconstruction) or from the undersampled data (GRAPPA-type reconstruction). The advantages of parallel imaging in a clinical setting include faster image acquisition, which can be used, for instance, to shorten breath-hold times resulting in fewer motion-corrupted examinations. In this article the basic concepts behind parallel imaging are introduced. The relationship between undersampling and aliasing is discussed and two commonly used parallel imaging methods, SENSE and GRAPPA, are explained in detail. Examples of artifacts arising from parallel imaging are shown and ways to detect and mitigate these artifacts are described. Finally, several current applications of parallel imaging are presented and recent advancements and promising research in parallel imaging are briefly reviewed. Copyright © 2012 Wiley Periodicals, Inc.

High-Performance Psychometrics: The Parallel-E Parallel-M Algorithm for Generalized Latent Variable Models. Research Report. ETS RR-16-34

Science.gov (United States)

von Davier, Matthias

2016-01-01

This report presents results on a parallel implementation of the expectation-maximization (EM) algorithm for multidimensional latent variable models. The developments presented here are based on code that parallelizes both the E step and the M step of the parallel-E parallel-M algorithm. Examples presented in this report include item response…

Algorithms and data structures for massively parallel generic adaptive finite element codes

KAUST Repository

Bangerth, Wolfgang

2011-12-01

Today\\'s largest supercomputers have 100,000s of processor cores and offer the potential to solve partial differential equations discretized by billions of unknowns. However, the complexity of scaling to such large machines and problem sizes has so far prevented the emergence of generic software libraries that support such computations, although these would lower the threshold of entry and enable many more applications to benefit from large-scale computing. We are concerned with providing this functionality for mesh-adaptive finite element computations. We assume the existence of an "oracle" that implements the generation and modification of an adaptive mesh distributed across many processors, and that responds to queries about its structure. Based on querying the oracle, we develop scalable algorithms and data structures for generic finite element methods. Specifically, we consider the parallel distribution of mesh data, global enumeration of degrees of freedom, constraints, and postprocessing. Our algorithms remove the bottlenecks that typically limit large-scale adaptive finite element analyses. We demonstrate scalability of complete finite element workflows on up to 16,384 processors. An implementation of the proposed algorithms, based on the open source software p4est as mesh oracle, is provided under an open source license through the widely used deal.II finite element software library. © 2011 ACM 0098-3500/2011/12-ART10 $10.00.

Fluctuations and transport in fusion plasmas. Final report

International Nuclear Information System (INIS)

Gould, R.W.; Liewer, P.C.

1995-01-01

The energy confinement in tokamaks in thought to be limited by transport caused by plasma turbulence. Three dimensional plasma particle-in-cell (PIC) codes are used to model the turbulent transport in tokamaks to attempt to understand this phenomena so that tokamaks can be made more efficient. Presently, hundreds of hours of Cray time are used to model these experiments and much bigger and longer runs are desired, to model a large tokamak with realistic parameters is beyond the capability of existing sequential supercomputers. Parallel supercomputers might be a cost effect tool for performing such large scale 3D tokamak simulations. The goal of the work was to develop algorithms for performing PIC codes on coarse-grained message passing parallel computers and to evaluate the performance of such parallel computers on PIC codes. This algorithm would be used in a large scale PIC production code such as the UCLA 3D gyrokinetic code

Upside to downsizing : Acceleware's graphic processor technology propels seismic data processing revolution

Energy Technology Data Exchange (ETDEWEB)

Smith, M.

2009-11-15

Accelware has developed a graphic processor technology (GPU) that is transforming the petroleum industry. The benefits of the technology are its small-footprint, low-wattage, and high speed. The software brings supercomputing speed to the desktop by leveraging the massive parallel processing capacity to the very latest in GPU technology. This article discussed the GPU technology and its emergence as a powerful supercomputing tool. Accelware's partnering with California-based NVIDIA was also outlined. The advantages of the technology were also discussed including its smaller footprint. Accelware's hardware takes up a fraction of the space and uses up to 70 per cent less power than a traditional central processing unit. By combining Accelware's core knowledge in making complex algorithms run in parallel with an in-house team of seismic industry experts, the company provides software solutions for seismic data processors that access the massively parallel processing capabilities of GPUs. 1 fig.

ACME: A scalable parallel system for extracting frequent patterns from a very long sequence

KAUST Repository

Sahli, Majed

2014-10-02

Modern applications, including bioinformatics, time series, and web log analysis, require the extraction of frequent patterns, called motifs, from one very long (i.e., several gigabytes) sequence. Existing approaches are either heuristics that are error-prone, or exact (also called combinatorial) methods that are extremely slow, therefore, applicable only to very small sequences (i.e., in the order of megabytes). This paper presents ACME, a combinatorial approach that scales to gigabyte-long sequences and is the first to support supermaximal motifs. ACME is a versatile parallel system that can be deployed on desktop multi-core systems, or on thousands of CPUs in the cloud. However, merely using more compute nodes does not guarantee efficiency, because of the related overheads. To this end, ACME introduces an automatic tuning mechanism that suggests the appropriate number of CPUs to utilize, in order to meet the user constraints in terms of run time, while minimizing the financial cost of cloud resources. Our experiments show that, compared to the state of the art, ACME supports three orders of magnitude longer sequences (e.g., DNA for the entire human genome); handles large alphabets (e.g., English alphabet for Wikipedia); scales out to 16,384 CPUs on a supercomputer; and supports elastic deployment in the cloud.

MOVEMENT OF NATURAL PARENTING AS (AS IF A CONFRONTATION WITH A CONSUMER SOCIETY

Directory of Open Access Journals (Sweden)

Alla Diomidova

2014-10-01

Full Text Available The article describes the movement of natural parenting and its confrontational ideology. The authors sought to provide a general understanding of the movement natural parenting and describe its confrontational ideology. Speaking in terms of sociology, sling parents form the imagined community and this particular ideology is the focus of the presents study. The hypothesis of the study lies in the assumption that discourse analysis of natural parenting is to discover traits of propaganda discourse. The subject of the analyzed discourse is set critically in relation to the modern practice of consumption, declares the personal position free from stereotypes and willingness to confront the dictatorial influence of consumer values on the style of parenting. The subject is prone to reflection and the generation of ideological texts. Despite the fact that natural parenting has positioned itself as anti-consumer-orientated, it creates a consumer niche of the “right” products for children. Being against some commodities, natural parenting creates demand for the other ones. Sling clothing for Moms (sling jackets, accessories and the like become the accompanying sling commodities. Natural parenting has positioned itself as focused on the child’s needs. The traditional educational discourse is marked as providing the convenience for a mother who does not love her child. Many of the arguments of the sling discourse are based on fear to fail to meet a child’s needs (or to cause harm to his\\her health, to threaten his\\her life, which relates it with the mainstream advertising discourse.

Molecular dynamics beyonds the limits: Massive scaling on 72 racks of a BlueGene/P and supercooled glass dynamics of a 1 billion particles system

KAUST Repository

Allsopp, Nicholas; Ruocco, Giancarlo; Fratalocchi, Andrea

2012-01-01

We report scaling results on the world's largest supercomputer of our recently developed Billions-Body Molecular Dynamics (BBMD) package, which was especially designed for massively parallel simulations of the short-range atomic dynamics

Assessment techniques for a learning-centered curriculum: evaluation design for adventures in supercomputing

Energy Technology Data Exchange (ETDEWEB)

Helland, B. [Ames Lab., IA (United States); Summers, B.G. [Oak Ridge National Lab., TN (United States)

1996-09-01

As the classroom paradigm shifts from being teacher-centered to being learner-centered, student assessments are evolving from typical paper and pencil testing to other methods of evaluation. Students should be probed for understanding, reasoning, and critical thinking abilities rather than their ability to return memorized facts. The assessment of the Department of Energy`s pilot program, Adventures in Supercomputing (AiS), offers one example of assessment techniques developed for learner-centered curricula. This assessment has employed a variety of methods to collect student data. Methods of assessment used were traditional testing, performance testing, interviews, short questionnaires via email, and student presentations of projects. The data obtained from these sources have been analyzed by a professional assessment team at the Center for Children and Technology. The results have been used to improve the AiS curriculum and establish the quality of the overall AiS program. This paper will discuss the various methods of assessment used and the results.

The BlueGene/L Supercomputer and Quantum ChromoDynamics

International Nuclear Information System (INIS)

Vranas, P; Soltz, R

2006-01-01

In summary our update contains: (1) Perfect speedup sustaining 19.3% of peak for the Wilson D D-slash Dirac operator. (2) Measurements of the full Conjugate Gradient (CG) inverter that inverts the Dirac operator. The CG inverter contains two global sums over the entire machine. Nevertheless, our measurements retain perfect speedup scaling demonstrating the robustness of our methods. (3) We ran on the largest BG/L system, the LLNL 64 rack BG/L supercomputer, and obtained a sustained speed of 59.1 TFlops. Furthermore, the speedup scaling of the Dirac operator and of the CG inverter are perfect all the way up to the full size of the machine, 131,072 cores (please see Figure II). The local lattice is rather small (4 x 4 x 4 x 16) while the total lattice has been a lattice QCD vision for thermodynamic studies (a total of 128 x 128 x 256 x 32 lattice sites). This speed is about five times larger compared to the speed we quoted in our submission. As we have pointed out in our paper QCD is notoriously sensitive to network and memory latencies, has a relatively high communication to computation ratio which can not be overlapped in BGL in virtual node mode, and as an application is in a class of its own. The above results are thrilling to us and a 30 year long dream for lattice QCD

Emergency Managers Confront Climate Change

Directory of Open Access Journals (Sweden)

John R. Labadie

2011-08-01

Full Text Available Emergency managers will have to deal with the impending, uncertain, and possibly extreme effects of climate change. Yet, many emergency managers are not aware of the full range of possible effects, and they are unsure of their place in the effort to plan for, adapt to, and cope with those effects. This may partly reflect emergency mangers’ reluctance to get caught up in the rancorous—and politically-charged—debate about climate change, but it mostly is due to the worldview shared by most emergency managers. We focus on: extreme events; acute vs. chronic hazards (floods vs. droughts; a shorter event horizon (5 years vs. 75–100 years; and a shorter planning and operational cycle. This paper explores the important intersection of emergency management, environmental management, and climate change mitigation and adaptation. It examines the different definitions of terms common to all three fields, the overlapping strategies used in all three fields, and the best means of collaboration and mutual re-enforcement among the three to confront and solve the many possible futures that we may face in the climate change world.

A SPECT reconstruction method for extending parallel to non-parallel geometries

International Nuclear Information System (INIS)

Wen Junhai; Liang Zhengrong

2010-01-01

Due to its simplicity, parallel-beam geometry is usually assumed for the development of image reconstruction algorithms. The established reconstruction methodologies are then extended to fan-beam, cone-beam and other non-parallel geometries for practical application. This situation occurs for quantitative SPECT (single photon emission computed tomography) imaging in inverting the attenuated Radon transform. Novikov reported an explicit parallel-beam formula for the inversion of the attenuated Radon transform in 2000. Thereafter, a formula for fan-beam geometry was reported by Bukhgeim and Kazantsev (2002 Preprint N. 99 Sobolev Institute of Mathematics). At the same time, we presented a formula for varying focal-length fan-beam geometry. Sometimes, the reconstruction formula is so implicit that we cannot obtain the explicit reconstruction formula in the non-parallel geometries. In this work, we propose a unified reconstruction framework for extending parallel-beam geometry to any non-parallel geometry using ray-driven techniques. Studies by computer simulations demonstrated the accuracy of the presented unified reconstruction framework for extending parallel-beam to non-parallel geometries in inverting the attenuated Radon transform.

The Lived Experience of Iranian Women Confronting Breast Cancer Diagnosis.

Science.gov (United States)

Mehrabi, Esmat; Hajian, Sepideh; Simbar, Masoomeh; Hoshyari, Mohammad; Zayeri, Farid

2016-03-01

The populations who survive from breast cancer are growing; nevertheless, they mostly encounter with many cancer related problems in their life, especially after early diagnosis and have to deal with these problems. Except for the disease entity, several socio-cultural factors may affect confronting this challenge among patients and the way they deal with. Present study was carried out to prepare clear understanding of Iranian women's lived experiences confronting breast cancer diagnosis and coping ways they applied to deal with it. This study was carried out by using qualitative phenomenological design. Data gathering was done through purposive sampling using semi-structured, in-depth interviews with 18 women who survived from breast cancer. The transcribed interviews were analyzed using Van Manen's thematic analysis approach. Two main themes were emerged from the interviews including "emotional turbulence" and "threat control". The first, comprised three sub themes including uncertainty, perceived worries, and living with fears. The second included risk control, recurrence control, immediate seeking help, seeking support and resource to spirituality. Emotional response was the immediate reflection to cancer diagnosis. However, during post-treatment period a variety of emotions were not uncommon findings, patients' perceptions have been changing along the time and problem-focused coping strategies have replaced. Although women may experience a degree of improvement and adjustment with illness, the emotional problems are not necessarily resolved, they may continue and gradually engender positive outcomes.

Self-management support and eHealth for patients and informal caregivers confronted with advanced cancer : An online focus group study among nurses

NARCIS (Netherlands)

Slev, Vina N.; Pasman, H. Roeline W.; Eeltink, Corien M.; Van Uden-Kraan, Cornelia F.; Verdonck-De Leeuw, Irma M.; Francke, Anneke L.

2017-01-01

Background: Self-management by patients and informal caregivers confronted with advanced cancer is not self-evident. Therefore they might need self-management support from nurses. This article reports on nurses' perspectives on self-management support for people confronted with advanced cancer, and