Science.gov

Sample records for facility distributed computer

  1. DNET: A communications facility for distributed heterogeneous computing

    NASA Technical Reports Server (NTRS)

    Tole, John; Nagappan, S.; Clayton, J.; Ruotolo, P.; Williamson, C.; Solow, H.

    1989-01-01

    This document describes DNET, a heterogeneous data communications networking facility. DNET allows programs operating on hosts on dissimilar networks to communicate with one another without concern for computer hardware, network protocol, or operating system differences. The overall DNET network is defined as the collection of host machines/networks on which the DNET software is operating. Each underlying network is considered a DNET 'domain'. Data communications service is provided between any two processes on any two hosts on any of the networks (domains) that may be reached via DNET. DNET provides protocol transparent, reliable, streaming data transmission between hosts (restricted, initially to DECnet and TCP/IP networks). DNET also provides variable length datagram service with optional return receipts.

  2. Improving CMS data transfers among its distributed computing facilities

    NASA Astrophysics Data System (ADS)

    Flix, J.; Magini, N.; Sartirana, A.

    2011-12-01

    CMS computing needs reliable, stable and fast connections among multi-tiered computing infrastructures. For data distribution, the CMS experiment relies on a data placement and transfer system, PhEDEx, managing replication operations at each site in the distribution network. PhEDEx uses the File Transfer Service (FTS), a low level data movement service responsible for moving sets of files from one site to another, while allowing participating sites to control the network resource usage. FTS servers are provided by Tier-0 and Tier-1 centres and are used by all computing sites in CMS, according to the established policy. FTS needs to be set up according to the Grid site's policies, and properly configured to satisfy the requirements of all Virtual Organizations making use of the Grid resources at the site. Managing the service efficiently requires good knowledge of the CMS needs for all kinds of transfer workflows. This contribution deals with a revision of FTS servers used by CMS, collecting statistics on their usage, customizing the topologies and improving their setup in order to keep CMS transferring data at the desired levels in a reliable and robust way.

  3. Lustre Distributed Name Space (DNE) Evaluation at the Oak Ridge Leadership Computing Facility (OLCF)

    SciTech Connect

    Simmons, James S.; Leverman, Dustin B.; Hanley, Jesse A.; Oral, Sarp

    2016-08-22

    This document describes the Lustre Distributed Name Space (DNE) evaluation carried at the Oak Ridge Leadership Computing Facility (OLCF) between 2014 and 2015. DNE is a development project funded by the OpenSFS, to improve Lustre metadata performance and scalability. The development effort has been split into two parts, the first part (DNE P1) providing support for remote directories over remote Lustre Metadata Server (MDS) nodes and Metadata Target (MDT) devices, while the second phase (DNE P2) addressed split directories over multiple remote MDS nodes and MDT devices. The OLCF have been actively evaluating the performance, reliability, and the functionality of both DNE phases. For these tests, internal OLCF testbed were used. Results are promising and OLCF is planning on a full DNE deployment by mid-2016 timeframe on production systems.

  4. The Overview of the National Ignition Facility Distributed Computer Control System

    NASA Astrophysics Data System (ADS)

    Lagin, Lawrence

    The Integrated Computer Control System (ICCS) for the National Ignition Facility (NIF) is a layered architecture of 300 front-end processors (FEP) coordinated by supervisor subsystems including automatic beam alignment and wavefront control, laser and target diagnostics, pulse power, and shot control timed to 30 ps. FEP computers incorporate either VxWorks on PowerPC or Solaris on UltraSPARC processors that interface to over 45,000 control points attached to VME-bus or PCI-bus crates respectively. Typical devices are stepping motors, transient digitizers, calorimeters, and photodiodes. The front-end layer is divided into another segment comprised of an additional 14,000 control points for industrial controls including vacuum, argon, synthetic air, and safety interlocks implemented with Allen-Bradley programmable logic controllers (PLCs). The computer network is augmented asynchronous transfer mode (ATM) that delivers video streams from 500 sensor cameras monitoring the 192 laser beams to operator workstations. Software is based on an object-oriented framework using CORBA distribution that incorporates services for archiving, machine configuration, graphical user interface, monitoring, event logging, scripting, alert management, and access control. Software coding using a mixed language environment of Ada95 and Java is one-third complete at over 300 thousand source lines. Control system installation is currently under way for the first 8 beams, with project completion scheduled for 2008.

  5. Distributed Computing.

    ERIC Educational Resources Information Center

    Ryland, Jane N.

    1988-01-01

    The microcomputer revolution, in which small and large computers have gained tremendously in capability, has created a distributed computing environment. This circumstance presents administrators with the opportunities and the dilemmas of choosing appropriate computing resources for each situation. (Author/MSE)

  6. Distributed computer control system in the Nova Laser Fusion Test Facility

    SciTech Connect

    Not Available

    1985-09-01

    The EE Technical Review has two purposes - to inform readers of various activities within the Electronics Engineering Department and to promote the exchange of ideas. The articles, by design, are brief summaries of EE work. The articles included in this report are as follows: Overview - Nova Control System; Centralized Computer-Based Controls for the Nova Laser Facility; Nova Pulse-Power Control System; Nova Laser Alignment Control System; Nova Beam Diagnostic System; Nova Target-Diagnostics Control System; and Nova Shot Scheduler. The 7 papers are individually abstracted.

  7. Redirecting Under-Utilised Computer Laboratories into Cluster Computing Facilities

    ERIC Educational Resources Information Center

    Atkinson, John S.; Spenneman, Dirk H. R.; Cornforth, David

    2005-01-01

    Purpose: To provide administrators at an Australian university with data on the feasibility of redirecting under-utilised computer laboratories facilities into a distributed high performance computing facility. Design/methodology/approach: The individual log-in records for each computer located in the computer laboratories at the university were…

  8. A computational test facility for distributed analysis of gravitational wave signals

    NASA Astrophysics Data System (ADS)

    Amico, P.; Bosi, L.; Cattuto, C.; Gammaitoni, L.; Punturo, M.; Travasso, F.; Vocca, H.

    2004-03-01

    In the gravitational wave detector Virgo, the in-time detection of a gravitational wave signal from a coalescing binary stellar system is an intensive computational task. A parallel computing scheme using the message passing interface (MPI) is described. Performance results on a small-scale cluster are reported.

  9. Chapter on Distributed Computing

    DTIC Science & Technology

    1989-02-01

    MASSACHUSETTS LABORATORY FOR INSTITUTE OF COMPUTER SCIENCE TECHNOLOGY ("D / o O MIT/LCS/TM-384 CHAPTER ON DISTRIBUTED COMPUTING Leslie Lamport Nancy...22217 ELEMENT NO. NO. NO. ACCESSION NO. 11. TITLE (Miude Secuwity Ciaifiation) Chapter on Distributed Computing 12. PERSONAL AUTHOR(S) Lamport... distributed computing , distributed systems models, dis- tributed algorithms, message-passing, shared variables, 19. UBSTRACT (Continue on reverse if

  10. Physics Division computer facilities

    SciTech Connect

    Cyborski, D.R.; Teh, K.M.

    1995-08-01

    The Physics Division maintains several computer systems for data analysis, general-purpose computing, and word processing. While the VMS VAX clusters are still used, this past year saw a greater shift to the Unix Cluster with the addition of more RISC-based Unix workstations. The main Divisional VAX cluster which consists of two VAX 3300s configured as a dual-host system serves as boot nodes and disk servers to seven other satellite nodes consisting of two VAXstation 3200s, three VAXstation 3100 machines, a VAX-11/750, and a MicroVAX II. There are three 6250/1600 bpi 9-track tape drives, six 8-mm tapes and about 9.1 GB of disk storage served to the cluster by the various satellites. Also, two of the satellites (the MicroVAX and VAX-11/750) have DAPHNE front-end interfaces for data acquisition. Since the tape drives are accessible cluster-wide via a software package, they are, in addition to replay, used for tape-to-tape copies. There is however, a satellite node outfitted with two 8 mm drives available for this purpose. Although not part of the main cluster, a DEC 3000 Alpha machine obtained for data acquisition is also available for data replay. In one case, users reported a performance increase by a factor of 10 when using this machine.

  11. AMRITA -- A computational facility

    SciTech Connect

    Shepherd, J.E.; Quirk, J.J.

    1998-02-23

    Amrita is a software system for automating numerical investigations. The system is driven using its own powerful scripting language, Amrita, which facilitates both the composition and archiving of complete numerical investigations, as distinct from isolated computations. Once archived, an Amrita investigation can later be reproduced by any interested party, and not just the original investigator, for no cost other than the raw CPU time needed to parse the archived script. In fact, this entire lecture can be reconstructed in such a fashion. To do this, the script: constructs a number of shock-capturing schemes; runs a series of test problems, generates the plots shown; outputs the LATEX to typeset the notes; performs a myriad of behind-the-scenes tasks to glue everything together. Thus Amrita has all the characteristics of an operating system and should not be mistaken for a common-or-garden code.

  12. Program Facilitates Distributed Computing

    NASA Technical Reports Server (NTRS)

    Hui, Joseph

    1993-01-01

    KNET computer program facilitates distribution of computing between UNIX-compatible local host computer and remote host computer, which may or may not be UNIX-compatible. Capable of automatic remote log-in. User communicates interactively with remote host computer. Data output from remote host computer directed to local screen, to local file, and/or to local process. Conversely, data input from keyboard, local file, or local process directed to remote host computer. Written in ANSI standard C language.

  13. Distributed computing in bioinformatics.

    PubMed

    Jain, Eric

    2002-01-01

    This paper provides an overview of methods and current applications of distributed computing in bioinformatics. Distributed computing is a strategy of dividing a large workload among multiple computers to reduce processing time, or to make use of resources such as programs and databases that are not available on all computers. Participating computers may be connected either through a local high-speed network or through the Internet.

  14. Parallel and Distributed Computing.

    DTIC Science & Technology

    1986-12-12

    program was devoted to parallel and distributed computing . Support for this part of the program was obtained from the present Army contract and a...Umesh Vazirani. A workshop on parallel and distributed computing was held from May 19 to May 23, 1986 and drew 141 participants. Keywords: Mathematical programming; Protocols; Randomized algorithms. (Author)

  15. Distributed Computing and Collaboration Framework (DCCF)

    DTIC Science & Technology

    2002-09-01

    The Distributed Computing and Collaboration Framework has been developed by the Space and Naval Warfare Systems Center, San Diego (a Naval research and development facility), under the sponsorship of the Office of Naval

  16. Quantum computing Hyper Terahertz Facility opens

    NASA Astrophysics Data System (ADS)

    Singh Chadha, Kulvinder

    2016-01-01

    A new facility has opened at the University of Surrey to use terahertz radiation for quantum computing. The Hyper Terahertz Facility (HTF) is a joint collaboration between the University of Surrey and the National Physical Laboratory (NPL).

  17. Coping with distributed computing

    SciTech Connect

    Cormell, L.

    1992-09-01

    The rapid increase in the availability of high performance, cost-effective RISC/UNIX workstations has been both a blessing and a curse. The blessing of having extremely powerful computing engines available on the desk top is well-known to many users. The user has tremendous freedom, flexibility, and control of his environment. That freedom can, however, become the curse of distributed computing. The user must become a system manager to some extent, he must worry about backups, maintenance, upgrades, etc. Traditionally these activities have been the responsibility of a central computing group. The central computing group, however, may find that it can no longer provide all of the traditional services. With the plethora of workstations now found on so many desktops throughout the entire campus or lab, the central computing group may be swamped by support requests. This talk will address several of these computer support and management issues by providing some examples of the approaches taken at various HEP institutions. In addition, a brief review of commercial directions or products for distributed computing and management will be given.

  18. 2014 Annual Report - Argonne Leadership Computing Facility

    SciTech Connect

    Collins, James R.; Papka, Michael E.; Cerny, Beth A.; Coffey, Richard M.

    2014-01-01

    The Argonne Leadership Computing Facility provides supercomputing capabilities to the scientific and engineering community to advance fundamental discovery and understanding in a broad range of disciplines.

  19. 2015 Annual Report - Argonne Leadership Computing Facility

    SciTech Connect

    Collins, James R.; Papka, Michael E.; Cerny, Beth A.; Coffey, Richard M.

    2015-01-01

    The Argonne Leadership Computing Facility provides supercomputing capabilities to the scientific and engineering community to advance fundamental discovery and understanding in a broad range of disciplines.

  20. The Survivable Distributed Computing Environment

    DTIC Science & Technology

    1994-06-01

    an architecture for a survivable Distributed Computing Environment (SDCE). In essence, the SDCE will be a base upon which survivable distributed...and/or ISIS distributed Computing Environments to provide many of the SDCE requirements.

  1. Central Computational Facility CCF communications subsystem options

    NASA Technical Reports Server (NTRS)

    Hennigan, K. B.

    1979-01-01

    A MITRE study which investigated the communication options available to support both the remaining Central Computational Facility (CCF) computer systems and the proposed U1108 replacements is presented. The facilities utilized to link the remote user terminals with the CCF were analyzed and guidelines to provide more efficient communications were established.

  2. Distributed Computing Framework for Synthetic Radar Application

    NASA Technical Reports Server (NTRS)

    Gurrola, Eric M.; Rosen, Paul A.; Aivazis, Michael

    2006-01-01

    We are developing an extensible software framework, in response to Air Force and NASA needs for distributed computing facilities for a variety of radar applications. The objective of this work is to develop a Python based software framework, that is the framework elements of the middleware that allows developers to control processing flow on a grid in a distributed computing environment. Framework architectures to date allow developers to connect processing functions together as interchangeable objects, thereby allowing a data flow graph to be devised for a specific problem to be solved. The Pyre framework, developed at the California Institute of Technology (Caltech), and now being used as the basis for next-generation radar processing at JPL, is a Python-based software framework. We have extended the Pyre framework to include new facilities to deploy processing components as services, including components that monitor and assess the state of the distributed network for eventual real-time control of grid resources.

  3. Distributed Real-Time Computing with Harness

    SciTech Connect

    Di Saverio, Emanuele; Cesati, Marco; Di Biagio, Christian; Pennella, Guido; Engelmann, Christian

    2007-01-01

    Modern parallel and distributed computing solutions are often built onto a ''middleware'' software layer providing a higher and common level of service between computational nodes. Harness is an adaptable, plugin-based middleware framework for parallel and distributed computing. This paper reports recent research and development results of using Harness for real-time distributed computing applications in the context of an industrial environment with the needs to perform several safety critical tasks. The presented work exploits the modular architecture of Harness in conjunction with a lightweight threaded implementation to resolve several real-time issues by adding three new Harness plug-ins to provide a prioritized lightweight execution environment, low latency communication facilities, and local timestamped event logging.

  4. Knowledge and Distributed computation

    DTIC Science & Technology

    1990-05-01

    convincing evidence that reasoning in terms of knowledge can lead to .. n... uif.yi ...... lts" about diStfibuLuc computation, and we extend the standard...can be made precise in the context of computer science. In this thesis, we pro- vide convincing evidence that reasoning in terms of knowledge can lead ...against different adversaries. We show how different adversaries lead to different definitions of probabilistic knowledge, and given a particular adversary

  5. Heterogeneous Distributed Computing for Computational Aerosciences

    NASA Technical Reports Server (NTRS)

    Sunderam, Vaidy S.

    1998-01-01

    The research supported under this award focuses on heterogeneous distributed computing for high-performance applications, with particular emphasis on computational aerosciences. The overall goal of this project was to and investigate issues in, and develop solutions to, efficient execution of computational aeroscience codes in heterogeneous concurrent computing environments. In particular, we worked in the context of the PVM[1] system and, subsequent to detailed conversion efforts and performance benchmarking, devising novel techniques to increase the efficacy of heterogeneous networked environments for computational aerosciences. Our work has been based upon the NAS Parallel Benchmark suite, but has also recently expanded in scope to include the NAS I/O benchmarks as specified in the NHT-1 document. In this report we summarize our research accomplishments under the auspices of the grant.

  6. Computational Science at the Argonne Leadership Computing Facility

    NASA Astrophysics Data System (ADS)

    Romero, Nichols

    2014-03-01

    The goal of the Argonne Leadership Computing Facility (ALCF) is to extend the frontiers of science by solving problems that require innovative approaches and the largest-scale computing systems. ALCF's most powerful computer - Mira, an IBM Blue Gene/Q system - has nearly one million cores. How does one program such systems? What software tools are available? Which scientific and engineering applications are able to utilize such levels of parallelism? This talk will address these questions and describe a sampling of projects that are using ALCF systems in their research, including ones in nanoscience, materials science, and chemistry. Finally, the ways to gain access to ALCF resources will be presented. This research used resources of the Argonne Leadership Computing Facility at Argonne National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under contract DE-AC02-06CH11357.

  7. Distributed GPU Computing in GIScience

    NASA Astrophysics Data System (ADS)

    Jiang, Y.; Yang, C.; Huang, Q.; Li, J.; Sun, M.

    2013-12-01

    Geoscientists strived to discover potential principles and patterns hidden inside ever-growing Big Data for scientific discoveries. To better achieve this objective, more capable computing resources are required to process, analyze and visualize Big Data (Ferreira et al., 2003; Li et al., 2013). Current CPU-based computing techniques cannot promptly meet the computing challenges caused by increasing amount of datasets from different domains, such as social media, earth observation, environmental sensing (Li et al., 2013). Meanwhile CPU-based computing resources structured as cluster or supercomputer is costly. In the past several years with GPU-based technology matured in both the capability and performance, GPU-based computing has emerged as a new computing paradigm. Compare to traditional computing microprocessor, the modern GPU, as a compelling alternative microprocessor, has outstanding high parallel processing capability with cost-effectiveness and efficiency(Owens et al., 2008), although it is initially designed for graphical rendering in visualization pipe. This presentation reports a distributed GPU computing framework for integrating GPU-based computing within distributed environment. Within this framework, 1) for each single computer, computing resources of both GPU-based and CPU-based can be fully utilized to improve the performance of visualizing and processing Big Data; 2) within a network environment, a variety of computers can be used to build up a virtual super computer to support CPU-based and GPU-based computing in distributed computing environment; 3) GPUs, as a specific graphic targeted device, are used to greatly improve the rendering efficiency in distributed geo-visualization, especially for 3D/4D visualization. Key words: Geovisualization, GIScience, Spatiotemporal Studies Reference : 1. Ferreira de Oliveira, M. C., & Levkowitz, H. (2003). From visual data exploration to visual data mining: A survey. Visualization and Computer Graphics, IEEE

  8. BESIII production with distributed computing

    NASA Astrophysics Data System (ADS)

    Zhang, X. M.; Yan, T.; Zhao, X. H.; Ma, Z. T.; Yan, X. F.; Lin, T.; Deng, Z. Y.; Li, W. D.; Belov, S.; Pelevanyuk, I.; Zhemchugov, A.; Cai, H.

    2015-12-01

    Distributed computing is necessary nowadays for high energy physics experiments to organize heterogeneous computing resources all over the world to process enormous amounts of data. The BESIII experiment in China, has established its own distributed computing system, based on DIRAC, as a supplement to local clusters, collecting cluster, grid, desktop and cloud resources from collaborating member institutes around the world. The system consists of workload management and data management to deal with the BESIII Monte Carlo production workflow in a distributed environment. A dataset-based data transfer system has been developed to support data movements among sites. File and metadata management tools and a job submission frontend have been developed to provide a virtual layer for BESIII physicists to use distributed resources. Moreover, the paper shows the experience to cope with lack of grid experience and low manpower among the BESIII community.

  9. Oak Ridge Leadership Computing Facility Position Paper

    SciTech Connect

    Oral, H Sarp; Hill, Jason J; Thach, Kevin G; Podhorszki, Norbert; Klasky, Scott A; Rogers, James H; Shipman, Galen M

    2011-01-01

    This paper discusses the business, administration, reliability, and usability aspects of storage systems at the Oak Ridge Leadership Computing Facility (OLCF). The OLCF has developed key competencies in architecting and administration of large-scale Lustre deployments as well as HPSS archival systems. Additionally as these systems are architected, deployed, and expanded over time reliability and availability factors are a primary driver. This paper focuses on the implementation of the Spider parallel Lustre file system as well as the implementation of the HPSS archive at the OLCF.

  10. Distributed computing at the SSCL

    SciTech Connect

    Cormell, L.; White, R.

    1993-05-01

    The rapid increase in the availability of high performance, cost- effective RISC/UNIX workstations has been both a blessing and a curse. The blessing of having extremely powerful computing engines available on the desk top is well-known to many users. The user has tremendous freedom, flexibility, and control of his environment. That freedom can, however, become the curse of distributed computing. The user must become a system manager to some extent, he must worry about backups, maintenance, upgrades, etc. Traditionally these activities have been the responsibility of a central computing group. The central computing group, however, may find that it can no linger provide all of the traditional services. With the plethora of workstations now found on so many desktops throughout the entire campus or lab, the central computing group may be swamped by support requests. This talk will address several of these computer support and management issues by discussing the approach taken at the Superconducting Super Collider Laboratory. In addition, a brief review of the future directions of commercial products for distributed computing and management will be given.

  11. Computing spatial information from Fourier coefficient distributions.

    PubMed

    Heinz, William F; Werbin, Jeffrey L; Lattman, Eaton; Hoh, Jan H

    2011-05-01

    The spatial relationships between molecules can be quantified in terms of information. In the case of membranes, the spatial organization of molecules in a bilayer is closely related to biophysically and biologically important properties. Here, we present an approach to computing spatial information based on Fourier coefficient distributions. The Fourier transform (FT) of an image contains a complete description of the image, and the values of the FT coefficients are uniquely associated with that image. For an image where the distribution of pixels is uncorrelated, the FT coefficients are normally distributed and uncorrelated. Further, the probability distribution for the FT coefficients of such an image can readily be obtained by Parseval's theorem. We take advantage of these properties to compute the spatial information in an image by determining the probability of each coefficient (both real and imaginary parts) in the FT, then using the Shannon formalism to calculate information. By using the probability distribution obtained from Parseval's theorem, an effective distance from the uncorrelated or most uncertain case is obtained. The resulting quantity is an information computed in k-space (kSI). This approach provides a robust, facile and highly flexible framework for quantifying spatial information in images and other types of data (of arbitrary dimensions). The kSI metric is tested on a 2D Ising model, frequently used as a model for lipid bilayer; and the temperature-dependent phase transition is accurately determined from the spatial information in configurations of the system.

  12. A distributed data base management facility for the CAD/CAM environment

    NASA Technical Reports Server (NTRS)

    Balza, R. M.; Beaudet, R. W.; Johnson, H. R.

    1984-01-01

    Current/PAD research in the area of distributed data base management considers facilities for supporting CAD/CAM data management in a heterogeneous network of computers encompassing multiple data base managers supporting a variety of data models. These facilities include coordinated execution of multiple DBMSs to provide for administration of and access to data distributed across them.

  13. Particle Size Distribution in Aluminum Manufacturing Facilities

    PubMed Central

    Liu, Sa; Noth, Elizabeth M.; Dixon-Ernst, Christine; Eisen, Ellen A.; Cullen, Mark R.; Hammond, S. Katharine

    2015-01-01

    As part of exposure assessment for an ongoing epidemiologic study of heart disease and fine particle exposures in aluminum industry, area particle samples were collected in production facilities to assess instrument reliability and particle size distribution at different process areas. Personal modular impactors (PMI) and Minimicro-orifice uniform deposition impactors (MiniMOUDI) were used. The coefficient of variation (CV) of co-located samples was used to evaluate the reproducibility of the samplers. PM2.5 measured by PMI was compared to PM2.5 calculated from MiniMOUDI data. Mass median aerodynamic diameter (MMAD) and concentrations of sub-micrometer (PM1.0) and quasi-ultrafine (PM0.56) particles were evaluated to characterize particle size distribution. Most of CVs were less than 30%. The slope of the linear regression of PMI_PM2.5 versus MiniMOUDI_PM2.5 was 1.03 mg/m3 per mg/m3 (± 0.05), with correlation coefficient of 0.97 (± 0.01). Particle size distribution varied substantively in smelters, whereas it was less variable in fabrication units with significantly smaller MMADs (arithmetic mean of MMADs: 2.59 μm in smelters vs. 1.31 μm in fabrication units, p = 0.001). Although the total particle concentration was more than two times higher in the smelters than in the fabrication units, the fraction of PM10 which was PM1.0 or PM0.56 was significantly lower in the smelters than in the fabrication units (p < 0.001). Consequently, the concentrations of sub-micrometer and quasi-ultrafine particles were similar in these two types of facilities. It would appear, studies evaluating ultrafine particle exposure in aluminum industry should focus on not only the smelters, but also the fabrication facilities. PMID:26478760

  14. Parallel distributed computing using Python

    NASA Astrophysics Data System (ADS)

    Dalcin, Lisandro D.; Paz, Rodrigo R.; Kler, Pablo A.; Cosimo, Alejandro

    2011-09-01

    This work presents two software components aimed to relieve the costs of accessing high-performance parallel computing resources within a Python programming environment: MPI for Python and PETSc for Python. MPI for Python is a general-purpose Python package that provides bindings for the Message Passing Interface (MPI) standard using any back-end MPI implementation. Its facilities allow parallel Python programs to easily exploit multiple processors using the message passing paradigm. PETSc for Python provides access to the Portable, Extensible Toolkit for Scientific Computation (PETSc) libraries. Its facilities allow sequential and parallel Python applications to exploit state of the art algorithms and data structures readily available in PETSc for the solution of large-scale problems in science and engineering. MPI for Python and PETSc for Python are fully integrated to PETSc-FEM, an MPI and PETSc based parallel, multiphysics, finite elements code developed at CIMEC laboratory. This software infrastructure supports research activities related to simulation of fluid flows with applications ranging from the design of microfluidic devices for biochemical analysis to modeling of large-scale stream/aquifer interactions.

  15. Towards an Infrastructure for MLS Distributed Computing

    DTIC Science & Technology

    1998-01-01

    Distributed computing owes its success to the development of infrastructure, middleware, and standards (e.g., CORBA) by the computing industry. This...Government must protect national security information against unauthorized information flow. To support MLS distributed computing , a MLS infrastructure...protection of classified information and use both the emerging distributed computing and commercial security infrastructures. The resulting infrastructure

  16. Apollo experience report: Real-time auxiliary computing facility development

    NASA Technical Reports Server (NTRS)

    Allday, C. E.

    1972-01-01

    The Apollo real time auxiliary computing function and facility were an extension of the facility used during the Gemini Program. The facility was expanded to include support of all areas of flight control, and computer programs were developed for mission and mission-simulation support. The scope of the function was expanded to include prime mission support functions in addition to engineering evaluations, and the facility became a mandatory mission support facility. The facility functioned as a full scale mission support activity until after the first manned lunar landing mission. After the Apollo 11 mission, the function and facility gradually reverted to a nonmandatory, offline, on-call operation because the real time program flexibility was increased and verified sufficiently to eliminate the need for redundant computations. The evaluation of the facility and function and recommendations for future programs are discussed in this report.

  17. Distributed Computing in Universities and Colleges.

    ERIC Educational Resources Information Center

    Sircar, Sumit

    1979-01-01

    Analyzes the implications of distributed computing in institutions of higher education. Discusses (1) the extent to which the quality of computing might be enhanced by adopting a distributed computing approach, (2) variations in distributed systems design and the cost of adoption, and (3) administration of distributed systems. (Author/CMV)

  18. National Ignition Facility integrated computer control system

    SciTech Connect

    Van Arsdall, P.J., LLNL

    1998-06-01

    The NIF design team is developing the Integrated Computer Control System (ICCS), which is based on an object-oriented software framework applicable to event-driven control systems. The framework provides an open, extensible architecture that is sufficiently abstract to construct future mission-critical control systems. The ICCS will become operational when the first 8 out of 192 beams are activated in mid 2000. The ICCS consists of 300 front-end processors attached to 60,000 control points coordinated by a supervisory system. Computers running either Solaris or VxWorks are networked over a hybrid configuration of switched fast Ethernet and asynchronous transfer mode (ATM). ATM carries digital motion video from sensors to operator consoles. Supervisory software is constructed by extending the reusable framework components for each specific application. The framework incorporates services for database persistence, system configuration, graphical user interface, status monitoring, event logging, scripting language, alert management, and access control. More than twenty collaborating software applications are derived from the common framework. The framework is interoperable among different kinds of computers and functions as a plug-in software bus by leveraging a common object request brokering architecture (CORBA). CORBA transparently distributes the software objects across the network. Because of the pivotal role played, CORBA was tested to ensure adequate performance.

  19. National Ignition Facility integrated computer control system

    NASA Astrophysics Data System (ADS)

    Van Arsdall, Paul J.; Bettenhausen, R. C.; Holloway, Frederick W.; Saroyan, R. A.; Woodruff, J. P.

    1999-07-01

    The NIF design team is developing the Integrated Computer Control System (ICCS), which is based on an object-oriented software framework applicable to event-driven control system. The framework provides an open, extensive architecture that is sufficiently abstract to construct future mission-critical control systems. The ICCS will become operational when the first 8 out of 192 beams are activated in mid 2000. THe ICCS consists of 300 front-end processors attached to 60,000 control points coordinated by a supervisory system. Computers running either Solaris or VxWorks are networked over a hybrid configuration of switched fast Ethernet and asynchronous transfer mode (ATM). ATM carries digital motion video from sensor to operator consoles. Supervisory software is constructed by extending the reusable framework components for each specific application. The framework incorporates services for database persistence, system configuration, graphical user interface, status monitoring, event logging, scripting language, alert management, and access control. More than twenty collaborating software applications are derived from the common framework. The framework is interoperable among different kinds of computers and functions as a plug-in software bus by leveraging a common object request brokering architecture (CORBA). CORBA transparently distributes the software objects across the network. Because of the pivotal role played, CORBA was tested to ensure adequate performance.

  20. Overlapping clusters for distributed computation.

    SciTech Connect

    Mirrokni, Vahab; Andersen, Reid; Gleich, David F.

    2010-11-01

    Scalable, distributed algorithms must address communication problems. We investigate overlapping clusters, or vertex partitions that intersect, for graph computations. This setup stores more of the graph than required but then affords the ease of implementation of vertex partitioned algorithms. Our hope is that this technique allows us to reduce communication in a computation on a distributed graph. The motivation above draws on recent work in communication avoiding algorithms. Mohiyuddin et al. (SC09) design a matrix-powers kernel that gives rise to an overlapping partition. Fritzsche et al. (CSC2009) develop an overlapping clustering for a Schwarz method. Both techniques extend an initial partitioning with overlap. Our procedure generates overlap directly. Indeed, Schwarz methods are commonly used to capitalize on overlap. Elsewhere, overlapping communities (Ahn et al, Nature 2009; Mishra et al. WAW2007) are now a popular model of structure in social networks. These have long been studied in statistics (Cole and Wishart, CompJ 1970). We present two types of results: (i) an estimated swapping probability {rho}{infinity}; and (ii) the communication volume of a parallel PageRank solution (link-following {alpha} = 0.85) using an additive Schwarz method. The volume ratio is the amount of extra storage for the overlap (2 means we store the graph twice). Below, as the ratio increases, the swapping probability and PageRank communication volume decreases.

  1. Computer Profile of School Facilities Energy Consumption.

    ERIC Educational Resources Information Center

    Oswalt, Felix E.

    This document outlines a computerized management tool designed to enable building managers to identify energy consumption as related to types and uses of school facilities for the purpose of evaluating and managing the operation, maintenance, modification, and planning of new facilities. Specifically, it is expected that the statistics generated…

  2. Cooperative Fault Tolerant Distributed Computing

    SciTech Connect

    Fagg, Graham E.

    2006-03-15

    HARNESS was proposed as a system that combined the best of emerging technologies found in current distributed computing research and commercial products into a very flexible, dynamically adaptable framework that could be used by applications to allow them to evolve and better handle their execution environment. The HARNESS system was designed using the considerable experience from previous projects such as PVM, MPI, IceT and Cumulvs. As such, the system was designed to avoid any of the common problems found with using these current systems, such as no single point of failure, ability to survive machine, node and software failures. Additional features included improved inter-component connectivity, with full support for dynamic down loading of addition components at run-time thus reducing the stress on application developers to build in all the libraries they need in advance.

  3. A comparison of queueing, cluster and distributed computing systems

    NASA Technical Reports Server (NTRS)

    Kaplan, Joseph A.; Nelson, Michael L.

    1993-01-01

    Using workstation clusters for distributed computing has become popular with the proliferation of inexpensive, powerful workstations. Workstation clusters offer both a cost effective alternative to batch processing and an easy entry into parallel computing. However, a number of workstations on a network does not constitute a cluster. Cluster management software is necessary to harness the collective computing power. A variety of cluster management and queuing systems are compared: Distributed Queueing Systems (DQS), Condor, Load Leveler, Load Balancer, Load Sharing Facility (LSF - formerly Utopia), Distributed Job Manager (DJM), Computing in Distributed Networked Environments (CODINE), and NQS/Exec. The systems differ in their design philosophy and implementation. Based on published reports on the different systems and conversations with the system's developers and vendors, a comparison of the systems are made on the integral issues of clustered computing.

  4. Performance of the ISIS Distributed Computing Toolkit

    DTIC Science & Technology

    1994-06-22

    Best Available Copy .. A a ~ d ~ . 1) - . Fs’A aiaer rnrgC"opyr~IL tI.ru~ Performance of the ISIS Distributed Computing Toolkit* Kenneth P. Birman...isis.com. Please cite as Technical Report TR-94-1432, Dept. of Computer Science, Cornell University. Performance of the Isis Distributed Computing Toolkit... Distributed computing , performance, process groups, atomic broadcast, causal and total message ordering, cbcast, abcast, multiple process groups

  5. Deadlock Detection in Distributed Computing Systems.

    DTIC Science & Technology

    1982-06-01

    With the advent of distributed computing systems, the problem of deadlock, which has been essentially solved for centralized computing systems, has...reappeared. Existing centralized deadlock detection techniques are either too expensive or they do not work correctly in distributed computing systems...incorrect. Additionally, although fault-tolerance is usually listed as an advantage of distributed computing systems, little has been done to analyze

  6. High Performance Computing Facility Operational Assessment, CY 2011 Oak Ridge Leadership Computing Facility

    SciTech Connect

    Baker, Ann E; Barker, Ashley D; Bland, Arthur S Buddy; Boudwin, Kathlyn J.; Hack, James J; Kendall, Ricky A; Messer, Bronson; Rogers, James H; Shipman, Galen M; Wells, Jack C; White, Julia C; Hudson, Douglas L

    2012-02-01

    Oak Ridge National Laboratory's Leadership Computing Facility (OLCF) continues to deliver the most powerful resources in the U.S. for open science. At 2.33 petaflops peak performance, the Cray XT Jaguar delivered more than 1.4 billion core hours in calendar year (CY) 2011 to researchers around the world for computational simulations relevant to national and energy security; advancing the frontiers of knowledge in physical sciences and areas of biological, medical, environmental, and computer sciences; and providing world-class research facilities for the nation's science enterprise. Users reported more than 670 publications this year arising from their use of OLCF resources. Of these we report the 300 in this review that are consistent with guidance provided. Scientific achievements by OLCF users cut across all range scales from atomic to molecular to large-scale structures. At the atomic scale, researchers discovered that the anomalously long half-life of Carbon-14 can be explained by calculating, for the first time, the very complex three-body interactions between all the neutrons and protons in the nucleus. At the molecular scale, researchers combined experimental results from LBL's light source and simulations on Jaguar to discover how DNA replication continues past a damaged site so a mutation can be repaired later. Other researchers combined experimental results from ORNL's Spallation Neutron Source and simulations on Jaguar to reveal the molecular structure of ligno-cellulosic material used in bioethanol production. This year, Jaguar has been used to do billion-cell CFD calculations to develop shock wave compression turbo machinery as a means to meet DOE goals for reducing carbon sequestration costs. General Electric used Jaguar to calculate the unsteady flow through turbo machinery to learn what efficiencies the traditional steady flow assumption is hiding from designers. Even a 1% improvement in turbine design can save the nation billions of gallons of

  7. On Deadlock Detection in Distributed Computing Systems.

    DTIC Science & Technology

    1983-04-01

    With the advent of distributed computing systems, the problem of deadlock, which has been essentially solved for centralized computing systems, has...reappeared. Existing centralized deadlock detection techniques are either too expensive or they do not work correctly in distributed computing systems

  8. A Different Look at Secure Distributed Computation

    DTIC Science & Technology

    1997-06-01

    9, 12]. Still, the worst-case view dominates the secure computing literature in general and the secure distributed computing literature in...The model we now suggest represents distributed computing as two or more interwoven networks of competing nodes. In 111 1997, pp. 109{115 the

  9. High Performance Computing Facility Operational Assessment 2015: Oak Ridge Leadership Computing Facility

    SciTech Connect

    Barker, Ashley D.; Bernholdt, David E.; Bland, Arthur S.; Gary, Jeff D.; Hack, James J.; McNally, Stephen T.; Rogers, James H.; Smith, Brian E.; Straatsma, T. P.; Sukumar, Sreenivas Rangan; Thach, Kevin G.; Tichenor, Suzy; Vazhkudai, Sudharshan S.; Wells, Jack C.

    2016-03-01

    Oak Ridge National Laboratory’s (ORNL’s) Leadership Computing Facility (OLCF) continues to surpass its operational target goals: supporting users; delivering fast, reliable systems; creating innovative solutions for high-performance computing (HPC) needs; and managing risks, safety, and security aspects associated with operating one of the most powerful computers in the world. The results can be seen in the cutting-edge science delivered by users and the praise from the research community. Calendar year (CY) 2015 was filled with outstanding operational results and accomplishments: a very high rating from users on overall satisfaction that ties the highest-ever mark set in CY 2014; the greatest number of core-hours delivered to research projects; the largest percentage of capability usage since the OLCF began tracking the metric in 2009; and success in delivering on the allocation of 60, 30, and 10% of core hours offered for the INCITE (Innovative and Novel Computational Impact on Theory and Experiment), ALCC (Advanced Scientific Computing Research Leadership Computing Challenge), and Director’s Discretionary programs, respectively. These accomplishments, coupled with the extremely high utilization rate, represent the fulfillment of the promise of Titan: maximum use by maximum-size simulations. The impact of all of these successes and more is reflected in the accomplishments of OLCF users, with publications this year in notable journals Nature, Nature Materials, Nature Chemistry, Nature Physics, Nature Climate Change, ACS Nano, Journal of the American Chemical Society, and Physical Review Letters, as well as many others. The achievements included in the 2015 OLCF Operational Assessment Report reflect first-ever or largest simulations in their communities; for example Titan enabled engineers in Los Angeles and the surrounding region to design and begin building improved critical infrastructure by enabling the highest-resolution Cybershake map for Southern

  10. Computer Graphics Simulations of Sampling Distributions.

    ERIC Educational Resources Information Center

    Gordon, Florence S.; Gordon, Sheldon P.

    1989-01-01

    Describes the use of computer graphics simulations to enhance student understanding of sampling distributions that arise in introductory statistics. Highlights include the distribution of sample proportions, the distribution of the difference of sample means, the distribution of the difference of sample proportions, and the distribution of sample…

  11. High Performance Computing Facility Operational Assessment, FY 2010 Oak Ridge Leadership Computing Facility

    SciTech Connect

    Bland, Arthur S Buddy; Hack, James J; Baker, Ann E; Barker, Ashley D; Boudwin, Kathlyn J.; Kendall, Ricky A; Messer, Bronson; Rogers, James H; Shipman, Galen M; White, Julia C

    2010-08-01

    Oak Ridge National Laboratory's (ORNL's) Cray XT5 supercomputer, Jaguar, kicked off the era of petascale scientific computing in 2008 with applications that sustained more than a thousand trillion floating point calculations per second - or 1 petaflop. Jaguar continues to grow even more powerful as it helps researchers broaden the boundaries of knowledge in virtually every domain of computational science, including weather and climate, nuclear energy, geosciences, combustion, bioenergy, fusion, and materials science. Their insights promise to broaden our knowledge in areas that are vitally important to the Department of Energy (DOE) and the nation as a whole, particularly energy assurance and climate change. The science of the 21st century, however, will demand further revolutions in computing, supercomputers capable of a million trillion calculations a second - 1 exaflop - and beyond. These systems will allow investigators to continue attacking global challenges through modeling and simulation and to unravel longstanding scientific questions. Creating such systems will also require new approaches to daunting challenges. High-performance systems of the future will need to be codesigned for scientific and engineering applications with best-in-class communications networks and data-management infrastructures and teams of skilled researchers able to take full advantage of these new resources. The Oak Ridge Leadership Computing Facility (OLCF) provides the nation's most powerful open resource for capability computing, with a sustainable path that will maintain and extend national leadership for DOE's Office of Science (SC). The OLCF has engaged a world-class team to support petascale science and to take a dramatic step forward, fielding new capabilities for high-end science. This report highlights the successful delivery and operation of a petascale system and shows how the OLCF fosters application development teams, developing cutting-edge tools and resources for next

  12. Spatial Distribution Characteristics of Healthcare Facilities in Nanjing: Network Point Pattern Analysis and Correlation Analysis

    PubMed Central

    Ni, Jianhua; Qian, Tianlu; Xi, Changbai; Rui, Yikang; Wang, Jiechen

    2016-01-01

    The spatial distribution of urban service facilities is largely constrained by the road network. In this study, network point pattern analysis and correlation analysis were used to analyze the relationship between road network and healthcare facility distribution. The weighted network kernel density estimation method proposed in this study identifies significant differences between the outside and inside areas of the Ming city wall. The results of network K-function analysis show that private hospitals are more evenly distributed than public hospitals, and pharmacy stores tend to cluster around hospitals along the road network. After computing the correlation analysis between different categorized hospitals and street centrality, we find that the distribution of these hospitals correlates highly with the street centralities, and that the correlations are higher with private and small hospitals than with public and large hospitals. The comprehensive analysis results could help examine the reasonability of existing urban healthcare facility distribution and optimize the location of new healthcare facilities. PMID:27548197

  13. Spatial Distribution Characteristics of Healthcare Facilities in Nanjing: Network Point Pattern Analysis and Correlation Analysis.

    PubMed

    Ni, Jianhua; Qian, Tianlu; Xi, Changbai; Rui, Yikang; Wang, Jiechen

    2016-08-18

    The spatial distribution of urban service facilities is largely constrained by the road network. In this study, network point pattern analysis and correlation analysis were used to analyze the relationship between road network and healthcare facility distribution. The weighted network kernel density estimation method proposed in this study identifies significant differences between the outside and inside areas of the Ming city wall. The results of network K-function analysis show that private hospitals are more evenly distributed than public hospitals, and pharmacy stores tend to cluster around hospitals along the road network. After computing the correlation analysis between different categorized hospitals and street centrality, we find that the distribution of these hospitals correlates highly with the street centralities, and that the correlations are higher with private and small hospitals than with public and large hospitals. The comprehensive analysis results could help examine the reasonability of existing urban healthcare facility distribution and optimize the location of new healthcare facilities.

  14. Solving the Quadratic Capacitated Facilities Location Problem by Computer.

    ERIC Educational Resources Information Center

    Cote, Leon C.; Smith, Wayland P.

    Several computer programs were developed to solve various versions of the quadratic capacitated facilities location problem. Matrices, which represent various business costs, are defined for the factors of sites, facilities, customers, commodities, and production units. The objective of the program is to find an optimization matrix for the lowest…

  15. National remote computational flight research facility

    NASA Technical Reports Server (NTRS)

    Rediess, Herman A.

    1989-01-01

    The extension of the NASA Ames-Dryden remotely augmented vehicle (RAV) facility to accommodate flight testing of a hypersonic aircraft utilizing the continental United States as a test range is investigated. The development and demonstration of an automated flight test management system (ATMS) that uses expert system technology for flight test planning, scheduling, and execution is documented.

  16. Parallel and Distributed Computing Combinatorial Algorithms

    DTIC Science & Technology

    1993-10-01

    FUPNDKC %2,•, PARALLEL AND DISTRIBUTED COMPUTING COMBINATORIAL ALGORITHMS 6. AUTHOR(S) 2304/DS F49620-92-J-0125 DR. LEIGHTON 7 PERFORMING ORGANIZATION NAME...on several problems involving parallel and distributed computing and combinatorial optimization. This research is reported in the numerous papers that...network decom- position. In Proceedings of the Eleventh Annual ACM Symposium on Principles of Distributed Computing , August 1992. [15] B. Awerbuch, B

  17. Modular Programming Techniques for Distributed Computing Tasks

    DTIC Science & Technology

    2004-08-01

    Modular Programming Techniques for Distributed Computing Tasks Anthony Cowley, Hwa-Chow Hsu, Camillo J. Taylor GRASP Laboratory University of...network, distributed computing , software design 1. INTRODUCTION As efforts to field sensor networks, or teams of mobile robots, become more...TITLE AND SUBTITLE Modular Programming Techniques for Distributed Computing Tasks 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

  18. Distributed Computing Environment for Mine Warfare Command

    DTIC Science & Technology

    1993-06-01

    AD-A268 799 j -•111lllli UliilllI ME ii El UU NAVAL POSTGRADUATE SCHOOL Monterey, California DTIC V4 * cLP i0 1993 RA THESIS DISTRIBUTED COMPUTING ENVIRONMENT...Project No [Task No lWork Unit Accession 1 -1 No 11 Title (include security classification) DISTRIBUTED COMPUTING ENVIRONMENT FOR MINE WARFARE COMMAND 12... DISTRIBUTED COMPUTING ..... .. 26 A. STANDARDS FOR OPEN SYSTEMS ... .......... 27 1. OSI Model .......... ................. 28 2. DOD Model

  19. LaRC local area networks to support distributed computing

    NASA Technical Reports Server (NTRS)

    Riddle, E. P.

    1984-01-01

    The Langley Research Center's (LaRC) Local Area Network (LAN) effort is discussed. LaRC initiated the development of a LAN to support a growing distributed computing environment at the Center. The purpose of the network is to provide an improved capability (over inteactive and RJE terminal access) for sharing multivendor computer resources. Specifically, the network will provide a data highway for the transfer of files between mainframe computers, minicomputers, work stations, and personal computers. An important influence on the overall network design was the vital need of LaRC researchers to efficiently utilize the large CDC mainframe computers in the central scientific computing facility. Although there was a steady migration from a centralized to a distributed computing environment at LaRC in recent years, the work load on the central resources increased. Major emphasis in the network design was on communication with the central resources within the distributed environment. The network to be implemented will allow researchers to utilize the central resources, distributed minicomputers, work stations, and personal computers to obtain the proper level of computing power to efficiently perform their jobs.

  20. Configuration and Management of a Cluster Computing Facility in Undergraduate Student Computer Laboratories

    ERIC Educational Resources Information Center

    Cornforth, David; Atkinson, John; Spennemann, Dirk H. R.

    2006-01-01

    Purpose: Many researchers require access to computer facilities beyond those offered by desktop workstations. Traditionally, these are offered either through partnerships, to share the cost of supercomputing facilities, or through purpose-built cluster facilities. However, funds are not always available to satisfy either of these options, and…

  1. Review of Test Facilities for Distributed Energy Resources

    SciTech Connect

    AKHIL,ABBAS ALI; MARNAY,CHRIS; KIPMAN,TIMOTHY

    2003-05-01

    Since initiating research on integration of distributed energy resources (DER) in 1999, the Consortium for Electric Reliability Technology Solutions (CERTS) has been actively assessing and reviewing existing DER test facilities for possible demonstrations of advanced DER system integration concepts. This report is a compendium of information collected by the CERTS team on DER test facilities during this period.

  2. Distribution of Corbicula fluminea at nuclear facilities

    SciTech Connect

    Counts, C.L. III

    1985-11-01

    A review of the zoogeographic records for the exotic Asian clam, Corbicula fluminea (Muller, 1774), reveals its presence in 27 states where nuclear powered electric generating plants are either operating or under construction. Nineteen plant sites reported infestation of varying severity in facilities, or source water bodies immediately adjacent to the facility, by C. fluminea. Thirteen plant sites are located within the zoogeographic limits of C. fluminea but have a low risk of infestation due to either salt water cooling systems or locations a great distance from known populations. Eighteen plant sites are located wholly outside of the known zoogeographic range of C. fluminea. Thirty plant sites are located in close proximity to known populations of C. fluminea and therefore should maintain surveillance of the source water body and within plant water systems for possible infestations by these bivalves. 27 figs.

  3. Distributed Computing at Belle II

    NASA Astrophysics Data System (ADS)

    Bansal, Vikas; Belle Collaboration, II

    2016-03-01

    The Belle II experiment at the SuperKEKB collider in Tsukuba, Japan, will start physics data taking in 2018 and will accumulate 50 ab-1 of e+e- collision data, about 50 times larger than the data set of the earlier Belle experiment. The computing requirements of Belle II are comparable to those of a RUN I high-pT LHC experiment. Computing will make full use of high speed networking and of the Computing Grids in North America, Asia and Europe. Results of an initial MC simulation campaign with 5 ab-1 equivalent luminosity will be described.

  4. Biomedical computing facility interface design plan

    NASA Technical Reports Server (NTRS)

    Puckett, R. D.

    1971-01-01

    The results are presented of a design study performed to establish overall system interface requirements for the Biomedical Laboratories Division's Sigma-3 computer system. Emphasis has been placed upon the definition of an overall implementation plan and associated schedule to meet both near-term and long-range requirements within the constraints at available resources.

  5. Distributed computing and nuclear reactor analysis

    SciTech Connect

    Brown, F.B.; Derstine, K.L.; Blomquist, R.N.

    1994-03-01

    Large-scale scientific and engineering calculations for nuclear reactor analysis can now be carried out effectively in a distributed computing environment, at costs far lower than for traditional mainframes. The distributed computing environment must include support for traditional system services, such as a queuing system for batch work, reliable filesystem backups, and parallel processing capabilities for large jobs. All ANL computer codes for reactor analysis have been adapted successfully to a distributed system based on workstations and X-terminals. Distributed parallel processing has been demonstrated to be effective for long-running Monte Carlo calculations.

  6. High Performance Computing Facility Operational Assessment, FY 2011 Oak Ridge Leadership Computing Facility

    SciTech Connect

    Baker, Ann E; Bland, Arthur S Buddy; Hack, James J; Barker, Ashley D; Boudwin, Kathlyn J.; Kendall, Ricky A; Messer, Bronson; Rogers, James H; Shipman, Galen M; Wells, Jack C; White, Julia C

    2011-08-01

    Oak Ridge National Laboratory's Leadership Computing Facility (OLCF) continues to deliver the most powerful resources in the U.S. for open science. At 2.33 petaflops peak performance, the Cray XT Jaguar delivered more than 1.5 billion core hours in calendar year (CY) 2010 to researchers around the world for computational simulations relevant to national and energy security; advancing the frontiers of knowledge in physical sciences and areas of biological, medical, environmental, and computer sciences; and providing world-class research facilities for the nation's science enterprise. Scientific achievements by OLCF users range from collaboration with university experimentalists to produce a working supercapacitor that uses atom-thick sheets of carbon materials to finely determining the resolution requirements for simulations of coal gasifiers and their components, thus laying the foundation for development of commercial-scale gasifiers. OLCF users are pushing the boundaries with software applications sustaining more than one petaflop of performance in the quest to illuminate the fundamental nature of electronic devices. Other teams of researchers are working to resolve predictive capabilities of climate models, to refine and validate genome sequencing, and to explore the most fundamental materials in nature - quarks and gluons - and their unique properties. Details of these scientific endeavors - not possible without access to leadership-class computing resources - are detailed in Section 4 of this report and in the INCITE in Review. Effective operations of the OLCF play a key role in the scientific missions and accomplishments of its users. This Operational Assessment Report (OAR) will delineate the policies, procedures, and innovations implemented by the OLCF to continue delivering a petaflop-scale resource for cutting-edge research. The 2010 operational assessment of the OLCF yielded recommendations that have been addressed (Reference Section 1) and where

  7. Next generation distributed computing for cancer research.

    PubMed

    Agarwal, Pankaj; Owzar, Kouros

    2014-01-01

    Advances in next generation sequencing (NGS) and mass spectrometry (MS) technologies have provided many new opportunities and angles for extending the scope of translational cancer research while creating tremendous challenges in data management and analysis. The resulting informatics challenge is invariably not amenable to the use of traditional computing models. Recent advances in scalable computing and associated infrastructure, particularly distributed computing for Big Data, can provide solutions for addressing these challenges. In this review, the next generation of distributed computing technologies that can address these informatics problems is described from the perspective of three key components of a computational platform, namely computing, data storage and management, and networking. A broad overview of scalable computing is provided to set the context for a detailed description of Hadoop, a technology that is being rapidly adopted for large-scale distributed computing. A proof-of-concept Hadoop cluster, set up for performance benchmarking of NGS read alignment, is described as an example of how to work with Hadoop. Finally, Hadoop is compared with a number of other current technologies for distributed computing.

  8. Next Generation Distributed Computing for Cancer Research

    PubMed Central

    Agarwal, Pankaj; Owzar, Kouros

    2014-01-01

    Advances in next generation sequencing (NGS) and mass spectrometry (MS) technologies have provided many new opportunities and angles for extending the scope of translational cancer research while creating tremendous challenges in data management and analysis. The resulting informatics challenge is invariably not amenable to the use of traditional computing models. Recent advances in scalable computing and associated infrastructure, particularly distributed computing for Big Data, can provide solutions for addressing these challenges. In this review, the next generation of distributed computing technologies that can address these informatics problems is described from the perspective of three key components of a computational platform, namely computing, data storage and management, and networking. A broad overview of scalable computing is provided to set the context for a detailed description of Hadoop, a technology that is being rapidly adopted for large-scale distributed computing. A proof-of-concept Hadoop cluster, set up for performance benchmarking of NGS read alignment, is described as an example of how to work with Hadoop. Finally, Hadoop is compared with a number of other current technologies for distributed computing. PMID:25983539

  9. Task allocation in a distributed computing system

    NASA Technical Reports Server (NTRS)

    Seward, Walter D.

    1987-01-01

    A conceptual framework is examined for task allocation in distributed systems. Application and computing system parameters critical to task allocation decision processes are discussed. Task allocation techniques are addressed which focus on achieving a balance in the load distribution among the system's processors. Equalization of computing load among the processing elements is the goal. Examples of system performance are presented for specific applications. Both static and dynamic allocation of tasks are considered and system performance is evaluated using different task allocation methodologies.

  10. Expanding the Scope of High-Performance Computing Facilities

    SciTech Connect

    Uram, Thomas D.; Papka, Michael E.

    2016-05-01

    The high-performance computing centers of the future will expand their roles as service providers, and as the machines scale up, so should the sizes of the communities they serve. National facilities must cultivate their users as much as they focus on operating machines reliably. The authors present five interrelated topic areas that are essential to expanding the value provided to those performing computational science.

  11. A Software Rejuvenation Framework for Distributed Computing

    NASA Technical Reports Server (NTRS)

    Chau, Savio

    2009-01-01

    A performability-oriented conceptual framework for software rejuvenation has been constructed as a means of increasing levels of reliability and performance in distributed stateful computing. As used here, performability-oriented signifies that the construction of the framework is guided by the concept of analyzing the ability of a given computing system to deliver services with gracefully degradable performance. The framework is especially intended to support applications that involve stateful replicas of server computers.

  12. GRIMD: distributed computing for chemists and biologists

    PubMed Central

    Piotto, Stefano; Biasi, Luigi Di; Concilio, Simona; Castiglione, Aniello; Cattaneo, Giuseppe

    2014-01-01

    Motivation: Biologists and chemists are facing problems of high computational complexity that require the use of several computers organized in clusters or in specialized grids. Examples of such problems can be found in molecular dynamics (MD), in silico screening, and genome analysis. Grid Computing and Cloud Computing are becoming prevalent mainly because of their competitive performance/cost ratio. Regrettably, the diffusion of Grid Computing is strongly limited because two main limitations: it is confined to scientists with strong Computer Science background and the analyses of the large amount of data produced can be cumbersome it. We have developed a package named GRIMD to provide an easy and flexible implementation of distributed computing for the Bioinformatics community. GRIMD is very easy to install and maintain, and it does not require any specific Computer Science skill. Moreover, permits preliminary analysis on the distributed machines to reduce the amount of data to transfer. GRIMD is very flexible because it shields the typical computational biologist from the need to write specific code for tasks such as molecular dynamics or docking calculations. Furthermore, it permits an efficient use of GPU cards whenever is possible. GRIMD calculations scale almost linearly and, therefore, permits to exploit efficiently each machine in the network. Here, we provide few examples of grid computing in computational biology (MD and docking) and bioinformatics (proteome analysis). Availability GRIMD is available for free for noncommercial research at www.yadamp.unisa.it/grimd Supplementary information www.yadamp.unisa.it/grimd/howto.aspx PMID:24516326

  13. Object-oriented Tools for Distributed Computing

    NASA Technical Reports Server (NTRS)

    Adler, Richard M.

    1993-01-01

    Distributed computing systems are proliferating, owing to the availability of powerful, affordable microcomputers and inexpensive communication networks. A critical problem in developing such systems is getting application programs to interact with one another across a computer network. Remote interprogram connectivity is particularly challenging across heterogeneous environments, where applications run on different kinds of computers and operating systems. NetWorks! (trademark) is an innovative software product that provides an object-oriented messaging solution to these problems. This paper describes the design and functionality of NetWorks! and illustrates how it is being used to build complex distributed applications for NASA and in the commercial sector.

  14. The impact of distributed computing on education

    NASA Technical Reports Server (NTRS)

    Utku, S.; Lestingi, J.; Salama, M.

    1982-01-01

    In this paper, developments in digital computer technology since the early Fifties are reviewed briefly, and the parallelism which exists between these developments and developments in analysis and design procedures of structural engineering is identified. The recent trends in digital computer technology are examined in order to establish the fact that distributed processing is now an accepted philosophy for further developments. The impact of this on the analysis and design practices of structural engineering is assessed by first examining these practices from a data processing standpoint to identify the key operations and data bases, and then fitting them to the characteristics of distributed processing. The merits and drawbacks of the present philosophy in educating structural engineers are discussed and projections are made for the industry-academia relations in the distributed processing environment of structural analysis and design. An ongoing experiment of distributed computing in a university environment is described.

  15. Distribution analysis of airborne nicotine concentrations in hospitality facilities.

    PubMed

    Schorp, Matthias K; Leyden, Donald E

    2002-02-01

    A number of publications report statistical summaries for environmental tobacco smoke (ETS) concentrations. Despite compelling evidence for the data not being normally distributed, these publications typically report the arithmetic mean and standard deviation of the data, thereby losing important information related to the distribution of values contained in the original data. We were interested in the frequency distributions of reported nicotine concentrations in hospitality environments and subjected available data to distribution analyses. The distribution of experimental indoor airborne nicotine concentration data taken from hospitality facilities worldwide was fit to lognormal, Weibull, exponential, Pearson (Type V), logistic, and loglogistic distribution models. Comparison of goodness of fit (GOF) parameters and indications from the literature verified the selection of a lognormal distribution as the overall best model. When individual data were not reported in the literature, statistical summaries of results were used to model sets of lognormally distributed data that are intended to mimic the original data distribution. Grouping the data into various categories led to 31 frequency distributions that were further interpreted. The median values in nonsmoking environments are about half of the median values in smoking sections. When different continents are compared, Asian, European, and North American median values in restaurants are about a factor of three below levels encountered in other hospitality facilities. On a comparison of nicotine concentrations in North American smoking sections and nonsmoking sections, median values are about one-third of the European levels. The results obtained may be used to address issues related to exposure to ETS in the hospitality sector.

  16. Computation and Analysis of the Global Distribution of the Radioxenon Isotope 133Xe based on Emissions from Nuclear Power Plants and Radioisotope Production Facilities and its Relevance for the Verification of the Nuclear-Test-Ban Treaty

    NASA Astrophysics Data System (ADS)

    Wotawa, Gerhard; Becker, Andreas; Kalinowski, Martin; Saey, Paul; Tuma, Matthias; Zähringer, Matthias

    2010-05-01

    Monitoring of radioactive noble gases, in particular xenon isotopes, is a crucial element of the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The capability of the noble gas network, which is currently under construction, to detect signals from a nuclear explosion critically depends on the background created by other sources. Therefore, the global distribution of these isotopes based on emissions and transport patterns needs to be understood. A significant xenon background exists in the reactor regions of North America, Europe and Asia. An emission inventory of the four relevant xenon isotopes has recently been created, which specifies source terms for each power plant. As the major emitters of xenon isotopes worldwide, a few medical radioisotope production facilities have been recently identified, in particular the facilities in Chalk River (Canada), Fleurus (Belgium), Pelindaba (South Africa) and Petten (Netherlands). Emissions from these sites are expected to exceed those of the other sources by orders of magnitude. In this study, emphasis is put on 133Xe, which is the most prevalent xenon isotope. First, based on the emissions known, the resulting 133Xe concentration levels at all noble gas stations of the final CTBT verification network were calculated and found to be consistent with observations. Second, it turned out that emissions from the radioisotope facilities can explain a number of observed peaks, meaning that atmospheric transport modelling is an important tool for the categorization of measurements. Third, it became evident that Nuclear Power Plant emissions are more difficult to treat in the models, since their temporal variation is high and not generally reported. Fourth, there are indications that the assumed annual emissions may be underestimated by factors of two to ten, while the general emission patterns seem to be well understood. Finally, it became evident that 133Xe sources mainly influence the sensitivity of the

  17. Sandia Laboratories hybrid computer and motion simulator facilities

    SciTech Connect

    Curry, W. H.; French, R. E.

    1980-05-01

    Hybrid computer and motion simulator facilities at Sandia National Laboratories include an AD/FIVE-AD10-PDP11/60, an AD/FIVE-PDP11/45, an EAI7800-EAI640, an EAI580/TR48-Nova 800, and two Carco S-45OR-3/R-493A three-axis motion simulators. An EAI680 is used in the analog mode only. This report describes the current equipment.

  18. Cryogenic distribution for the Facility for Rare Isotope Beams

    SciTech Connect

    S. Jones, Dana Arenius, Adam Fila, P. Geutschow, Helmut Laumer, Matt Johnson, Cory S. Waltz, J. G. Weisend II

    2012-06-01

    The Facility for Rare Isotope Beams (FRIB) is a new National User Facility for nuclear science funded by the Department of Energy Office of Science and operated by Michigan State University. The FRIB accelerator linac consists of superconducting radio-frequency (SCRF) cavities operating at 2 K and SC magnets operating at 4.5 K all cooled by a large scale cryogenic refrigeration system. A major subsystem of the cryogenic system will be the distribution system whose primary components will include a distribution box, the transfer lines and the interconnect valve boxes at each cryogenic device. An overview of the conceptual design of the distribution system including engineering details, capabilities and schedule is described.

  19. Icing simulation: A survey of computer models and experimental facilities

    NASA Technical Reports Server (NTRS)

    Potapczuk, M. G.; Reinmann, J. J.

    1991-01-01

    A survey of the current methods for simulation of the response of an aircraft or aircraft subsystem to an icing encounter is presented. The topics discussed include a computer code modeling of aircraft icing and performance degradation, an evaluation of experimental facility simulation capabilities, and ice protection system evaluation tests in simulated icing conditions. Current research focussed on upgrading simulation fidelity of both experimental and computational methods is discussed. The need for increased understanding of the physical processes governing ice accretion, ice shedding, and iced airfoil aerodynamics is examined.

  20. Pattern recognition and massively distributed computing.

    PubMed

    Davies, E Keith; Glick, Meir; Harrison, Karl N; Richards, W Graham

    2002-12-01

    A feature of Peter Kollman's research was his exploitation of the latest computational techniques to devise novel applications of the free energy perturbation method. He would certainly have seized upon the opportunities offered by massively distributed computing. Here we describe the use of over a million personal computers to perform virtual screening of 3.5 billion druglike molecules against protein targets by pharmacophore pattern matching, together with other applications of pattern recognition such as docking ligands without any a priori knowledge about the binding site location.

  1. Molecular Science Computing Facility Scientific Challenges: Linking Across Scales

    SciTech Connect

    De Jong, Wibe A.; Windus, Theresa L.

    2005-07-01

    The purpose of this document is to define the evolving science drivers for performing environmental molecular research at the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL) and to provide guidance associated with the next-generation high-performance computing center that must be developed at EMSL's Molecular Science Computing Facility (MSCF) in order to address this critical research. The MSCF is the pre-eminent computing facility?supported by the U.S. Department of Energy's (DOE's) Office of Biological and Environmental Research (BER)?tailored to provide the fastest time-to-solution for current computational challenges in chemistry and biology, as well as providing the means for broad research in the molecular and environmental sciences. The MSCF provides integral resources and expertise to emerging EMSL Scientific Grand Challenges and Collaborative Access Teams that are designed to leverage the multiple integrated research capabilities of EMSL, thereby creating a synergy between computation and experiment to address environmental molecular science challenges critical to DOE and the nation.

  2. Great Expectations: Distributed Financial Computing at Cornell.

    ERIC Educational Resources Information Center

    Schulden, Louise; Sidle, Clint

    1988-01-01

    The Cornell University Distributed Accounting (CUDA) system is an attempt to provide departments a software tool for better managing their finances, creating microcomputer standards, creating a vehicle for better administrative microcomputer support, and insuring local systems are consistent with central computer systems. (Author/MLW)

  3. Distributed Computing: Options in the Eighties.

    ERIC Educational Resources Information Center

    Klingenstein, Kenneth; Devine, Gary D.

    1985-01-01

    University administrative data processing is moving toward a more distributed environment. An architecture must be established that incorporates central sites, campus centers, and end users in a networked pool of computer systems, with applications located at appropriate nodes in the network. (Author/MLW)

  4. Computer Systems for Distributed and Distance Learning.

    ERIC Educational Resources Information Center

    Anderson, M.; Jackson, David

    2000-01-01

    Discussion of network-based learning focuses on a survey of computer systems for distributed and distance learning. Both Web-based systems and non-Web-based systems are reviewed in order to highlight some of the major trends of past projects and to suggest ways in which progress may be made in the future. (Contains 92 references.) (Author/LRW)

  5. Computationally intensive econometrics using a distributed matrix-programming language.

    PubMed

    Doornik, Jurgen A; Hendry, David F; Shephard, Neil

    2002-06-15

    This paper reviews the need for powerful computing facilities in econometrics, focusing on concrete problems which arise in financial economics and in macroeconomics. We argue that the profession is being held back by the lack of easy-to-use generic software which is able to exploit the availability of cheap clusters of distributed computers. Our response is to extend, in a number of directions, the well-known matrix-programming interpreted language Ox developed by the first author. We note three possible levels of extensions: (i) Ox with parallelization explicit in the Ox code; (ii) Ox with a parallelized run-time library; and (iii) Ox with a parallelized interpreter. This paper studies and implements the first case, emphasizing the need for deterministic computing in science. We give examples in the context of financial economics and time-series modelling.

  6. Research computing in a distributed cloud environment

    NASA Astrophysics Data System (ADS)

    Fransham, K.; Agarwal, A.; Armstrong, P.; Bishop, A.; Charbonneau, A.; Desmarais, R.; Hill, N.; Gable, I.; Gaudet, S.; Goliath, S.; Impey, R.; Leavett-Brown, C.; Ouellete, J.; Paterson, M.; Pritchet, C.; Penfold-Brown, D.; Podaima, W.; Schade, D.; Sobie, R. J.

    2010-11-01

    The recent increase in availability of Infrastructure-as-a-Service (IaaS) computing clouds provides a new way for researchers to run complex scientific applications. However, using cloud resources for a large number of research jobs requires significant effort and expertise. Furthermore, running jobs on many different clouds presents even more difficulty. In order to make it easy for researchers to deploy scientific applications across many cloud resources, we have developed a virtual machine resource manager (Cloud Scheduler) for distributed compute clouds. In response to a user's job submission to a batch system, the Cloud Scheduler manages the distribution and deployment of user-customized virtual machines across multiple clouds. We describe the motivation for and implementation of a distributed cloud using the Cloud Scheduler that is spread across both commercial and dedicated private sites, and present some early results of scientific data analysis using the system.

  7. GEANT4 distributed computing for compact clusters

    NASA Astrophysics Data System (ADS)

    Harrawood, Brian P.; Agasthya, Greeshma A.; Lakshmanan, Manu N.; Raterman, Gretchen; Kapadia, Anuj J.

    2014-11-01

    A new technique for distribution of GEANT4 processes is introduced to simplify running a simulation in a parallel environment such as a tightly coupled computer cluster. Using a new C++ class derived from the GEANT4 toolkit, multiple runs forming a single simulation are managed across a local network of computers with a simple inter-node communication protocol. The class is integrated with the GEANT4 toolkit and is designed to scale from a single symmetric multiprocessing (SMP) machine to compact clusters ranging in size from tens to thousands of nodes. User designed 'work tickets' are distributed to clients using a client-server work flow model to specify the parameters for each individual run of the simulation. The new g4DistributedRunManager class was developed and well tested in the course of our Neutron Stimulated Emission Computed Tomography (NSECT) experiments. It will be useful for anyone running GEANT4 for large discrete data sets such as covering a range of angles in computed tomography, calculating dose delivery with multiple fractions or simply speeding the through-put of a single model.

  8. Implementation of Grid Tier 2 and Tier 3 facilities on a Distributed OpenStack Cloud

    NASA Astrophysics Data System (ADS)

    Limosani, Antonio; Boland, Lucien; Coddington, Paul; Crosby, Sean; Huang, Joanna; Sevior, Martin; Wilson, Ross; Zhang, Shunde

    2014-06-01

    The Australian Government is making a AUD 100 million investment in Compute and Storage for the academic community. The Compute facilities are provided in the form of 30,000 CPU cores located at 8 nodes around Australia in a distributed virtualized Infrastructure as a Service facility based on OpenStack. The storage will eventually consist of over 100 petabytes located at 6 nodes. All will be linked via a 100 Gb/s network. This proceeding describes the development of a fully connected WLCG Tier-2 grid site as well as a general purpose Tier-3 computing cluster based on this architecture. The facility employs an extension to Torque to enable dynamic allocations of virtual machine instances. A base Scientific Linux virtual machine (VM) image is deployed in the OpenStack cloud and automatically configured as required using Puppet. Custom scripts are used to launch multiple VMs, integrate them into the dynamic Torque cluster and to mount remote file systems. We report on our experience in developing this nation-wide ATLAS and Belle II Tier 2 and Tier 3 computing infrastructure using the national Research Cloud and storage facilities.

  9. Open Source Live Distributions for Computer Forensics

    NASA Astrophysics Data System (ADS)

    Giustini, Giancarlo; Andreolini, Mauro; Colajanni, Michele

    Current distributions of open source forensic software provide digital investigators with a large set of heterogeneous tools. Their use is not always focused on the target and requires high technical expertise. We present a new GNU/Linux live distribution, named CAINE (Computer Aided INvestigative Environment) that contains a collection of tools wrapped up into a user friendly environment. The CAINE forensic framework introduces novel important features, aimed at filling the interoperability gap across different forensic tools. Moreover, it provides a homogeneous graphical interface that drives digital investigators during the acquisition and analysis of electronic evidence, and it offers a semi-automatic mechanism for the creation of the final report.

  10. BES-III distributed computing status

    NASA Astrophysics Data System (ADS)

    Belov, S. D.; Deng, Z. Y.; Korenkov, V. V.; Li, W. D.; Lin, T.; Ma, Z. T.; Nicholson, C.; Pelevanyuk, I. S.; Suo, B.; Trofimov, V. V.; Tsaregorodtsev, A. U.; Uzhinskiy, A. V.; Yan, T.; Yan, X. F.; Zhang, X. M.; Zhemchugov, A. S.

    2016-09-01

    The BES-III experiment at the Institute of High Energy Physics (Beijing, China) is aimed at the precision measurements in e+e- annihilation in the energy range from 2.0 till 4.6 GeV. The world's largest samples of J/psi and psi' events and unique samples of XYZ data have been already collected. The expected increase of the data volume in the coming years required a significant evolution of the computing model, namely shift from a centralized data processing to a distributed one. This report summarizes a current design of the BES-III distributed computing system, some of key decisions and experience gained during 2 years of operations.

  11. Subtlenoise: sonification of distributed computing operations

    NASA Astrophysics Data System (ADS)

    Love, P. A.

    2015-12-01

    The operation of distributed computing systems requires comprehensive monitoring to ensure reliability and robustness. There are two components found in most monitoring systems: one being visually rich time-series graphs and another being notification systems for alerting operators under certain pre-defined conditions. In this paper the sonification of monitoring messages is explored using an architecture that fits easily within existing infrastructures based on mature opensource technologies such as ZeroMQ, Logstash, and Supercollider (a synth engine). Message attributes are mapped onto audio attributes based on broad classification of the message (continuous or discrete metrics) but keeping the audio stream subtle in nature. The benefits of audio rendering are described in the context of distributed computing operations and may provide a less intrusive way to understand the operational health of these systems.

  12. High Performance Distributed Computing in a Supercomputer Environment: Computational Services and Applications Issues

    NASA Technical Reports Server (NTRS)

    Kramer, Williams T. C.; Simon, Horst D.

    1994-01-01

    This tutorial proposes to be a practical guide for the uninitiated to the main topics and themes of high-performance computing (HPC), with particular emphasis to distributed computing. The intent is first to provide some guidance and directions in the rapidly increasing field of scientific computing using both massively parallel and traditional supercomputers. Because of their considerable potential computational power, loosely or tightly coupled clusters of workstations are increasingly considered as a third alternative to both the more conventional supercomputers based on a small number of powerful vector processors, as well as high massively parallel processors. Even though many research issues concerning the effective use of workstation clusters and their integration into a large scale production facility are still unresolved, such clusters are already used for production computing. In this tutorial we will utilize the unique experience made at the NAS facility at NASA Ames Research Center. Over the last five years at NAS massively parallel supercomputers such as the Connection Machines CM-2 and CM-5 from Thinking Machines Corporation and the iPSC/860 (Touchstone Gamma Machine) and Paragon Machines from Intel were used in a production supercomputer center alongside with traditional vector supercomputers such as the Cray Y-MP and C90.

  13. Distributed Computing for the Pierre Auger Observatory

    NASA Astrophysics Data System (ADS)

    Chudoba, J.

    2015-12-01

    Pierre Auger Observatory operates the largest system of detectors for ultra-high energy cosmic ray measurements. Comparison of theoretical models of interactions with recorded data requires thousands of computing cores for Monte Carlo simulations. Since 2007 distributed resources connected via EGI grid are successfully used. The first and the second versions of production system based on bash scripts and MySQL database were able to submit jobs to all reliable sites supporting Virtual Organization auger. For many years VO auger belongs to top ten of EGI users based on the total used computing time. Migration of the production system to DIRAC interware started in 2014. Pilot jobs improve efficiency of computing jobs and eliminate problems with small and less reliable sites used for the bulk production. The new system has also possibility to use available resources in clouds. Dirac File Catalog replaced LFC for new files, which are organized in datasets defined via metadata. CVMFS is used for software distribution since 2014. In the presentation we give a comparison of the old and the new production system and report the experience on migrating to the new system.

  14. The Argonne Leadership Computing Facility 2010 annual report.

    SciTech Connect

    Drugan, C.

    2011-05-09

    Researchers found more ways than ever to conduct transformative science at the Argonne Leadership Computing Facility (ALCF) in 2010. Both familiar initiatives and innovative new programs at the ALCF are now serving a growing, global user community with a wide range of computing needs. The Department of Energy's (DOE) INCITE Program remained vital in providing scientists with major allocations of leadership-class computing resources at the ALCF. For calendar year 2011, 35 projects were awarded 732 million supercomputer processor-hours for computationally intensive, large-scale research projects with the potential to significantly advance key areas in science and engineering. Argonne also continued to provide Director's Discretionary allocations - 'start up' awards - for potential future INCITE projects. And DOE's new ASCR Leadership Computing (ALCC) Program allocated resources to 10 ALCF projects, with an emphasis on high-risk, high-payoff simulations directly related to the Department's energy mission, national emergencies, or for broadening the research community capable of using leadership computing resources. While delivering more science today, we've also been laying a solid foundation for high performance computing in the future. After a successful DOE Lehman review, a contract was signed to deliver Mira, the next-generation Blue Gene/Q system, to the ALCF in 2012. The ALCF is working with the 16 projects that were selected for the Early Science Program (ESP) to enable them to be productive as soon as Mira is operational. Preproduction access to Mira will enable ESP projects to adapt their codes to its architecture and collaborate with ALCF staff in shaking down the new system. We expect the 10-petaflops system to stoke economic growth and improve U.S. competitiveness in key areas such as advancing clean energy and addressing global climate change. Ultimately, we envision Mira as a stepping-stone to exascale-class computers that will be faster than petascale

  15. 78 FR 18353 - Guidance for Industry: Blood Establishment Computer System Validation in the User's Facility...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-26

    ... HUMAN SERVICES Food and Drug Administration Guidance for Industry: Blood Establishment Computer System... ``Guidance for Industry: Blood Establishment Computer System Validation in the User's Facility'' dated April... establishment computer system validation program, consistent with recognized principles of software...

  16. Pseudo-interactive monitoring in distributed computing

    SciTech Connect

    Sfiligoi, I.; Bradley, D.; Livny, M.; /Wisconsin U., Madison

    2009-05-01

    Distributed computing, and in particular Grid computing, enables physicists to use thousands of CPU days worth of computing every day, by submitting thousands of compute jobs. Unfortunately, a small fraction of such jobs regularly fail; the reasons vary from disk and network problems to bugs in the user code. A subset of these failures result in jobs being stuck for long periods of time. In order to debug such failures, interactive monitoring is highly desirable; users need to browse through the job log files and check the status of the running processes. Batch systems typically don't provide such services; at best, users get job logs at job termination, and even this may not be possible if the job is stuck in an infinite loop. In this paper we present a novel approach of using regular batch system capabilities of Condor to enable users to access the logs and processes of any running job. This does not provide true interactive access, so commands like vi are not viable, but it does allow operations like ls, cat, top, ps, lsof, netstat and dumping the stack of any process owned by the user; we call this pseudo-interactive monitoring. It is worth noting that the same method can be used to monitor Grid jobs in a glidein-based environment. We further believe that the same mechanism could be applied to many other batch systems.

  17. Pseudo-interactive monitoring in distributed computing

    NASA Astrophysics Data System (ADS)

    Sfiligoi, I.; Bradley, D.; Livny, M.

    2010-04-01

    Distributed computing, and in particular Grid computing, enables physicists to use thousands of CPU days worth of computing every day, by submitting thousands of compute jobs. Unfortunately, a small fraction of such jobs regularly fail; the reasons vary from disk and network problems to bugs in the user code. A subset of these failures result in jobs being stuck for long periods of time. In order to debug such failures, interactive monitoring is highly desirable; users need to browse through the job log files and check the status of the running processes. Batch systems typically don't provide such services; at best, users get job logs at job termination, and even this may not be possible if the job is stuck in an infinite loop. In this paper we present a novel approach of using regular batch system capabilities of Condor to enable users to access the logs and processes of any running job. This does not provide true interactive access, so commands like vi are not viable, but it does allow operations like ls, cat, top, ps, lsof, netstat and dumping the stack of any process owned by the user; we call this pseudo-interactive monitoring. It is worth noting that the same method can be used to monitor Grid jobs in a glidein-based environment. We further believe that the same mechanism could be applied to many other batch systems.

  18. A Generalized Management Information System for Computer Facilities at Educational Institutions.

    ERIC Educational Resources Information Center

    Bowman, Patrick Awalt

    The problem of managing computer facilities at educational institutions is examined. User categories are defined, and the interrelations between user requirements and the goals/objectives of the facility are discussed. Enumerations of the factors that influence computer facility operations is also accomplished. In addition, management information…

  19. A Hundred Impossibility Proofs for Distributed Computing

    DTIC Science & Technology

    1989-08-01

    distributed computing . In this category, I include not just results that say that a particular task cannot be accomplished, but also lower bound results, which say that a task cannot be accomplished within a certain bound on cost. I started out with a simple plan for preparing this talk: I would spend a couple of weeks reading all the impossibility proofs in our fields, and would categorize them according to the ideas used. Then I would make wise and general observations, and try to predict where the future of this area is headed. That turned out to be a bit too ambitious;

  20. Interoperable PKI Data Distribution in Computational Grids

    SciTech Connect

    Pala, Massimiliano; Cholia, Shreyas; Rea, Scott A.; Smith, Sean W.

    2008-07-25

    One of the most successful working examples of virtual organizations, computational grids need authentication mechanisms that inter-operate across domain boundaries. Public Key Infrastructures(PKIs) provide sufficient flexibility to allow resource managers to securely grant access to their systems in such distributed environments. However, as PKIs grow and services are added to enhance both security and usability, users and applications must struggle to discover available resources-particularly when the Certification Authority (CA) is alien to the relying party. This article presents how to overcome these limitations of the current grid authentication model by integrating the PKI Resource Query Protocol (PRQP) into the Grid Security Infrastructure (GSI).

  1. Airport Simulations Using Distributed Computational Resources

    NASA Technical Reports Server (NTRS)

    McDermott, William J.; Maluf, David A.; Gawdiak, Yuri; Tran, Peter; Clancy, Daniel (Technical Monitor)

    2002-01-01

    The Virtual National Airspace Simulation (VNAS) will improve the safety of Air Transportation. In 2001, using simulation and information management software running over a distributed network of super-computers, researchers at NASA Ames, Glenn, and Langley Research Centers developed a working prototype of a virtual airspace. This VNAS prototype modeled daily operations of the Atlanta airport by integrating measured operational data and simulation data on up to 2,000 flights a day. The concepts and architecture developed by NASA for this prototype are integral to the National Airspace Simulation to support the development of strategies improving aviation safety, identifying precursors to component failure.

  2. Computer model to simulate testing at the National Transonic Facility

    NASA Technical Reports Server (NTRS)

    Mineck, Raymond E.; Owens, Lewis R., Jr.; Wahls, Richard A.; Hannon, Judith A.

    1995-01-01

    A computer model has been developed to simulate the processes involved in the operation of the National Transonic Facility (NTF), a large cryogenic wind tunnel at the Langley Research Center. The simulation was verified by comparing the simulated results with previously acquired data from three experimental wind tunnel test programs in the NTF. The comparisons suggest that the computer model simulates reasonably well the processes that determine the liquid nitrogen (LN2) consumption, electrical consumption, fan-on time, and the test time required to complete a test plan at the NTF. From these limited comparisons, it appears that the results from the simulation model are generally within about 10 percent of the actual NTF test results. The use of actual data acquisition times in the simulation produced better estimates of the LN2 usage, as expected. Additional comparisons are needed to refine the model constants. The model will typically produce optimistic results since the times and rates included in the model are typically the optimum values. Any deviation from the optimum values will lead to longer times or increased LN2 and electrical consumption for the proposed test plan. Computer code operating instructions and listings of sample input and output files have been included.

  3. Shipboard Application of a Ring Structured Distributed Computing System.

    DTIC Science & Technology

    Considerable research is currently going on into the application of distributed computing systems. They appear particularly suitable for the...structured distributed computing system might be adapted to function in this environment. Included in this consideration are the feasibility of

  4. Development of a Defence Distributed Computing Environment (DCE) Database Demonstrator,

    DTIC Science & Technology

    1995-11-01

    This report discusses the development of a Defence Distributed Computing Environment (DCE) database demonstrator program. The Demonstrator program...showcases the interoperability, portability, survivability and security features of Open Software Foundation’s Distributed Computing Environment.

  5. Models and Measurements of Parallelism for a Distributed Computer System.

    DTIC Science & Technology

    1982-01-01

    that parallel execution of the processes comprising an application program will defray U the overhead costs of distributed computing . This...of Different Approaches to Distributed Computing ", Proceedings of the Ist International Conference on Distributed Comput er Systems, Huntsville, AL...Oct. 1-5, 1979), pp. 222-232. [20] Liskov, B., "Primitives for Distributed Computing ", Froceedings of the 7--th Symposium on Operating System

  6. Testing the CDF distributed computing framework

    SciTech Connect

    Bartsch, Valeria; Baranovski, Andrew; Belforte, Stefano; Burgon-Lyon, Morag; Garzoglio, Gabriele; Herber, Randolph; Illingworth, Robert; Kennedy, Rob; Kerzel, Ulrich; Kreymer, Art; Leslie, Matt; Loebel-Carpenter, Lauri; Lueking, Lee; Lyon, Adam; Merritt, Wyatt; Ratnikov, Fedor; Sill, Alan; St. Denis, Richard; Stonjek, Stefan; Terekhov, Igor; Trumbo, Julie; /Fermilab /Oxford U. /INFN, Trieste /Glasgow U. /Karlsruhe U. /Rutgers U., Piscataway /Texas Tech.

    2004-12-01

    A major source of CPU power for CDF (Collider Detector at Fermilab) is the CAF (Central Analysis Farm) [1] at Fermilab. The CAF is a farm of computers running Linux with access to the CDF data handling system and databases to allow CDF collaborators to run batch analysis jobs. Beside providing CPU power it has a good monitoring tool. The CAF software is a wrapper around a batch system, either fbsng [3] or condor, to submit jobs in a uniform way. So the submission to the CAF clusters inside and outside Fermilab from many computers with kerberos authentification is possible. It is mainly used to access datasets which comprise a large amount of files and analyze the data. Up to now the DCache system has been used to access the files. In autumn 2004 some of the important datasets will only be readable with the help of the data handling system SAM (Sequential Access to data via Metadata) [2]. This will be done in order to switch to using only one data handling system at Fermilab and on the remote sites. SAM has been used in run II to store, manage, deliver and track the processing of all data. It is designed to copy data to remote sites with remote analysis in mind. To prove CAF and SAM could provide the required CPU power and Data Handling, stress tests of the combined system were carried out. A second goal of CDF is to distribute computing. In 2005 50% of the computing shall be located outside of Fermilab. For this purpose CDF will use the DCAF (Decentralized CDF Analysis Farms) in combination with SAM. To achieve user friendliness the SAM station environment has to be common to all stations and adaptations to the environment have to be made.

  7. An Applet-based Anonymous Distributed Computing System.

    ERIC Educational Resources Information Center

    Finkel, David; Wills, Craig E.; Ciaraldi, Michael J.; Amorin, Kevin; Covati, Adam; Lee, Michael

    2001-01-01

    Defines anonymous distributed computing systems and focuses on the specifics of a Java, applet-based approach for large-scale, anonymous, distributed computing on the Internet. Explains the possibility of a large number of computers participating in a single computation and describes a test of the functionality of the system. (Author/LRW)

  8. Absolute nonlocality via distributed computing without communication

    NASA Astrophysics Data System (ADS)

    Czekaj, Ł.; Pawłowski, M.; Vértesi, T.; Grudka, A.; Horodecki, M.; Horodecki, R.

    2015-09-01

    Understanding the role that quantum entanglement plays as a resource in various information processing tasks is one of the crucial goals of quantum information theory. Here we propose an alternative perspective for studying quantum entanglement: distributed computation of functions without communication between nodes. To formalize this approach, we propose identity games. Surprisingly, despite no signaling, we obtain that nonlocal quantum strategies beat classical ones in terms of winning probability for identity games originating from certain bipartite and multipartite functions. Moreover we show that, for a majority of functions, access to general nonsignaling resources boosts success probability two times in comparison to classical ones for a number of large enough outputs. Because there are no constraints on the inputs and no processing of the outputs in the identity games, they detect very strong types of correlations: absolute nonlocality.

  9. Equilibrium distribution from distributed computing (simulations of protein folding).

    PubMed

    Scalco, Riccardo; Caflisch, Amedeo

    2011-05-19

    Multiple independent molecular dynamics (MD) simulations are often carried out starting from a single protein structure or a set of conformations that do not correspond to a thermodynamic ensemble. Therefore, a significant statistical bias is usually present in the Markov state model generated by simply combining the whole MD sampling into a network whose nodes and links are clusters of snapshots and transitions between them, respectively. Here, we introduce a depth-first search algorithm to extract from the whole conformation space network the largest ergodic component, i.e., the subset of nodes of the network whose transition matrix corresponds to an ergodic Markov chain. For multiple short MD simulations of a globular protein (as in distributed computing), the steady state, i.e., stationary distribution determined using the largest ergodic component, yields more accurate free energy profiles and mean first passage times than the original network or the ergodic network obtained by imposing detailed balance by means of symmetrization of the transition counts.

  10. LHCbDirac: distributed computing in LHCb

    NASA Astrophysics Data System (ADS)

    Stagni, F.; Charpentier, P.; Graciani, R.; Tsaregorodtsev, A.; Closier, J.; Mathe, Z.; Ubeda, M.; Zhelezov, A.; Lanciotti, E.; Romanovskiy, V.; Ciba, K. D.; Casajus, A.; Roiser, S.; Sapunov, M.; Remenska, D.; Bernardoff, V.; Santana, R.; Nandakumar, R.

    2012-12-01

    We present LHCbDirac, an extension of the DIRAC community Grid solution that handles LHCb specificities. The DIRAC software has been developed for many years within LHCb only. Nowadays it is a generic software, used by many scientific communities worldwide. Each community wanting to take advantage of DIRAC has to develop an extension, containing all the necessary code for handling their specific cases. LHCbDirac is an actively developed extension, implementing the LHCb computing model and workflows handling all the distributed computing activities of LHCb. Such activities include real data processing (reconstruction, stripping and streaming), Monte-Carlo simulation and data replication. Other activities are groups and user analysis, data management, resources management and monitoring, data provenance, accounting for user and production jobs. LHCbDirac also provides extensions of the DIRAC interfaces, including a secure web client, python APIs and CLIs. Before putting in production a new release, a number of certification tests are run in a dedicated setup. This contribution highlights the versatility of the system, also presenting the experience with real data processing, data and resources management, monitoring for activities and resources.

  11. Computation-distributed probability hypothesis density filter

    NASA Astrophysics Data System (ADS)

    Wang, Junjie; Zhao, Lingling; Su, Xiaohong; Shi, Chunmei; Ma, JiQuan

    2016-12-01

    Particle probability hypothesis density filtering has become a promising approach for multi-target tracking due to its capability of handling an unknown and time-varying number of targets in a nonlinear, non-Gaussian system. However, its computational complexity linearly increases with the number of obtained observations and the number of particles, which can be very time consuming, particularly when numerous targets and clutter exist in the surveillance region. To address this issue, we present a distributed computation particle probability hypothesis density(PHD) filter for target tracking. It runs several local decomposed particle PHD filters in parallel while processing elements. Each processing element takes responsibility for a portion of particles but all measurements and provides local estimates. A central unit controls particle exchange among the processing elements and specifies a fusion rule to match and fuse the estimates from different local filters. The proposed framework is suitable for parallel implementation. Simulations verify that the proposed method can significantly accelerate and maintain a comparative accuracy compared to the standard particle PHD filter.

  12. Automating usability of ATLAS Distributed Computing resources

    NASA Astrophysics Data System (ADS)

    Tupputi, S. A.; Di Girolamo, A.; Kouba, T.; Schovancová, J.; Atlas Collaboration

    2014-06-01

    The automation of ATLAS Distributed Computing (ADC) operations is essential to reduce manpower costs and allow performance-enhancing actions, which improve the reliability of the system. In this perspective a crucial case is the automatic handling of outages of ATLAS computing sites storage resources, which are continuously exploited at the edge of their capabilities. It is challenging to adopt unambiguous decision criteria for storage resources of non-homogeneous types, sizes and roles. The recently developed Storage Area Automatic Blacklisting (SAAB) tool has provided a suitable solution, by employing an inference algorithm which processes history of storage monitoring tests outcome. SAAB accomplishes both the tasks of providing global monitoring as well as automatic operations on single sites. The implementation of the SAAB tool has been the first step in a comprehensive review of the storage areas monitoring and central management at all levels. Such review has involved the reordering and optimization of SAM tests deployment and the inclusion of SAAB results in the ATLAS Site Status Board with both dedicated metrics and views. The resulting structure allows monitoring the storage resources status with fine time-granularity and automatic actions to be taken in foreseen cases, like automatic outage handling and notifications to sites. Hence, the human actions are restricted to reporting and following up problems, where and when needed. In this work we show SAAB working principles and features. We present also the decrease of human interactions achieved within the ATLAS Computing Operation team. The automation results in a prompt reaction to failures, which leads to the optimization of resource exploitation.

  13. Argonne Leadership Computing Facility 2011 annual report : Shaping future supercomputing.

    SciTech Connect

    Papka, M.; Messina, P.; Coffey, R.; Drugan, C.

    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 implement those algorithms

  14. Space power distribution system technology. Volume 3: Test facility design

    NASA Technical Reports Server (NTRS)

    Decker, D. K.; Cannady, M. D.; Cassinelli, J. E.; Farber, B. F.; Lurie, C.; Fleck, G. W.; Lepisto, J. W.; Messner, A.; Ritterman, P. F.

    1983-01-01

    The AMPS test facility is a major tool in the attainment of more economical space power. The ultimate goals of the test facility, its primary functional requirements and conceptual design, and the major equipment it contains are discussed.

  15. Distributed Design and Analysis of Computer Experiments

    SciTech Connect

    Doak, Justin

    2002-11-11

    DDACE is a C++ object-oriented software library for the design and analysis of computer experiments. DDACE can be used to generate samples from a variety of sampling techniques. These samples may be used as input to a application code. DDACE also contains statistical tools such as response surface models and correlation coefficients to analyze input/output relationships between variables in an application code. DDACE can generate input values for uncertain variables within a user's application. For example, a user might like to vary a temperature variable as well as some material variables in a series of simulations. Through the series of simulations the user might be looking for optimal settings of parameters based on some user criteria. Or the user may be interested in the sensitivity to input variability shown by an output variable. In either case, the user may provide information about the suspected ranges and distributions of a set of input variables, along with a sampling scheme, and DDACE will generate input points based on these specifications. The input values generated by DDACE and the one or more outputs computed through the user's application code can be analyzed with a variety of statistical methods. This can lead to a wealth of information about the relationships between the variables in the problem. While statistical and mathematical packages may be employeed to carry out the analysis on the input/output relationships, DDACE also contains some tools for analyzing the simulation data. DDACE incorporates a software package called MARS (Multivariate Adaptive Regression Splines), developed by Jerome Friedman. MARS is used for generating a spline surface fit of the data. With MARS, a model simplification may be calculated using the input and corresponding output, values for the user's application problem. The MARS grid data may be used for generating 3-dimensional response surface plots of the simulation data. DDACE also contains an implementation of an

  16. Improvement of the Computing - Related Procurement Process at a Government Research Facility

    SciTech Connect

    Gittins, C.

    2000-04-03

    The purpose of the project was to develop, implement, and market value-added services through the Computing Resource Center in an effort to streamline computing-related procurement processes across the Lawrence Livermore National Laboratory (LLNL). The power of the project was in focusing attention on and value of centralizing the delivery of computer related products and services to the institution. The project required a plan and marketing strategy that would drive attention to the facility's value-added offerings and services. A significant outcome of the project has been the change in the CRC internal organization. The realignment of internal policies and practices, together with additions to its product and service offerings has brought an increased focus to the facility. This movement from a small, fractious organization into one that is still small yet well organized and focused on its mission and goals has been a significant transition. Indicative of this turnaround was the sharing of information. One-on-one and small group meetings, together with statistics showing work activity was invaluable in gaining support for more equitable workload distribution, and the removal of blame and finger pointing. Sharing monthly reports on sales and operating costs also had a positive impact.

  17. Public Computer Assisted Learning Facilities for Children with Visual Impairment: Universal Design for Inclusive Learning

    ERIC Educational Resources Information Center

    Siu, Kin Wai Michael; Lam, Mei Seung

    2012-01-01

    Although computer assisted learning (CAL) is becoming increasingly popular, people with visual impairment face greater difficulty in accessing computer-assisted learning facilities. This is primarily because most of the current CAL facilities are not visually impaired friendly. People with visual impairment also do not normally have access to…

  18. UTILIZATION OF COMPUTER FACILITIES IN THE MATHEMATICS AND BUSINESS CURRICULUM IN A LARGE SUBURBAN HIGH SCHOOL.

    ERIC Educational Resources Information Center

    RENO, MARTIN; AND OTHERS

    A STUDY WAS UNDERTAKEN TO EXPLORE IN A QUALITATIVE WAY THE POSSIBLE UTILIZATION OF COMPUTER AND DATA PROCESSING METHODS IN HIGH SCHOOL EDUCATION. OBJECTIVES WERE--(1) TO ESTABLISH A WORKING RELATIONSHIP WITH A COMPUTER FACILITY SO THAT ABLE STUDENTS AND THEIR TEACHERS WOULD HAVE ACCESS TO THE FACILITIES, (2) TO DEVELOP A UNIT FOR THE UTILIZATION…

  19. An Evaluation of Spatial Distribution of Public Parking Facilities in Huizhou Downtown

    NASA Astrophysics Data System (ADS)

    Chen, Jiasheng; Bai, Yang; Chen, Ying

    2016-11-01

    The survey and evaluation of existing public parking facilities were carried out, which had important practical significance to resolve conflicts over demand and supply of parking facilities. Taking Huizhou downtown as a study area, we surveyed parking facilities mainly by daily observing and recording. Parking facilities supply, characteristics, and demand were analysed by calculating parking utilization and turnover rate. Based on GIS, the distance-based and time-based accessibility of parking facilities were analysed to evaluate spatial distribution. The results indicated that a large spatial difference in supply and characteristics of parking was shown in public parking facilities of Huizhou downtown and that the parking demand was large. Furthermore, there existed imbalance in spatial distribution of parking facilities in Huizhou downtown area. Our study suggested that it was imbalanced and irrational between parking facilities supply and parking demand, that the planning of parking facilities was inadequate and that management system was incomplete.

  20. The ICAAP Project, Part Three: OSF Distributed Computing Environment.

    ERIC Educational Resources Information Center

    Cantor, Scott

    1997-01-01

    DCE (Distributed Computing Environment) is a collection of services, tools, and libraries for building the infrastructure necessary for distributed computing within an enterprise. This articles discusses the Open Software Foundation (OSF); the components of DCE, including the Directory and Security Services, the Distributed Time Service, and the…

  1. A distributed data acquisition system for aeronautics test facilities

    NASA Technical Reports Server (NTRS)

    Fronek, Dennis L.; Setter, Robert N.; Blumenthal, Philip Z.; Smalley, Robert R.

    1987-01-01

    The NASA Lewis Research Center is in the process of installing a new data acquisition and display system. This new system will provide small and medium sized aeronautics test facilities with a state-of-the-art real-time data acquisition and display system. The new data system will provide for the acquisition of signals from a variety of instrumentation sources. They include analog measurements of temperatures, pressures, and other steady state voltage inputs; frequency inputs to measure speed and flow; discrete I/O for significant events, and modular instrument systems such as multiplexed pressure modules or electronic instrumentation with a IEEE 488 interface. The data system is designed to acquire data, convert it to engineering units, compute test dependent performance calculations, limit check selected channels or calculations, and display the information in alphanumeric or graphical form with a cycle time of one second for the alphanumeric data. This paper describes the system configuration, its salient features, and the expected impact on testing.

  2. Facility optimization to improve activation rate distributions during IVNAA

    PubMed Central

    Ebrahimi Khankook, Atiyeh; Rafat Motavalli, Laleh; Miri Hakimabad, Hashem

    2013-01-01

    Currently, determination of body composition is the most useful method for distinguishing between certain diseases. The prompt-gamma in vivo neutron activation analysis (IVNAA) facility for non-destructive elemental analysis of the human body is the gold standard method for this type of analysis. In order to obtain accurate measurements using the IVNAA system, the activation probability in the body must be uniform. This can be difficult to achieve, as body shape and body composition affect the rate of activation. The aim of this study was to determine the optimum pre-moderator, in terms of material for attaining uniform activation probability with a CV value of about 10% and changing the collimator role to increase activation rate within the body. Such uniformity was obtained with a high thickness of paraffin pre-moderator, however, because of increasing secondary photon flux received by the detectors it was not an appropriate choice. Our final calculations indicated that using two paraffin slabs with a thickness of 3 cm as a pre-moderator, in the presence of 2 cm Bi on the collimator, achieves a satisfactory distribution of activation rate in the body. PMID:23386375

  3. Facility optimization to improve activation rate distributions during IVNAA.

    PubMed

    Ebrahimi Khankook, Atiyeh; Rafat Motavalli, Laleh; Miri Hakimabad, Hashem

    2013-05-01

    Currently, determination of body composition is the most useful method for distinguishing between certain diseases. The prompt-gamma in vivo neutron activation analysis (IVNAA) facility for non-destructive elemental analysis of the human body is the gold standard method for this type of analysis. In order to obtain accurate measurements using the IVNAA system, the activation probability in the body must be uniform. This can be difficult to achieve, as body shape and body composition affect the rate of activation. The aim of this study was to determine the optimum pre-moderator, in terms of material for attaining uniform activation probability with a CV value of about 10% and changing the collimator role to increase activation rate within the body. Such uniformity was obtained with a high thickness of paraffin pre-moderator, however, because of increasing secondary photon flux received by the detectors it was not an appropriate choice. Our final calculations indicated that using two paraffin slabs with a thickness of 3 cm as a pre-moderator, in the presence of 2 cm Bi on the collimator, achieves a satisfactory distribution of activation rate in the body.

  4. Development of Distributed Computing Systems Software Design Methodologies.

    DTIC Science & Technology

    1982-11-05

    R12i 941 DEVELOPMENT OF DISTRIBUTED COMPUTING SYSTEMS SOFTWARE ± DESIGN METHODOLOGIES(U) NORTHWESTERN UNIV EVANSTON IL DEPT OF ELECTRICAL...GUIRWAU OF STANDARDS -16 5 A Ax u FINAL REPORT Development of Distributed Computing System Software Design Methodologies C)0 Stephen S. Yau September 22...of Distributed Computing Systems Software pt.22,, 80 -OJu1, 2 * Dsig Mehodloges PERFORMING ORG REPORT NUMBERDesign th ol ies" 7. AUTHOR() .. CONTRACT

  5. Distributing an executable job load file to compute nodes in a parallel computer

    DOEpatents

    Gooding, Thomas M.

    2016-08-09

    Distributing an executable job load file to compute nodes in a parallel computer, the parallel computer comprising a plurality of compute nodes, including: determining, by a compute node in the parallel computer, whether the compute node is participating in a job; determining, by the compute node in the parallel computer, whether a descendant compute node is participating in the job; responsive to determining that the compute node is participating in the job or that the descendant compute node is participating in the job, communicating, by the compute node to a parent compute node, an identification of a data communications link over which the compute node receives data from the parent compute node; constructing a class route for the job, wherein the class route identifies all compute nodes participating in the job; and broadcasting the executable load file for the job along the class route for the job.

  6. Distributing an executable job load file to compute nodes in a parallel computer

    DOEpatents

    Gooding, Thomas M.

    2016-09-13

    Distributing an executable job load file to compute nodes in a parallel computer, the parallel computer comprising a plurality of compute nodes, including: determining, by a compute node in the parallel computer, whether the compute node is participating in a job; determining, by the compute node in the parallel computer, whether a descendant compute node is participating in the job; responsive to determining that the compute node is participating in the job or that the descendant compute node is participating in the job, communicating, by the compute node to a parent compute node, an identification of a data communications link over which the compute node receives data from the parent compute node; constructing a class route for the job, wherein the class route identifies all compute nodes participating in the job; and broadcasting the executable load file for the job along the class route for the job.

  7. Distributed computing environments for future space control systems

    NASA Technical Reports Server (NTRS)

    Viallefont, Pierre

    1993-01-01

    The aim of this paper is to present the results of a CNES research project on distributed computing systems. The purpose of this research was to study the impact of the use of new computer technologies in the design and development of future space applications. The first part of this study was a state-of-the-art review of distributed computing systems. One of the interesting ideas arising from this review is the concept of a 'virtual computer' allowing the distributed hardware architecture to be hidden from a software application. The 'virtual computer' can improve system performance by adapting the best architecture (addition of computers) to the software application without having to modify its source code. This concept can also decrease the cost and obsolescence of the hardware architecture. In order to verify the feasibility of the 'virtual computer' concept, a prototype representative of a distributed space application is being developed independently of the hardware architecture.

  8. 32 CFR 766.8 - Procedure for review, approval, execution and distribution of aviation facility licenses.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... distribution of aviation facility licenses. 766.8 Section 766.8 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY MISCELLANEOUS RULES USE OF DEPARTMENT OF THE NAVY AVIATION FACILITIES BY CIVIL AIRCRAFT § 766.8 Procedure for review, approval, execution and distribution of aviation...

  9. 32 CFR 766.8 - Procedure for review, approval, execution and distribution of aviation facility licenses.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... distribution of aviation facility licenses. 766.8 Section 766.8 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY MISCELLANEOUS RULES USE OF DEPARTMENT OF THE NAVY AVIATION FACILITIES BY CIVIL AIRCRAFT § 766.8 Procedure for review, approval, execution and distribution of aviation...

  10. 32 CFR 766.8 - Procedure for review, approval, execution and distribution of aviation facility licenses.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... distribution of aviation facility licenses. 766.8 Section 766.8 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY MISCELLANEOUS RULES USE OF DEPARTMENT OF THE NAVY AVIATION FACILITIES BY CIVIL AIRCRAFT § 766.8 Procedure for review, approval, execution and distribution of aviation...

  11. 32 CFR 766.8 - Procedure for review, approval, execution and distribution of aviation facility licenses.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... distribution of aviation facility licenses. 766.8 Section 766.8 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY MISCELLANEOUS RULES USE OF DEPARTMENT OF THE NAVY AVIATION FACILITIES BY CIVIL AIRCRAFT § 766.8 Procedure for review, approval, execution and distribution of aviation...

  12. 32 CFR 766.8 - Procedure for review, approval, execution and distribution of aviation facility licenses.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... distribution of aviation facility licenses. 766.8 Section 766.8 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY MISCELLANEOUS RULES USE OF DEPARTMENT OF THE NAVY AVIATION FACILITIES BY CIVIL AIRCRAFT § 766.8 Procedure for review, approval, execution and distribution of aviation...

  13. Optimization of an interactive distributive computer network

    NASA Technical Reports Server (NTRS)

    Frederick, V.

    1985-01-01

    The activities under a cooperative agreement for the development of a computer network are briefly summarized. Research activities covered are: computer operating systems optimization and integration; software development and implementation of the IRIS (Infrared Imaging of Shuttle) Experiment; and software design, development, and implementation of the APS (Aerosol Particle System) Experiment.

  14. Equation solvers for distributed-memory computers

    NASA Technical Reports Server (NTRS)

    Storaasli, Olaf O.

    1994-01-01

    A large number of scientific and engineering problems require the rapid solution of large systems of simultaneous equations. The performance of parallel computers in this area now dwarfs traditional vector computers by nearly an order of magnitude. This talk describes the major issues involved in parallel equation solvers with particular emphasis on the Intel Paragon, IBM SP-1 and SP-2 processors.

  15. National facility for advanced computational science: A sustainable path to scientific discovery

    SciTech Connect

    Simon, Horst; Kramer, William; Saphir, William; Shalf, John; Bailey, David; Oliker, Leonid; Banda, Michael; McCurdy, C. William; Hules, John; Canning, Andrew; Day, Marc; Colella, Philip; Serafini, David; Wehner, Michael; Nugent, Peter

    2004-04-02

    Lawrence Berkeley National Laboratory (Berkeley Lab) proposes to create a National Facility for Advanced Computational Science (NFACS) and to establish a new partnership between the American computer industry and a national consortium of laboratories, universities, and computing facilities. NFACS will provide leadership-class scientific computing capability to scientists and engineers nationwide, independent of their institutional affiliation or source of funding. This partnership will bring into existence a new class of computational capability in the United States that is optimal for science and will create a sustainable path towards petaflops performance.

  16. Distributed Computing Environment: An Architecture For Supporting Change?

    DTIC Science & Technology

    1995-11-01

    Distributed Computing Environment (DCE) has been in development for about five years but has only been widely used in the last two years. It consists...these services form an architecture for distributed computing that enables users to carry out the new, cheaper operations they require with the

  17. Distributed Computing: Considerations for Its Use within Educational Environments.

    ERIC Educational Resources Information Center

    Pratt, S. J.

    1985-01-01

    Emphasizing more effective use of existing equipment, this article highlights distributed computing design considerations applicable to educational environments; identifies potential roles of networking in the provision of adequate teaching aids; presents a networking model; and describes the development of a distributed computing configuration at…

  18. Distributed-Computer System Optimizes SRB Joints

    NASA Technical Reports Server (NTRS)

    Rogers, James L., Jr.; Young, Katherine C.; Barthelemy, Jean-Francois M.

    1991-01-01

    Initial calculations of redesign of joint on solid rocket booster (SRB) that failed during Space Shuttle tragedy showed redesign increased weight. Optimization techniques applied to determine whether weight could be reduced while keeping joint closed and limiting stresses. Analysis system developed by use of existing software coupling structural analysis with optimization computations. Software designed executable on network of computer workstations. Took advantage of parallelism offered by finite-difference technique of computing gradients to enable several workstations to contribute simultaneously to solution of problem. Key features, effective use of redundancies in hardware and flexible software, enabling optimization to proceed with minimal delay and decreased overall time to completion.

  19. A Weibull distribution accrual failure detector for cloud computing

    PubMed Central

    Wu, Zhibo; Wu, Jin; Zhao, Yao; Wen, Dongxin

    2017-01-01

    Failure detectors are used to build high availability distributed systems as the fundamental component. To meet the requirement of a complicated large-scale distributed system, accrual failure detectors that can adapt to multiple applications have been studied extensively. However, several implementations of accrual failure detectors do not adapt well to the cloud service environment. To solve this problem, a new accrual failure detector based on Weibull Distribution, called the Weibull Distribution Failure Detector, has been proposed specifically for cloud computing. It can adapt to the dynamic and unexpected network conditions in cloud computing. The performance of the Weibull Distribution Failure Detector is evaluated and compared based on public classical experiment data and cloud computing experiment data. The results show that the Weibull Distribution Failure Detector has better performance in terms of speed and accuracy in unstable scenarios, especially in cloud computing. PMID:28278229

  20. A Weibull distribution accrual failure detector for cloud computing.

    PubMed

    Liu, Jiaxi; Wu, Zhibo; Wu, Jin; Dong, Jian; Zhao, Yao; Wen, Dongxin

    2017-01-01

    Failure detectors are used to build high availability distributed systems as the fundamental component. To meet the requirement of a complicated large-scale distributed system, accrual failure detectors that can adapt to multiple applications have been studied extensively. However, several implementations of accrual failure detectors do not adapt well to the cloud service environment. To solve this problem, a new accrual failure detector based on Weibull Distribution, called the Weibull Distribution Failure Detector, has been proposed specifically for cloud computing. It can adapt to the dynamic and unexpected network conditions in cloud computing. The performance of the Weibull Distribution Failure Detector is evaluated and compared based on public classical experiment data and cloud computing experiment data. The results show that the Weibull Distribution Failure Detector has better performance in terms of speed and accuracy in unstable scenarios, especially in cloud computing.

  1. Configuring computation tree topologies on a distributed computing system

    SciTech Connect

    Woei Lin; Chuan-lin Wu

    1983-01-01

    The authors describe an approach to connecting hardware resources for high-performance computation. Two basic algorithms are designed for configuring binary tree topologies. The configuring command can be issued from any processing mode. The algorithms can select proper modes for connection while maintaining good utilization of processing nodes. 7 references.

  2. Computation of the sampling distribution of coherence estimate.

    PubMed

    Nadarajah, Saralees; Kotz, Samuel

    2006-12-01

    The recent paper published by Miranda de Sa (2004) derived, for the first time, the sampling distribution of coherence estimated between two signals. The paper also considered computational issues of the sampling distribution, using an approximate method. In this short note, we provided several 1-line programs for the exact computation of various measures of the sampling distribution. The advantages of using these programs are discussed.

  3. [Use of personal computers in forensic medicine facilities].

    PubMed

    Vorel, F

    1995-08-01

    The authors present a brief account of possibilities to use computers, type PC, in departments of forensic medicine and discuss basic technical and programme equipment. In the author's opinion the basic reason for using computers is to create an extensive database of post-mortem findings which would make it possible to process them on a large scale and use them for research and prevention. Introduction of computers depends on the management of the department and it is necessary to persuade workers-future users of computers-of the advantages associated with their use.

  4. Distributing Computer Resources in Education and Training.

    ERIC Educational Resources Information Center

    Bell, Wynne

    1982-01-01

    The future direction of computers in educational settings is the topic of speculation. It is noted that resources in education are so meagre that only practical ventures can be considered. Suggestions are made for stretching available resources and maximizing the benefits to be gained through the new technology. (MP)

  5. Language Facilities for Programming User-Computer Dialogues.

    ERIC Educational Resources Information Center

    Lafuente, J. M.; Gries, D.

    1978-01-01

    Proposes extensions to PASCAL that provide for programing man-computer dialogues. An interactive dialogue application program is viewed as a sequence of frames and separate computational steps. PASCAL extensions allow the description of the items of information in each frame and the inclusion of behavior rules specifying the interactive dialogue.…

  6. A distributed computing approach to mission operations support. [for spacecraft

    NASA Technical Reports Server (NTRS)

    Larsen, R. L.

    1975-01-01

    Computing mission operation support includes orbit determination, attitude processing, maneuver computation, resource scheduling, etc. The large-scale third-generation distributed computer network discussed is capable of fulfilling these dynamic requirements. It is shown that distribution of resources and control leads to increased reliability, and exhibits potential for incremental growth. Through functional specialization, a distributed system may be tuned to very specific operational requirements. Fundamental to the approach is the notion of process-to-process communication, which is effected through a high-bandwidth communications network. Both resource-sharing and load-sharing may be realized in the system.

  7. Tactical Airborne Distributed Computing and Networks

    DTIC Science & Technology

    1981-10-01

    material supplied by AGARD or the authors. Published October 1981 Copyright Q AGARD 1981 All Rights Reserved ISBN 92-835-0302-3 Printed by Technical...identifiable, common goal. That goal may be the supplying of general-purpose computing support, a collection of integrated applications such as corporate...uptd in the air to air weapon system. Range of target was still being entered i.ito the system from a subjective appreciation supplied by thi pilot

  8. Effects of wind-energy facilities on grassland bird distributions

    USGS Publications Warehouse

    Shaffer, Jill A.; Buhl, Deb

    2016-01-01

    The contribution of renewable energy to meet worldwide demand continues to grow. Wind energy is one of the fastest growing renewable sectors, but new wind facilities are often placed in prime wildlife habitat. Long-term studies that incorporate a rigorous statistical design to evaluate the effects of wind facilities on wildlife are rare. We conducted a before-after-control-impact (BACI) assessment to determine if wind facilities placed in native mixed-grass prairies displaced breeding grassland birds. During 2003–2012, we monitored changes in bird density in 3 study areas in North Dakota and South Dakota (U.S.A.). We examined whether displacement or attraction occurred 1 year after construction (immediate effect) and the average displacement or attraction 2–5 years after construction (delayed effect). We tested for these effects overall and within distance bands of 100, 200, 300, and >300 m from turbines. We observed displacement for 7 of 9 species. One species was unaffected by wind facilities and one species exhibited attraction. Displacement and attraction generally occurred within 100 m and often extended up to 300 m. In a few instances, displacement extended beyond 300 m. Displacement and attraction occurred 1 year after construction and persisted at least 5 years. Our research provides a framework for applying a BACI design to displacement studies and highlights the erroneous conclusions that can be made without the benefit of adopting such a design. More broadly, species-specific behaviors can be used to inform management decisions about turbine placement and the potential impact to individual species. Additionally, the avoidance distance metrics we estimated can facilitate future development of models evaluating impacts of wind facilities under differing land-use scenarios.

  9. The Design Methodology of Distributed Computer Systems.

    DTIC Science & Technology

    1980-12-01

    This remedies most of the drawbacks of the ccntralized approach . However, due to the inherent communication delay, the chosen control node may get an...alternative approach is the bayesian approach advocated by Littlewood -31 - (LIT 79(B)). Here we postulate a prior distribution for each of 1, 2, .. j- Then...sses A-i Chapter 2 describes top-down deve lopment approach . The development process is pdivided into four successive phases; (1) requirement, and

  10. Simulation model of load balancing in distributed computing systems

    NASA Astrophysics Data System (ADS)

    Botygin, I. A.; Popov, V. N.; Frolov, S. G.

    2017-02-01

    The availability of high-performance computing, high speed data transfer over the network and widespread of software for the design and pre-production in mechanical engineering have led to the fact that at the present time the large industrial enterprises and small engineering companies implement complex computer systems for efficient solutions of production and management tasks. Such computer systems are generally built on the basis of distributed heterogeneous computer systems. The analytical problems solved by such systems are the key models of research, but the system-wide problems of efficient distribution (balancing) of the computational load and accommodation input, intermediate and output databases are no less important. The main tasks of this balancing system are load and condition monitoring of compute nodes, and the selection of a node for transition of the user’s request in accordance with a predetermined algorithm. The load balancing is one of the most used methods of increasing productivity of distributed computing systems through the optimal allocation of tasks between the computer system nodes. Therefore, the development of methods and algorithms for computing optimal scheduling in a distributed system, dynamically changing its infrastructure, is an important task.

  11. Moments of inclination error distribution computer program

    NASA Technical Reports Server (NTRS)

    Myler, T. R.

    1981-01-01

    A FORTRAN coded computer program is described which calculates orbital inclination error statistics using a closed-form solution. This solution uses a data base of trajectory errors from actual flights to predict the orbital inclination error statistics. The Scott flight history data base consists of orbit insertion errors in the trajectory parameters - altitude, velocity, flight path angle, flight azimuth, latitude and longitude. The methods used to generate the error statistics are of general interest since they have other applications. Program theory, user instructions, output definitions, subroutine descriptions and detailed FORTRAN coding information are included.

  12. A Computability Theory for Distributed Systems.

    DTIC Science & Technology

    1986-03-13

    the following two elementary properties. * [p] is an equivalence relation over system computations. * For z a prefix of V, there is an event on p...assumption. C1 CO ’ We note that the two conditions in the last sentence of the theorem are not exclusive. Con-Obserration I. Any occurrence of "P" in a...Basic Tense Logic, in D. Gab- 10~th POPL (1983) 141-1,54. bay and F. Guenthner (eds.) Handbook of [MP31 Manna, Z., Pnueli, A. - Verification of Con

  13. 2-out-of-3 selecting facility in a 3-computer system

    SciTech Connect

    Uebel, H.

    1986-10-07

    This patent describes a 2-out-of-3- selecting facility for a 3-computer system in which all computers process the same information in parallel, and in which a result is delivered for further processing only if at least two of the computers have arrived at this result. The facility comprises an output port (A1...A3) in each of the computers and a comparison data input port (E1...E3) in each of the computers which is connected to the output ports of the other two computers for the transfer of the results produced by these computers. It comprises comparison circuitry in each of the computers for comparing the result produced by it with the results produced by the neighboring computers and providing a corresponding comparison indication, to a majority voting circuit (MS). The circuit is connected to receive the comparison indication depending on the comparison indications from all computers. The computers have outlet ports and the facility has two separate data output channels.

  14. A distributed computing model for telemetry data processing

    NASA Astrophysics Data System (ADS)

    Barry, Matthew R.; Scott, Kevin L.; Weismuller, Steven P.

    1994-05-01

    We present a new approach to distributing processed telemetry data among spacecraft flight controllers within the control centers at NASA's Johnson Space Center. This approach facilitates the development of application programs which integrate spacecraft-telemetered data and ground-based synthesized data, then distributes this information to flight controllers for analysis and decision-making. The new approach combines various distributed computing models into one hybrid distributed computing model. The model employs both client-server and peer-to-peer distributed computing models cooperating to provide users with information throughout a diverse operations environment. Specifically, it provides an attractive foundation upon which we are building critical real-time monitoring and control applications, while simultaneously lending itself to peripheral applications in playback operations, mission preparations, flight controller training, and program development and verification. We have realized the hybrid distributed computing model through an information sharing protocol. We shall describe the motivations that inspired us to create this protocol, along with a brief conceptual description of the distributed computing models it employs. We describe the protocol design in more detail, discussing many of the program design considerations and techniques we have adopted. Finally, we describe how this model is especially suitable for supporting the implementation of distributed expert system applications.

  15. A distributed computing model for telemetry data processing

    NASA Technical Reports Server (NTRS)

    Barry, Matthew R.; Scott, Kevin L.; Weismuller, Steven P.

    1994-01-01

    We present a new approach to distributing processed telemetry data among spacecraft flight controllers within the control centers at NASA's Johnson Space Center. This approach facilitates the development of application programs which integrate spacecraft-telemetered data and ground-based synthesized data, then distributes this information to flight controllers for analysis and decision-making. The new approach combines various distributed computing models into one hybrid distributed computing model. The model employs both client-server and peer-to-peer distributed computing models cooperating to provide users with information throughout a diverse operations environment. Specifically, it provides an attractive foundation upon which we are building critical real-time monitoring and control applications, while simultaneously lending itself to peripheral applications in playback operations, mission preparations, flight controller training, and program development and verification. We have realized the hybrid distributed computing model through an information sharing protocol. We shall describe the motivations that inspired us to create this protocol, along with a brief conceptual description of the distributed computing models it employs. We describe the protocol design in more detail, discussing many of the program design considerations and techniques we have adopted. Finally, we describe how this model is especially suitable for supporting the implementation of distributed expert system applications.

  16. Have computers, will travel: providing on-site library instruction in rural health facilities using a portable computer lab.

    PubMed

    Neilson, Christine J

    2010-01-01

    The Saskatchewan Health Information Resources Partnership (SHIRP) provides library instruction to Saskatchewan's health care practitioners and students on placement in health care facilities as part of its mission to provide province-wide access to evidence-based health library resources. A portable computer lab was assembled in 2007 to provide hands-on training in rural health facilities that do not have computer labs of their own. Aside from some minor inconveniences, the introduction and operation of the portable lab has gone smoothly. The lab has been well received by SHIRP patrons and continues to be an essential part of SHIRP outreach.

  17. The process group approach to reliable distributed computing

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.

    1992-01-01

    The difficulty of developing reliable distribution software is an impediment to applying distributed computing technology in many settings. Experience with the ISIS system suggests that a structured approach based on virtually synchronous process groups yields systems that are substantially easier to develop, exploit sophisticated forms of cooperative computation, and achieve high reliability. Six years of research on ISIS, describing the model, its implementation challenges, and the types of applications to which ISIS has been applied are reviewed.

  18. Actors: A Model of Concurrent Computation in Distributed Systems.

    DTIC Science & Technology

    1985-06-01

    RD-A157 917 ACTORS: A MODEL OF CONCURRENT COMPUTATION IN 1/3- DISTRIBUTED SY𔃿TEMS(U) MASSACHUSETTS INST OF TECH CRMBRIDGE ARTIFICIAL INTELLIGENCE...EmmmmmmEmmmmmE mmmmmmmmmmmmmmlfllfllf EEEEEEEmmmmmEE Sa~WNVS AO nflWl ,VNOIJVN 27 n- -o :1 ~ili0 Technical Report 844 Actors: A Model Of Concurrent...Computation In Distributed Systems Gui A. Aghai MIT Artificial Intelligence Laboratory Thsdocument ha. been cipp -oved I= pblicrelease and sale; itsI

  19. Gasoline Distribution Facilities (Bulk Gasoline Terminals and Pipeline Breakout Stations) Air Toxics Rule Fact Sheets

    EPA Pesticide Factsheets

    This page contains a November 1994 fact sheet for the final NESHAP for Gasoline Distribution Facilities. This page also contains a December fact sheet with information regarding the final amendments to the 2003 final rule for the NESHAP.

  20. Distributed sensor networks with collective computation

    SciTech Connect

    Lanman, D. R.

    2001-01-01

    Simulations of a network of N sensors have been performed. The simulation space contains a number of sound sources and a large number of sensors. Each sensor is equipped with an omni-directional microphone and is capable of measuring only the time of arrival of a signal. Sensors are able to wirelessly transmit and receive packets of information, and have some computing power. The sensors were programmed to merge all information (received packets as well as local measurements) into a 'world view' for that node. This world view is then transmitted. In this way, information can slowly diffuse across the network. One node was monitored in the network as a proxy for when information had diffused across the network. Simulations demonstrated that the energy expended per sensor per time step was approximately independent of N.

  1. Nonlinear Fluid Computations in a Distributed Environment

    NASA Technical Reports Server (NTRS)

    Atwood, Christopher A.; Smith, Merritt H.

    1995-01-01

    The performance of a loosely and tightly-coupled workstation cluster is compared against a conventional vector supercomputer for the solution the Reynolds- averaged Navier-Stokes equations. The application geometries include a transonic airfoil, a tiltrotor wing/fuselage, and a wing/body/empennage/nacelle transport. Decomposition is of the manager-worker type, with solution of one grid zone per worker process coupled using the PVM message passing library. Task allocation is determined by grid size and processor speed, subject to available memory penalties. Each fluid zone is computed using an implicit diagonal scheme in an overset mesh framework, while relative body motion is accomplished using an additional worker process to re-establish grid communication.

  2. Clock distribution system for digital computers

    DOEpatents

    Wyman, Robert H.; Loomis, Jr., Herschel H.

    1981-01-01

    Apparatus for eliminating, in each clock distribution amplifier of a clock distribution system, sequential pulse catch-up error due to one pulse "overtaking" a prior clock pulse. The apparatus includes timing means to produce a periodic electromagnetic signal with a fundamental frequency having a fundamental frequency component V'.sub.01 (t); an array of N signal characteristic detector means, with detector means No. 1 receiving the timing means signal and producing a change-of-state signal V.sub.1 (t) in response to receipt of a signal above a predetermined threshold; N substantially identical filter means, one filter means being operatively associated with each detector means, for receiving the change-of-state signal V.sub.n (t) and producing a modified change-of-state signal V'.sub.n (t) (n=1, . . . , N) having a fundamental frequency component that is substantially proportional to V'.sub.01 (t-.theta..sub.n (t) with a cumulative phase shift .theta..sub.n (t) having a time derivative that may be made uniformly and arbitrarily small; and with the detector means n+1 (1.ltoreq.n

  3. A Web-based Distributed Voluntary Computing Platform for Large Scale Hydrological Computations

    NASA Astrophysics Data System (ADS)

    Demir, I.; Agliamzanov, R.

    2014-12-01

    Distributed volunteer computing can enable researchers and scientist to form large parallel computing environments to utilize the computing power of the millions of computers on the Internet, and use them towards running large scale environmental simulations and models to serve the common good of local communities and the world. Recent developments in web technologies and standards allow client-side scripting languages to run at speeds close to native application, and utilize the power of Graphics Processing Units (GPU). Using a client-side scripting language like JavaScript, we have developed an open distributed computing framework that makes it easy for researchers to write their own hydrologic models, and run them on volunteer computers. Users will easily enable their websites for visitors to volunteer sharing their computer resources to contribute running advanced hydrological models and simulations. Using a web-based system allows users to start volunteering their computational resources within seconds without installing any software. The framework distributes the model simulation to thousands of nodes in small spatial and computational sizes. A relational database system is utilized for managing data connections and queue management for the distributed computing nodes. In this paper, we present a web-based distributed volunteer computing platform to enable large scale hydrological simulations and model runs in an open and integrated environment.

  4. Influence of computational fluid dynamics on experimental aerospace facilities: A fifteen year projection

    NASA Technical Reports Server (NTRS)

    1983-01-01

    An assessment was made of the impact of developments in computational fluid dynamics (CFD) on the traditional role of aerospace ground test facilities over the next fifteen years. With improvements in CFD and more powerful scientific computers projected over this period it is expected to have the capability to compute the flow over a complete aircraft at a unit cost three orders of magnitude lower than presently possible. Over the same period improvements in ground test facilities will progress by application of computational techniques including CFD to data acquisition, facility operational efficiency, and simulation of the light envelope; however, no dramatic change in unit cost is expected as greater efficiency will be countered by higher energy and labor costs.

  5. Computer Power: Part 1: Distribution of Power (and Communications).

    ERIC Educational Resources Information Center

    Price, Bennett J.

    1988-01-01

    Discussion of the distribution of power to personal computers and computer terminals addresses options such as extension cords, perimeter raceways, and interior raceways. Sidebars explain: (1) the National Electrical Code; (2) volts, amps, and watts; (3) transformers, circuit breakers, and circuits; and (4) power vs. data wiring. (MES)

  6. The Penalty of Context-Switch Time in Distributed Computing

    DTIC Science & Technology

    1988-05-13

    Context-switch time is a significant cost in distributed computing , affecting through-put and response time. We report statistics gathered for a large network of Sun 2’s, Sun 3’s and DEC VAX computers.

  7. Developing a Distributed Computing Architecture at Arizona State University.

    ERIC Educational Resources Information Center

    Armann, Neil; And Others

    1994-01-01

    Development of Arizona State University's computing architecture, designed to ensure that all new distributed computing pieces will work together, is described. Aspects discussed include the business rationale, the general architectural approach, characteristics and objectives of the architecture, specific services, and impact on the university…

  8. Pladipus Enables Universal Distributed Computing in Proteomics Bioinformatics.

    PubMed

    Verheggen, Kenneth; Maddelein, Davy; Hulstaert, Niels; Martens, Lennart; Barsnes, Harald; Vaudel, Marc

    2016-03-04

    The use of proteomics bioinformatics substantially contributes to an improved understanding of proteomes, but this novel and in-depth knowledge comes at the cost of increased computational complexity. Parallelization across multiple computers, a strategy termed distributed computing, can be used to handle this increased complexity; however, setting up and maintaining a distributed computing infrastructure requires resources and skills that are not readily available to most research groups. Here we propose a free and open-source framework named Pladipus that greatly facilitates the establishment of distributed computing networks for proteomics bioinformatics tools. Pladipus is straightforward to install and operate thanks to its user-friendly graphical interface, allowing complex bioinformatics tasks to be run easily on a network instead of a single computer. As a result, any researcher can benefit from the increased computational efficiency provided by distributed computing, hence empowering them to tackle more complex bioinformatics challenges. Notably, it enables any research group to perform large-scale reprocessing of publicly available proteomics data, thus supporting the scientific community in mining these data for novel discoveries.

  9. Survey of Computer Facilities in Minnesota and North Dakota.

    ERIC Educational Resources Information Center

    MacGregor, Donald

    In order to attain a better understanding of the data processing manpower needs of business and industry, a survey instrument was designed and mailed to 570 known and possible computer installations in the Minnesota/North Dakota area. The survey was conducted during the spring of 1975, and concentrated on the kinds of equipment and computer…

  10. Computer Programs for Predicting Private Development of Student Housing Facilities.

    ERIC Educational Resources Information Center

    Graaskamp, James A.

    Low cost as well as timely statistics are required of University policy planning decisions regarding student housing. Since a data bank already existed at the University of Wisconsin, a study of student housing needs could readily be undertaken by means of a computer. The study defines the status of the existing supply and demand in student…

  11. NNS computing facility manual P-17 Neutron and Nuclear Science

    SciTech Connect

    Hoeberling, M.; Nelson, R.O.

    1993-11-01

    This document describes basic policies and provides information and examples on using the computing resources provided by P-17, the Neutron and Nuclear Science (NNS) group. Information on user accounts, getting help, network access, electronic mail, disk drives, tape drives, printers, batch processing software, XSYS hints, PC networking hints, and Mac networking hints is given.

  12. Computation, measurement and mitigation of neutral-to-earth potentials on electrical distribution systems

    SciTech Connect

    Dick, W.K.; Winter, D.F.

    1987-04-01

    This paper presents computer generated profiles of primary-neutral-to-earth potentials of electrical distribution systems which incorporate a variety of techniques used to mitigate neutral-to-earth potential (''stray voltage'') at dairy farm facilities. Techniques available to the power supplier and power user include an Electronic Grounding System which provides voltage reduction factors of as much as 200 to 1. A new method of measuring these voltages using a computer data acquisition system which monitors every cycle of the power-frequency voltages on eight totally independent channels for extended periods is described.

  13. Perspectives on distributed computing : thirty people, four user types, and the distributed computing user experience.

    SciTech Connect

    Childers, L.; Liming, L.; Foster, I.; Mathematics and Computer Science; Univ. of Chicago

    2008-10-15

    This report summarizes the methodology and results of a user perspectives study conducted by the Community Driven Improvement of Globus Software (CDIGS) project. The purpose of the study was to document the work-related goals and challenges facing today's scientific technology users, to record their perspectives on Globus software and the distributed-computing ecosystem, and to provide recommendations to the Globus community based on the observations. Globus is a set of open source software components intended to provide a framework for collaborative computational science activities. Rather than attempting to characterize all users or potential users of Globus software, our strategy has been to speak in detail with a small group of individuals in the scientific community whose work appears to be the kind that could benefit from Globus software, learn as much as possible about their work goals and the challenges they face, and describe what we found. The result is a set of statements about specific individuals experiences. We do not claim that these are representative of a potential user community, but we do claim to have found commonalities and differences among the interviewees that may be reflected in the user community as a whole. We present these as a series of hypotheses that can be tested by subsequent studies, and we offer recommendations to Globus developers based on the assumption that these hypotheses are representative. Specifically, we conducted interviews with thirty technology users in the scientific community. We included both people who have used Globus software and those who have not. We made a point of including individuals who represent a variety of roles in scientific projects, for example, scientists, software developers, engineers, and infrastructure providers. The following material is included in this report: (1) A summary of the reported work-related goals, significant issues, and points of satisfaction with the use of Globus software; (2

  14. Distriblets: Java-Based Distributed Computing on the Web.

    ERIC Educational Resources Information Center

    Finkel, David; Wills, Craig E.; Brennan, Brian; Brennan, Chris

    1999-01-01

    Describes a system for using the World Wide Web to distribute computational tasks to multiple hosts on the Web that is written in Java programming language. Describes the programs written to carry out the load distribution, the structure of a "distriblet" class, and experiences in using this system. (Author/LRW)

  15. Issues and recommendations associated with distributed computation and data management systems for the space sciences

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The primary purpose of the report is to explore management approaches and technology developments for computation and data management systems designed to meet future needs in the space sciences.The report builds on work presented in previous reports on solar-terrestrial and planetary reports, broadening the outlook to all of the space sciences, and considering policy issues aspects related to coordiantion between data centers, missions, and ongoing research activities, because it is perceived that the rapid growth of data and the wide geographic distribution of relevant facilities will present especially troublesome problems for data archiving, distribution, and analysis.

  16. Arcade: A Web-Java Based Framework for Distributed Computing

    NASA Technical Reports Server (NTRS)

    Chen, Zhikai; Maly, Kurt; Mehrotra, Piyush; Zubair, Mohammad; Bushnell, Dennis M. (Technical Monitor)

    2000-01-01

    Distributed heterogeneous environments are being increasingly used to execute a variety of large size simulations and computational problems. We are developing Arcade, a web-based environment to design, execute, monitor, and control distributed applications. These targeted applications consist of independent heterogeneous modules which can be executed on a distributed heterogeneous environment. In this paper we describe the overall design of the system and discuss the prototype implementation of the core functionalities required to support such a framework.

  17. Protocols for configuring computation loops on a distributed multiprocessor system

    SciTech Connect

    Woei Lin; Chuan-lin Wu

    1983-01-01

    Protocols for configuring computation loops in a multiprocessing system are examined. Processing nodes are connected by a reconfigurable communication subnet using a multistage interconnection network. Configuration protocols are presented in terms of distributed algorithms such that processing nodes are configured in loop topologies. The configurability of loop topologies is first investigated. It is verified that the communication subnet can emulate loop distributed systems. It is also proven that multiple loops of various lengths can be configured in the distributed network. The technique demonstrated for configuring loop topologies can be used to configure other computation topologies. 6 references.

  18. One approach for evaluating the Distributed Computing Design System (DCDS)

    NASA Technical Reports Server (NTRS)

    Ellis, J. T.

    1985-01-01

    The Distributed Computer Design System (DCDS) provides an integrated environment to support the life cycle of developing real-time distributed computing systems. The primary focus of DCDS is to significantly increase system reliability and software development productivity, and to minimize schedule and cost risk. DCDS consists of integrated methodologies, languages, and tools to support the life cycle of developing distributed software and systems. Smooth and well-defined transistions from phase to phase, language to language, and tool to tool provide a unique and unified environment. An approach to evaluating DCDS highlights its benefits.

  19. Parallel and Distributed Computational Fluid Dynamics: Experimental Results and Challenges

    NASA Technical Reports Server (NTRS)

    Djomehri, Mohammad Jahed; Biswas, R.; VanderWijngaart, R.; Yarrow, M.

    2000-01-01

    This paper describes several results of parallel and distributed computing using a large scale production flow solver program. A coarse grained parallelization based on clustering of discretization grids combined with partitioning of large grids for load balancing is presented. An assessment is given of its performance on distributed and distributed-shared memory platforms using large scale scientific problems. An experiment with this solver, adapted to a Wide Area Network execution environment is presented. We also give a comparative performance assessment of computation and communication times on both the tightly and loosely-coupled machines.

  20. Exact Score Distribution Computation for Similarity Searches in Ontologies

    NASA Astrophysics Data System (ADS)

    Schulz, Marcel H.; Köhler, Sebastian; Bauer, Sebastian; Vingron, Martin; Robinson, Peter N.

    Semantic similarity searches in ontologies are an important component of many bioinformatic algorithms, e.g., protein function prediction with the Gene Ontology. In this paper we consider the exact computation of score distributions for similarity searches in ontologies, and introduce a simple null hypothesis which can be used to compute a P-value for the statistical significance of similarity scores. We concentrate on measures based on Resnik’s definition of ontological similarity. A new algorithm is proposed that collapses subgraphs of the ontology graph and thereby allows fast score distribution computation. The new algorithm is several orders of magnitude faster than the naive approach, as we demonstrate by computing score distributions for similarity searches in the Human Phenotype Ontology.

  1. Computer software configuration management plan for 200 East/West Liquid Effluent Facilities

    SciTech Connect

    Graf, F.A. Jr.

    1995-02-27

    This computer software management configuration plan covers the control of the software for the monitor and control system that operates the Effluent Treatment Facility and its associated truck load in station and some key aspects of the Liquid Effluent Retention Facility that stores condensate to be processed. Also controlled is the Treated Effluent Disposal System`s pumping stations and monitors waste generator flows in this system as well as the Phase Two Effluent Collection System.

  2. COMPUTATIONAL SIMULATION OF REFRIGERATION PROCESS FOR BEPC II SUPERCONDUCTING FACILITIES.

    SciTech Connect

    WANG,L.JIA,L.X.DU,H.P.YANG,G.D.

    2003-09-22

    The main challenge to build the cryogenic system for the Beijing Electron-Positron Collider Upgrade is to accommodate the strong differences among three types of superconducting devices with regard to their structure, location, as well as the cryogenic operating requirement. Three kinds of cooling methods are applied in the overall cryogenic system, saturated liquid helium cooling for the SRF cavities, single-phase helium cooling for the SCQ magnets, and two-phase helium cooling for the SSM solenoid. The optimization for the BEPCII cryogenic system was carried out by using a large-scale computational simulation package. This paper presents thermal parameters and numerical analyses for the BEPCII cryogenic system.

  3. Activities and operations of the Advanced Computing Research Facility, July-October 1986

    SciTech Connect

    Pieper, G.W.

    1986-01-01

    Research activities and operations of the Advanced Computing Research Facility (ACRF) at Argonne National Laboratory are discussed for the period from July 1986 through October 1986. The facility is currently supported by the Department of Energy, and is operated by the Mathematics and Computer Science Division at Argonne. Over the past four-month period, a new commercial multiprocessor, the Intel iPSC-VX/d4 hypercube was installed. In addition, four other commercial multiprocessors continue to be available for research - an Encore Multimax, a Sequent Balance 21000, an Alliant FX/8, and an Intel iPSC/d5 - as well as a locally designed multiprocessor, the Lemur. These machines are being actively used by scientists at Argonne and throughout the nation in a wide variety of projects concerning computer systems with parallel and vector architectures. A variety of classes, workshops, and seminars have been sponsored to train researchers on computing techniques for the advanced computer systems at the Advanced Computing Research Facility. For example, courses were offered on writing programs for parallel computer systems and hosted the first annual Alliant users group meeting. A Sequent users group meeting and a two-day workshop on performance evaluation of parallel computers and programs are being organized.

  4. Peta-scale QMC simulations on DOE leadership computing facilities

    NASA Astrophysics Data System (ADS)

    Kim, Jeongnim; Ab Initio Network Collaboration

    2014-03-01

    Continuum quantum Monte Carlo (QMC) has proved to be an invaluable tool for predicting the properties of matter from fundamental principles. Even with numerous innovations in methods, algorithms and codes, QMC simulations of realistic problems of 1000s and more electrons are demanding, requiring millions of core hours to achieve the target chemical accuracy. The multiple forms of parallelism afforded by QMC algorithms and high compute-to-communication ratio make them ideal candidates for acceleration in the multi/many-core paradigm. We have ported and tuned QMCPACK to recently deployed DOE doca-petaflop systems, Titan (Cray XK7 CPU/GPGPU) and Mira (IBM Blue Gene/Q). The efficiency gains through improved algorithms and architecture-specific tuning and, most importantly, the vast increase in computing powers have opened up opportunities to apply QMC at unprecedent scales, accuracy and time-to-solution. We present large-scale QMC simulations to study energetics of layered materials where vdW interactions play critical roles. Collaboration supported through the Predictive Theory and Modeling for Materials and Chemical Science program by the Basic Energy Science, Department of Energy.

  5. Computer control and data acquisition system for the R. F. Test Facility

    SciTech Connect

    Stewart, K.A.; Burris, R.D.; Mankin, J.B.; Thompson, D.H.

    1986-01-01

    The Radio Frequency Test Facility (RFTF) at Oak Ridge National Laboratory, used to test and evaluate high-power ion cyclotron resonance heating (ICRH) systems and components, is monitored and controlled by a multicomponent computer system. This data acquisition and control system consists of three major hardware elements: (1) an Allen-Bradley PLC-3 programmable controller; (2) a VAX 11/780 computer; and (3) a CAMAC serial highway interface. Operating in LOCAL as well as REMOTE mode, the programmable logic controller (PLC) performs all the control functions of the test facility. The VAX computer acts as the operator's interface to the test facility by providing color mimic panel displays and allowing input via a trackball device. The VAX also provides archiving of trend data acquired by the PLC. Communications between the PLC and the VAX are via the CAMAC serial highway. Details of the hardware, software, and the operation of the system are presented in this paper.

  6. Computational Tools and Facilities for the Next-Generation Analysis and Design Environment

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K. (Compiler); Malone, John B. (Compiler)

    1997-01-01

    This document contains presentations from the joint UVA/NASA Workshop on Computational Tools and Facilities for the Next-Generation Analysis and Design Environment held at the Virginia Consortium of Engineering and Science Universities in Hampton, Virginia on September 17-18, 1996. The presentations focused on the computational tools and facilities for analysis and design of engineering systems, including, real-time simulations, immersive systems, collaborative engineering environment, Web-based tools and interactive media for technical training. Workshop attendees represented NASA, commercial software developers, the aerospace industry, government labs, and academia. The workshop objectives were to assess the level of maturity of a number of computational tools and facilities and their potential for application to the next-generation integrated design environment.

  7. Bringing the CMS distributed computing system into scalable operations

    NASA Astrophysics Data System (ADS)

    Belforte, S.; Fanfani, A.; Fisk, I.; Flix, J.; Hernández, J. M.; Kress, T.; Letts, J.; Magini, N.; Miccio, V.; Sciabà, A.

    2010-04-01

    Establishing efficient and scalable operations of the CMS distributed computing system critically relies on the proper integration, commissioning and scale testing of the data and workload management tools, the various computing workflows and the underlying computing infrastructure, located at more than 50 computing centres worldwide and interconnected by the Worldwide LHC Computing Grid. Computing challenges periodically undertaken by CMS in the past years with increasing scale and complexity have revealed the need for a sustained effort on computing integration and commissioning activities. The Processing and Data Access (PADA) Task Force was established at the beginning of 2008 within the CMS Computing Program with the mandate of validating the infrastructure for organized processing and user analysis including the sites and the workload and data management tools, validating the distributed production system by performing functionality, reliability and scale tests, helping sites to commission, configure and optimize the networking and storage through scale testing data transfers and data processing, and improving the efficiency of accessing data across the CMS computing system from global transfers to local access. This contribution reports on the tools and procedures developed by CMS for computing commissioning and scale testing as well as the improvements accomplished towards efficient, reliable and scalable computing operations. The activities include the development and operation of load generators for job submission and data transfers with the aim of stressing the experiment and Grid data management and workload management systems, site commissioning procedures and tools to monitor and improve site availability and reliability, as well as activities targeted to the commissioning of the distributed production, user analysis and monitoring systems.

  8. Computational Analyses in Support of Sub-scale Diffuser Testing for the A-3 Facility. Part 1; Steady Predictions

    NASA Technical Reports Server (NTRS)

    Allgood, Daniel C.; Graham, Jason S.; Ahuja, Vineet; Hosangadi, Ashvin

    2008-01-01

    levels in CFD based flowpath modeling of the facility. The analyses tools used here expand on the multi-element unstructured CFD which has been tailored and validated for impingement dynamics of dry plumes, complex valve/feed systems, and high pressure propellant delivery systems used in engine and component test stands at NASA SSC. The analyses performed in the evaluation of the sub-scale diffuser facility explored several important factors that influence modeling and understanding of facility operation such as (a) importance of modeling the facility with Real Gas approximation, (b) approximating the cluster of steam ejector nozzles as a single annular nozzle, (c) existence of mixed subsonic/supersonic flow downstream of the turning duct, and (d) inadequacy of two-equation turbulence models in predicting the correct pressurization in the turning duct and expansion of the second stage steam ejectors. The procedure used for modeling the facility was as follows: (i) The engine, test cell and first stage ejectors were simulated with an axisymmetric approximation (ii) the turning duct, second stage ejectors and the piping downstream of the second stage ejectors were analyzed with a three-dimensional simulation utilizing a half-plane symmetry approximation. The solution i.e. primitive variables such as pressure, velocity components, temperature and turbulence quantities were passed from the first computational domain and specified as a supersonic boundary condition for the second simulation. (iii) The third domain comprised of the exit diffuser and the region in the vicinity of the facility (primary included to get the correct shock structure at the exit of the facility and entrainment characteristics). The first set of simulations comprising the engine, test cell and first stage ejectors was carried out both as a turbulent real gas calculation as well as a turbulent perfect gas calculation. A comparison for the two cases (Real Turbulent and Perfect gas turbulent) of the Ma

  9. Computational Analyses in Support of Sub-scale Diffuser Testing for the A-3 Facility. Part 1; Steady Predictions

    NASA Technical Reports Server (NTRS)

    Allgood, Daniel C.; Graham, Jason S.; Ahuja, Vineet; Hosangadi, Ashvin

    2010-01-01

    levels in CFD based flowpath modeling of the facility. The analyses tools used here expand on the multi-element unstructured CFD which has been tailored and validated for impingement dynamics of dry plumes, complex valve/feed systems, and high pressure propellant delivery systems used in engine and component test stands at NASA SSC. The analyses performed in the evaluation of the sub-scale diffuser facility explored several important factors that influence modeling and understanding of facility operation such as (a) importance of modeling the facility with Real Gas approximation, (b) approximating the cluster of steam ejector nozzles as a single annular nozzle, (c) existence of mixed subsonic/supersonic flow downstream of the turning duct, and (d) inadequacy of two-equation turbulence models in predicting the correct pressurization in the turning duct and expansion of the second stage steam ejectors. The procedure used for modeling the facility was as follows: (i) The engine, test cell and first stage ejectors were simulated with an axisymmetric approximation (ii) the turning duct, second stage ejectors and the piping downstream of the second stage ejectors were analyzed with a three-dimensional simulation utilizing a half-plane symmetry approximation. The solution i.e. primitive variables such as pressure, velocity components, temperature and turbulence quantities were passed from the first computational domain and specified as a supersonic boundary condition for the second simulation. (iii) The third domain comprised of the exit diffuser and the region in the vicinity of the facility (primary included to get the correct shock structure at the exit of the facility and entrainment characteristics). The first set of simulations comprising the engine, test cell and first stage ejectors was carried out both as a turbulent real gas calculation as well as a turbulent perfect gas calculation. A comparison for the two cases (Real Turbulent and Perfect gas turbulent) of the Ma

  10. Status of the National Ignition Facility Integrated Computer Control System (ICCS) on the Path to Ignition

    SciTech Connect

    Lagin, L J; Bettenhauasen, R C; Bowers, G A; Carey, R W; Edwards, O D; Estes, C M; Demaret, R D; Ferguson, S W; . Fisher, J M; Ho, J C; Ludwigsen, A P; Mathisen, D G; Marshall, C D; Matone, J M; McGuigan, D L; Sanchez, R J; Shelton, R T; Stout, E A; Tekle, E; Townsend, S L; Van Arsdall, P J; Wilson, E F

    2007-09-11

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory is a stadium-sized facility under construction that will contain a 192-beam, 1.8-Megajoule, 500-Terawatt, ultraviolet laser system together with a 10-meter diameter target chamber with room for multiple experimental diagnostics. NIF is the world's largest and most energetic laser experimental system, providing a scientific center to study inertial confinement fusion (ICF) and matter at extreme energy densities and pressures. NIF's laser beams are designed to compress fusion targets to conditions required for thermonuclear burn, liberating more energy than required to initiate the fusion reactions. NIF is comprised of 24 independent bundles of 8 beams each using laser hardware that is modularized into more than 6,000 line replaceable units such as optical assemblies, laser amplifiers, and multifunction sensor packages containing 60,000 control and diagnostic points. NIF is operated by the large-scale Integrated Computer Control System (ICCS) in an architecture partitioned by bundle and distributed among over 800 front-end processors and 50 supervisory servers. NIF's automated control subsystems are built from a common object-oriented software framework based on CORBA distribution that deploys the software across the computer network and achieves interoperation between different languages and target architectures. A shot automation framework has been deployed during the past year to orchestrate and automate shots performed at the NIF using the ICCS. In December 2006, a full cluster of 48 beams of NIF was fired simultaneously, demonstrating that the independent bundle control system will scale to full scale of 192 beams. At present, 72 beams have been commissioned and have demonstrated 1.4-Megajoule capability of infrared light. During the next two years, the control system will be expanded to include automation of target area systems including final optics, target positioners and

  11. Computer/information security design approaches for Complex 21/Reconfiguration facilities

    SciTech Connect

    Hunteman, W.J.; Zack, N.R.; Jaeger, C.D.

    1993-08-01

    Los Alamos National Laboratory and Sandia National Laboratories have been designated the technical lead laboratories to develop the design of the computer/information security, safeguards, and physical security systems for all of the DOE Complex 21/Reconfiguration facilities. All of the automated information processing systems and networks in these facilities will be required to implement the new DOE orders on computer and information security. The planned approach for a highly integrated information processing capability in each of the facilities will require careful consideration of the requirements in DOE Orders 5639.6 and 1360.2A. The various information protection requirements and user clearances within the facilities will also have a significant effect on the design of the systems and networks. Fulfilling the requirements for proper protection of the information and compliance with DOE orders will be possible because the computer and information security concerns are being incorporated in the early design activities. This paper will discuss the computer and information security addressed in the integrated design effort, uranium/lithium, plutonium, plutonium high explosive/assembly facilities.

  12. 41 CFR 101-26.503 - Multiple award schedule purchases made by GSA supply distribution facilities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Multiple award schedule... Multiple award schedule purchases made by GSA supply distribution facilities. GSA supply distribution... items. Stocking a variety of commercial, high-demand items purchased from FSS multiple award...

  13. LBNL Computational Research and Theory Facility Groundbreaking. February 1st, 2012

    SciTech Connect

    Yelick, Kathy

    2012-01-01

    Energy Secretary Steven Chu, along with Berkeley Lab and UC leaders, broke ground on the Lab's Computational Research and Theory (CRT) facility yesterday. The CRT will be at the forefront of high-performance supercomputing research and be DOE's most efficient facility of its kind. Joining Secretary Chu as speakers were Lab Director Paul Alivisatos, UC President Mark Yudof, Office of Science Director Bill Brinkman, and UC Berkeley Chancellor Robert Birgeneau. The festivities were emceed by Associate Lab Director for Computing Sciences, Kathy Yelick, and Berkeley Mayor Tom Bates joined in the shovel ceremony.

  14. LBNL Computational Research and Theory Facility Groundbreaking. February 1st, 2012

    ScienceCinema

    Yelick, Kathy

    2016-07-12

    Energy Secretary Steven Chu, along with Berkeley Lab and UC leaders, broke ground on the Lab's Computational Research and Theory (CRT) facility yesterday. The CRT will be at the forefront of high-performance supercomputing research and be DOE's most efficient facility of its kind. Joining Secretary Chu as speakers were Lab Director Paul Alivisatos, UC President Mark Yudof, Office of Science Director Bill Brinkman, and UC Berkeley Chancellor Robert Birgeneau. The festivities were emceed by Associate Lab Director for Computing Sciences, Kathy Yelick, and Berkeley Mayor Tom Bates joined in the shovel ceremony.

  15. LBNL Computational Research & Theory Facility Groundbreaking - Full Press Conference. Feb 1st, 2012

    ScienceCinema

    Yelick, Kathy

    2016-07-12

    Energy Secretary Steven Chu, along with Berkeley Lab and UC leaders, broke ground on the Lab's Computational Research and Theory (CRT) facility yesterday. The CRT will be at the forefront of high-performance supercomputing research and be DOE's most efficient facility of its kind. Joining Secretary Chu as speakers were Lab Director Paul Alivisatos, UC President Mark Yudof, Office of Science Director Bill Brinkman, and UC Berkeley Chancellor Robert Birgeneau. The festivities were emceed by Associate Lab Director for Computing Sciences, Kathy Yelick, and Berkeley Mayor Tom Bates joined in the shovel ceremony.

  16. Online measurement of dose and dose distribution at bremsstrahlung facilities

    NASA Astrophysics Data System (ADS)

    Auslender, V. L.; Bryazgin, A. A.; Bukin, A. D.; Voronin, L. A.; Lukin, A. N.; Sidorov, A. V.

    2004-09-01

    A real-time measurement system of the spatial dose distribution is developed and realized for monitoring the bremsstrahlung flow generated on X-ray target by 5 MeV 50 kW electron accelerator. The sensors of the system consist of semiconductor diodes. The beam target and electron accelerator (ILU-10) are briefly described. The practice of using the system in the experimental and start-up procedure is included.

  17. New security infrastructure model for distributed computing systems

    NASA Astrophysics Data System (ADS)

    Dubenskaya, J.; Kryukov, A.; Demichev, A.; Prikhodko, N.

    2016-02-01

    At the paper we propose a new approach to setting up a user-friendly and yet secure authentication and authorization procedure in a distributed computing system. The security concept of the most heterogeneous distributed computing systems is based on the public key infrastructure along with proxy certificates which are used for rights delegation. In practice a contradiction between the limited lifetime of the proxy certificates and the unpredictable time of the request processing is a big issue for the end users of the system. We propose to use unlimited in time hashes which are individual for each request instead of proxy certificate. Our approach allows to avoid using of the proxy certificates. Thus the security infrastructure of distributed computing system becomes easier for development, support and use.

  18. Computation of glint, glare, and solar irradiance distribution

    DOEpatents

    Ho, Clifford Kuofei; Khalsa, Siri Sahib Singh

    2015-08-11

    Described herein are technologies pertaining to computing the solar irradiance distribution on a surface of a receiver in a concentrating solar power system or glint/glare emitted from a reflective entity. At least one camera captures images of the Sun and the entity of interest, wherein the images have pluralities of pixels having respective pluralities of intensity values. Based upon the intensity values of the pixels in the respective images, the solar irradiance distribution on the surface of the entity or glint/glare corresponding to the entity is computed.

  19. Distributed computer taxonomy based on O/S structure

    NASA Technical Reports Server (NTRS)

    Foudriat, Edwin C.

    1985-01-01

    The taxonomy considers the resource structure at the operating system level. It compares a communication based taxonomy with the new taxonomy to illustrate how the latter does a better job when related to the client's view of the distributed computer. The results illustrate the fundamental features and what is required to construct fully distributed processing systems. The problem of using network computers on the space station is addressed. A detailed discussion of the taxonomy is not given here. Information is given in the form of charts and diagrams that were used to illustrate a talk.

  20. First Experiences with LHC Grid Computing and Distributed Analysis

    SciTech Connect

    Fisk, Ian

    2010-12-01

    In this presentation the experiences of the LHC experiments using grid computing were presented with a focus on experience with distributed analysis. After many years of development, preparation, exercises, and validation the LHC (Large Hadron Collider) experiments are in operations. The computing infrastructure has been heavily utilized in the first 6 months of data collection. The general experience of exploiting the grid infrastructure for organized processing and preparation is described, as well as the successes employing the infrastructure for distributed analysis. At the end the expected evolution and future plans are outlined.

  1. A directory service for configuring high-performance distributed computations

    SciTech Connect

    Fitzgerald, S.; Kesselman, C.; Foster, I.

    1997-08-01

    High-performance execution in distributed computing environments often requires careful selection and configuration not only of computers, networks, and other resources but also of the protocols and algorithms used by applications. Selection and configuration in turn require access to accurate, up-to-date information on the structure and state of available resources. Unfortunately, no standard mechanism exists for organizing or accessing such information. Consequently, different tools and applications adopt ad hoc mechanisms, or they compromise their portability and performance by using default configurations. We propose a Metacomputing Directory Service that provides efficient and scalable access to diverse, dynamic, and distributed information about resource structure and state. We define an extensible data model to represent required information and present a scalable, high-performance, distributed implementation. The data representation and application programming interface are adopted from the Lightweight Directory Access Protocol; the data model and implementation are new. We use the Globus distributed computing toolkit to illustrate how this directory service enables the development of more flexible and efficient distributed computing services and applications.

  2. Distributed computing system with dual independent communications paths between computers and employing split tokens

    NASA Technical Reports Server (NTRS)

    Rasmussen, Robert D. (Inventor); Manning, Robert M. (Inventor); Lewis, Blair F. (Inventor); Bolotin, Gary S. (Inventor); Ward, Richard S. (Inventor)

    1990-01-01

    This is a distributed computing system providing flexible fault tolerance; ease of software design and concurrency specification; and dynamic balance of the loads. The system comprises a plurality of computers each having a first input/output interface and a second input/output interface for interfacing to communications networks each second input/output interface including a bypass for bypassing the associated computer. A global communications network interconnects the first input/output interfaces for providing each computer the ability to broadcast messages simultaneously to the remainder of the computers. A meshwork communications network interconnects the second input/output interfaces providing each computer with the ability to establish a communications link with another of the computers bypassing the remainder of computers. Each computer is controlled by a resident copy of a common operating system. Communications between respective ones of computers is by means of split tokens each having a moving first portion which is sent from computer to computer and a resident second portion which is disposed in the memory of at least one of computer and wherein the location of the second portion is part of the first portion. The split tokens represent both functions to be executed by the computers and data to be employed in the execution of the functions. The first input/output interfaces each include logic for detecting a collision between messages and for terminating the broadcasting of a message whereby collisions between messages are detected and avoided.

  3. Next Generation Workload Management System For Big Data on Heterogeneous Distributed Computing

    NASA Astrophysics Data System (ADS)

    Klimentov, A.; Buncic, P.; De, K.; Jha, S.; Maeno, T.; Mount, R.; Nilsson, P.; Oleynik, D.; Panitkin, S.; Petrosyan, A.; Porter, R. J.; Read, K. F.; Vaniachine, A.; Wells, J. C.; Wenaus, T.

    2015-05-01

    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 and ALICE are the largest collaborations ever assembled in the sciences and are at the forefront of research at the LHC. To address an unprecedented multi-petabyte data processing challenge, both experiments rely on a heterogeneous distributed computational infrastructure. The ATLAS experiment uses PanDA (Production and Data Analysis) Workload Management System (WMS) for managing the workflow for all data processing on hundreds of 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. The scale is demonstrated by the following numbers: PanDA manages O(102) sites, O(105) cores, O(108) jobs per year, O(103) users, and ATLAS data volume is O(1017) bytes. In 2013 we started an ambitious program to expand PanDA to all available computing resources, including opportunistic use of commercial and academic clouds and Leadership Computing Facilities (LCF). The project titled ‘Next Generation Workload Management and Analysis System for Big Data’ (BigPanDA) is funded by DOE ASCR and HEP. Extending PanDA to clouds and LCF presents new challenges in managing heterogeneity and supporting workflow. The BigPanDA project is underway to setup and tailor PanDA at the Oak Ridge Leadership Computing Facility (OLCF) and at the National Research Center "Kurchatov Institute" together with ALICE distributed computing and ORNL computing professionals. Our approach to integration of HPC platforms at the OLCF and elsewhere is to reuse, as much as possible, existing components of the PanDA system. We

  4. Next Generation Workload Management System For Big Data on Heterogeneous Distributed Computing

    SciTech Connect

    Klimentov, A.; Buncic, P.; De, K.; Jha, S.; Maeno, T.; Mount, R.; Nilsson, P.; Oleynik, D.; Panitkin, S.; Petrosyan, A.; Porter, R. J.; Read, K. F.; Vaniachine, A.; Wells, J. C.; Wenaus, T.

    2015-05-22

    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 and ALICE are the largest collaborations ever assembled in the sciences and are at the forefront of research at the LHC. To address an unprecedented multi-petabyte data processing challenge, both experiments rely on a heterogeneous distributed computational infrastructure. The ATLAS experiment uses PanDA (Production and Data Analysis) Workload Management System (WMS) for managing the workflow for all data processing on hundreds of 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. The scale is demonstrated by the following numbers: PanDA manages O(102) sites, O(105) cores, O(108) jobs per year, O(103) users, and ATLAS data volume is O(1017) bytes. In 2013 we started an ambitious program to expand PanDA to all available computing resources, including opportunistic use of commercial and academic clouds and Leadership Computing Facilities (LCF). The project titled 'Next Generation Workload Management and Analysis System for Big Data' (BigPanDA) is funded by DOE ASCR and HEP. Extending PanDA to clouds and LCF presents new challenges in managing heterogeneity and supporting workflow. The BigPanDA project is underway to setup and tailor PanDA at the Oak Ridge Leadership Computing Facility (OLCF) and at the National Research Center "Kurchatov Institute" together with ALICE distributed computing and ORNL computing professionals. Our approach to integration of HPC platforms at the OLCF and elsewhere is to reuse, as much as

  5. Next Generation Workload Management System For Big Data on Heterogeneous Distributed Computing

    DOE PAGES

    Klimentov, A.; Buncic, P.; De, K.; ...

    2015-05-22

    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 and ALICE are the largest collaborations ever assembled in the sciences and are at the forefront of research at the LHC. To address an unprecedented multi-petabyte data processing challenge, both experiments rely on a heterogeneous distributed computational infrastructure. The ATLAS experiment uses PanDA (Production and Data Analysis) Workload Managementmore » System (WMS) for managing the workflow for all data processing on hundreds of 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. The scale is demonstrated by the following numbers: PanDA manages O(102) sites, O(105) cores, O(108) jobs per year, O(103) users, and ATLAS data volume is O(1017) bytes. In 2013 we started an ambitious program to expand PanDA to all available computing resources, including opportunistic use of commercial and academic clouds and Leadership Computing Facilities (LCF). The project titled 'Next Generation Workload Management and Analysis System for Big Data' (BigPanDA) is funded by DOE ASCR and HEP. Extending PanDA to clouds and LCF presents new challenges in managing heterogeneity and supporting workflow. The BigPanDA project is underway to setup and tailor PanDA at the Oak Ridge Leadership Computing Facility (OLCF) and at the National Research Center "Kurchatov Institute" together with ALICE distributed computing and ORNL computing professionals. Our approach to integration of HPC platforms at the OLCF and elsewhere is to reuse, as much as possible, existing components of the PanDA system

  6. A digital computer propulsion control facility: Description of capabilities and summary of experimental program results

    NASA Technical Reports Server (NTRS)

    Zeller, J. R.; Arpasi, D. J.; Lehtinen, B.

    1976-01-01

    Flight weight digital computers are being used today to carry out many of the propulsion system control functions previously delegated exclusively to hydromechanical controllers. An operational digital computer facility for propulsion control mode studies has been used successfully in several experimental programs. This paper describes the system and some of the results concerned with engine control, inlet control, and inlet engine integrated control. Analytical designs for the digital propulsion control modes include both classical and modern/optimal techniques.

  7. Evolution of facility layout requirements and CAD (computer-aided design) system development

    SciTech Connect

    Jones, M. )

    1990-06-01

    The overall configuration of the Superconducting Super Collider (SSC) including the infrastructure and land boundary requirements were developed using a computer-aided design (CAD) system. The evolution of the facility layout requirements and the use of the CAD system are discussed. The emphasis has been on minimizing the amount of input required and maximizing the speed by which the output may be obtained. The computer system used to store the data is also described.

  8. The CT Scanner Facility at Stellenbosch University: An open access X-ray computed tomography laboratory

    NASA Astrophysics Data System (ADS)

    du Plessis, Anton; le Roux, Stephan Gerhard; Guelpa, Anina

    2016-10-01

    The Stellenbosch University CT Scanner Facility is an open access laboratory providing non-destructive X-ray computed tomography (CT) and a high performance image analysis services as part of the Central Analytical Facilities (CAF) of the university. Based in Stellenbosch, South Africa, this facility offers open access to the general user community, including local researchers, companies and also remote users (both local and international, via sample shipment and data transfer). The laboratory hosts two CT instruments, i.e. a micro-CT system, as well as a nano-CT system. A workstation-based Image Analysis Centre is equipped with numerous computers with data analysis software packages, which are to the disposal of the facility users, along with expert supervision, if required. All research disciplines are accommodated at the X-ray CT laboratory, provided that non-destructive analysis will be beneficial. During its first four years, the facility has accommodated more than 400 unique users (33 in 2012; 86 in 2013; 154 in 2014; 140 in 2015; 75 in first half of 2016), with diverse industrial and research applications using X-ray CT as means. This paper summarises the existence of the laboratory's first four years by way of selected examples, both from published and unpublished projects. In the process a detailed description of the capabilities and facilities available to users is presented.

  9. MIP models for connected facility location: A theoretical and computational study☆

    PubMed Central

    Gollowitzer, Stefan; Ljubić, Ivana

    2011-01-01

    This article comprises the first theoretical and computational study on mixed integer programming (MIP) models for the connected facility location problem (ConFL). ConFL combines facility location and Steiner trees: given a set of customers, a set of potential facility locations and some inter-connection nodes, ConFL searches for the minimum-cost way of assigning each customer to exactly one open facility, and connecting the open facilities via a Steiner tree. The costs needed for building the Steiner tree, facility opening costs and the assignment costs need to be minimized. We model ConFL using seven compact and three mixed integer programming formulations of exponential size. We also show how to transform ConFL into the Steiner arborescence problem. A full hierarchy between the models is provided. For two exponential size models we develop a branch-and-cut algorithm. An extensive computational study is based on two benchmark sets of randomly generated instances with up to 1300 nodes and 115,000 edges. We empirically compare the presented models with respect to the quality of obtained bounds and the corresponding running time. We report optimal values for all but 16 instances for which the obtained gaps are below 0.6%. PMID:25009366

  10. The future of PanDA in ATLAS distributed computing

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    Experiments at the Large Hadron Collider (LHC) face unprecedented computing challenges. Heterogeneous resources are distributed worldwide at hundreds of sites, thousands of physicists analyse the data remotely, the volume of processed data is beyond the exabyte scale, while data processing requires more than a few billion hours of computing usage per year. The PanDA (Production and Distributed Analysis) system was developed to meet the scale and complexity of LHC distributed computing for the ATLAS experiment. In the process, the old batch job paradigm of locally managed computing in HEP was discarded in favour of a far more automated, flexible and scalable model. The success of PanDA in ATLAS is leading to widespread adoption and testing by other experiments. PanDA is the first exascale workload management system in HEP, already operating at more than a million computing jobs per day, and processing over an exabyte of data in 2013. There are many new challenges that PanDA will face in the near future, in addition to new challenges of scale, heterogeneity and increasing user base. PanDA will need to handle rapidly changing computing infrastructure, will require factorization of code for easier deployment, will need to incorporate additional information sources including network metrics in decision making, be able to control network circuits, handle dynamically sized workload processing, provide improved visualization, and face many other challenges. In this talk we will focus on the new features, planned or recently implemented, that are relevant to the next decade of distributed computing workload management using PanDA.

  11. 300 Area Treated Effluent Disposal Facility computer software release cover sheet and revision record

    SciTech Connect

    McCarthy, R.J.

    1994-11-28

    This supporting document contains the computer software release cover sheet and revision records for the 300 Area Treated Effluent Disposal Facility (TEDF). The previous revision was controlled by CH2M Hill which developed the software. A 7-page listing of the contents of directory C:{backslash}TEDF is contained in this report.

  12. An approach to experimental evaluation of real-time fault-tolerant distributed computing schemes

    NASA Technical Reports Server (NTRS)

    Kim, K. H.

    1989-01-01

    A testbed-based approach to the evaluation of fault-tolerant distributed computing schemes is discussed. The approach is based on experimental incorporation of system structuring and design techniques into real-time distributed-computing testbeds centered around tightly coupled microcomputer networks. The effectiveness of this approach has been experimentally confirmed. Primary advantages of this approach include the accuracy of the timing and logical-complexity data and the degree of assurance of the practical effectiveness of the scheme evaluated. Various design issues encountered in the course of establishing the network testbed facilities are discussed, along with their augmentation to support some experiments. The shortcomings of the testbeds are also discussed together with the desired extensions of the testbeds.

  13. CMS Monte Carlo production operations in a distributed computing environment

    SciTech Connect

    Mohapatra, A.; Lazaridis, C.; Hernandez, J.M.; Caballero, J.; Hof, C.; Kalinin, S.; Flossdorf, A.; Abbrescia, M.; De Filippis, N.; Donvito, G.; Maggi, G.; /Bari U. /INFN, Bari /INFN, Pisa /Vrije U., Brussels /Brussels U. /Imperial Coll., London /CERN /Princeton U. /Fermilab

    2008-01-01

    Monte Carlo production for the CMS experiment is carried out in a distributed computing environment; the goal of producing 30M simulated events per month in the first half of 2007 has been reached. A brief overview of the production operations and statistics is presented.

  14. Distributed Computing with Centralized Support Works at Brigham Young.

    ERIC Educational Resources Information Center

    McDonald, Kelly; Stone, Brad

    1992-01-01

    Brigham Young University (Utah) has addressed the need for maintenance and support of distributed computing systems on campus by implementing a program patterned after a national business franchise, providing the support and training of a centralized administration but allowing each unit to operate much as an independent small business.…

  15. Chandrasekhar equations and computational algorithms for distributed parameter systems

    NASA Technical Reports Server (NTRS)

    Burns, J. A.; Ito, K.; Powers, R. K.

    1984-01-01

    The Chandrasekhar equations arising in optimal control problems for linear distributed parameter systems are considered. The equations are derived via approximation theory. This approach is used to obtain existence, uniqueness, and strong differentiability of the solutions and provides the basis for a convergent computation scheme for approximating feedback gain operators. A numerical example is presented to illustrate these ideas.

  16. A fault detection service for wide area distributed computations.

    SciTech Connect

    Stelling, P.

    1998-06-09

    The potential for faults in distributed computing systems is a significant complicating factor for application developers. While a variety of techniques exist for detecting and correcting faults, the implementation of these techniques in a particular context can be difficult. Hence, we propose a fault detection service designed to be incorporated, in a modular fashion, into distributed computing systems, tools, or applications. This service uses well-known techniques based on unreliable fault detectors to detect and report component failure, while allowing the user to tradeoff timeliness of reporting against false positive rates. We describe the architecture of this service, report on experimental results that quantify its cost and accuracy, and describe its use in two applications, monitoring the status of system components of the GUSTO computational grid testbed and as part of the NetSolve network-enabled numerical solver.

  17. Accelerating Computation of DNA Sequence Alignment in Distributed Environment

    NASA Astrophysics Data System (ADS)

    Guo, Tao; Li, Guiyang; Deaton, Russel

    Sequence similarity and alignment are most important operations in computational biology. However, analyzing large sets of DNA sequence seems to be impractical on a regular PC. Using multiple threads with JavaParty mechanism, this project has successfully implemented in extending the capabilities of regular Java to a distributed environment for simulation of DNA computation. With the aid of JavaParty and the design of multiple threads, the results of this study demonstrated that the modified regular Java program could perform parallel computing without using RMI or socket communication. In this paper, an efficient method for modeling and comparing DNA sequences with dynamic programming and JavaParty was firstly proposed. Additionally, results of this method in distributed environment have been discussed.

  18. Parallelization of Finite Element Analysis Codes Using Heterogeneous Distributed Computing

    NASA Technical Reports Server (NTRS)

    Ozguner, Fusun

    1996-01-01

    Performance gains in computer design are quickly consumed as users seek to analyze larger problems to a higher degree of accuracy. Innovative computational methods, such as parallel and distributed computing, seek to multiply the power of existing hardware technology to satisfy the computational demands of large applications. In the early stages of this project, experiments were performed using two large, coarse-grained applications, CSTEM and METCAN. These applications were parallelized on an Intel iPSC/860 hypercube. It was found that the overall speedup was very low, due to large, inherently sequential code segments present in the applications. The overall execution time T(sub par), of the application is dependent on these sequential segments. If these segments make up a significant fraction of the overall code, the application will have a poor speedup measure.

  19. Performance Assessment of OVERFLOW on Distributed Computing Environment

    NASA Technical Reports Server (NTRS)

    Djomehri, M. Jahed; Rizk, Yehia M.

    2000-01-01

    The aerodynamic computer code, OVERFLOW, with a multi-zone overset grid feature, has been parallelized to enhance its performance on distributed and shared memory paradigms. Practical application benchmarks have been set to assess the efficiency of code's parallelism on high-performance architectures. The code's performance has also been experimented with in the context of the distributed computing paradigm on distant computer resources using the Information Power Grid (IPG) toolkit, Globus. Two parallel versions of the code, namely OVERFLOW-MPI and -MLP, have developed around the natural coarse grained parallelism inherent in a multi-zonal domain decomposition paradigm. The algorithm invokes a strategy that forms a number of groups, each consisting of a zone, a cluster of zones and/or a partition of a large zone. Each group can be thought of as a process with one or multithreads assigned to it and that all groups run in parallel. The -MPI version of the code uses explicit message-passing based on the standard MPI library for sending and receiving interzonal boundary data across processors. The -MLP version employs no message-passing paradigm; the boundary data is transferred through the shared memory. The -MPI code is suited for both distributed and shared memory architectures, while the -MLP code can only be used on shared memory platforms. The IPG applications are implemented by the -MPI code using the Globus toolkit. While a computational task is distributed across multiple computer resources, the parallelism can be explored on each resource alone. Performance studies are achieved with some practical aerodynamic problems with complex geometries, consisting of 2.5 up to 33 million grid points and a large number of zonal blocks. The computations were executed primarily on SGI Origin 2000 multiprocessors and on the Cray T3E. OVERFLOW's IPG applications are carried out on NASA homogeneous metacomputing machines located at three sites, Ames, Langley and Glenn. Plans

  20. Feasibility Study for a Remote Terminal Central Computing Facility Serving School and College Institutions. Volume I, Functional Requirements.

    ERIC Educational Resources Information Center

    International Business Machines Corp., White Plains, NY.

    The economic and technical feasibility of providing a remote terminal central computing facility to serve a group of 25-75 secondary schools and colleges was investigated. The general functions of a central facility for an educational cluster were defined to include training in computer techniques, the solution of student development problems in…

  1. Computational strategies for three-dimensional flow simulations on distributed computer systems

    NASA Technical Reports Server (NTRS)

    Sankar, Lakshmi N.; Weed, Richard A.

    1995-01-01

    This research effort is directed towards an examination of issues involved in porting large computational fluid dynamics codes in use within the industry to a distributed computing environment. This effort addresses strategies for implementing the distributed computing in a device independent fashion and load balancing. A flow solver called TEAM presently in use at Lockheed Aeronautical Systems Company was acquired to start this effort. The following tasks were completed: (1) The TEAM code was ported to a number of distributed computing platforms including a cluster of HP workstations located in the School of Aerospace Engineering at Georgia Tech; a cluster of DEC Alpha Workstations in the Graphics visualization lab located at Georgia Tech; a cluster of SGI workstations located at NASA Ames Research Center; and an IBM SP-2 system located at NASA ARC. (2) A number of communication strategies were implemented. Specifically, the manager-worker strategy and the worker-worker strategy were tested. (3) A variety of load balancing strategies were investigated. Specifically, the static load balancing, task queue balancing and the Crutchfield algorithm were coded and evaluated. (4) The classical explicit Runge-Kutta scheme in the TEAM solver was replaced with an LU implicit scheme. And (5) the implicit TEAM-PVM solver was extensively validated through studies of unsteady transonic flow over an F-5 wing, undergoing combined bending and torsional motion. These investigations are documented in extensive detail in the dissertation, 'Computational Strategies for Three-Dimensional Flow Simulations on Distributed Computing Systems', enclosed as an appendix.

  2. Computational strategies for three-dimensional flow simulations on distributed computer systems

    NASA Astrophysics Data System (ADS)

    Sankar, Lakshmi N.; Weed, Richard A.

    1995-08-01

    This research effort is directed towards an examination of issues involved in porting large computational fluid dynamics codes in use within the industry to a distributed computing environment. This effort addresses strategies for implementing the distributed computing in a device independent fashion and load balancing. A flow solver called TEAM presently in use at Lockheed Aeronautical Systems Company was acquired to start this effort. The following tasks were completed: (1) The TEAM code was ported to a number of distributed computing platforms including a cluster of HP workstations located in the School of Aerospace Engineering at Georgia Tech; a cluster of DEC Alpha Workstations in the Graphics visualization lab located at Georgia Tech; a cluster of SGI workstations located at NASA Ames Research Center; and an IBM SP-2 system located at NASA ARC. (2) A number of communication strategies were implemented. Specifically, the manager-worker strategy and the worker-worker strategy were tested. (3) A variety of load balancing strategies were investigated. Specifically, the static load balancing, task queue balancing and the Crutchfield algorithm were coded and evaluated. (4) The classical explicit Runge-Kutta scheme in the TEAM solver was replaced with an LU implicit scheme. And (5) the implicit TEAM-PVM solver was extensively validated through studies of unsteady transonic flow over an F-5 wing, undergoing combined bending and torsional motion. These investigations are documented in extensive detail in the dissertation, 'Computational Strategies for Three-Dimensional Flow Simulations on Distributed Computing Systems', enclosed as an appendix.

  3. A fission matrix based validation protocol for computed power distributions in the advanced test reactor

    SciTech Connect

    Nielsen, J. W.; Nigg, D. W.; LaPorta, A. W.

    2013-07-01

    The Idaho National Laboratory (INL) has been engaged in a significant multi year effort to modernize the computational reactor physics tools and validation procedures used to support operations of the Advanced Test Reactor (ATR) and its companion critical facility (ATRC). Several new protocols for validation of computed neutron flux distributions and spectra as well as for validation of computed fission power distributions, based on new experiments and well-recognized least-squares statistical analysis techniques, have been under development. In the case of power distributions, estimates of the a priori ATR-specific fuel element-to-element fission power correlation and covariance matrices are required for validation analysis. A practical method for generating these matrices using the element-to-element fission matrix is presented, along with a high-order scheme for estimating the underlying fission matrix itself. The proposed methodology is illustrated using the MCNP5 neutron transport code for the required neutronics calculations. The general approach is readily adaptable for implementation using any multidimensional stochastic or deterministic transport code that offers the required level of spatial, angular, and energy resolution in the computed solution for the neutron flux and fission source. (authors)

  4. Distributed parallel computing in stochastic modeling of groundwater systems.

    PubMed

    Dong, Yanhui; Li, Guomin; Xu, Haizhen

    2013-03-01

    Stochastic modeling is a rapidly evolving, popular approach to the study of the uncertainty and heterogeneity of groundwater systems. However, the use of Monte Carlo-type simulations to solve practical groundwater problems often encounters computational bottlenecks that hinder the acquisition of meaningful results. To improve the computational efficiency, a system that combines stochastic model generation with MODFLOW-related programs and distributed parallel processing is investigated. The distributed computing framework, called the Java Parallel Processing Framework, is integrated into the system to allow the batch processing of stochastic models in distributed and parallel systems. As an example, the system is applied to the stochastic delineation of well capture zones in the Pinggu Basin in Beijing. Through the use of 50 processing threads on a cluster with 10 multicore nodes, the execution times of 500 realizations are reduced to 3% compared with those of a serial execution. Through this application, the system demonstrates its potential in solving difficult computational problems in practical stochastic modeling.

  5. File and metadata management for BESIII distributed computing

    NASA Astrophysics Data System (ADS)

    Nicholson, C.; Lin, L.; Deng, Z. Y.; Li, W. D.; Zhang, X. M.; Zheng, Y. H.

    2012-12-01

    The BESIII experiment at the Institute of High Energy Physics (IHEP), Beijing, uses the high-luminosity BEPCII e+e- collider to study physics in the π-charm energy region around 3.7 GeV; BEPCII has produced the worlds largest samples of J/phi and phi’ events to date. An order of magnitude increase in the data sample size over the 2011-2012 data-taking period demanded a move from a very centralized to a distributed computing environment, as well as the development of an efficient file and metadata management system. While BESIII is on a smaller scale than some other HEP experiments, this poses particular challenges for its distributed computing and data management system. These constraints include limited resources and manpower, and low quality of network connections to IHEP. Drawing on the rich experience of the HEP community, a system has been developed which meets these constraints. The design and development of the BESIII distributed data management system, including its integration with other BESIII distributed computing components, such as job management, are presented here.

  6. Money for Research, Not for Energy Bills: Finding Energy and Cost Savings in High Performance Computer Facility Designs

    SciTech Connect

    Drewmark Communications; Sartor, Dale; Wilson, Mark

    2010-07-01

    High-performance computing facilities in the United States consume an enormous amount of electricity, cutting into research budgets and challenging public- and private-sector efforts to reduce energy consumption and meet environmental goals. However, these facilities can greatly reduce their energy demand through energy-efficient design of the facility itself. Using a case study of a facility under design, this article discusses strategies and technologies that can be used to help achieve energy reductions.

  7. Improving flow distribution in influent channels using computational fluid dynamics.

    PubMed

    Park, No-Suk; Yoon, Sukmin; Jeong, Woochang; Lee, Seungjae

    2016-10-01

    Although the flow distribution in an influent channel where the inflow is split into each treatment process in a wastewater treatment plant greatly affects the efficiency of the process, and a weir is the typical structure for the flow distribution, to the authors' knowledge, there is a paucity of research on the flow distribution in an open channel with a weir. In this study, the influent channel of a real-scale wastewater treatment plant was used, installing a suppressed rectangular weir that has a horizontal crest to cross the full channel width. The flow distribution in the influent channel was analyzed using a validated computational fluid dynamics model to investigate (1) the comparison of single-phase and two-phase simulation, (2) the improved procedure of the prototype channel, and (3) the effect of the inflow rate on flow distribution. The results show that two-phase simulation is more reliable due to the description of the free-surface fluctuations. It should first be considered for improving flow distribution to prevent a short-circuit flow, and the difference in the kinetic energy with the inflow rate makes flow distribution trends different. The authors believe that this case study is helpful for improving flow distribution in an influent channel.

  8. A facile synthesis of Te nanoparticles with binary size distribution by green chemistry.

    PubMed

    He, Weidong; Krejci, Alex; Lin, Junhao; Osmulski, Max E; Dickerson, James H

    2011-04-01

    Our work reports a facile route to colloidal Te nanocrystals with binary uniform size distributions at room temperature. The binary-sized Te nanocrystals were well separated into two size regimes and assembled into films by electrophoretic deposition. The research provides a new platform for nanomaterials to be efficiently synthesized and manipulated.

  9. Distributed Computer Networks in Support of Complex Group Practices

    PubMed Central

    Wess, Bernard P.

    1978-01-01

    The economics of medical computer networks are presented in context with the patient care and administrative goals of medical networks. Design alternatives and network topologies are discussed with an emphasis on medical network design requirements in distributed data base design, telecommunications, satellite systems, and software engineering. The success of the medical computer networking technology is predicated on the ability of medical and data processing professionals to design comprehensive, efficient, and virtually impenetrable security systems to protect data bases, network access and services, and patient confidentiality.

  10. EST analysis pipeline: use of distributed computing resources.

    PubMed

    González, Francisco Javier; Vizcaíno, Juan Antonio

    2011-01-01

    This chapter describes how a pipeline for the analysis of expressed sequence tag (EST) data can be -implemented, based on our previous experience generating ESTs from Trichoderma spp. We focus on key steps in the workflow, such as the processing of raw data from the sequencers, the clustering of ESTs, and the functional annotation of the sequences using BLAST, InterProScan, and BLAST2GO. Some of the steps require the use of intensive computing power. Since these resources are not available for small research groups or institutes without bioinformatics support, an alternative will be described: the use of distributed computing resources (local grids and Amazon EC2).

  11. Computed voltage distributions around solar electric propulsion spacecraft

    NASA Technical Reports Server (NTRS)

    Stevens, N. J.

    1979-01-01

    The NASA Charging Analyzer Program is used to conduct preliminary computations of the voltage distributions around such large spacecraft in geomagnetic substorm environments at geosynchronous altitudes. Both a standard operating voltage (+ or - 150 volts on solar arrays) and direct-drive (+1200 volts on arrays) configurations are considered. Thruster-off simulations are computed for both operating voltage configurations while the effect of simulated thruster-on conditions are evaluated only for direct-drive configuration. These simulated thruster-on conditions are evaluated only for direct-drive configuration. These simulated thruster operations appear to alleviate surface charging.

  12. The process group approach to reliable distributed computing

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.

    1991-01-01

    The difficulty of developing reliable distributed software is an impediment to applying distributed computing technology in many settings. Experience with the ISIS system suggests that a structured approach based on virtually synchronous process groups yields systems which are substantially easier to develop, fault-tolerance, and self-managing. Six years of research on ISIS are reviewed, describing the model, the types of applications to which ISIS was applied, and some of the reasoning that underlies a recent effort to redesign and reimplement ISIS as a much smaller, lightweight system.

  13. Parallel and distributed computation for fault-tolerant object recognition

    NASA Technical Reports Server (NTRS)

    Wechsler, Harry

    1988-01-01

    The distributed associative memory (DAM) model is suggested for distributed and fault-tolerant computation as it relates to object recognition tasks. The fault-tolerance is with respect to geometrical distortions (scale and rotation), noisy inputs, occulsion/overlap, and memory faults. An experimental system was developed for fault-tolerant structure recognition which shows the feasibility of such an approach. The approach is futher extended to the problem of multisensory data integration and applied successfully to the recognition of colored polyhedral objects.

  14. Radar data processing using a distributed computational system

    NASA Astrophysics Data System (ADS)

    Mota, Gilberto F.

    1992-06-01

    This research specifies and validates a new concurrent decomposition scheme, called Confined Space Search Decomposition (CSSD), to exploit parallelism of Radar Data Processing algorithms using a Distributed Computational System. To formalize the specification, we propose and apply an object-oriented methodology called Decomposition Cost Evaluation Model (DCEM). To reduce the penalties of load imbalance, we propose a distributed dynamic load balance heuristic called Object Reincarnation (OR). To validate the research, we first compare our decomposition with an identified alternative using the proposed DCEM model and then develop a theoretical prediction of selected parameters. We also develop a simulation to check the Object Reincarnation Concept.

  15. Integrating Xgrid into the HENP distributed computing model

    NASA Astrophysics Data System (ADS)

    Hajdu, L.; Kocoloski, A.; Lauret, J.; Miller, M.

    2008-07-01

    Modern Macintosh computers feature Xgrid, a distributed computing architecture built directly into Apple's OS X operating system. While the approach is radically different from those generally expected by the Unix based Grid infrastructures (Open Science Grid, TeraGrid, EGEE), opportunistic computing on Xgrid is nonetheless a tempting and novel way to assemble a computing cluster with a minimum of additional configuration. In fact, it requires only the default operating system and authentication to a central controller from each node. OS X also implements arbitrarily extensible metadata, allowing an instantly updated file catalog to be stored as part of the filesystem itself. The low barrier to entry allows an Xgrid cluster to grow quickly and organically. This paper and presentation will detail the steps that can be taken to make such a cluster a viable resource for HENP research computing. We will further show how to provide to users a unified job submission framework by integrating Xgrid through the STAR Unified Meta-Scheduler (SUMS), making tasks and jobs submission effortlessly at reach for those users already using the tool for traditional Grid or local cluster job submission. We will discuss additional steps that can be taken to make an Xgrid cluster a full partner in grid computing initiatives, focusing on Open Science Grid integration. MIT's Xgrid system currently supports the work of multiple research groups in the Laboratory for Nuclear Science, and has become an important tool for generating simulations and conducting data analyses at the Massachusetts Institute of Technology.

  16. Semiquantum key distribution with secure delegated quantum computation.

    PubMed

    Li, Qin; Chan, Wai Hong; Zhang, Shengyu

    2016-01-27

    Semiquantum key distribution allows a quantum party to share a random key with a "classical" party who only can prepare and measure qubits in the computational basis or reorder some qubits when he has access to a quantum channel. In this work, we present a protocol where a secret key can be established between a quantum user and an almost classical user who only needs the quantum ability to access quantum channels, by securely delegating quantum computation to a quantum server. We show the proposed protocol is robust even when the delegated quantum server is a powerful adversary, and is experimentally feasible with current technology. As one party of our protocol is the most quantum-resource efficient, it can be more practical and significantly widen the applicability scope of quantum key distribution.

  17. Semiquantum key distribution with secure delegated quantum computation

    PubMed Central

    Li, Qin; Chan, Wai Hong; Zhang, Shengyu

    2016-01-01

    Semiquantum key distribution allows a quantum party to share a random key with a “classical” party who only can prepare and measure qubits in the computational basis or reorder some qubits when he has access to a quantum channel. In this work, we present a protocol where a secret key can be established between a quantum user and an almost classical user who only needs the quantum ability to access quantum channels, by securely delegating quantum computation to a quantum server. We show the proposed protocol is robust even when the delegated quantum server is a powerful adversary, and is experimentally feasible with current technology. As one party of our protocol is the most quantum-resource efficient, it can be more practical and significantly widen the applicability scope of quantum key distribution. PMID:26813384

  18. A biological solution to a fundamental distributed computing problem.

    PubMed

    Afek, Yehuda; Alon, Noga; Barad, Omer; Hornstein, Eran; Barkai, Naama; Bar-Joseph, Ziv

    2011-01-14

    Computational and biological systems are often distributed so that processors (cells) jointly solve a task, without any of them receiving all inputs or observing all outputs. Maximal independent set (MIS) selection is a fundamental distributed computing procedure that seeks to elect a set of local leaders in a network. A variant of this problem is solved during the development of the fly's nervous system, when sensory organ precursor (SOP) cells are chosen. By studying SOP selection, we derived a fast algorithm for MIS selection that combines two attractive features. First, processors do not need to know their degree; second, it has an optimal message complexity while only using one-bit messages. Our findings suggest that simple and efficient algorithms can be developed on the basis of biologically derived insights.

  19. Optimal eigenvalue computation on distributed-memory MIMD multiprocessors

    SciTech Connect

    Crivelli, S.; Jessup, E. R.

    1992-10-01

    Simon proves that bisection is not the optimal method for computing an eigenvalue on a single vector processor. In this paper, we show that his analysis does not extend in a straightforward way to the computation of an eigenvalue on a distributed-memory MIMD multiprocessor. In particular, we show how the optimal number of sections (and processors) to use for multisection depends on variables such as the matrix size and certain parameters inherent to the machine. We also show that parallel multisection outperforms the variant of parallel bisection proposed by Swarztrauber or this problem on a distributed-memory MIMD multiprocessor. We present the results of experiments on the 64-processor Intel iPSC/2 hypercube and the 512-processor Intel Touchstone Delta mesh multiprocessor.

  20. Computational investigations of low-emission burner facilities for char gas burning in a power boiler

    NASA Astrophysics Data System (ADS)

    Roslyakov, P. V.; Morozov, I. V.; Zaychenko, M. N.; Sidorkin, V. T.

    2016-04-01

    Various variants for the structure of low-emission burner facilities, which are meant for char gas burning in an operating TP-101 boiler of the Estonia power plant, are considered. The planned increase in volumes of shale reprocessing and, correspondingly, a rise in char gas volumes cause the necessity in their cocombustion. In this connection, there was a need to develop a burner facility with a given capacity, which yields effective char gas burning with the fulfillment of reliability and environmental requirements. For this purpose, the burner structure base was based on the staging burning of fuel with the gas recirculation. As a result of the preliminary analysis of possible structure variants, three types of early well-operated burner facilities were chosen: vortex burner with the supply of recirculation gases into the secondary air, vortex burner with the baffle supply of recirculation gases between flows of the primary and secondary air, and burner facility with the vortex pilot burner. Optimum structural characteristics and operation parameters were determined using numerical experiments. These experiments using ANSYS CFX bundled software of computational hydrodynamics were carried out with simulation of mixing, ignition, and burning of char gas. Numerical experiments determined the structural and operation parameters, which gave effective char gas burning and corresponded to required environmental standard on nitrogen oxide emission, for every type of the burner facility. The burner facility for char gas burning with the pilot diffusion burner in the central part was developed and made subject to computation results. Preliminary verification nature tests on the TP-101 boiler showed that the actual content of nitrogen oxides in burner flames of char gas did not exceed a claimed concentration of 150 ppm (200 mg/m3).

  1. Distributed Cognition (DCOG): Foundations for a Computational Associative Memory Model

    DTIC Science & Technology

    2006-08-01

    This isolates the skateboard as the one that doesn’t belong. Certain automatic, attention-shifting mechanisms will be required in our model . We...STINFO COPY AFRL-HE-WP-TR-2006-0160 Distributed Cognition (DCOG): Foundations for a Computational Associative Memory Model Robert G. Eggleston...reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions , searching

  2. Scalable Quantum Networks for Distributed Computing and Sensing

    DTIC Science & Technology

    2016-04-01

    AFRL-AFOSR-UK-TR-2016-0007 Scalable Quantum Networks for Distributed Computing and Sensing Ian Walmsley THE UNIVERSITY OF OXFORD Final Report 04/01...MM-YYYY) 12/07/2015 2. REPORT TYPE Final 3. DATES COVERED (From - To) 01-Sep-2012 to 31-Aug-2015 4. TITLE AND SUBTITLE Scalable Quantum Networks...SUPPLEMENTARY NOTES 14. ABSTRACT We identified two barriers to the implementation of large-scale photonic quantum networks. First, as scalability requires

  3. Information modification and particle collisions in distributed computation.

    PubMed

    Lizier, Joseph T; Prokopenko, Mikhail; Zomaya, Albert Y

    2010-09-01

    Distributed computation can be described in terms of the fundamental operations of information storage, transfer, and modification. To describe the dynamics of information in computation, we need to quantify these operations on a local scale in space and time. In this paper we extend previous work regarding the local quantification of information storage and transfer, to explore how information modification can be quantified at each spatiotemporal point in a system. We introduce the separable information, a measure which locally identifies information modification events where separate inspection of the sources to a computation is misleading about its outcome. We apply this measure to cellular automata, where it is shown to be the first direct quantitative measure to provide evidence for the long-held conjecture that collisions between emergent particles therein are the dominant information modification events.

  4. Multi-VO support in IHEP's distributed computing environment

    NASA Astrophysics Data System (ADS)

    Yan, T.; Suo, B.; Zhao, X. H.; Zhang, X. M.; Ma, Z. T.; Yan, X. F.; Lin, T.; Deng, Z. Y.; Li, W. D.; Belov, S.; Pelevanyuk, I.; Zhemchugov, A.; Cai, H.

    2015-12-01

    Inspired by the success of BESDIRAC, the distributed computing environment based on DIRAC for BESIII experiment, several other experiments operated by Institute of High Energy Physics (IHEP), such as Circular Electron Positron Collider (CEPC), Jiangmen Underground Neutrino Observatory (JUNO), Large High Altitude Air Shower Observatory (LHAASO) and Hard X-ray Modulation Telescope (HXMT) etc, are willing to use DIRAC to integrate the geographically distributed computing resources available by their collaborations. In order to minimize manpower and hardware cost, we extended the BESDIRAC platform to support multi-VO scenario, instead of setting up a self-contained distributed computing environment for each VO. This makes DIRAC as a service for the community of those experiments. To support multi-VO, the system architecture of BESDIRAC is adjusted for scalability. The VOMS and DIRAC servers are reconfigured to manage users and groups belong to several VOs. A lightweight storage resource manager StoRM is employed as the central SE to integrate local and grid data. A frontend system is designed for user's massive job splitting, submission and management, with plugins to support new VOs. A monitoring and accounting system is also considered to easy the system administration and VO related resources usage accounting.

  5. Opportunities for artificial intelligence application in computer- aided management of mixed waste incinerator facilities

    SciTech Connect

    Rivera, A.L.; Ferrada, J.J.; Singh, S.P.N.

    1992-01-01

    The Department of Energy/Oak Ridge Field Office (DOE/OR) operates a mixed waste incinerator facility at the Oak Ridge K-25 Site. It is designed for the thermal treatment of incinerable liquid, sludge, and solid waste regulated under the Toxic Substances Control Act (TSCA) and the Resource Conservation and Recovery Act (RCRA). This facility, known as the TSCA Incinerator, services seven DOE/OR installations. This incinerator was recently authorized for production operation in the United States for the processing of mixed (radioactively contaminated-chemically hazardous) wastes as regulated under TSCA and RCRA. Operation of the TSCA Incinerator is highly constrained as a result of the regulatory, institutional, technical, and resource availability requirements. These requirements impact the characteristics and disposition of incinerator residues, limits the quality of liquid and gaseous effluents, limit the characteristics and rates of waste feeds and operating conditions, and restrict the handling of the waste feed inventories. This incinerator facility presents an opportunity for applying computer technology as a technical resource for mixed waste incinerator operation to facilitate promoting and sustaining a continuous performance improvement process while demonstrating compliance. Demonstrated computer-aided management systems could be transferred to future mixed waste incinerator facilities.

  6. Opportunities for artificial intelligence application in computer- aided management of mixed waste incinerator facilities

    SciTech Connect

    Rivera, A.L.; Ferrada, J.J.; Singh, S.P.N.

    1992-05-01

    The Department of Energy/Oak Ridge Field Office (DOE/OR) operates a mixed waste incinerator facility at the Oak Ridge K-25 Site. It is designed for the thermal treatment of incinerable liquid, sludge, and solid waste regulated under the Toxic Substances Control Act (TSCA) and the Resource Conservation and Recovery Act (RCRA). This facility, known as the TSCA Incinerator, services seven DOE/OR installations. This incinerator was recently authorized for production operation in the United States for the processing of mixed (radioactively contaminated-chemically hazardous) wastes as regulated under TSCA and RCRA. Operation of the TSCA Incinerator is highly constrained as a result of the regulatory, institutional, technical, and resource availability requirements. These requirements impact the characteristics and disposition of incinerator residues, limits the quality of liquid and gaseous effluents, limit the characteristics and rates of waste feeds and operating conditions, and restrict the handling of the waste feed inventories. This incinerator facility presents an opportunity for applying computer technology as a technical resource for mixed waste incinerator operation to facilitate promoting and sustaining a continuous performance improvement process while demonstrating compliance. Demonstrated computer-aided management systems could be transferred to future mixed waste incinerator facilities.

  7. Distributing Data from Desktop to Hand-Held Computers

    NASA Technical Reports Server (NTRS)

    Elmore, Jason L.

    2005-01-01

    A system of server and client software formats and redistributes data from commercially available desktop to commercially available hand-held computers via both wired and wireless networks. This software is an inexpensive means of enabling engineers and technicians to gain access to current sensor data while working in locations in which such data would otherwise be inaccessible. The sensor data are first gathered by a data-acquisition server computer, then transmitted via a wired network to a data-distribution computer that executes the server portion of the present software. Data in all sensor channels -- both raw sensor outputs in millivolt units and results of conversion to engineering units -- are made available for distribution. Selected subsets of the data are transmitted to each hand-held computer via the wired and then a wireless network. The selection of the subsets and the choice of the sequences and formats for displaying the data is made by means of a user interface generated by the client portion of the software. The data displayed on the screens of hand-held units can be updated at rates from 1 to

  8. Lightweight distributed computing for intraoperative real-time image guidance

    NASA Astrophysics Data System (ADS)

    Suwelack, Stefan; Katic, Darko; Wagner, Simon; Spengler, Patrick; Bodenstedt, Sebastian; Röhl, Sebastian; Dillmann, Rüdiger; Speidel, Stefanie

    2012-02-01

    In order to provide real-time intraoperative guidance, computer assisted surgery (CAS) systems often rely on computationally expensive algorithms. The real-time constraint is especially challenging if several components such as intraoperative image processing, soft tissue registration or context aware visualization are combined in a single system. In this paper, we present a lightweight approach to distribute the workload over several workstations based on the OpenIGTLink protocol. We use XML-based message passing for remote procedure calls and native types for transferring data such as images, meshes or point coordinates. Two different, but typical scenarios are considered in order to evaluate the performance of the new system. First, we analyze a real-time soft tissue registration algorithm based on a finite element (FE) model. Here, we use the proposed approach to distribute the computational workload between a primary workstation that handles sensor data processing and visualization and a dedicated workstation that runs the real-time FE algorithm. We show that the additional overhead that is introduced by the technique is small compared to the total execution time. Furthermore, the approach is used to speed up a context aware augmented reality based navigation system for dental implant surgery. In this scenario, the additional delay for running the computationally expensive reasoning server on a separate workstation is less than a millisecond. The results show that the presented approach is a promising strategy to speed up real-time CAS systems.

  9. Algorithm-dependent fault tolerance for distributed computing

    SciTech Connect

    P. D. Hough; M. e. Goldsby; E. J. Walsh

    2000-02-01

    Large-scale distributed systems assembled from commodity parts, like CPlant, have become common tools in the distributed computing world. Because of their size and diversity of parts, these systems are prone to failures. Applications that are being run on these systems have not been equipped to efficiently deal with failures, nor is there vendor support for fault tolerance. Thus, when a failure occurs, the application crashes. While most programmers make use of checkpoints to allow for restarting of their applications, this is cumbersome and incurs substantial overhead. In many cases, there are more efficient and more elegant ways in which to address failures. The goal of this project is to develop a software architecture for the detection of and recovery from faults in a cluster computing environment. The detection phase relies on the latest techniques developed in the fault tolerance community. Recovery is being addressed in an application-dependent manner, thus allowing the programmer to take advantage of algorithmic characteristics to reduce the overhead of fault tolerance. This architecture will allow large-scale applications to be more robust in high-performance computing environments that are comprised of clusters of commodity computers such as CPlant and SMP clusters.

  10. Simulation of emission tomography using grid middleware for distributed computing.

    PubMed

    Thomason, M G; Longton, R F; Gregor, J; Smith, G T; Hutson, R K

    2004-09-01

    SimSET is Monte Carlo simulation software for emission tomography. This paper describes a simple but effective scheme for parallel execution of SimSET using NetSolve, a client-server system for distributed computation. NetSolve (version 1.4.1) is "grid middleware" which enables a user (the client) to run specific computations remotely and simultaneously on a grid of networked computers (the servers). Since the servers do not have to be identical machines, computation may take place in a heterogeneous environment. To take advantage of diversity in machines and their workloads, a client-side scheduler was implemented for the Monte Carlo simulation. The scheduler partitions the total decay events by taking into account the inherent compute-speeds and recent average workloads, i.e., the scheduler assigns more decay events to processors expected to give faster service and fewer decay events to those expected to give slower service. When compute-speeds and sustained workloads are taken into account, the speed-up is essentially linear in the number of equivalent "maximum-service" processors. One modification in the SimSET code (version 2.6.2.3) was made to ensure that the total number of decay events specified by the user is maintained in the distributed simulation. No other modifications in the standard SimSET code were made. Each processor runs complete SimSET code for its assignment of decay events, independently of others running simultaneously. Empirical results are reported for simulation of a clinical-quality lung perfusion study.

  11. Power Hardware-in-the-Loop (PHIL) Testing Facility for Distributed Energy Storage (Poster)

    SciTech Connect

    Neubauer.J.; Lundstrom, B.; Simpson, M.; Pratt, A.

    2014-06-01

    The growing deployment of distributed, variable generation and evolving end-user load profiles presents a unique set of challenges to grid operators responsible for providing reliable and high quality electrical service. Mass deployment of distributed energy storage systems (DESS) has the potential to solve many of the associated integration issues while offering reliability and energy security benefits other solutions cannot. However, tools to develop, optimize, and validate DESS control strategies and hardware are in short supply. To fill this gap, NREL has constructed a power hardware-in-the-loop (PHIL) test facility that connects DESS, grid simulator, and load bank hardware to a distribution feeder simulation.

  12. National Ignition Facility computational fluid dynamics modeling and light fixture case studies

    SciTech Connect

    Martin, R.; Bernardin, J.; Parietti, L.; Dennison, B.

    1998-02-01

    This report serves as a guide to the use of computational fluid dynamics (CFD) as a design tool for the National Ignition Facility (NIF) program Title I and Title II design phases at Lawrence Livermore National Laboratory. In particular, this report provides general guidelines on the technical approach to performing and interpreting any and all CFD calculations. In addition, a complete CFD analysis is presented to illustrate these guidelines on a NIF-related thermal problem.

  13. 120. Back side technical facilities S.R. radar transmitter & computer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    120. Back side technical facilities S.R. radar transmitter & computer building no. 102, section II "foundation & first floor plan" - structural, AS-BLT AW 35-46-04, sheet 65, dated 23 January, 1961. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  14. 122. Back side technical facilities S.R. radar transmitter & computer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    122. Back side technical facilities S.R. radar transmitter & computer building no. 102, section II "elevations & details" - structural, AS-BLT AW 35-46-04, sheet 73, dated 23 January, 1961. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  15. 118. Back side technical facilities S.R. radar transmitter & computer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    118. Back side technical facilities S.R. radar transmitter & computer building no. 102, "building sections - sheet I" - architectural, AS-BLT AW 35-46-04, sheet 13, dated 23 January, 1961. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  16. 121. Back side technical facilities S.R. radar transmitter & computer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    121. Back side technical facilities S.R. radar transmitter & computer building no. 102, section II "sections & elevations" - structural, AS-BLT AW 35-46-04, sheet 72, dated 23 January, 1961. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  17. 119. Back side technical facilities S.R. radar transmitter & computer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    119. Back side technical facilities S.R. radar transmitter & computer building no. 102, section I "tower plan, sections & details" - structural, AS-BLT AW 35-46-04, sheet 62, dated 23 January, 1961. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  18. 117. Back side technical facilities S.R. radar transmitter & computer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    117. Back side technical facilities S.R. radar transmitter & computer building no. 102, "building sections - sheet I" - architectural, AS-BLT AW 35-46-04, sheet 12, dated 23 January, 1961. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  19. Fermilab Central Computing Facility: Energy conservation report and mechanical systems design optimization and cost analysis study

    SciTech Connect

    Krstulovich, S.F.

    1986-11-12

    This report is developed as part of the Fermilab Central Computing Facility Project Title II Design Documentation Update under the provisions of DOE Document 6430.1, Chapter XIII-21, Section 14, paragraph a. As such, it concentrates primarily on HVAC mechanical systems design optimization and cost analysis and should be considered as a supplement to the Title I Design Report date March 1986 wherein energy related issues are discussed pertaining to building envelope and orientation as well as electrical systems design.

  20. Multi-threaded, discrete event simulation of distributed computing systems

    NASA Astrophysics Data System (ADS)

    Legrand, Iosif; MONARC Collaboration

    2001-10-01

    The LHC experiments have envisaged computing systems of unprecedented complexity, for which is necessary to provide a realistic description and modeling of data access patterns, and of many jobs running concurrently on large scale distributed systems and exchanging very large amounts of data. A process oriented approach for discrete event simulation is well suited to describe various activities running concurrently, as well the stochastic arrival patterns specific for such type of simulation. Threaded objects or "Active Objects" can provide a natural way to map the specific behaviour of distributed data processing into the simulation program. The simulation tool developed within MONARC is based on Java (TM) technology which provides adequate tools for developing a flexible and distributed process oriented simulation. Proper graphics tools, and ways to analyze data interactively, are essential in any simulation project. The design elements, status and features of the MONARC simulation tool are presented. The program allows realistic modeling of complex data access patterns by multiple concurrent users in large scale computing systems in a wide range of possible architectures, from centralized to highly distributed. Comparison between queuing theory and realistic client-server measurements is also presented.

  1. Distributed Computation Resources for Earth System Grid Federation (ESGF)

    NASA Astrophysics Data System (ADS)

    Duffy, D.; Doutriaux, C.; Williams, D. N.

    2014-12-01

    The Intergovernmental Panel on Climate Change (IPCC), prompted by the United Nations General Assembly, has published a series of papers in their Fifth Assessment Report (AR5) on processes, impacts, and mitigations of climate change in 2013. The science used in these reports was generated by an international group of domain experts. They studied various scenarios of climate change through the use of highly complex computer models to simulate the Earth's climate over long periods of time. The resulting total data of approximately five petabytes are stored in a distributed data grid known as the Earth System Grid Federation (ESGF). Through the ESGF, consumers of the data can find and download data with limited capabilities for server-side processing. The Sixth Assessment Report (AR6) is already in the planning stages and is estimated to create as much as two orders of magnitude more data than the AR5 distributed archive. It is clear that data analysis capabilities currently in use will be inadequate to allow for the necessary science to be done with AR6 data—the data will just be too big. A major paradigm shift from downloading data to local systems to perform data analytics must evolve to moving the analysis routines to the data and performing these computations on distributed platforms. In preparation for this need, the ESGF has started a Compute Working Team (CWT) to create solutions that allow users to perform distributed, high-performance data analytics on the AR6 data. The team will be designing and developing a general Application Programming Interface (API) to enable highly parallel, server-side processing throughout the ESGF data grid. This API will be integrated with multiple analysis and visualization tools, such as the Ultrascale Visualization Climate Data Analysis Tools (UV-CDAT), netCDF Operator (NCO), and others. This presentation will provide an update on the ESGF CWT's overall approach toward enabling the necessary storage proximal computational

  2. Using mobile distributed pyrolysis facilities to deliver a forest residue resource for bio-fuel production

    NASA Astrophysics Data System (ADS)

    Brown, Duncan

    Distributed mobile conversion facilities using either fast pyrolysis or torrefaction processes can be used to convert forest residues to more energy dense substances (bio-oil, bio-slurry or torrefied wood) that can be transported as feedstock for bio-fuel facilities. All feedstock are suited for gasification, which produces syngas that can be used to synthesise petrol or diesel via Fischer-Tropsch reactions, or produce hydrogen via water gas shift reactions. Alternatively, the bio-oil product of fast pyrolysis may be upgraded to produce petrol and diesel, or can undergo steam reformation to produce hydrogen. Implementing a network of mobile facilities reduces the energy content of forest residues delivered to a bio-fuel facility as mobile facilities use a fraction of the biomass energy content to meet thermal or electrical demands. The total energy delivered by bio-oil, bio-slurry and torrefied wood is 45%, 65% and 87% of the initial forest residue energy content, respectively. However, implementing mobile facilities is economically feasible when large transport distances are required. For an annual harvest of 1.717 million m3 (equivalent to 2000 ODTPD), transport costs are reduced to less than 40% of the total levelised delivered feedstock cost when mobile facilities are implemented; transport costs account for up to 80% of feedstock costs for conventional woodchip delivery. Torrefaction provides the lowest cost pathway of delivering a forest residue resource when using mobile facilities. Cost savings occur against woodchip delivery for annual forest residue harvests above 2.25 million m3 or when transport distances greater than 250 km are required. Important parameters that influence levelised delivered costs of feedstock are transport distances (forest residue spatial density), haul cost factors, thermal and electrical demands of mobile facilities, and initial moisture content of forest residues. Relocating mobile facilities can be optimised for lowest cost

  3. An environmental testing facility for Space Station Freedom power management and distribution hardware

    NASA Astrophysics Data System (ADS)

    Jackola, Arthur S.; Hartjen, Gary L.

    1992-11-01

    The plans for a new test facility, including new environmental test systems, which are presently under construction, and the major environmental Test Support Equipment (TSE) used therein are addressed. This all-new Rocketdyne facility will perform space simulation environmental tests on Power Management and Distribution (PMAD) hardware to Space Station Freedom (SSF) at the Engineering Model, Qualification Model, and Flight Model levels of fidelity. Testing will include Random Vibration in three axes - Thermal Vacuum, Thermal Cycling and Thermal Burn-in - as well as numerous electrical functional tests. The facility is designed to support a relatively high throughput of hardware under test, while maintaining the high standards required for a man-rated space program.

  4. A Distributed Computing Infrastructure for Computational Thermodynamic Calculations of Solid-Liquid Phase Equilibria

    NASA Astrophysics Data System (ADS)

    Ghiorso, M. S.; Kress, V. C.

    2004-12-01

    Software tools like MELTS (Ghiorso and Sack, 1995, CMP 119:197) and its derivatives (Ghiorso et al., 2002, G3 3:10.1029/2001GC000217) are sophisticated calculators used by geoscientists to quantify the chemistry of melt production, transport and storage. These tools utilize computational thermodynamics to evaluate the equilibrium state of the system under specified external conditions by minimizing a suitably constructed thermodynamic potential. Like any thermodynamically based tool, the principal advantage in employing these techniques to model igneous processes is the intrinsic ability to couple the chemistry and energetics of the evolution of the system in a self consistent and rigorous formalism. Access to MELTS is normally accomplished via a standalone X11-based executable or as a Java-based web applet. The latter is a dedicated client-server application rooted at the University of Chicago. Our on-going objective is the development of a distributed computing infrastructure to provide "MELTS-like" computations on demand to remote network users by utilizing a language independent client-server protocol based on CORBA. The advantages of this model are numerous. First, the burden of implementing and executing MELTS computations is centralized with a software implementation optimized to a compute cluster dedicated for that purpose. Improvements and updates to MELTS software are handled locally on the server side without intervention of the user and the server-model lessens the burden of supporting the computational code on a variety of hardware and OS platforms. Second, the client hardware platform does not incur the computational cost of performing a MELTS simulation and the remote user can focus on the task of incorporating results into their model. Third, the client user can write software in a computer language of their choosing and procedural calls to the MELTS library can be executed transparently over the network as if a local language-compatible library of

  5. Probability distributions of molecular observables computed from Markov models.

    PubMed

    Noé, Frank

    2008-06-28

    Molecular dynamics (MD) simulations can be used to estimate transition rates between conformational substates of the simulated molecule. Such an estimation is associated with statistical uncertainty, which depends on the number of observed transitions. In turn, it induces uncertainties in any property computed from the simulation, such as free energy differences or the time scales involved in the system's kinetics. Assessing these uncertainties is essential for testing the reliability of a given observation and also to plan further simulations in such a way that the most serious uncertainties will be reduced with minimal effort. Here, a rigorous statistical method is proposed to approximate the complete statistical distribution of any observable of an MD simulation provided that one can identify conformational substates such that the transition process between them may be modeled with a memoryless jump process, i.e., Markov or Master equation dynamics. The method is based on sampling the statistical distribution of Markov transition matrices that is induced by the observed transition events. It allows physically meaningful constraints to be included, such as sampling only matrices that fulfill detailed balance, or matrices that produce a predefined equilibrium distribution of states. The method is illustrated on mus MD simulations of a hexapeptide for which the distributions and uncertainties of the free energy differences between conformations, the transition matrix elements, and the transition matrix eigenvalues are estimated. It is found that both constraints, detailed balance and predefined equilibrium distribution, can significantly reduce the uncertainty of some observables.

  6. Analytical and Computational Properties of Distributed Approaches to MDO

    NASA Technical Reports Server (NTRS)

    Alexandrov, Natalia M.; Lewis, Robert Michael

    2000-01-01

    Historical evolution of engineering disciplines and the complexity of the MDO problem suggest that disciplinary autonomy is a desirable goal in formulating and solving MDO problems. We examine the notion of disciplinary autonomy and discuss the analytical properties of three approaches to formulating and solving MDO problems that achieve varying degrees of autonomy by distributing the problem along disciplinary lines. Two of the approaches-Optimization by Linear Decomposition and Collaborative Optimization-are based on bi-level optimization and reflect what we call a structural perspective. The third approach, Distributed Analysis Optimization, is a single-level approach that arises from what we call an algorithmic perspective. The main conclusion of the paper is that disciplinary autonomy may come at a price: in the bi-level approaches, the system-level constraints introduced to relax the interdisciplinary coupling and enable disciplinary autonomy can cause analytical and computational difficulties for optimization algorithms. The single-level alternative we discuss affords a more limited degree of autonomy than that of the bi-level approaches, but without the computational difficulties of the bi-level methods. Key Words: Autonomy, bi-level optimization, distributed optimization, multidisciplinary optimization, multilevel optimization, nonlinear programming, problem integration, system synthesis

  7. Parallel matrix transpose algorithms on distributed memory concurrent computers

    SciTech Connect

    Choi, J.; Walker, D.W.; Dongarra, J.J. |

    1993-10-01

    This paper describes parallel matrix transpose algorithms on distributed memory concurrent processors. It is assumed that the matrix is distributed over a P x Q processor template with a block scattered data distribution. P, Q, and the block size can be arbitrary, so the algorithms have wide applicability. The communication schemes of the algorithms are determined by the greatest common divisor (GCD) of P and Q. If P and Q are relatively prime, the matrix transpose algorithm involves complete exchange communication. If P and Q are not relatively prime, processors are divided into GCD groups and the communication operations are overlapped for different groups of processors. Processors transpose GCD wrapped diagonal blocks simultaneously, and the matrix can be transposed with LCM/GCD steps, where LCM is the least common multiple of P and Q. The algorithms make use of non-blocking, point-to-point communication between processors. The use of nonblocking communication allows a processor to overlap the messages that it sends to different processors, thereby avoiding unnecessary synchronization. Combined with the matrix multiplication routine, C = A{center_dot}B, the algorithms are used to compute parallel multiplications of transposed matrices, C = A{sup T}{center_dot}B{sup T}, in the PUMMA package. Details of the parallel implementation of the algorithms are given, and results are presented for runs on the Intel Touchstone Delta computer.

  8. A distributed computing tool for generating neural simulation databases.

    PubMed

    Calin-Jageman, Robert J; Katz, Paul S

    2006-12-01

    After developing a model neuron or network, it is important to systematically explore its behavior across a wide range of parameter values or experimental conditions, or both. However, compiling a very large set of simulation runs is challenging because it typically requires both access to and expertise with high-performance computing facilities. To lower the barrier for large-scale model analysis, we have developed NeuronPM, a client/server application that creates a "screen-saver" cluster for running simulations in NEURON (Hines & Carnevale, 1997). NeuronPM provides a user-friendly way to use existing computing resources to catalog the performance of a neural simulation across a wide range of parameter values and experimental conditions. The NeuronPM client is a Windows-based screen saver, and the NeuronPM server can be hosted on any Apache/PHP/MySQL server. During idle time, the client retrieves model files and work assignments from the server, invokes NEURON to run the simulation, and returns results to the server. Administrative panels make it simple to upload model files, define the parameters and conditions to vary, and then monitor client status and work progress. NeuronPM is open-source freeware and is available for download at http://neuronpm.homeip.net . It is a useful entry-level tool for systematically analyzing complex neuron and network simulations.

  9. Advances in the archiving and distribution facilities at the Space Telescope Science Institute

    NASA Astrophysics Data System (ADS)

    Hanisch, Robert J.; Postman, Marc; Pollizzi, Joseph; Richon, J.

    1998-07-01

    The Hubble Data Archive at the Space Telescope Science Institute contains over 4.3 TB of data, primarily for the Hubble Space Telescope, but also from complementary space- based and ground-based facilities. We are in the process of upgrading and generalizing many of the HDA's component system, developing tools to provide more integrated access to the HDA holdings, and working with other major data providing organizations to implement global data location services for astronomy and other space science disciplines. This paper describes the key elements of our archiving and data distribution systems, including a planned transition to DVD media, data compression, data segregation, on-the-fly calibration, an engineering data warehouse, and distributed search and retrieval facilities.

  10. The Gain of Resource Delegation in Distributed Computing Environments

    NASA Astrophysics Data System (ADS)

    Fölling, Alexander; Grimme, Christian; Lepping, Joachim; Papaspyrou, Alexander

    In this paper, we address job scheduling in Distributed Computing Infrastructures, that is a loosely coupled network of autonomous acting High Performance Computing systems. In contrast to the common approach of mutual workload exchange, we consider the more intuitive operator's viewpoint of load-dependent resource reconfiguration. In case of a site's over-utilization, the scheduling system is able to lease resources from other sites to keep up service quality for its local user community. Contrary, the granting of idle resources can increase utilization in times of low local workload and thus ensure higher efficiency. The evaluation considers real workload data and is done with respect to common service quality indicators. For two simple resource exchange policies and three basic setups we show the possible gain of this approach and analyze the dynamics in workload-adaptive reconfiguration behavior.

  11. Overset grid applications on distributed memory MIMD computers

    NASA Technical Reports Server (NTRS)

    Chawla, Kalpana; Weeratunga, Sisira

    1994-01-01

    Analysis of modern aerospace vehicles requires the computation of flowfields about complex three dimensional geometries composed of regions with varying spatial resolution requirements. Overset grid methods allow the use of proven structured grid flow solvers to address the twin issues of geometrical complexity and the resolution variation by decomposing the complex physical domain into a collection of overlapping subdomains. This flexibility is accompanied by the need for irregular intergrid boundary communication among the overlapping component grids. This study investigates a strategy for implementing such a static overset grid implicit flow solver on distributed memory, MIMD computers; i.e., the 128 node Intel iPSC/860 and the 208 node Intel Paragon. Performance data for two composite grid configurations characteristic of those encountered in present day aerodynamic analysis are also presented.

  12. Facilities

    NASA Technical Reports Server (NTRS)

    1999-01-01

    An expansion of medical data collection facilities was necessary to implement the Extended Duration Orbiter Medical Project (EDOMP). The primary objective of the EDOMP was to ensure the capability of crew members to reenter the Earth's atmosphere, land, and egress safely following a 16-day flight. Therefore, access to crew members as soon as possible after landing was crucial for most data collection activities. Also, with the advent of EDOMP, the quantity of investigations increased such that the landing day maximum data collection time increased accordingly from two hours to four hours. The preflight and postflight testing facilities at the Johnson Space Center (JSC) required only some additional testing equipment and minor modifications to the existing laboratories in order to fulfill EDOMP requirements. Necessary modifications at the landing sites were much more extensive.

  13. Accommodating Heterogeneity in a Debugger for Distributed Computations

    NASA Technical Reports Server (NTRS)

    Hood, Robert; Cheng, Doreen; Cooper, D. M. (Technical Monitor)

    1994-01-01

    In an ongoing project at NASA Ames Research Center, we are building debugger for distributed computations running on a heterogeneous set of machines. Historically, such debuggers have been built as front-ends to existing source-level debuggers on the target platforms. In effect, these back-end debuggers are providing a collection of debugger services to a client. The major drawback is that because of inconsistencies among the back-end debuggers, the front-end must use a different protocol when talking to each back-end debugger. This can make the front-end quite complex. We have avoided this complexity problem by defining the client-server debugger protocol. While it does require vendors to adapt their existing debugger code to meet the protocol, vendors are generally interested in doing so because the approach has several advantages. In addition to solving the heterogenous platform debugging problem, it will be possible to write interesting debugger user interfaces that can be easily ported across a variety of machines. This will likely encourage investment in application-domain specific debuggers. In fact, the user interface of our debugger will be geared to scientists developing computational fluid dynamics codes. This paper describes some of the problems encountered in developing a portable debugger for heterogenous, distributed computing and how the architecture of our debugger avoids them. It then provides a detailed description of the debugger client-server protocol. Some of the more interesting attributes of the protocol are: (1) It is object-oriented; (2) It uses callback functions to capture the asynchronous nature of debugging in a procedural fashion; (3) It contains abstractions, such as in-line instrumentation, for the debugging of computationally intensive programs; (4) For remote debugging, it has operations that enable the implementor to optimize message passing traffic between client and server. The soundness of the protocol is being tested through

  14. KNET - DISTRIBUTED COMPUTING AND/OR DATA TRANSFER PROGRAM

    NASA Technical Reports Server (NTRS)

    Hui, J.

    1994-01-01

    KNET facilitates distributed computing between a UNIX compatible local host and a remote host which may or may not be UNIX compatible. It is capable of automatic remote login. That is, it performs on the user's behalf the chore of handling host selection, user name, and password to the designated host. Once the login has been successfully completed, the user may interactively communicate with the remote host. Data output from the remote host may be directed to the local screen, to a local file, and/or to a local process. Conversely, data input from the keyboard, a local file, or a local process may be directed to the remote host. KNET takes advantage of the multitasking and terminal mode control features of the UNIX operating system. A parent process is used as the upper layer for interfacing with the local user. A child process is used for a lower layer for interfacing with the remote host computer, and optionally one or more child processes can be used for the remote data output. Output may be directed to the screen and/or to the local processes under the control of a data pipe switch. In order for KNET to operate, the local and remote hosts must observe a common communications protocol. KNET is written in ANSI standard C-language for computers running UNIX. It has been successfully implemented on several Sun series computers and a DECstation 3100 and used to run programs remotely on VAX VMS and UNIX based computers. It requires 100K of RAM under SunOS and 120K of RAM under DEC RISC ULTRIX. An electronic copy of the documentation is provided on the distribution medium. The standard distribution medium for KNET is a .25 inch streaming magnetic tape cartridge in UNIX tar format. It is also available on a 3.5 inch diskette in UNIX tar format. KNET was developed in 1991 and is a copyrighted work with all copyright vested in NASA. UNIX is a registered trademark of AT&T Bell Laboratories. Sun and SunOS are trademarks of Sun Microsystems, Inc. DECstation, VAX, VMS, and

  15. Job monitoring on DIRAC for Belle II distributed computing

    NASA Astrophysics Data System (ADS)

    Kato, Yuji; Hayasaka, Kiyoshi; Hara, Takanori; Miyake, Hideki; Ueda, Ikuo

    2015-12-01

    We developed a monitoring system for Belle II distributed computing, which consists of active and passive methods. In this paper we describe the passive monitoring system, where information stored in the DIRAC database is processed and visualized. We divide the DIRAC workload management flow into steps and store characteristic variables which indicate issues. These variables are chosen carefully based on our experiences, then visualized. As a result, we are able to effectively detect issues. Finally, we discuss the future development for automating log analysis, notification of issues, and disabling problematic sites.

  16. Performance Evaluation of Three Distributed Computing Environments for Scientific Applications

    NASA Technical Reports Server (NTRS)

    Fatoohi, Rod; Weeratunga, Sisira; Lasinski, T. A. (Technical Monitor)

    1994-01-01

    We present performance results for three distributed computing environments using the three simulated CFD applications in the NAS Parallel Benchmark suite. These environments are the DCF cluster, the LACE cluster, and an Intel iPSC/860 machine. The DCF is a prototypic cluster of loosely coupled SGI R3000 machines connected by Ethernet. The LACE cluster is a tightly coupled cluster of 32 IBM RS6000/560 machines connected by Ethernet as well as by either FDDI or an IBM Allnode switch. Results of several parallel algorithms for the three simulated applications are presented and analyzed based on the interplay between the communication requirements of an algorithm and the characteristics of the communication network of a distributed system.

  17. A Distributed Simulation Facility to Support Human Factors Research in Advanced Air Transportation Technology

    NASA Technical Reports Server (NTRS)

    Amonlirdviman, Keith; Farley, Todd C.; Hansman, R. John, Jr.; Ladik, John F.; Sherer, Dana Z.

    1998-01-01

    A distributed real-time simulation of the civil air traffic environment developed to support human factors research in advanced air transportation technology is presented. The distributed environment is based on a custom simulation architecture designed for simplicity and flexibility in human experiments. Standard Internet protocols are used to create the distributed environment, linking all advanced cockpit simulator, all Air Traffic Control simulator, and a pseudo-aircraft control and simulation management station. The pseudo-aircraft control station also functions as a scenario design tool for coordinating human factors experiments. This station incorporates a pseudo-pilot interface designed to reduce workload for human operators piloting multiple aircraft simultaneously in real time. The application of this distributed simulation facility to support a study of the effect of shared information (via air-ground datalink) on pilot/controller shared situation awareness and re-route negotiation is also presented.

  18. DOE High Performance Computing Operational Review (HPCOR): Enabling Data-Driven Scientific Discovery at HPC Facilities

    SciTech Connect

    Gerber, Richard; Allcock, William; Beggio, Chris; Campbell, Stuart; Cherry, Andrew; Cholia, Shreyas; Dart, Eli; England, Clay; Fahey, Tim; Foertter, Fernanda; Goldstone, Robin; Hick, Jason; Karelitz, David; Kelly, Kaki; Monroe, Laura; Prabhat,; Skinner, David; White, Julia

    2014-10-17

    U.S. Department of Energy (DOE) High Performance Computing (HPC) facilities are on the verge of a paradigm shift in the way they deliver systems and services to science and engineering teams. Research projects are producing a wide variety of data at unprecedented scale and level of complexity, with community-specific services that are part of the data collection and analysis workflow. On June 18-19, 2014 representatives from six DOE HPC centers met in Oakland, CA at the DOE High Performance Operational Review (HPCOR) to discuss how they can best provide facilities and services to enable large-scale data-driven scientific discovery at the DOE national laboratories. The report contains findings from that review.

  19. Computer software design description for the Treated Effluent Disposal Facility (TEDF), Project L-045H, Operator Training Station (OTS)

    SciTech Connect

    Carter, R.L. Jr.

    1994-11-07

    The Treated Effluent Disposal Facility (TEDF) Operator Training Station (OTS) is a computer-based training tool designed to aid plant operations and engineering staff in familiarizing themselves with the TEDF Central Control System (CCS).

  20. Where and Why Students Choose to Use Computer Facilities: A Collaborative Study at an Australian and United Kingdom University

    ERIC Educational Resources Information Center

    Burke, Liz; Beranek, Lea; Walton, Graham; Stubbings, Ruth

    2008-01-01

    The authors describe a collaborative study at two universities, one in Australia and the other in the UK. The main objectives of the study were to gain an understanding of the factors that influence a student's choice of location when using computing facilities, what applications they use, and how adequate various services and facilities provided…

  1. A uniform approach for programming distributed heterogeneous computing systems

    PubMed Central

    Grasso, Ivan; Pellegrini, Simone; Cosenza, Biagio; Fahringer, Thomas

    2014-01-01

    Large-scale compute clusters of heterogeneous nodes equipped with multi-core CPUs and GPUs are getting increasingly popular in the scientific community. However, such systems require a combination of different programming paradigms making application development very challenging. In this article we introduce libWater, a library-based extension of the OpenCL programming model that simplifies the development of heterogeneous distributed applications. libWater consists of a simple interface, which is a transparent abstraction of the underlying distributed architecture, offering advanced features such as inter-context and inter-node device synchronization. It provides a runtime system which tracks dependency information enforced by event synchronization to dynamically build a DAG of commands, on which we automatically apply two optimizations: collective communication pattern detection and device-host-device copy removal. We assess libWater’s performance in three compute clusters available from the Vienna Scientific Cluster, the Barcelona Supercomputing Center and the University of Innsbruck, demonstrating improved performance and scaling with different test applications and configurations. PMID:25844015

  2. Performance evaluation of communication software systems for distributed computing

    NASA Astrophysics Data System (ADS)

    Fatoohi, R. A.

    1997-09-01

    In recent years there has been an increasing interest in object-oriented distributed computing since it is better equipped to deal with complex systems while providing extensibility, maintainability and reusability. At the same time, several new high-speed network technologies have emerged for local and wide area networks. However, the performance of networking software is not improving as fast as the networking hardware and the workstation microprocessors. This paper gives an overview and evaluates the performance of the Common Object Request Broker Architecture (CORBA) standard in a distributed computing environment at NASA Ames Research Center. The environment consists of two testbeds of SGI workstations connected by four networks: Ethernet, FDDI, HiPPI and ATM. The performance results for three communication software systems are presented, analysed and compared. These systems are: BSD socket programming interface, IONA's Orbix, an implementation of the CORBA specification and the PVM message passing library. The results show that high-level communication interfaces, such as CORBA and PVM, can achieve reasonable performance under certain conditions.

  3. Performance Evaluation of Communication Software Systems for Distributed Computing

    NASA Technical Reports Server (NTRS)

    Fatoohi, Rod

    1996-01-01

    In recent years there has been an increasing interest in object-oriented distributed computing since it is better quipped to deal with complex systems while providing extensibility, maintainability, and reusability. At the same time, several new high-speed network technologies have emerged for local and wide area networks. However, the performance of networking software is not improving as fast as the networking hardware and the workstation microprocessors. This paper gives an overview and evaluates the performance of the Common Object Request Broker Architecture (CORBA) standard in a distributed computing environment at NASA Ames Research Center. The environment consists of two testbeds of SGI workstations connected by four networks: Ethernet, FDDI, HiPPI, and ATM. The performance results for three communication software systems are presented, analyzed and compared. These systems are: BSD socket programming interface, IONA's Orbix, an implementation of the CORBA specification, and the PVM message passing library. The results show that high-level communication interfaces, such as CORBA and PVM, can achieve reasonable performance under certain conditions.

  4. A uniform approach for programming distributed heterogeneous computing systems.

    PubMed

    Grasso, Ivan; Pellegrini, Simone; Cosenza, Biagio; Fahringer, Thomas

    2014-12-01

    Large-scale compute clusters of heterogeneous nodes equipped with multi-core CPUs and GPUs are getting increasingly popular in the scientific community. However, such systems require a combination of different programming paradigms making application development very challenging. In this article we introduce libWater, a library-based extension of the OpenCL programming model that simplifies the development of heterogeneous distributed applications. libWater consists of a simple interface, which is a transparent abstraction of the underlying distributed architecture, offering advanced features such as inter-context and inter-node device synchronization. It provides a runtime system which tracks dependency information enforced by event synchronization to dynamically build a DAG of commands, on which we automatically apply two optimizations: collective communication pattern detection and device-host-device copy removal. We assess libWater's performance in three compute clusters available from the Vienna Scientific Cluster, the Barcelona Supercomputing Center and the University of Innsbruck, demonstrating improved performance and scaling with different test applications and configurations.

  5. Beyond input-output computings: error-driven emergence with parallel non-distributed slime mold computer.

    PubMed

    Aono, Masashi; Gunji, Yukio-Pegio

    2003-10-01

    The emergence derived from errors is the key importance for both novel computing and novel usage of the computer. In this paper, we propose an implementable experimental plan for the biological computing so as to elicit the emergent property of complex systems. An individual plasmodium of the true slime mold Physarum polycephalum acts in the slime mold computer. Modifying the Elementary Cellular Automaton as it entails the global synchronization problem upon the parallel computing provides the NP-complete problem solved by the slime mold computer. The possibility to solve the problem by giving neither all possible results nor explicit prescription of solution-seeking is discussed. In slime mold computing, the distributivity in the local computing logic can change dynamically, and its parallel non-distributed computing cannot be reduced into the spatial addition of multiple serial computings. The computing system based on exhaustive absence of the super-system may produce, something more than filling the vacancy.

  6. GAiN: Distributed Array Computation with Python

    SciTech Connect

    Daily, Jeffrey A.

    2009-05-01

    Scientific computing makes use of very large, multidimensional numerical arrays - typically, gigabytes to terabytes in size - much larger than can fit on even the largest single compute node. Such arrays must be distributed across a "cluster" of nodes. Global Arrays is a cluster-based software system from Battelle Pacific Northwest National Laboratory that enables an efficient, portable, and parallel shared-memory programming interface to manipulate these arrays. Written in and for the C and FORTRAN programming languages, it takes advantage of high-performance cluster interconnections to allow any node in the cluster to access data on any other node very rapidly. The "numpy" module is the de facto standard for numerical calculation in the Python programming language, a language whose use is growing rapidly in the scientific and engineering communities. numpy provides a powerful N-dimensional array class as well as other scientific computing capabilities. However, like the majority of the core Python modules, numpy is inherently serial. Our system, GAiN (Global Arrays in NumPy), is a parallel extension to Python that accesses Global Arrays through numpy. This allows parallel processing and/or larger problem sizes to be harnessed almost transparently within new or existing numpy programs.

  7. Burnup calculations for KIPT accelerator driven subcritical facility using Monte Carlo computer codes-MCB and MCNPX.

    SciTech Connect

    Gohar, Y.; Zhong, Z.; Talamo, A.; Nuclear Engineering Division

    2009-06-09

    Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of an electron accelerator driven subcritical (ADS) facility, using the KIPT electron accelerator. The neutron source of the subcritical assembly is generated from the interaction of 100 KW electron beam with a natural uranium target. The electron beam has a uniform spatial distribution and electron energy in the range of 100 to 200 MeV. The main functions of the subcritical assembly are the production of medical isotopes and the support of the Ukraine nuclear power industry. Neutron physics experiments and material structure analyses are planned using this facility. With the 100 KW electron beam power, the total thermal power of the facility is {approx}375 kW including the fission power of {approx}260 kW. The burnup of the fissile materials and the buildup of fission products reduce continuously the reactivity during the operation, which reduces the neutron flux level and consequently the facility performance. To preserve the neutron flux level during the operation, fuel assemblies should be added after long operating periods to compensate for the lost reactivity. This process requires accurate prediction of the fuel burnup, the decay behavior of the fission produces, and the introduced reactivity from adding fresh fuel assemblies. The recent developments of the Monte Carlo computer codes, the high speed capability of the computer processors, and the parallel computation techniques made it possible to perform three-dimensional detailed burnup simulations. A full detailed three-dimensional geometrical model is used for the burnup simulations with continuous energy nuclear data libraries for the transport calculations and 63-multigroup or one group cross sections libraries for the depletion calculations. Monte Carlo Computer code MCNPX and MCB are utilized for this study. MCNPX transports the

  8. Impact of Distributed Energy Resources on the Reliability of a Critical Telecommunications Facility

    SciTech Connect

    Robinson, D.; Atcitty, C.; Zuffranieri, J.; Arent, D.

    2006-03-01

    Telecommunications has been identified by the Department of Homeland Security as a critical infrastructure to the United States. Failures in the power systems supporting major telecommunications service nodes are a main contributor to major telecommunications outages, as documented by analyses of Federal Communications Commission (FCC) outage reports by the National Reliability Steering Committee (under auspices of the Alliance for Telecommunications Industry Solutions). There are two major issues that are having increasing impact on the sensitivity of the power distribution to telecommunication facilities: deregulation of the power industry, and changing weather patterns. A logical approach to improve the robustness of telecommunication facilities would be to increase the depth and breadth of technologies available to restore power in the face of power outages. Distributed energy resources such as fuel cells and gas turbines could provide one more onsite electric power source to provide backup power, if batteries and diesel generators fail. But does the diversity in power sources actually increase the reliability of offered power to the office equipment, or does the complexity of installing and managing the extended power system induce more potential faults and higher failure rates? This report analyzes a system involving a telecommunications facility consisting of two switch-bays and a satellite reception system.

  9. Computer Modeling of Crystallization and Crystal Size distributions

    NASA Astrophysics Data System (ADS)

    Amenta, R. V.

    2002-05-01

    The crystal size distribution of an igneous rock has been shown to be related to the crystallization kinetics. In order to better understand crystallization processes, the nucleation and growth of crystals in a closed system is modeled computationally and graphically. Units of volume analogous to unit cells are systematically attached to stationary crystal nuclei. The number of volume units attached to each crystal per growth stage is proportional to the crystal size insuring that crystal dimensional growth rates are constant regardless of their size. The number of new crystal nuclei per total system volume that form in each growth stage increases exponentially Cumulative crystal size distributions (CCSD) are determined for various stages of crystallization (30 percent, 60 pct, etc) from a database generated by the computer model, and each distribution is fit to an exponential function of the same form. Simulation results show that CCSD functions appear to fit the data reasonably well (R-square) with the greatest misfit at 100 pct crystallization. The crystal size distribution at each pct crystallization can be obtained from the derivative of the respective CCSD function. The log form of each crystal size distribution (CSD) is a linear function with negative slope. Results show that the slopes of the CSD functions at pcts crystallization up to 90 pct are parallel, but the slope at 100 pct crystallization differs from the others although still in approximate alignment. We suggest that real crystallization of igneous rocks may show this pattern. In the early stages of crystallization crystals are far apart and CSD's are ideal as predicted by theory based on growth of crystals in a brine. At advanced stages of crystallization growth collision boundaries develop between crystals. As contiguity increases crystals become blocked and inactive because they can no longer grow. As crystallization approaches 100 pct a significant number of inactive crystals exist resulting in

  10. Execution of the SimSET Monte Carlo PET/SPECT simulator in the condor distributed computing environment.

    PubMed

    Baum, Karl G; Helguera, María

    2007-11-01

    SimSET is a package for simulation of emission tomography data sets. Condor is a popular distributed computing environment. Simple C/C++ applications and shell scripts are presented which allow the execution of SimSET on the Condor environment. This is accomplished without any modification to SimSET by executing multiple instances and using its combinebin utility. This enables research facilities without dedicated parallel computing systems to utilize the idle cycles of desktop workstations to greatly reduce the run times of their SimSET simulations. The necessary steps to implement this approach in other environments are presented along with sample results.

  11. Classification of bacterial contamination using image processing and distributed computing.

    PubMed

    Ahmed, W M; Bayraktar, B; Bhunia, A; Hirleman, E D; Robinson, J P; Rajwa, B

    2013-01-01

    Disease outbreaks due to contaminated food are a major concern not only for the food-processing industry but also for the public at large. Techniques for automated detection and classification of microorganisms can be a great help in preventing outbreaks and maintaining the safety of the nations food supply. Identification and classification of foodborne pathogens using colony scatter patterns is a promising new label-free technique that utilizes image-analysis and machine-learning tools. However, the feature-extraction tools employed for this approach are computationally complex, and choosing the right combination of scatter-related features requires extensive testing with different feature combinations. In the presented work we used computer clusters to speed up the feature-extraction process, which enables us to analyze the contribution of different scatter-based features to the overall classification accuracy. A set of 1000 scatter patterns representing ten different bacterial strains was used. Zernike and Chebyshev moments as well as Haralick texture features were computed from the available light-scatter patterns. The most promising features were first selected using Fishers discriminant analysis, and subsequently a support-vector-machine (SVM) classifier with a linear kernel was used. With extensive testing we were able to identify a small subset of features that produced the desired results in terms of classification accuracy and execution speed. The use of distributed computing for scatter-pattern analysis, feature extraction, and selection provides a feasible mechanism for large-scale deployment of a light scatter-based approach to bacterial classification.

  12. Computer-based data acquisition system in the Large Coil Test Facility

    SciTech Connect

    Gould, S.S.; Layman, L.R.; Million, D.L.

    1983-01-01

    The utilization of computers for data acquisition and control is of paramount importance on large-scale fusion experiments because they feature the ability to acquire data from a large number of sensors at various sample rates and provide for flexible data interpretation, presentation, reduction, and analysis. In the Large Coil Test Facility (LCTF) a Digital Equipment Corporation (DEC) PDP-11/60 host computer with the DEC RSX-11M operating system coordinates the activities of five DEC LSI-11/23 front-end processors (FEPs) via direct memory access (DMA) communication links. This provides host control of scheduled data acquisition and FEP event-triggered data collection tasks. Four of the five FEPs have no operating system.

  13. Impact of Distributed Energy Resources on the Reliability of Critical Telecommunications Facilities: Preprint

    SciTech Connect

    Robinson, D. G.; Arent, D. J.; Johnson, L.

    2006-06-01

    This paper documents a probabilistic risk assessment of existing and alternative power supply systems at a large telecommunications office. The analysis characterizes the increase in the reliability of power supply through the use of two alternative power configurations. Failures in the power systems supporting major telecommunications service nodes are a main contributor to significant telecommunications outages. A logical approach to improving the robustness of telecommunication facilities is to increase the depth and breadth of technologies available to restore power during power outages. Distributed energy resources such as fuel cells and gas turbines could provide additional on-site electric power sources to provide backup power, if batteries and diesel generators fail. The analysis is based on a hierarchical Bayesian approach and focuses on the failure probability associated with each of three possible facility configurations, along with assessment of the uncertainty or confidence level in the probability of failure. A risk-based characterization of final best configuration is presented.

  14. Research into display sharing techniques for distributed computing environments

    NASA Technical Reports Server (NTRS)

    Hugg, Steven B.; Fitzgerald, Paul F., Jr.; Rosson, Nina Y.; Johns, Stephen R.

    1990-01-01

    The X-based Display Sharing solution for distributed computing environments is described. The Display Sharing prototype includes the base functionality for telecast and display copy requirements. Since the prototype implementation is modular and the system design provided flexibility for the Mission Control Center Upgrade (MCCU) operational consideration, the prototype implementation can be the baseline for a production Display Sharing implementation. To facilitate the process the following discussions are presented: Theory of operation; System of architecture; Using the prototype; Software description; Research tools; Prototype evaluation; and Outstanding issues. The prototype is based on the concept of a dedicated central host performing the majority of the Display Sharing processing, allowing minimal impact on each individual workstation. Each workstation participating in Display Sharing hosts programs to facilitate the user's access to Display Sharing as host machine.

  15. Enhanced Computational Infrastructure for Data Analysis at the DIII-D National Fusion Facility

    SciTech Connect

    Schissel, D.P.; Peng, Q.; Schachter, J.; Terpstra, T.B.; Casper, T.A.; Freeman, J.; Jong, R.; Keith, K.M.; Meyer, W.H.; Parker, C.T.

    1999-08-01

    Recently a number of enhancements to the computer hardware infrastructure have been implemented at the DIII-D National Fusion Facility. Utilizing these improvements to the hardware infrastructure, software enhancements are focusing on streamlined analysis, automation, and graphical user interface (GUI) systems to enlarge the user base. The adoption of the load balancing software package LSF Suite by Platform Computing has dramatically increased the availability of CPU cycles and the efficiency of their use. Streamlined analysis has been aided by the adoption of the MDSplus system to provide a unified interface to analyzed DIII-D data. The majority of MDSplus data is made available in between pulses giving the researcher critical information before setting up the next pulse. Work on data viewing and analysis tools focuses on efficient GUI design with object-oriented programming (OOP) for maximum code flexibility. Work to enhance the computational infrastructure at DIII-D has included a significant effort to aid the remote collaborator since the DIII-D National Team consists of scientists from 9 national laboratories, 19 foreign laboratories, 16 universities, and 5 industrial partnerships. As a result of this work, DIII-D data is available on a 24 x 7 basis from a set of viewing and analysis tools that can be run either on the collaborators' or DIII-Ds computer systems. Additionally, a Web based data and code documentation system has been created to aid the novice and expert user alike.

  16. Stand alone computer system to aid the development of Mirror Fusion Test Facility rf heating systems

    SciTech Connect

    Thomas, R.A.

    1983-12-01

    The Mirror Fusion Test Facility (MFTF-B) control system architecture requires the Supervisory Control and Diagnostic System (SCDS) to communicate with a LSI-11 Local Control Computer (LCC) that in turn communicates via a fiber optic link to CAMAC based control hardware located near the machine. In many cases, the control hardware is very complex and requires a sizable development effort prior to being integrated into the overall MFTF-B system. One such effort was the development of the Electron Cyclotron Resonance Heating (ECRH) system. It became clear that a stand alone computer system was needed to simulate the functions of SCDS. This paper describes the hardware and software necessary to implement the SCDS Simulation Computer (SSC). It consists of a Digital Equipment Corporation (DEC) LSI-11 computer and a Winchester/Floppy disk operating under the DEC RT-11 operating system. All application software for MFTF-B is programmed in PASCAL, which allowed us to adapt procedures originally written for SCDS to the SSC. This nearly identical software interface means that software written during the equipment development will be useful to the SCDS programmers in the integration phase.

  17. Comparison of TCP automatic tuning techniques for distributed computing

    SciTech Connect

    Weigle, E. H.; Feng, W. C.

    2002-01-01

    Rather than painful, manual, static, per-connection optimization of TCP buffer sizes simply to achieve acceptable performance for distributed applications, many researchers have proposed techniques to perform this tuning automatically. This paper first discusses the relative merits of the various approaches in theory, and then provides substantial experimental data concerning two competing implementations - the buffer autotuning already present in Linux 2.4.x and 'Dynamic Right-Sizing.' This paper reveals heretofore unknown aspects of the problem and current solutions, provides insight into the proper approach for various circumstances, and points toward ways to further improve performance. TCP, for good or ill, is the only protocol widely available for reliable end-to-end congestion-controlled network communication, and thus it is the one used for almost all distributed computing. Unfortunately, TCP was not designed with high-performance computing in mind - its original design decisions focused on long-term fairness first, with performance a distant second. Thus users must often perform tortuous manual optimizations simply to achieve acceptable behavior. The most important and often most difficult task is determining and setting appropriate buffer sizes. Because of this, at least six ways of automatically setting these sizes have been proposed. In this paper, we compare and contrast these tuning methods. First we explain each method, followed by an in-depth discussion of their features. Next we discuss the experiments to fully characterize two particularly interesting methods (Linux 2.4 autotuning and Dynamic Right-Sizing). We conclude with results and possible improvements.

  18. Toward unification of taxonomy databases in a distributed computer environment

    SciTech Connect

    Kitakami, Hajime; Tateno, Yoshio; Gojobori, Takashi

    1994-12-31

    All the taxonomy databases constructed with the DNA databases of the international DNA data banks are powerful electronic dictionaries which aid in biological research by computer. The taxonomy databases are, however not consistently unified with a relational format. If we can achieve consistent unification of the taxonomy databases, it will be useful in comparing many research results, and investigating future research directions from existent research results. In particular, it will be useful in comparing relationships between phylogenetic trees inferred from molecular data and those constructed from morphological data. The goal of the present study is to unify the existent taxonomy databases and eliminate inconsistencies (errors) that are present in them. Inconsistencies occur particularly in the restructuring of the existent taxonomy databases, since classification rules for constructing the taxonomy have rapidly changed with biological advancements. A repair system is needed to remove inconsistencies in each data bank and mismatches among data banks. This paper describes a new methodology for removing both inconsistencies and mismatches from the databases on a distributed computer environment. The methodology is implemented in a relational database management system, SYBASE.

  19. Dynamic resource allocation scheme for distributed heterogeneous computer systems

    NASA Technical Reports Server (NTRS)

    Liu, Howard T. (Inventor); Silvester, John A. (Inventor)

    1991-01-01

    This invention relates to a resource allocation in computer systems, and more particularly, to a method and associated apparatus for shortening response time and improving efficiency of a heterogeneous distributed networked computer system by reallocating the jobs queued up for busy nodes to idle, or less-busy nodes. In accordance with the algorithm (SIDA for short), the load-sharing is initiated by the server device in a manner such that extra overhead in not imposed on the system during heavily-loaded conditions. The algorithm employed in the present invention uses a dual-mode, server-initiated approach. Jobs are transferred from heavily burdened nodes (i.e., over a high threshold limit) to low burdened nodes at the initiation of the receiving node when: (1) a job finishes at a node which is burdened below a pre-established threshold level, or (2) a node is idle for a period of time as established by a wakeup timer at the node. The invention uses a combination of the local queue length and the local service rate ratio at each node as the workload indicator.

  20. Advanced distribution, switching, and conversion technology for fluids/combustion facility electric power control

    NASA Astrophysics Data System (ADS)

    Poljak, Mark D.; Soltis, James V.; Fox, David A.

    1997-01-01

    The Electrical Power Control Unit (EPCU) under development for use in the Fluids/Combustion Facility (FCF) on International Space Station (ISS) is the precursor of modular power distribution and conversion concepts for future high power and small spacecraft applications. The EPCU is built from modular, current limiting Flexible Remote Power Controllers (FRPCs) and paralleled power converters packaged into a common orbital replacement unit. Multiple EPCUs are combined at the next higher level of integration to form the three-rack FCF Electrical Power System (EPS). This modular building block approach allows for the quick development of expandable power systems tailored to customer needs.

  1. Simulation Study of Gyrotron Traveling Wave Amplifier with Distributed-Loss in Facilities for Aquaculture

    NASA Astrophysics Data System (ADS)

    Hua, Xufeng; Chen, Chengxun; Xu, Dawei; Xing, Kezhi

    In this paper, we introduce a W-band gyro-traveling wave (gyro-TWT) tube to suppress spurious oscillations, which is used in facilities for Aquaculture. The spurious oscillations block achieving high gain and high power in high-power broadband millimeter amplifier. In order to suppress spurious oscillations, we study the interaction circuit including input coupler and output section, design the gyro-traveling wave tube with distributed-loss based on MIG. The results of simulation show that high power and broad-band capabilities.

  2. Distributed Monitoring Infrastructure for Worldwide LHC Computing Grid

    NASA Astrophysics Data System (ADS)

    Andrade, P.; Babik, M.; Bhatt, K.; Chand, P.; Collados, D.; Duggal, V.; Fuente, P.; Hayashi, S.; Imamagic, E.; Joshi, P.; Kalmady, R.; Karnani, U.; Kumar, V.; Lapka, W.; Quick, R.; Tarragon, J.; Teige, S.; Triantafyllidis, C.

    2012-12-01

    The journey of a monitoring probe from its development phase to the moment its execution result is presented in an availability report is a complex process. It goes through multiple phases such as development, testing, integration, release, deployment, execution, data aggregation, computation, and reporting. Further, it involves people with different roles (developers, site managers, VO[1] managers, service managers, management), from different middleware providers (ARC[2], dCache[3], gLite[4], UNICORE[5] and VDT[6]), consortiums (WLCG[7], EMI[11], EGI[15], OSG[13]), and operational teams (GOC[16], OMB[8], OTAG[9], CSIRT[10]). The seamless harmonization of these distributed actors is in daily use for monitoring of the WLCG infrastructure. In this paper we describe the monitoring of the WLCG infrastructure from the operational perspective. We explain the complexity of the journey of a monitoring probe from its execution on a grid node to the visualization on the MyWLCG[27] portal where it is exposed to other clients. This monitoring workflow profits from the interoperability established between the SAM[19] and RSV[20] frameworks. We show how these two distributed structures are capable of uniting technologies and hiding the complexity around them, making them easy to be used by the community. Finally, the different supported deployment strategies, tailored not only for monitoring the entire infrastructure but also for monitoring sites and virtual organizations, are presented and the associated operational benefits highlighted.

  3. GASFLOW: A computational model to analyze accidents in nuclear containment and facility buildings

    SciTech Connect

    Travis, J.R. ); Nichols, B.D.; Wilson, T.L.; Lam, K.L.; Spore, J.W.; Niederauer, G.F. )

    1993-01-01

    GASFLOW is a finite-volume computer code that solves the time-dependent, compressible Navier-Stokes equations for multiple gas species. The fluid-dynamics algorithm is coupled to the chemical kinetics of combusting liquids or gases to simulate diffusion or propagating flames in complex geometries of nuclear containment or confinement and facilities' buildings. Fluid turbulence is calculated to enhance the transport and mixing of gases in rooms and volumes that may be connected by a ventilation system. The ventilation system may consist of extensive ductwork, filters, dampers or valves, and fans. Condensation and heat transfer to walls, floors, ceilings, and internal structures are calculated to model the appropriate energy sinks. Solid and liquid aerosol behavior is simulated to give the time and space inventory of radionuclides. The solution procedure of the governing equations is a modified Los Alamos ICE'd-ALE methodology. Complex facilities can be represented by separate computational domains (multiblocks) that communicate through overlapping boundary conditions. The ventilation system is superimposed throughout the multiblock mesh. Gas mixtures and aerosols are transported through the free three-dimensional volumes and the restricted one-dimensional ventilation components as the accident and fluid flow fields evolve. Combustion may occur if sufficient fuel and reactant or oxidizer are present and have an ignition source. Pressure and thermal loads on the building, structural components, and safety-related equipment can be determined for specific accident scenarios. GASFLOW calculations have been compared with large oil-pool fire tests in the 1986 HDR containment test T52.14, which is a 3000-kW fire experiment. The computed results are in good agreement with the observed data.

  4. Availability and distribution of safe abortion services in rural areas: a facility assessment study in Madhya Pradesh, India

    PubMed Central

    Chaturvedi, Sarika; Ali, Sayyed; Randive, Bharat; Sabde, Yogesh; Diwan, Vishal; De Costa, Ayesha

    2015-01-01

    Background Unsafe abortion contributes to a significant portion of maternal mortality in India. Access to safe abortion care is known to reduce maternal mortality. Availability and distribution of abortion care facilities can influence women's access to these services, especially in rural areas. Objectives To assess the availability and distribution of abortion care at facilities providing childbirth care in three districts of Madhya Pradesh (MP) province of India. Design Three socio demographically heterogeneous districts of MP were selected for this study. Facilities conducting at least 10 deliveries a month were surveyed to assess availability and provision of abortion services using UN signal functions for emergency obstetric care. Geographical Information System was used for visualisation of the distribution of facilities. Results The three districts had 99 facilities that conducted >10 deliveries a month: 74 in public and 25 in private sector. Overall, 48% of facilities reported an ability to provide safe surgical abortion service. Of public centres, 32% reported the ability compared to 100% among private centres while 18% of public centres and 77% of private centres had performed an abortion in the last 3 months. The availability of abortion services was higher at higher facility levels with better equipped and skilled personnel availability, in urban areas and in private sector facilities. Conclusions Findings showed that availability of safe abortion care is limited especially in rural areas. More emphasis on providing safe abortion services, particularly at primary care level, is important to more significantly dent maternal mortality in India. PMID:25797220

  5. Raman distributed temperature measurement at CERN high energy accelerator mixed field radiation test facility (CHARM)

    NASA Astrophysics Data System (ADS)

    Toccafondo, Iacopo; Nannipieri, Tiziano; Signorini, Alessandro; Guillermain, Elisa; Kuhnhenn, Jochen; Brugger, Markus; Di Pasquale, Fabrizio

    2015-09-01

    In this paper we present a validation of distributed Raman temperature sensing (RDTS) at the CERN high energy accelerator mixed field radiation test facility (CHARM), newly developed in order to qualify electronics for the challenging radiation environment of accelerators and connected high energy physics experiments. By investigating the effect of wavelength dependent radiation induced absorption (RIA) on the Raman Stokes and anti-Stokes light components in radiation tolerant Ge-doped multi-mode (MM) graded-index optical fibers, we demonstrate that Raman DTS used in loop configuration is robust to harsh environments in which the fiber is exposed to a mixed radiation field. The temperature profiles measured on commercial Ge-doped optical fibers is fully reliable and therefore, can be used to correct the RIA temperature dependence in distributed radiation sensing systems based on P-doped optical fibers.

  6. Spatially Resolved Temperature and Water Vapor Concentration Distributions in Supersonic Combustion Facilities by TDLAT

    NASA Technical Reports Server (NTRS)

    Busa, K. M.; McDaniel J. C.; Diskin, G. S.; DePiro, M. J.; Capriotti, D. P.; Gaffney, R. L.

    2012-01-01

    Detailed knowledge of the internal structure of high-enthalpy flows can provide valuable insight to the performance of scramjet combustors. Tunable Diode Laser Absorption Spectroscopy (TDLAS) is often employed to measure temperature and species concentration. However, TDLAS is a path-integrated line-of-sight (LOS) measurement, and thus does not produce spatially resolved distributions. Tunable Diode Laser Absorption Tomography (TDLAT) is a non-intrusive measurement technique for determining two-dimensional spatially resolved distributions of temperature and species concentration in high enthalpy flows. TDLAT combines TDLAS with tomographic image reconstruction. More than 2500 separate line-of-sight TDLAS measurements are analyzed in order to produce highly resolved temperature and species concentration distributions. Measurements have been collected at the University of Virginia's Supersonic Combustion Facility (UVaSCF) as well as at the NASA Langley Direct-Connect Supersonic Combustion Test Facility (DCSCTF). Due to the UVaSCF s unique electrical heating and ability for vitiate addition, measurements collected at the UVaSCF are presented as a calibration of the technique. Measurements collected at the DCSCTF required significant modifications to system hardware and software designs due to its larger measurement area and shorter test duration. Tomographic temperature and water vapor concentration distributions are presented from experimentation on the UVaSCF operating at a high temperature non-reacting case for water vitiation level of 12%. Initial LOS measurements from the NASA Langley DCSCTF operating at an equivalence ratio of 0.5 are also presented. Results show the capability of TDLAT to adapt to several experimental setups and test parameters.

  7. Distributed computing feasibility in a non-dedicated homogeneous distributed system

    NASA Technical Reports Server (NTRS)

    Leutenegger, Scott T.; Sun, Xian-He

    1993-01-01

    The low cost and availability of clusters of workstations have lead researchers to re-explore distributed computing using independent workstations. This approach may provide better cost/performance than tightly coupled multiprocessors. In practice, this approach often utilizes wasted cycles to run parallel jobs. The feasibility of such a non-dedicated parallel processing environment assuming workstation processes have preemptive priority over parallel tasks is addressed. An analytical model is developed to predict parallel job response times. Our model provides insight into how significantly workstation owner interference degrades parallel program performance. A new term task ratio, which relates the parallel task demand to the mean service demand of nonparallel workstation processes, is introduced. It was proposed that task ratio is a useful metric for determining how large the demand of a parallel applications must be in order to make efficient use of a non-dedicated distributed system.

  8. Achieving production-level use of HEP software at the Argonne Leadership Computing Facility

    NASA Astrophysics Data System (ADS)

    Uram, T. D.; Childers, J. T.; LeCompte, T. J.; Papka, M. E.; Benjamin, D.

    2015-12-01

    HEP's demand for computing resources has grown beyond the capacity of the Grid, and these demands will accelerate with the higher energy and luminosity planned for Run II. Mira, the ten petaFLOPs supercomputer at the Argonne Leadership Computing Facility, is a potentially significant compute resource for HEP research. Through an award of fifty million hours on Mira, we have delivered millions of events to LHC experiments by establishing the means of marshaling jobs through serial stages on local clusters, and parallel stages on Mira. We are running several HEP applications, including Alpgen, Pythia, Sherpa, and Geant4. Event generators, such as Sherpa, typically have a split workload: a small scale integration phase, and a second, more scalable, event-generation phase. To accommodate this workload on Mira we have developed two Python-based Django applications, Balsam and ARGO. Balsam is a generalized scheduler interface which uses a plugin system for interacting with scheduler software such as HTCondor, Cobalt, and TORQUE. ARGO is a workflow manager that submits jobs to instances of Balsam. Through these mechanisms, the serial and parallel tasks within jobs are executed on the appropriate resources. This approach and its integration with the PanDA production system will be discussed.

  9. Addressing capability computing challenges of high-resolution global climate modelling at the Oak Ridge Leadership Computing Facility

    NASA Astrophysics Data System (ADS)

    Anantharaj, Valentine; Norman, Matthew; Evans, Katherine; Taylor, Mark; Worley, Patrick; Hack, James; Mayer, Benjamin

    2014-05-01

    During 2013, high-resolution climate model simulations accounted for over 100 million "core hours" using Titan at the Oak Ridge Leadership Computing Facility (OLCF). The suite of climate modeling experiments, primarily using the Community Earth System Model (CESM) at nearly 0.25 degree horizontal resolution, generated over a petabyte of data and nearly 100,000 files, ranging in sizes from 20 MB to over 100 GB. Effective utilization of leadership class resources requires careful planning and preparation. The application software, such as CESM, need to be ported, optimized and benchmarked for the target platform in order to meet the computational readiness requirements. The model configuration needs to be "tuned and balanced" for the experiments. This can be a complicated and resource intensive process, especially for high-resolution configurations using complex physics. The volume of I/O also increases with resolution; and new strategies may be required to manage I/O especially for large checkpoint and restart files that may require more frequent output for resiliency. It is also essential to monitor the application performance during the course of the simulation exercises. Finally, the large volume of data needs to be analyzed to derive the scientific results; and appropriate data and information delivered to the stakeholders. Titan is currently the largest supercomputer available for open science. The computational resources, in terms of "titan core hours" are allocated primarily via the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) and ASCR Leadership Computing Challenge (ALCC) programs, both sponsored by the U.S. Department of Energy (DOE) Office of Science. Titan is a Cray XK7 system, capable of a theoretical peak performance of over 27 PFlop/s, consists of 18,688 compute nodes, with a NVIDIA Kepler K20 GPU and a 16-core AMD Opteron CPU in every node, for a total of 299,008 Opteron cores and 18,688 GPUs offering a cumulative 560

  10. Maintaining Traceability in an Evolving Distributed Computing Environment

    NASA Astrophysics Data System (ADS)

    Collier, I.; Wartel, R.

    2015-12-01

    The management of risk is fundamental to the operation of any distributed computing infrastructure. Identifying the cause of incidents is essential to prevent them from re-occurring. In addition, it is a goal to contain the impact of an incident while keeping services operational. For response to incidents to be acceptable this needs to be commensurate with the scale of the problem. The minimum level of traceability for distributed computing infrastructure usage is to be able to identify the source of all actions (executables, file transfers, pilot jobs, portal jobs, etc.) and the individual who initiated them. In addition, sufficiently fine-grained controls, such as blocking the originating user and monitoring to detect abnormal behaviour, are necessary for keeping services operational. It is essential to be able to understand the cause and to fix any problems before re-enabling access for the user. The aim is to be able to answer the basic questions who, what, where, and when concerning any incident. This requires retaining all relevant information, including timestamps and the digital identity of the user, sufficient to identify, for each service instance, and for every security event including at least the following: connect, authenticate, authorize (including identity changes) and disconnect. In traditional grid infrastructures (WLCG, EGI, OSG etc.) best practices and procedures for gathering and maintaining the information required to maintain traceability are well established. In particular, sites collect and store information required to ensure traceability of events at their sites. With the increased use of virtualisation and private and public clouds for HEP workloads established procedures, which are unable to see 'inside' running virtual machines no longer capture all the information required. Maintaining traceability will at least involve a shift of responsibility from sites to Virtual Organisations (VOs) bringing with it new requirements for their

  11. High-performance computing, high-speed networks, and configurable computing environments: progress toward fully distributed computing.

    PubMed

    Johnston, W E; Jacobson, V L; Loken, S C; Robertson, D W; Tierney, B L

    1992-01-01

    The next several years will see the maturing of a collection of technologies that will enable fully and transparently distributed computing environments. Networks will be used to configure independent computing, storage, and I/O elements into "virtual systems" that are optimal for solving a particular problem. This environment will make the most powerful computing systems those that are logically assembled from network-based components and will also make those systems available to a widespread audience. Anticipating that the necessary technology and communications infrastructure will be available in the next 3 to 5 years, we are developing and demonstrating prototype applications that test and exercise the currently available elements of this configurable environment. The Lawrence Berkeley Laboratory (LBL) Information and Computing Sciences and Research Medicine Divisions have collaborated with the Pittsburgh Supercomputer Center to demonstrate one distributed application that illuminates the issues and potential of using networks to configure virtual systems. This application allows the interactive visualization of large three-dimensional (3D) scalar fields (voxel data sets) by using a network-based configuration of heterogeneous supercomputers and workstations. The specific test case is visualization of 3D magnetic resonance imaging (MRI) data. The virtual system architecture consists of a Connection Machine-2 (CM-2) that performs surface reconstruction from the voxel data, a Cray Y-MP that renders the resulting geometric data into an image, and a workstation that provides the display of the image and the user interface for specifying the parameters for the geometry generation and 3D viewing. These three elements are configured into a virtual system by using several different network technologies. This paper reviews the current status of the software, hardware, and communications technologies that are needed to enable this configurable environment. These

  12. Protein folding by distributed computing and the denatured state ensemble.

    PubMed

    Marianayagam, Neelan J; Fawzi, Nicolas L; Head-Gordon, Teresa

    2005-11-15

    The distributed computing (DC) paradigm in conjunction with the folding@home (FH) client server has been used to study the folding kinetics of small peptides and proteins, giving excellent agreement with experimentally measured folding rates, although pathways sampled in these simulations are not always consistent with the folding mechanism. In this study, we use a coarse-grain model of protein L, whose two-state kinetics have been characterized in detail by using long-time equilibrium simulations, to rigorously test a FH protocol using approximately 10,000 short-time, uncoupled folding simulations starting from an extended state of the protein. We show that the FH results give non-Poisson distributions and early folding events that are unphysical, whereas longer folding events experience a correct barrier to folding but are not representative of the equilibrium folding ensemble. Using short-time, uncoupled folding simulations started from an equilibrated denatured state ensemble (DSE), we also do not get agreement with the equilibrium two-state kinetics because of overrepresented folding events arising from higher energy subpopulations in the DSE. The DC approach using uncoupled short trajectories can make contact with traditionally measured experimental rates and folding mechanism when starting from an equilibrated DSE, when the simulation time is long enough to sample the lowest energy states of the unfolded basin and the simulated free-energy surface is correct. However, the DC paradigm, together with faster time-resolved and single-molecule experiments, can also reveal the breakdown in the two-state approximation due to observation of folding events from higher energy subpopulations in the DSE.

  13. Characterizing W-2 SLSF experiment temperature oscillations using computer graphics. [Sodium Loop Safety Facility

    SciTech Connect

    Smith, D.E.

    1983-06-23

    The W-2 SLSF (Sodium Loop Safety Facility) experiment was an instrumented in-reactor test performed to characterize the failure response of full-length, preconditioned LMFBR prototypic fuel pins to slow transient overpower (TOP) conditions. Although the test results were expected to confirm analytical predictions of upper level failure and fuel expulsion, an axial midplane failure was experienced. Extensive post-test analyses were conducted to understand all of the unexpected behavior in the experiment. (1) The initial post-test effort focused on the temperature oscillations recorded by the 54 thermocouples used in the experiment. In order to synthesize the extensive data records and identify patterns of behavior in the data records, a computer-generated film was used to present the temperature data recorded during the experiment.

  14. A design study for the upgraded ALICE O2 computing facility

    NASA Astrophysics Data System (ADS)

    Richter, Matthias

    2015-12-01

    An upgrade of the ALICE detector is currently prepared for the Run 3 period of the Large Hadron Collider (LHC) at CERN starting in 2020. The physics topics under study by ALICE during this period will require the inspection of all collisions at a rate of 50 kHz for minimum bias Pb-Pb and 200 kHz for pp and p-Pb collisions in order to extract physics signals embedded into a large background. The upgraded ALICE detector will produce more than 1 TByte/s of data. Both collision and data rate impose new challenges onto the detector readout and compute system. Some detectors will not use a triggered readout, which will require a continuous processing of the detector data. The challenging requirements will be met by a combined online and offline facility developed and managed by the ALICE O2 project. The combined facility will accommodate the necessary substantial increase of data taking rate. In this paper we present first results of a prototype with estimates for scalability and feasibility for a full scale system.

  15. Systems analysis of the space shuttle. [communication systems, computer systems, and power distribution

    NASA Technical Reports Server (NTRS)

    Schilling, D. L.; Oh, S. J.; Thau, F.

    1975-01-01

    Developments in communications systems, computer systems, and power distribution systems for the space shuttle are described. The use of high speed delta modulation for bit rate compression in the transmission of television signals is discussed. Simultaneous Multiprocessor Organization, an approach to computer organization, is presented. Methods of computer simulation and automatic malfunction detection for the shuttle power distribution system are also described.

  16. The FOSS GIS Workbench on the GFZ Load Sharing Facility compute cluster

    NASA Astrophysics Data System (ADS)

    Löwe, P.; Klump, J.; Thaler, J.

    2012-04-01

    Compute clusters can be used as GIS workbenches, their wealth of resources allow us to take on geocomputation tasks which exceed the limitations of smaller systems. To harness these capabilities requires a Geographic Information System (GIS), able to utilize the available cluster configuration/architecture and a sufficient degree of user friendliness to allow for wide application. In this paper we report on the first successful porting of GRASS GIS, the oldest and largest Free Open Source (FOSS) GIS project, onto a compute cluster using Platform Computing's Load Sharing Facility (LSF). In 2008, GRASS6.3 was installed on the GFZ compute cluster, which at that time comprised 32 nodes. The interaction with the GIS was limited to the command line interface, which required further development to encapsulate the GRASS GIS business layer to facilitate its use by users not familiar with GRASS GIS. During the summer of 2011, multiple versions of GRASS GIS (v 6.4, 6.5 and 7.0) were installed on the upgraded GFZ compute cluster, now consisting of 234 nodes with 480 CPUs providing 3084 cores. The GFZ compute cluster currently offers 19 different processing queues with varying hardware capabilities and priorities, allowing for fine-grained scheduling and load balancing. After successful testing of core GIS functionalities, including the graphical user interface, mechanisms were developed to deploy scripted geocomputation tasks onto dedicated processing queues. The mechanisms are based on earlier work by NETELER et al. (2008). A first application of the new GIS functionality was the generation of maps of simulated tsunamis in the Mediterranean Sea for the Tsunami Atlas of the FP-7 TRIDEC Project (www.tridec-online.eu). For this, up to 500 processing nodes were used in parallel. Further trials included the processing of geometrically complex problems, requiring significant amounts of processing time. The GIS cluster successfully completed all these tasks, with processing times

  17. Facility Microgrids

    SciTech Connect

    Ye, Z.; Walling, R.; Miller, N.; Du, P.; Nelson, K.

    2005-05-01

    Microgrids are receiving a considerable interest from the power industry, partly because their business and technical structure shows promise as a means of taking full advantage of distributed generation. This report investigates three issues associated with facility microgrids: (1) Multiple-distributed generation facility microgrids' unintentional islanding protection, (2) Facility microgrids' response to bulk grid disturbances, and (3) Facility microgrids' intentional islanding.

  18. Use of the Web by a Distributed Research group Performing Distributed Computing

    NASA Astrophysics Data System (ADS)

    Burke, David A.; Peterkin, Robert E.

    2001-06-01

    A distributed research group that uses distributed computers faces a spectrum of challenges--some of which can be met by using various electronic means of communication. The particular challenge of our group involves three physically separated research entities. We have had to link two collaborating groups at AFRL and NRL together for software development, and the same AFRL group with a LANL group for software applications. We are developing and using a pair of general-purpose, portable, parallel, unsteady, plasma physics simulation codes. The first collaboration is centered around a formal weekly video teleconference on relatively inexpensive equipment that we have set up in convenient locations in our respective laboratories. The formal virtual meetings are augmented with informal virtual meetings as the need arises. Both collaborations share research data in a variety of forms on a secure URL that is set up behind the firewall at the AFRL. Of course, a computer-generated animation is a particularly efficient way of displaying results from time-dependent numerical simulations, so we generally like to post such animations (along with proper documentation) on our web page. In this presentation, we will discuss some of our accomplishments and disappointments.

  19. An evaluation of biosurveillance grid--dynamic algorithm distribution across multiple computer nodes.

    PubMed

    Tsai, Ming-Chi; Tsui, Fu-Chiang; Wagner, Michael M

    2007-10-11

    Performing fast data analysis to detect disease outbreaks plays a critical role in real-time biosurveillance. In this paper, we described and evaluated an Algorithm Distribution Manager Service (ADMS) based on grid technologies, which dynamically partition and distribute detection algorithms across multiple computers. We compared the execution time to perform the analysis on a single computer and on a grid network (3 computing nodes) with and without using dynamic algorithm distribution. We found that algorithms with long runtime completed approximately three times earlier in distributed environment than in a single computer while short runtime algorithms performed worse in distributed environment. A dynamic algorithm distribution approach also performed better than static algorithm distribution approach. This pilot study shows a great potential to reduce lengthy analysis time through dynamic algorithm partitioning and parallel processing, and provides the opportunity of distributing algorithms from a client to remote computers in a grid network.

  20. Above the cloud computing orbital services distributed data model

    NASA Astrophysics Data System (ADS)

    Straub, Jeremy

    2014-05-01

    Technology miniaturization and system architecture advancements have created an opportunity to significantly lower the cost of many types of space missions by sharing capabilities between multiple spacecraft. Historically, most spacecraft have been atomic entities that (aside from their communications with and tasking by ground controllers) operate in isolation. Several notable example exist; however, these are purpose-designed systems that collaborate to perform a single goal. The above the cloud computing (ATCC) concept aims to create ad-hoc collaboration between service provider and consumer craft. Consumer craft can procure processing, data transmission, storage, imaging and other capabilities from provider craft. Because of onboard storage limitations, communications link capability limitations and limited windows of communication, data relevant to or required for various operations may span multiple craft. This paper presents a model for the identification, storage and accessing of this data. This model includes appropriate identification features for this highly distributed environment. It also deals with business model constraints such as data ownership, retention and the rights of the storing craft to access, resell, transmit or discard the data in its possession. The model ensures data integrity and confidentiality (to the extent applicable to a given data item), deals with unique constraints of the orbital environment and tags data with business model (contractual) obligation data.

  1. Parallelizing Sylvester-like operations on a distributed memory computer

    SciTech Connect

    Hu, D.Y.; Sorensen, D.C.

    1994-12-31

    Discretization of linear operators arising in applied mathematics often leads to matrices with the following structure: M(x) = (D {circle_times} A + B {circle_times} I{sub n} + V)x, where x {element_of} R{sup mn}, B, D {element_of} R{sup nxn}, A {element_of} R{sup mxm} and V {element_of} R{sup mnxmn}; both D and V are diagonal. For the notational convenience, the authors assume that both A and B are symmetric. All the results through this paper can be easily extended to the cases with general A and B. The linear operator on R{sup mn} defined above can be viewed as a generalization of the Sylvester operator: S(x) = (I{sub m} {circle_times} A + B {circle_times} I{sub n})x. The authors therefore refer to it as a Sylvester-like operator. The schemes discussed in this paper therefore also apply to Sylvester operator. In this paper, the authors present the SIMD scheme for parallelization of the Sylvester-like operator on a distributed memory computer. This scheme is designed to approach the best possible efficiency by avoiding unnecessary communication among processors.

  2. Automatic distribution of vision-tasks on computing clusters

    NASA Astrophysics Data System (ADS)

    Müller, Thomas; Tran, Binh An; Knoll, Alois

    2011-01-01

    In this paper a consistent and efficient but yet convenient system for parallel computer vision, and in fact also realtime actuator control is proposed. The system implements the multi-agent paradigm and a blackboard information storage. This, in combination with a generic interface for hardware abstraction and integration of external software components, is setup on basis of the message passing interface (MPI). The system allows for data- and task-parallel processing, and supports both synchronous communication, as data exchange can be triggered by events, and asynchronous communication, as data can be polled, strategies. Also, by duplication of processing units (agents) redundant processing is possible to achieve greater robustness. As the system automatically distributes the task units to available resources, and a monitoring concept allows for combination of tasks and their composition to complex processes, it is easy to develop efficient parallel vision / robotics applications quickly. Multiple vision based applications have already been implemented, including academic, research related fields and prototypes for industrial automation. For the scientific community the system has been recently launched open-source.

  3. Computational spectroscopy using the Quantum ESPRESSO distribution (Invited)

    NASA Astrophysics Data System (ADS)

    Baroni, S.; Giannozzi, P.

    2009-12-01

    Quantum ESPRESSO (QE) [1,2] is an integrated suite of computer codes for electronic-structure calculations and materials modeling, based on density-functional theory, plane waves, and pseudopotentials. QE freely available to researchers around the world under the terms of the GNU general public licence. In this talk I will introduce the QE distribution, with emphasis on some of its features that may appeal to the Earth Sciences and Mineralogy communities. I will focus on the determination of vibrational frequencies to be used for spectroscopic purposes, for the determination of soft modes leading to mechanical instabilities, and as ingredients for the simulation of thermal properties in the (quasi-) harmonic approximations. I will conclude with some recent developments which are allowing for the simulation of electronic (absorption and photo-emission) spectroscopies, using many-body and time-dependent density-functional perturbation theories. [1] P. Giannozzi et al. J. Phys.: Condens. Matter 21, 395502 (2009); http://dx.doi.org/10.1088/0953-8984/21/39/395502 [2] http://www.quantum-espresso.org

  4. Distributed Computing Over New Technology Networks: Quality of Service for CORBA Objects.

    DTIC Science & Technology

    1996-10-01

    technology. This was accomplished in four (largely sequential) steps: (1) Study the impact of new technology networks on distributed computing environments...distributed programs such as C3 or collaborative planning applications; (2) Study how Distributed Computing Environments (DCEs) should support QoS in

  5. Distributed Computer-Supported Team Work: A Reasearch Paradigm

    DTIC Science & Technology

    1989-12-01

    e.g., looks of disgust, lack of eye contact, body position, etc.) which may be crucial in interpreting other group member’s positions and avoiding...their eyes only. This button was programmed to not permit access to the "classified" information if "Observers Allowed" was checked in the "Communications...Timbuktu were conducted in the Classroom -2000 facility, College of Management, Georgia Tech. In this facility there are 35 MACUs networked for instructional

  6. Navier-Stokes Simulation of Airconditioning Facility of a Large Modem Computer Room

    NASA Technical Reports Server (NTRS)

    2005-01-01

    NASA recently assembled one of the world's fastest operational supercomputers to meet the agency's new high performance computing needs. This large-scale system, named Columbia, consists of 20 interconnected SGI Altix 512-processor systems, for a total of 10,240 Intel Itanium-2 processors. High-fidelity CFD simulations were performed for the NASA Advanced Supercomputing (NAS) computer room at Ames Research Center. The purpose of the simulations was to assess the adequacy of the existing air handling and conditioning system and make recommendations for changes in the design of the system if needed. The simulations were performed with NASA's OVERFLOW-2 CFD code which utilizes overset structured grids. A new set of boundary conditions were developed and added to the flow solver for modeling the roomls air-conditioning and proper cooling of the equipment. Boundary condition parameters for the flow solver are based on cooler CFM (flow rate) ratings and some reasonable assumptions of flow and heat transfer data for the floor and central processing units (CPU) . The geometry modeling from blue prints and grid generation were handled by the NASA Ames software package Chimera Grid Tools (CGT). This geometric model was developed as a CGT-scripted template, which can be easily modified to accommodate any changes in shape and size of the room, locations and dimensions of the CPU racks, disk racks, coolers, power distribution units, and mass-storage system. The compute nodes are grouped in pairs of racks with an aisle in the middle. High-speed connection cables connect the racks with overhead cable trays. The cool air from the cooling units is pumped into the computer room from a sub-floor through perforated floor tiles. The CPU cooling fans draw cool air from the floor tiles, which run along the outside length of each rack, and eject warm air into the center isle between the racks. This warm air is eventually drawn into the cooling units located near the walls of the room. One

  7. Enabling Extreme Scale Earth Science Applications at the Oak Ridge Leadership Computing Facility

    NASA Astrophysics Data System (ADS)

    Anantharaj, V. G.; Mozdzynski, G.; Hamrud, M.; Deconinck, W.; Smith, L.; Hack, J.

    2014-12-01

    The Oak Ridge Leadership Facility (OLCF), established at the Oak Ridge National Laboratory (ORNL) under the auspices of the U.S. Department of Energy (DOE), welcomes investigators from universities, government agencies, national laboratories and industry who are prepared to perform breakthrough research across a broad domain of scientific disciplines, including earth and space sciences. Titan, the OLCF flagship system, is currently listed as #2 in the Top500 list of supercomputers in the world, and the largest available for open science. The computational resources are allocated primarily via the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program, sponsored by the U.S. DOE Office of Science. In 2014, over 2.25 billion core hours on Titan were awarded via INCITE projects., including 14% of the allocation toward earth sciences. The INCITE competition is also open to research scientists based outside the USA. In fact, international research projects account for 12% of the INCITE awards in 2014. The INCITE scientific review panel also includes 20% participation from international experts. Recent accomplishments in earth sciences at OLCF include the world's first continuous simulation of 21,000 years of earth's climate history (2009); and an unprecedented simulation of a magnitude 8 earthquake over 125 sq. miles. One of the ongoing international projects involves scaling the ECMWF Integrated Forecasting System (IFS) model to over 200K cores of Titan. ECMWF is a partner in the EU funded Collaborative Research into Exascale Systemware, Tools and Applications (CRESTA) project. The significance of the research carried out within this project is the demonstration of techniques required to scale current generation Petascale capable simulation codes towards the performance levels required for running on future Exascale systems. One of the techniques pursued by ECMWF is to use Fortran2008 coarrays to overlap computations and communications and

  8. Impact of distributed energy resources on the reliability of a critical telecommunications facility.

    SciTech Connect

    Robinson, David; Zuffranieri, Jason V.; Atcitty, Christopher B.; Arent, Douglas

    2006-03-01

    This report documents a probabilistic risk assessment of an existing power supply system at a large telecommunications office. The focus is on characterizing the increase in the reliability of power supply through the use of two alternative power configurations. Telecommunications has been identified by the Department of Homeland Security as a critical infrastructure to the United States. Failures in the power systems supporting major telecommunications service nodes are a main contributor to major telecommunications outages. A logical approach to improve the robustness of telecommunication facilities would be to increase the depth and breadth of technologies available to restore power in the face of power outages. Distributed energy resources such as fuel cells and gas turbines could provide one more onsite electric power source to provide backup power, if batteries and diesel generators fail. The analysis is based on a hierarchical Bayesian approach and focuses on the failure probability associated with each of three possible facility configurations, along with assessment of the uncertainty or confidence level in the probability of failure. A risk-based characterization of final best configuration is presented.

  9. Radon gas distribution in natural gas processing facilities and workplace air environment.

    PubMed

    Al-Masri, M S; Shwiekani, R

    2008-04-01

    Evaluation was made of the distribution of radon gas and radiation exposure rates in the four main natural gas treatment facilities in Syria. The results showed that radiation exposure rates at contact of all equipment were within the natural levels (0.09-0.1 microSvh(-1)) except for the reflex pumps where a dose rate value of 3 microSvh(-1) was recorded. Radon concentrations in Syrian natural gas varied between 15.4 Bq m(-3) and 1141 Bq m(-3); natural gas associated with oil production was found to contain higher concentrations than the non-associated natural gas. In addition, radon concentrations were higher in the central processing facilities than the wellheads; these high levels are due to pressurizing and concentrating processes that enhance radon gas and its decay products. Moreover, the lowest 222Rn concentration was in the natural gas fraction used for producing sulfur; a value of 80 Bq m(-3) was observed. On the other hand, maximum radon gas and its decay product concentrations in workplace air environments were found to be relatively high in the gas analysis laboratories; a value of 458 Bq m(-3) was observed. However, all reported levels in the workplaces in the four main stations were below the action level set by IAEA for chronic exposure situations involving radon, which is 1000 Bq m(-3).

  10. Autonomous management of distributed information systems using evolutionary computation techniques

    NASA Astrophysics Data System (ADS)

    Oates, Martin J.

    1999-03-01

    As the size of typical industrial strength information systems continues to rise, particularly in the arena of Internet based management information systems and multimedia servers, the issue of managing data distribution over clusters or `farms' to overcome performance and scalability issues is becoming of paramount importance. Further, where access is global, this can cause points of geographically localized load contention to `follow the sun' during the day. Traditional site mirroring is not overly effective in addressing this contention and so a more dynamic approach is being investigated to tackle load balancing. The general objective is to manage a self-adapting, distributed database so as to reliably and consistently provide near optimal performance as perceived by client applications. Such a management system must be ultimately capable of operating over a range of time varying usage profiles and fault scenarios, incorporate considerations for communications network delays, multiple updates and maintenance operations. It must also be shown to be capable of being scaled in a practical fashion to ever larger sized networks and databases. Two key components of such an automated system are an optimiser capable of efficiently finding new configuration options, and a suitable model of the system capable of accurately reflecting the performance (or any other required quality of service metric) of the real world system. As conditions change in the real world system, these are fed into the model. The optimiser is then run to find new configurations which are tested in the model prior to implementation in the real world. The model therefore forms an evaluation function which the optimiser utilises to direct its search. Whilst it has already been shown that Genetic Algorithms can provide good solutions to this problem, there are a number of issues associated with this approach. In particular, for industrial strength applications, it must be shown that the GA employed

  11. First thoughts on KM3NeT on-shore data storage and distribution facilities

    NASA Astrophysics Data System (ADS)

    Stavrianakou, M.

    2009-04-01

    The KM3NeT project studies the design of an underwater neutrino telescope combined with a multidisciplinary underwater observatory in the Mediterranean. Data from the telescope will arrive on shore where they will be processed in real time at a data filter farm and subsequently stored and backed up at a central computing centre located on site. From there we propose a system whereby the data are distributed to participating institutes equipped with large computing centres for further processing, duplication and distribution to smaller centres. The data taking site hosts the central data management services, including the database servers, bookkeeping systems and file catalogue services, the data access and file transfer systems, data quality monitoring systems and transaction monitoring daemons and is equipped with fast network connection to all large computing sites. Data and service challenges in the course of the preparatory phase must be anticipated in order to test the hardware and software components in terms of robustness and performance, scalability as well as modularity and replaceability, given the rapid evolution of the market both in terms of CPU performance and storage capacity. The role of the GRID would also have to be evaluated and the appropriate implementation selected on time for an eventual test in the context of a data challenge before the start of data taking.

  12. A techno-economic analysis of using mobile distributed pyrolysis facilities to deliver a forest residue resource.

    PubMed

    Brown, Duncan; Rowe, Andrew; Wild, Peter

    2013-12-01

    Distributed mobile conversion facilities using either fast pyrolysis or torrefaction processes can be used to convert forest residues to more energy dense substances (bio-oil, bio-slurry or torrefied wood) that can be transported as feedstock for bio-fuel facilities. Results show that the levelised delivered cost of a forest residue resource using mobile facility networks can be lower than using conventional woodchip delivery methods under appropriate conditions. Torrefied wood is the lowest cost pathway of delivering a forest residue resource when using mobile facilities. Cost savings occur against woodchip delivery for annual forest residue harvests above 2.5 million m(3) or when transport distances greater than 300 km are required. Important parameters that influence levelised delivered costs are transport distances (forest residue spatial density), haul cost factors, and initial moisture content of forest residues. Relocating mobile facilities can be optimised for lowest cost delivery as transport distances of raw biomass are reduced.

  13. Chemical fate and transport of atrazine in soil gravel materials at agrichemical distribution facilities

    USGS Publications Warehouse

    Roy, W.R.; Krapac, I.G.; Chou, S.-F.J.

    1999-01-01

    The gravel commonly used to cover parking lots and roadways at retail agrichemical facilities may contain relatively large concentrations of pesticides that resulted from past management problems. These pesticides may threaten groundwater quality. Previous studies, however, suggested that the pesticides had not moved from the gravel in several sample profiles. Excavations at a closed facility revealed tremendous variability in pesticide distribution within the site. Pesticides were present below the gravel in two profiles, but the mechanism(s) for their movement were not clear. The objectives of this study were to investigate how the physical and chemical properties of the gravel influence the environmental fate of atrazine. All of the gravel samples collected and characterized contained atrazine and sufficient organic C to adsorb significant amounts of atrazine, thus retarding its movement through the gravel. Laboratory column leaching experiments, however, suggested that much of the atrazine should leach from the gravel within a year or two. A field-scale test plot was constructed to study how atrazine moves through the gravel under controlled conditions. Atrazine was "spilled" in the test plot. Atrazine moved from the gravel both vertically and horizontally. It appears that formulated product spilled on gravel will leach. A single discrete spill can give rise to phantom spills whose occurrence and distribution is not related to any specific pesticide-management practice. The apparent lack of atrazine leaching from gravel appeared to be a transient phenomenon and/or the result of sampling limitations in previous studies. The contaminated gravel clearly poses a risk to groundwater quality.

  14. Impact of Nitrification on the Formation of N-Nitrosamines and Halogenated Disinfection Byproducts within Distribution System Storage Facilities.

    PubMed

    Zeng, Teng; Mitch, William A

    2016-03-15

    Distribution system storage facilities are a critical, yet often overlooked, component of the urban water infrastructure. This study showed elevated concentrations of N-nitrosodimethylamine (NDMA), total N-nitrosamines (TONO), regulated trihalomethanes (THMs) and haloacetic acids (HAAs), 1,1-dichloropropanone (1,1-DCP), trichloroacetaldehyde (TCAL), haloacetonitriles (HANs), and haloacetamides (HAMs) in waters with ongoing nitrification as compared to non-nitrifying waters in storage facilities within five different chloraminated drinking water distribution systems. The concentrations of NDMA, TONO, HANs, and HAMs in the nitrifying waters further increased upon application of simulated distribution system chloramination. The addition of a nitrifying biofilm sample collected from a nitrifying facility to its non-nitrifying influent water led to increases in N-nitrosamine and halogenated DBP formation, suggesting the release of precursors from nitrifying biofilms. Periodic treatment of two nitrifying facilities with breakpoint chlorination (BPC) temporarily suppressed nitrification and reduced precursor levels for N-nitrosamines, HANs, and HAMs, as reflected by lower concentrations of these DBPs measured after re-establishment of a chloramine residual within the facilities than prior to the BPC treatment. However, BPC promoted the formation of halogenated DBPs while a free chlorine residual was maintained. Strategies that minimize application of free chlorine while preventing nitrification are needed to control DBP precursor release in storage facilities.

  15. Access Control for Agent-based Computing: A Distributed Approach.

    ERIC Educational Resources Information Center

    Antonopoulos, Nick; Koukoumpetsos, Kyriakos; Shafarenko, Alex

    2001-01-01

    Discusses the mobile software agent paradigm that provides a foundation for the development of high performance distributed applications and presents a simple, distributed access control architecture based on the concept of distributed, active authorization entities (lock cells), any combination of which can be referenced by an agent to provide…

  16. Scientific workflow and support for high resolution global climate modeling at the Oak Ridge Leadership Computing Facility

    NASA Astrophysics Data System (ADS)

    Anantharaj, V.; Mayer, B.; Wang, F.; Hack, J.; McKenna, D.; Hartman-Baker, R.

    2012-04-01

    The Oak Ridge Leadership Computing Facility (OLCF) facilitates the execution of computational experiments that require tens of millions of CPU hours (typically using thousands of processors simultaneously) while generating hundreds of terabytes of data. A set of ultra high resolution climate experiments in progress, using the Community Earth System Model (CESM), will produce over 35,000 files, ranging in sizes from 21 MB to 110 GB each. The execution of the experiments will require nearly 70 Million CPU hours on the Jaguar and Titan supercomputers at OLCF. The total volume of the output from these climate modeling experiments will be in excess of 300 TB. This model output must then be archived, analyzed, distributed to the project partners in a timely manner, and also made available more broadly. Meeting this challenge would require efficient movement of the data, staging the simulation output to a large and fast file system that provides high volume access to other computational systems used to analyze the data and synthesize results. This file system also needs to be accessible via high speed networks to an archival system that can provide long term reliable storage. Ideally this archival system is itself directly available to other systems that can be used to host services making the data and analysis available to the participants in the distributed research project and to the broader climate community. The various resources available at the OLCF now support this workflow. The available systems include the new Jaguar Cray XK6 2.63 petaflops (estimated) supercomputer, the 10 PB Spider center-wide parallel file system, the Lens/EVEREST analysis and visualization system, the HPSS archival storage system, the Earth System Grid (ESG), and the ORNL Climate Data Server (CDS). The ESG features federated services, search & discovery, extensive data handling capabilities, deep storage access, and Live Access Server (LAS) integration. The scientific workflow enabled on

  17. Playable Serious Games for Studying and Programming Computational STEM and Informatics Applications of Distributed and Parallel Computer Architectures

    ERIC Educational Resources Information Center

    Amenyo, John-Thones

    2012-01-01

    Carefully engineered playable games can serve as vehicles for students and practitioners to learn and explore the programming of advanced computer architectures to execute applications, such as high performance computing (HPC) and complex, inter-networked, distributed systems. The article presents families of playable games that are grounded in…

  18. Computational investigation of the discharge coefficient of bellmouth flow meters in engine test facilities

    NASA Astrophysics Data System (ADS)

    Sebourn, Charles Lynn

    2002-11-01

    In this thesis computation of the discharge coefficient of bellmouth flow meters installed in engine test facilities is presented. The discharge coefficient is a critical parameter for accurately calculating flow rate in any flow meter which operates by means of creating a pressure differential. Engine airflow is a critical performance parameter and therefore, it is necessary for engine test facilities to accurately measure airflow. In this report the author investigates the use of computational fluid dynamics using finite difference methods to calculate the flow in bellmouth flow meters and hence the discharge coefficient at any measurement station desired. Experimental boundary layer and core flow data was used to verify the capability of the WIND code to calculate the discharge coefficient accurately. Good results were obtained for Reynolds numbers equal to or greater than about three million which is the primary range of interest. After verifying the WIND code performance, results were calculated for a range of Reynolds numbers and Mach numbers. Also the variation in discharge coefficient as a function of measurement location was examined. It is demonstrated that by picking the proper location for pressure measurement, sensitivity to measurement location can be minimized. Also of interest was the effect of bellmouth geometry. Calculations were performed to investigate the effect of duct to bellmouth diameter ratio and the eccentricity of the bellmouth contraction. In general the effects of the beta ratio were seen to be quite small. For the eccentricity, the variation in discharge coefficient was as high as several percent for axial locations less than half a diameter downstream from the throat. The second portion of the thesis examined the effect of a turbofan engine stationed just downstream of the bellmouth flow meter. The study approximated this effect by examining a single fan stage installed in the duct. This calculation was performed by making use of a

  19. Advanced Technology Airfoil Research, volume 1, part 1. [conference on development of computational codes and test facilities

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A comprehensive review of all NASA airfoil research, conducted both in-house and under grant and contract, as well as a broad spectrum of airfoil research outside of NASA is presented. Emphasis is placed on the development of computational aerodynamic codes for airfoil analysis and design, the development of experimental facilities and test techniques, and all types of airfoil applications.

  20. Sentinel-1 Data System at the Alaska Satellite Facility Distributed Active Archive Center

    NASA Astrophysics Data System (ADS)

    Wolf, V. G.

    2014-12-01

    The Alaska Satellite Facility Distributed Active Archive Center (ASF DAAC) has a long history of supporting international collaborations between NASA and foreign flight agencies to promote access to Synthetic Aperture Radar (SAR) data for US science research. Based on the agreement between the US and the EC, data from the Sentinel missions will be distributed by NASA through archives that mirror those established by ESA. The ASF DAAC is the designated archive and distributor for Sentinel-1 data. The data will be copied from the ESA archive to a rolling archive at the NASA Goddard center, and then pushed to a landing area at the ASF DAAC. The system at ASF DAAC will take the files as they arrive and put them through an ingest process. Ingest will populate the database with the information required to enable search and download of the data through Vertex, the ASF DAAC user interface. Metadata will be pushed to the NASA Common Metadata Repository, enabling data discovery through clients that utilize the repository. Visual metadata will be pushed to the NASA GIBS system for visualization through clients linked to that system. Data files will be archived in the DataDirect Networks (DDN) device that is the primary storage device for the ASF DAAC. A backup copy of the data will be placed in a second DDN device that serves as the disaster recovery solution for the ASF DAAC.

  1. DISTRIBUTION OF LEGIONELLA PNEUMOPHILA SEROGROUPS ISOLATED FROM WATER SYSTEMS OF PUBLIC FACILITIES IN BUSAN, SOUTH KOREA.

    PubMed

    Hwang, In-Yeong; Park, Eun-Hee; Park, Yon-Koung; Park, Sun-Hee; Sung, Gyung-Hye; Park, Hye-Young; Lee, Young-Choon

    2016-05-01

    Legionella pneumophila is the major causes of legionellosis worldwide. The distribution of L. pneumophila was investigated in water systems of public facilities in Busan, South Korea during 2007 and 2013-2014. L. pneumophila was isolated from 8.3% of 3,055 samples, of which the highest isolation rate (49%) was from ships and the lowest 4% from fountains. Serogroups of L. pneumophila isolated in 2007 were distributed among serogroups (sgs) 1-7 with the exception of sg 4, while those of isolates during 2013 and 2014 included also 11 sgs ( 1, 2, 3, 4, 5, 6, 7, 8, 12, 13, 15). L. pneumophila sg 1 was predominated among isolates from fountains (75%), hotels (60%), buildings (44%), hospitals (38%), and public baths (37%), whereas sg 3 and sg 7 was the most prevalent from ships (46%) and factories (40%), respectively. The predominated serogroup of L. pneumophila isolates from hot and cooling tower water was sg 1 (35% and 46%, respectively), while from cold water was sg 3 (29%). These results should be useful for epidemiological surveys to identify sources of outbreaks of legionellosis in Busan, South Korea.

  2. Genetic algorithms in a distributed computing environment using PVM

    SciTech Connect

    Cronje, G.A.; Steeb, W.H.

    1997-04-01

    The Parallel Virtual Machine (PVM) is a software system that enables a collection of heterogeneous computer systems to be used as a coherent and flexible concurrent computation resource. We show that genetic algorithms can be implemented using a Parallel Virtual Machine and C++. Problems with constraints are also discussed.

  3. Integration of distributed computing into the drug discovery process.

    PubMed

    von Korff, Modest; Rufener, Christian; Stritt, Manuel; Freyss, Joel; Bär, Roman; Sander, Thomas

    2011-02-01

    Grid computing offers an opportunity to gain massive computing power at low costs. We give a short introduction into the drug discovery process and exemplify the use of grid computing for image processing, docking and 3D pharmacophore descriptor calculations. The principle of a grid and its architecture are briefly explained. More emphasis is laid on the issues related to a company-wide grid installation and embedding the grid into the research process. The future of grid computing in drug discovery is discussed in the expert opinion section. Most needed, besides reliable algorithms to predict compound properties, is embedding the grid seamlessly into the discovery process. User friendly access to powerful algorithms without any restrictions, that is, by a limited number of licenses, has to be the goal of grid computing in drug discovery.

  4. Distributed network, wireless and cloud computing enabled 3-D ultrasound; a new medical technology paradigm.

    PubMed

    Meir, Arie; Rubinsky, Boris

    2009-11-19

    Medical technologies are indispensable to modern medicine. However, they have become exceedingly expensive and complex and are not available to the economically disadvantaged majority of the world population in underdeveloped as well as developed parts of the world. For example, according to the World Health Organization about two thirds of the world population does not have access to medical imaging. In this paper we introduce a new medical technology paradigm centered on wireless technology and cloud computing that was designed to overcome the problems of increasing health technology costs. We demonstrate the value of the concept with an example; the design of a wireless, distributed network and central (cloud) computing enabled three-dimensional (3-D) ultrasound system. Specifically, we demonstrate the feasibility of producing a 3-D high end ultrasound scan at a central computing facility using the raw data acquired at the remote patient site with an inexpensive low end ultrasound transducer designed for 2-D, through a mobile device and wireless connection link between them. Producing high-end 3D ultrasound images with simple low-end transducers reduces the cost of imaging by orders of magnitude. It also removes the requirement of having a highly trained imaging expert at the patient site, since the need for hand-eye coordination and the ability to reconstruct a 3-D mental image from 2-D scans, which is a necessity for high quality ultrasound imaging, is eliminated. This could enable relatively untrained medical workers in developing nations to administer imaging and a more accurate diagnosis, effectively saving the lives of people.

  5. Assess and improve the sustainability of water treatment facility using Computational Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; Tejada-Martinez, Andres; Lei, Hongxia; Zhang, Qiong

    2016-11-01

    Fluids problems in water treatment industry are often simplified or omitted since the focus is usually on chemical process only. However hydraulics also plays an important role in determining effluent water quality. Recent studies have demonstrated that computational fluid dynamics (CFD) has the ability to simulate the physical and chemical processes in reactive flows in water treatment facilities, such as in chlorine and ozone disinfection tanks. This study presents the results from CFD simulations of reactive flow in an existing full-scale ozone disinfection tank and in potential designs. Through analysis of the simulation results, we found that baffling factor and CT10 are not optimal indicators of disinfection performance. We also found that the relationship between effluent CT (the product of disinfectant concentration and contact time) obtained from CT transport simulation and baffling factor depends on the location of ozone release. In addition, we analyzed the environmental and economic impacts of ozone disinfection tank designs and developed a composite indicator to quantify the sustainability of ozone disinfection tank in technological, environmental and economic dimensions.

  6. The Development of a Computer Assisted Distribution and Assignment (CADA) System for Navy Enlisted Personnel.

    ERIC Educational Resources Information Center

    Whitehead, Randall F.; And Others

    This report describes the development of a computerized system to assist Navy personnel managers in carrying out the functions associated with the distribution and assignment of enlisted personnel. This Computer Assisted Distribution and Assignment (CADA) System is aimed at the most efficient interaction between the computer and human manager to…

  7. Formal Methods for Quality of Service Analysis in Component-Based Distributed Computing

    DTIC Science & Technology

    2003-12-01

    Component-Based Software Architecture is a promising solution for distributed computing . To develop high quality software, analysis of non-functional...based distributed computing is proposed and represented formally using Two-Level Grammar (TLG), an object-oriented formal specification language. TLG

  8. Distributed computing and data storage in proteomics: many hands make light work, and a stronger memory.

    PubMed

    Verheggen, Kenneth; Barsnes, Harald; Martens, Lennart

    2014-03-01

    Modern day proteomics generates ever more complex data, causing the requirements on the storage and processing of such data to outgrow the capacity of most desktop computers. To cope with the increased computational demands, distributed architectures have gained substantial popularity in the recent years. In this review, we provide an overview of the current techniques for distributed computing, along with examples of how the techniques are currently being employed in the field of proteomics. We thus underline the benefits of distributed computing in proteomics, while also pointing out the potential issues and pitfalls involved.

  9. High-performance, distributed computing software libraries and services

    SciTech Connect

    Foster, Ian; Kesselman, Carl; Tuecke, Steven

    2002-01-24

    The Globus toolkit provides basic Grid software infrastructure (i.e. middleware), to facilitate the development of applications which securely integrate geographically separated resources, including computers, storage systems, instruments, immersive environments, etc.

  10. Computational methods for the control of distributed parameter systems

    NASA Technical Reports Server (NTRS)

    Burns, J. A.; Cliff, E. M.; Powers, R. K.

    1986-01-01

    Finite dimensional approximation schemes that work well for distributed parameter systems are often not suitable for the analysis and implementation of feedback control systems. The relationship between approximation schemes for distributed parameter systems and their application to optimal control problems is discussed. A numerical example is given.

  11. An inverse method for computation of structural stiffness distributions of aeroelastically optimized wings

    NASA Astrophysics Data System (ADS)

    Schuster, David M.

    1993-04-01

    An inverse method has been developed to compute the structural stiffness properties of wings given a specified wing loading and aeroelastic twist distribution. The method directly solves for the bending and torsional stiffness distribution of the wing using a modal representation of these properties. An aeroelastic design problem involving the use of a computational aerodynamics method to optimize the aeroelastic twist distribution of a tighter wing operating at maneuver flight conditions is used to demonstrate the application of the method. This exercise verifies the ability of the inverse scheme to accurately compute the structural stiffness distribution required to generate a specific aeroelastic twist under a specified aeroelastic load.

  12. Size distribution and speciation of chromium in paint spray aerosol at an aerospace facility.

    PubMed

    Sabty-Daily, Rania A; Harris, Patricia A; Hinds, William C; Froines, John R

    2005-01-01

    Spray painters are potentially exposed to aerosol containing Cr(VI) via inhalation of chromate-based paint spray. Two field studies were conducted at an aerospace facility to determine the size distribution and speciation of Cr(VI) in paint spray aerosol. Sampled paint products consisted of sparingly soluble strontium chromate in an epoxy resin matrix, a matrix generally known for its durability and toughness. Personal aerosol samples were collected using Sierra Marple personal cascade impactors and analyzed for Cr(VI) and total Cr. The size distribution of total Cr particles in the paint aerosol had a Mass Median Aerodynamic Diameter (MMAD) of 7.5 mum [Geometric Standard Deviation (GSD = 2.7 mum)] in both field studies. The MMAD of Cr(VI) particles was 8.5 mum (GSD = 2.2 mum). Particles >2 mum constituted 90% or more of the total Cr and the Cr(VI) mass, in all sampled paint aerosols and were lognormally distributed. The target site for respiratory deposition of Cr in the aerosol was estimated based on the mass distribution of Cr according to particle size. On an average, 62% of the Cr and Cr(VI) mass in the paint aerosol consisted of particles >10 mum. This study showed that 71.8% of Cr(VI) mass in paint spray aerosol potentially inhaled by a spray painter may deposit in the head airways region. Only 2.0 and 1.4% of Cr(VI) mass in the paint aerosol may potentially deposit in the alveolar and tracheobronchial region, respectively. The ratio of Cr(VI) mass to total Cr mass was determined in bulk paint and the data indicate that Cr was predominantly in the Cr(VI) valence state, before spraying. The ratio of Cr(VI) mass to total Cr mass was also determined in paint aerosol samples. The data indicated that there was a reduction of Cr(VI) regardless of Cr aerosol particle size. Cr(VI) reduction occurred most likely during the 8 h sample collection time period. These findings are in agreement with the findings that observed Cr(VI) reduction during collection of airborne

  13. Analysis of neutron flux distribution for the validation of computational methods for the optimization of research reactor utilization.

    PubMed

    Snoj, L; Trkov, A; Jaćimović, R; Rogan, P; Zerovnik, G; Ravnik, M

    2011-01-01

    In order to verify and validate the computational methods for neutron flux calculation in TRIGA research reactor calculations, a series of experiments has been performed. The neutron activation method was used to verify the calculated neutron flux distribution in the TRIGA reactor. Aluminium (99.9 wt%)-Gold (0.1 wt%) foils (disks of 5mm diameter and 0.2mm thick) were irradiated in 33 locations; 6 in the core and 27 in the carrousel facility in the reflector. The experimental results were compared to the calculations performed with Monte Carlo code MCNP using detailed geometrical model of the reactor. The calculated and experimental normalized reaction rates in the core are in very good agreement for both isotopes indicating that the material and geometrical properties of the reactor core are modelled well. In conclusion one can state that our computational model describes very well the neutron flux and reaction rate distribution in the reactor core. In the reflector however, the accuracy of the epithermal and thermal neutron flux distribution and attenuation is lower, mainly due to lack of information about the material properties of the graphite reflector surrounding the core, but the differences between measurements and calculations are within 10%. Since our computational model properly describes the reactor core it can be used for calculations of reactor core parameters and for optimization of research reactor utilization.

  14. Advanced Distributed Measurements and Data Processing at the Vibro-Acoustic Test Facility, GRC Space Power Facility, Sandusky, Ohio - an Architecture and an Example

    NASA Technical Reports Server (NTRS)

    Hill, Gerald M.; Evans, Richard K.

    2009-01-01

    A large-scale, distributed, high-speed data acquisition system (HSDAS) is currently being installed at the Space Power Facility (SPF) at NASA Glenn Research Center s Plum Brook Station in Sandusky, OH. This installation is being done as part of a facility construction project to add Vibro-acoustic Test Capabilities (VTC) to the current thermal-vacuum testing capability of SPF in support of the Orion Project s requirement for Space Environments Testing (SET). The HSDAS architecture is a modular design, which utilizes fully-remotely managed components, enables the system to support multiple test locations with a wide-range of measurement types and a very large system channel count. The architecture of the system is presented along with details on system scalability and measurement verification. In addition, the ability of the system to automate many of its processes such as measurement verification and measurement system analysis is also discussed.

  15. Prevalence, distribution, and molecular characterization of Salmonella recovered from swine finishing herds and a slaughter facility in Santa Catarina, Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Swine are a reservoir for Salmonella spp., and pork and pork products are vehicles of Salmonella infections. The objective of this investigation was to determine the distribution and types of Salmonella in 12 swine finishing herds and a slaughter facility in Santa Catarina, Brazil. A total of 1,258 ...

  16. Measurement of depth distributions of (3)H and (14)C induced in concrete shielding of an electron accelerator facility.

    PubMed

    Endo, Akira; Harada, Yasunori; Kawasaki, Katsuya; Kikuchi, Masamitsu

    2004-06-01

    The estimation of radioactivity induced in concrete shielding is important for the decommissioning of accelerator facilities. Concentrations of (3)H and (14)C in the concrete shielding of an electron linear accelerator were measured, and the depth distributions of (3)H and (14)C and gamma-ray emitters were discussed in relation to their formation reactions.

  17. Computer routines for probability distributions, random numbers, and related functions

    USGS Publications Warehouse

    Kirby, W.H.

    1980-01-01

    Use of previously codes and tested subroutines simplifies and speeds up program development and testing. This report presents routines that can be used to calculate various probability distributions and other functions of importance in statistical hydrology. The routines are designed as general-purpose Fortran subroutines and functions to be called from user-written main programs. The probability distributions provided include the beta, chisquare, gamma, Gaussian (normal), Pearson Type III (tables and approximation), and Weibull. Also provided are the distributions of the Grubbs-Beck outlier test, Kolmogorov 's and Smirnov 's D, Student 's t, noncentral t (approximate), and Snedecor F tests. Other mathematical functions include the Bessel function I (subzero), gamma and log-gamma functions, error functions and exponential integral. Auxiliary services include sorting and printer plotting. Random number generators for uniform and normal numbers are provided and may be used with some of the above routines to generate numbers from other distributions. (USGS)

  18. Computer routines for probability distributions, random numbers, and related functions

    USGS Publications Warehouse

    Kirby, W.

    1983-01-01

    Use of previously coded and tested subroutines simplifies and speeds up program development and testing. This report presents routines that can be used to calculate various probability distributions and other functions of importance in statistical hydrology. The routines are designed as general-purpose Fortran subroutines and functions to be called from user-written main progress. The probability distributions provided include the beta, chi-square, gamma, Gaussian (normal), Pearson Type III (tables and approximation), and Weibull. Also provided are the distributions of the Grubbs-Beck outlier test, Kolmogorov 's and Smirnov 's D, Student 's t, noncentral t (approximate), and Snedecor F. Other mathematical functions include the Bessel function, I sub o, gamma and log-gamma functions, error functions, and exponential integral. Auxiliary services include sorting and printer-plotting. Random number generators for uniform and normal numbers are provided and may be used with some of the above routines to generate numbers from other distributions. (USGS)

  19. Distributed Computer Systems for the Republic of Turkish Navy.

    DTIC Science & Technology

    1985-12-01

    52 1. Resource and Process Management ...... .52 2. Scheduling ...... ................ 54 IV. SELECTION AN DESIGN OF DISTRIBUTED...LAN). DCS covers many areas including the management of communications, operating systems, distributed database systems, concurrency, fault toleration...Recovery X Error control x x X x Logging X (X) (X) Sharing connections X X X X Network management X (X) x 13) ! i " 13 communication medium is a branching

  20. Parallel grid generation algorithm for distributed memory computers

    NASA Technical Reports Server (NTRS)

    Moitra, Stuti; Moitra, Anutosh

    1994-01-01

    A parallel grid-generation algorithm and its implementation on the Intel iPSC/860 computer are described. The grid-generation scheme is based on an algebraic formulation of homotopic relations. Methods for utilizing the inherent parallelism of the grid-generation scheme are described, and implementation of multiple levELs of parallelism on multiple instruction multiple data machines are indicated. The algorithm is capable of providing near orthogonality and spacing control at solid boundaries while requiring minimal interprocessor communications. Results obtained on the Intel hypercube for a blended wing-body configuration are used to demonstrate the effectiveness of the algorithm. Fortran implementations bAsed on the native programming model of the iPSC/860 computer and the Express system of software tools are reported. Computational gains in execution time speed-up ratios are given.

  1. Evaluation of Near Field Atmospheric Dispersion Around Nuclear Facilities Using a Lorentzian Distribution Methodology

    SciTech Connect

    Hawkley, Gavin

    2014-01-01

    Atmospheric dispersion modeling within the near field of a nuclear facility typically applies a building wake correction to the Gaussian plume model, whereby a point source is modeled as a plane source. The plane source results in greater near field dilution and reduces the far field effluent concentration. However, the correction does not account for the concentration profile within the near field. Receptors of interest, such as the maximally exposed individual, may exist within the near field and thus the realm of building wake effects. Furthermore, release parameters and displacement characteristics may be unknown, particularly during upset conditions. Therefore, emphasis is placed upon the need to analyze and estimate an enveloping concentration profile within the near field of a release. This investigation included the analysis of 64 air samples collected over 128 wk. Variables of importance were then derived from the measurement data, and a methodology was developed that allowed for the estimation of Lorentzian-based dispersion coefficients along the lateral axis of the near field recirculation cavity; the development of recirculation cavity boundaries; and conservative evaluation of the associated concentration profile. The results evaluated the effectiveness of the Lorentzian distribution methodology for estimating near field releases and emphasized the need to place air-monitoring stations appropriately for complete concentration characterization. Additionally, the importance of the sampling period and operational conditions were discussed to balance operational feedback and the reporting of public dose.

  2. An Alternative Method for Computing Mean and Covariance Matrix of Some Multivariate Distributions

    ERIC Educational Resources Information Center

    Radhakrishnan, R.; Choudhury, Askar

    2009-01-01

    Computing the mean and covariance matrix of some multivariate distributions, in particular, multivariate normal distribution and Wishart distribution are considered in this article. It involves a matrix transformation of the normal random vector into a random vector whose components are independent normal random variables, and then integrating…

  3. A study of standard building blocks for the design of fault-tolerant distributed computer systems

    NASA Technical Reports Server (NTRS)

    Rennels, D. A.; Avizienis, A.; Ercegovac, M.

    1978-01-01

    This paper presents the results of a study that has established a standard set of four semiconductor VLSI building-block circuits. These circuits can be assembled with off-the-shelf microprocessors and semiconductor memory modules into fault-tolerant distributed computer configurations. The resulting multi-computer architecture uses self-checking computer modules backed up by a limited number of spares. A redundant bus system is employed for communication between computer modules.

  4. Lattice gauge theory on a massively parallel computing facility. Final report

    SciTech Connect

    Sugar, R.

    1998-08-07

    This grant provided access to the massively parallel computing facilities at Oak Ridge National Laboratory for the study of lattice gauge theory. The major project was a calculation of the weak decay constants of pseudoscalar mesons with one light and one heavy quark. A number of these constants have not yet been measured, so the calculations constituted a set of predictions which will be tested by future experiments. More importantly, f{sub B} and f{sub B{sub s}}, the decay constants of the B and B{sub s} mesons, are crucial inputs for extracting information regarding the CKM matrix element V{sub td} from experimental measurements of B-{anti B} mixing, and future measurements of B{sub s}-{anti B}{sub s} mixing planned for the B-factory currently under construction at the Stanford Linear Accelerator Center. V{sub td} is one of the least well determined parameters of the Standard Model of High Energy Physics. It does not appear likely that F{sub B} and f{sub B{sub s}} will be measured experimentally in the near future, so lattice calculations such as this will play a crucial role in extracting information about the Standard Model from the B-factory experiments. The author has carried out the most accurate calculations of the heavy-light decay constants to date within the quenched approximation, that is ignoring the effects of sea quarks. Furthermore, his was the only group to have estimated the errors in the decay constants associated with the quenched approximation.

  5. Distributed sequence alignment applications for the public computing architecture.

    PubMed

    Pellicer, S; Chen, G; Chan, K C C; Pan, Y

    2008-03-01

    The public computer architecture shows promise as a platform for solving fundamental problems in bioinformatics such as global gene sequence alignment and data mining with tools such as the basic local alignment search tool (BLAST). Our implementation of these two problems on the Berkeley open infrastructure for network computing (BOINC) platform demonstrates a runtime reduction factor of 1.15 for sequence alignment and 16.76 for BLAST. While the runtime reduction factor of the global gene sequence alignment application is modest, this value is based on a theoretical sequential runtime extrapolated from the calculation of a smaller problem. Because this runtime is extrapolated from running the calculation in memory, the theoretical sequential runtime would require 37.3 GB of memory on a single system. With this in mind, the BOINC implementation not only offers the reduced runtime, but also the aggregation of the available memory of all participant nodes. If an actual sequential run of the problem were compared, a more drastic reduction in the runtime would be seen due to an additional secondary storage I/O overhead for a practical system. Despite the limitations of the public computer architecture, most notably in communication overhead, it represents a practical platform for grid- and cluster-scale bioinformatics computations today and shows great potential for future implementations.

  6. Distributed computing for autonomous on board planning and sequence validations

    NASA Technical Reports Server (NTRS)

    Ko, A. Y.; Alkalai, L.; Chau, S.; Cheung, K.; Tong, D.; Maldague, P. F.

    2002-01-01

    We propose a new conceptual approach to system-level autonomy that exploits in a synergistic way recent breakthroughs in three specific areas: automatic generation of embeddable planning and validation software, integration of telecommunications forecaster and planning tools, and fault-tolerant assignment of computing tasks to multiple processors.

  7. A lightweight distributed framework for computational offloading in mobile cloud computing.

    PubMed

    Shiraz, Muhammad; Gani, Abdullah; Ahmad, Raja Wasim; Adeel Ali Shah, Syed; Karim, Ahmad; Rahman, Zulkanain Abdul

    2014-01-01

    The latest developments in mobile computing technology have enabled intensive applications on the modern Smartphones. However, such applications are still constrained by limitations in processing potentials, storage capacity and battery lifetime of the Smart Mobile Devices (SMDs). Therefore, Mobile Cloud Computing (MCC) leverages the application processing services of computational clouds for mitigating resources limitations in SMDs. Currently, a number of computational offloading frameworks are proposed for MCC wherein the intensive components of the application are outsourced to computational clouds. Nevertheless, such frameworks focus on runtime partitioning of the application for computational offloading, which is time consuming and resources intensive. The resource constraint nature of SMDs require lightweight procedures for leveraging computational clouds. Therefore, this paper presents a lightweight framework which focuses on minimizing additional resources utilization in computational offloading for MCC. The framework employs features of centralized monitoring, high availability and on demand access services of computational clouds for computational offloading. As a result, the turnaround time and execution cost of the application are reduced. The framework is evaluated by testing prototype application in the real MCC environment. The lightweight nature of the proposed framework is validated by employing computational offloading for the proposed framework and the latest existing frameworks. Analysis shows that by employing the proposed framework for computational offloading, the size of data transmission is reduced by 91%, energy consumption cost is minimized by 81% and turnaround time of the application is decreased by 83.5% as compared to the existing offloading frameworks. Hence, the proposed framework minimizes additional resources utilization and therefore offers lightweight solution for computational offloading in MCC.

  8. A Lightweight Distributed Framework for Computational Offloading in Mobile Cloud Computing

    PubMed Central

    Shiraz, Muhammad; Gani, Abdullah; Ahmad, Raja Wasim; Adeel Ali Shah, Syed; Karim, Ahmad; Rahman, Zulkanain Abdul

    2014-01-01

    The latest developments in mobile computing technology have enabled intensive applications on the modern Smartphones. However, such applications are still constrained by limitations in processing potentials, storage capacity and battery lifetime of the Smart Mobile Devices (SMDs). Therefore, Mobile Cloud Computing (MCC) leverages the application processing services of computational clouds for mitigating resources limitations in SMDs. Currently, a number of computational offloading frameworks are proposed for MCC wherein the intensive components of the application are outsourced to computational clouds. Nevertheless, such frameworks focus on runtime partitioning of the application for computational offloading, which is time consuming and resources intensive. The resource constraint nature of SMDs require lightweight procedures for leveraging computational clouds. Therefore, this paper presents a lightweight framework which focuses on minimizing additional resources utilization in computational offloading for MCC. The framework employs features of centralized monitoring, high availability and on demand access services of computational clouds for computational offloading. As a result, the turnaround time and execution cost of the application are reduced. The framework is evaluated by testing prototype application in the real MCC environment. The lightweight nature of the proposed framework is validated by employing computational offloading for the proposed framework and the latest existing frameworks. Analysis shows that by employing the proposed framework for computational offloading, the size of data transmission is reduced by 91%, energy consumption cost is minimized by 81% and turnaround time of the application is decreased by 83.5% as compared to the existing offloading frameworks. Hence, the proposed framework minimizes additional resources utilization and therefore offers lightweight solution for computational offloading in MCC. PMID:25127245

  9. Automation of the CFD Process on Distributed Computing Systems

    NASA Technical Reports Server (NTRS)

    Tejnil, Ed; Gee, Ken; Rizk, Yehia M.

    2000-01-01

    A script system was developed to automate and streamline portions of the CFD process. The system was designed to facilitate the use of CFD flow solvers on supercomputer and workstation platforms within a parametric design event. Integrating solver pre- and postprocessing phases, the fully automated ADTT script system marshalled the required input data, submitted the jobs to available computational resources, and processed the resulting output data. A number of codes were incorporated into the script system, which itself was part of a larger integrated design environment software package. The IDE and scripts were used in a design event involving a wind tunnel test. This experience highlighted the need for efficient data and resource management in all parts of the CFD process. To facilitate the use of CFD methods to perform parametric design studies, the script system was developed using UNIX shell and Perl languages. The goal of the work was to minimize the user interaction required to generate the data necessary to fill a parametric design space. The scripts wrote out the required input files for the user-specified flow solver, transferred all necessary input files to the computational resource, submitted and tracked the jobs using the resource queuing structure, and retrieved and post-processed the resulting dataset. For computational resources that did not run queueing software, the script system established its own simple first-in-first-out queueing structure to manage the workload. A variety of flow solvers were incorporated in the script system, including INS2D, PMARC, TIGER and GASP. Adapting the script system to a new flow solver was made easier through the use of object-oriented programming methods. The script system was incorporated into an ADTT integrated design environment and evaluated as part of a wind tunnel experiment. The system successfully generated the data required to fill the desired parametric design space. This stressed the computational

  10. Lilith: A scalable secure tool for massively parallel distributed computing

    SciTech Connect

    Armstrong, R.C.; Camp, L.J.; Evensky, D.A.; Gentile, A.C.

    1997-06-01

    Changes in high performance computing have necessitated the ability to utilize and interrogate potentially many thousands of processors. The ASCI (Advanced Strategic Computing Initiative) program conducted by the United States Department of Energy, for example, envisions thousands of distinct operating systems connected by low-latency gigabit-per-second networks. In addition multiple systems of this kind will be linked via high-capacity networks with latencies as low as the speed of light will allow. Code which spans systems of this sort must be scalable; yet constructing such code whether for applications, debugging, or maintenance is an unsolved problem. Lilith is a research software platform that attempts to answer these questions with an end toward meeting these needs. Presently, Lilith exists as a test-bed, written in Java, for various spanning algorithms and security schemes. The test-bed software has, and enforces, hooks allowing implementation and testing of various security schemes.

  11. Partitioning problems in parallel, pipelined and distributed computing

    NASA Technical Reports Server (NTRS)

    Bokhari, S.

    1985-01-01

    The problem of optimally assigning the modules of a parallel program over the processors of a multiple computer system is addressed. A Sum-Bottleneck path algorithm is developed that permits the efficient solution of many variants of this problem under some constraints on the structure of the partitions. In particular, the following problems are solved optimally for a single-host, multiple satellite system: partitioning multiple chain structured parallel programs, multiple arbitrarily structured serial programs and single tree structured parallel programs. In addition, the problems of partitioning chain structured parallel programs across chain connected systems and across shared memory (or shared bus) systems are also solved under certain constraints. All solutions for parallel programs are equally applicable to pipelined programs. These results extend prior research in this area by explicitly taking concurrency into account and permit the efficient utilization of multiple computer architectures for a wide range of problems of practical interest.

  12. Partitioning problems in parallel, pipelined, and distributed computing

    NASA Technical Reports Server (NTRS)

    Bokhari, Shahid H.

    1988-01-01

    The problem of optimally assigning the modules of a parallel program over the processors of a multiple-computer system is addressed. A sum-bottleneck path algorithm is developed that permits the efficient solution of many variants of this problem under some constraints on the structure of the partitions. In particular, the following problems are solved optimally for a single-host, multiple-satellite system: partitioning multiple chain-structured parallel programs, multiple arbitrarily structured serial programs, and single-tree structured parallel programs. In addition, the problem of partitioning chain-structured parallel programs across chain-connected systems is solved under certain constraints. All solutions for parallel programs are equally applicable to pipelined programs. These results extend prior research in this area by explicitly taking concurrency into account and permit the efficient utilization of multiple-computer architectures for a wide range of problems of practical interest.

  13. Distributed UHV system for the folded tandem ion accelerator facility at BARC

    NASA Astrophysics Data System (ADS)

    Gupta, S. K.; Agarwal, A.; Singh, S. K.; Basu, A.; P, Sapna; Sarode, S. P.; Singh, V. P.; Subrahmanyam, N. B. V.; Bhatt, J. P.; Pol, S. S.; Raut, P. J.; Ware, S. V.; Singh, P.; Choudhury, R. K.; Kailas, S.

    2008-05-01

    The 6 MV Folded Tandem Ion Accelerator (FOTIA) Facility at the Nuclear Physics Division, BARC is operational and accelerated beams of both light and heavy ions are being used extensively for basic and applied research. An average vacuum of the order of 10-8-10-9 Torr is maintained for maximum beam transmission and minimum beam energy spreads. The FOTIA vacuum system comprises of about 55 meter long, 100 mm diameter beam lines including various diagnostic devices, two accelerating tubes and four narrow vacuum chambers. The cross sections of the vacuum chambers are 14mm × 24mm for 180°, 38mm × 60mm and 19 × 44 mm for the and 70° & 90° bending magnets and Switching chambers respectively. All the beam line components are UHV compatible, fabricated from stainless steel 304L grade material fitted with metal gaskets. The total volume ~5.8 × 105 cm3 and surface area of 4.6 × 104 cm2, interspersed with total 18 pumping stations. The accelerating tubes are subjected to very high voltage gradient, 20.4 kV/cm, which requires a hydrocarbon free and clean vacuum for smooth operation of the accelerator. Vacuum interlocks are provided to various devices for safe operation of the accelerator. Specially designed sputter ion pumps for higher environmental pressure of 8 atmospheres are used to pump the accelerating tubes and the vacuum chamber for the 180° bending magnet. Fast acting valves are provided for isolating main accelerator against accidental air rush from rest of the beam lines. All the vacuum readings are displayed locally and are also available remotely through computer interface to the Control Room. Vacuum system details are described in this paper.

  14. A support architecture for reliable distributed computing systems

    NASA Technical Reports Server (NTRS)

    Dasgupta, Partha; Leblanc, Richard J., Jr.

    1988-01-01

    The Clouds project is well underway to its goal of building a unified distributed operating system supporting the object model. The operating system design uses the object concept of structuring software at all levels of the system. The basic operating system was developed and work is under progress to build a usable system.

  15. [Computer simulated images of radiopharmaceutical distributions in anthropomorphic phantoms

    SciTech Connect

    Not Available

    1991-05-17

    We have constructed an anatomically correct human geometry, which can be used to store radioisotope concentrations in 51 various internal organs. Each organ is associated with an index number which references to its attenuating characteristics (composition and density). The initial development of Computer Simulated Images of Radiopharmaceuticals in Anthropomorphic Phantoms (CSIRDAP) over the first 3 years has been very successful. All components of the simulation have been coded, made operational and debugged.

  16. Unwrapping ADMM: Efficient Distributed Computing via Transpose Reduction

    DTIC Science & Technology

    2016-05-11

    Figures 2a and 2b. 8.2 Empirical Case Study: Classifying Guide Stars We perform experiments using the Second Genera- tion Guide Star Catalog (GSC-II...the bottom horizontal axis denotes the number of computing cores used. database containing spectral and geometric features for 950 million stars and...other objects. The GSC-II also classifies each astronomical body as “ star ” or “not a star .” We train a sparse logistic classifier to discern this

  17. Real-time computer data system for the 40- by 80-foot wind tunnel facility at Ames Research Center

    NASA Technical Reports Server (NTRS)

    Cambra, J. M.; Tolari, G. P.

    1975-01-01

    The background material and operational concepts of a computer-based system for an operating wind tunnel are described. An on-line real-time computer system was installed in a wind tunnel facility to gather static and dynamic data. The computer system monitored aerodynamic forces and moments of periodic and quasi-periodic functions, and displayed and plotted computed results in real time. The total system is comprised of several off-the-shelf, interconnected subsystems that are linked to a large data processing center. The system includes a central processor unit with 32,000 24-bit words of core memory, a number of standard peripherals, and several special processors; namely, a dynamic analysis subsystem, a 256-channel PCM-data subsystem and ground station, a 60-channel high-speed data acquisition subsystem, a communication link, and static force and pressure subsystems. The role of the test engineer as a vital link in the system is also described.

  18. Using spatial principles to optimize distributed computing for enabling the physical science discoveries

    PubMed Central

    Yang, Chaowei; Wu, Huayi; Huang, Qunying; Li, Zhenlong; Li, Jing

    2011-01-01

    Contemporary physical science studies rely on the effective analyses of geographically dispersed spatial data and simulations of physical phenomena. Single computers and generic high-end computing are not sufficient to process the data for complex physical science analysis and simulations, which can be successfully supported only through distributed computing, best optimized through the application of spatial principles. Spatial computing, the computing aspect of a spatial cyberinfrastructure, refers to a computing paradigm that utilizes spatial principles to optimize distributed computers to catalyze advancements in the physical sciences. Spatial principles govern the interactions between scientific parameters across space and time by providing the spatial connections and constraints to drive the progression of the phenomena. Therefore, spatial computing studies could better position us to leverage spatial principles in simulating physical phenomena and, by extension, advance the physical sciences. Using geospatial science as an example, this paper illustrates through three research examples how spatial computing could (i) enable data intensive science with efficient data/services search, access, and utilization, (ii) facilitate physical science studies with enabling high-performance computing capabilities, and (iii) empower scientists with multidimensional visualization tools to understand observations and simulations. The research examples demonstrate that spatial computing is of critical importance to design computing methods to catalyze physical science studies with better data access, phenomena simulation, and analytical visualization. We envision that spatial computing will become a core technology that drives fundamental physical science advancements in the 21st century. PMID:21444779

  19. Using spatial principles to optimize distributed computing for enabling the physical science discoveries.

    PubMed

    Yang, Chaowei; Wu, Huayi; Huang, Qunying; Li, Zhenlong; Li, Jing

    2011-04-05

    Contemporary physical science studies rely on the effective analyses of geographically dispersed spatial data and simulations of physical phenomena. Single computers and generic high-end computing are not sufficient to process the data for complex physical science analysis and simulations, which can be successfully supported only through distributed computing, best optimized through the application of spatial principles. Spatial computing, the computing aspect of a spatial cyberinfrastructure, refers to a computing paradigm that utilizes spatial principles to optimize distributed computers to catalyze advancements in the physical sciences. Spatial principles govern the interactions between scientific parameters across space and time by providing the spatial connections and constraints to drive the progression of the phenomena. Therefore, spatial computing studies could better position us to leverage spatial principles in simulating physical phenomena and, by extension, advance the physical sciences. Using geospatial science as an example, this paper illustrates through three research examples how spatial computing could (i) enable data intensive science with efficient data/services search, access, and utilization, (ii) facilitate physical science studies with enabling high-performance computing capabilities, and (iii) empower scientists with multidimensional visualization tools to understand observations and simulations. The research examples demonstrate that spatial computing is of critical importance to design computing methods to catalyze physical science studies with better data access, phenomena simulation, and analytical visualization. We envision that spatial computing will become a core technology that drives fundamental physical science advancements in the 21st century.

  20. Alternative measures of spatial distribution and availability of health facilities for the delivery of emergency obstetric services in island communities.

    PubMed

    Oyerinde, Koyejo; Baravilala, Wame

    2014-12-01

    International guidelines and recommendations for availability and spatial distribution of emergency obstetric care services do not adequately address the challenges of providing emergency health services in island communities. The isolation and small population sizes that are typical of islands and remote populations limit the applicability of international guidelines in such communities. Universal access to emergency obstetric care services, when pregnant women encounter complications, is one of the three key strategies for reducing maternal and newborn mortality; the other two being family planning and skilled care during labor. The performance of selected lifesaving clinical interventions (signal functions) over a 3-month period is commonly used to assess and assign performance categories to health facilities but island communities might not have a large enough population to generate demand for all the signal functions over a 3-month period. Similarly, availability and spatial distribution recommendations are typically based on the size of catchment populations, but the populations of island communities tend to be sparsely distributed. With illustrations from six South Pacific Island states, we argue that the recommendation for availability of health facilities, that there should be at least five emergency obstetric care facilities (including at least one comprehensive facility) for every 500,000 population, and the recommendation for equitable distribution of health facilities, that all subnational areas meet the availability recommendation, can be substituted with a focus on access to blood transfusion and obstetric surgical care within 2 hours for all pregnant residents of islands. Island communities could replace the performance of signal functions over a 3-month period with a demonstrated capacity to perform signal functions if the need arises.

  1. School Facilities Funding and Capital-Outlay Distribution in the States

    ERIC Educational Resources Information Center

    Duncombe, William; Wang, Wen

    2009-01-01

    Traditionally, financing the construction of school facilities has been a local responsibility. In the past several decades, states have increased their support for school facilities. Using data collected from various sources, this study first classifies the design of capital aid programs in all 50 states into various categories based on the scope…

  2. Open-Source, Distributed Computational Environment for Virtual Materials Exploration

    DTIC Science & Technology

    2015-01-01

    Statement A. Approved for public release; distribution unlimited. See additional restrictions described on inside pages STINFO COPY AIR FORCE...RESEARCH LABORATORY MATERIALS AND MANUFACTURING DIRECTORATE WRIGHT-PATTERSON AIR FORCE BASE, OH 45433-7750 AIR FORCE MATERIEL COMMAND UNITED STATES...specifications, or other data does not license the holder or any other person or corporation; or convey any rights or permission to manufacture , use, or

  3. Applications Analysis: Principles and Examples from Various Distributed Computer Applications at Sandia National Laboratories New Mexico

    SciTech Connect

    Bateman, Dennis; Evans, David; Jensen, Dal; Nelson, Spencer

    1999-08-01

    As information systems have become distributed over many computers within the enterprise, managing those applications has become increasingly important. This is an emerging area of work, recognized as such by many large organizations as well as many start-up companies. In this report, we present a summary of the move to distributed applications, some of the problems that came along for the ride, and some specific examples of the tools and techniques we have used to analyze distributed applications and gain some insight into the mechanics and politics of distributed computing.

  4. An interactive computer program for randomization analysis of response curves with facilities for multiple comparisons.

    PubMed

    Tan, E S; Roos, J M; Volovics, A; Van Baak, M A; Does, R J

    1992-04-01

    An interactive Fortran program, MUCRA, is presented. The program can perform randomization analysis of a completely randomized or randomized-blocks design extended to growth and response curves. A single-step Scheffé-type procedure as well as the Peritz's closed step-down procedure have been implemented which control the familywise type I error-rate. In general, MUCRA is suitable as a computer tool for a distribution-free analysis of variance with repeated measures. The use of MUCRA is demonstrated by analyzing the effects oxprenolol and atenolol have on exercise heart rate. Oxprenolol is a non-selective beta-blocker with moderate intrinsic sympathomimetic activity (ISA), given by the Oros delivery system. Atenolol is a beta 1-selective blocker without ISA. A randomized placebo-controlled crossover design was used to compare the effects of the beta 1-blockers on heart rate during a progressive maximal exercise test on a bicycle ergometer. Application of the Scheffé-type procedure showed that the two drugs significantly (alpha = .05) reduce the heart rate during the exercise test at the three prechosen times (2, 5, and 24 hr) after intake. The reduction from atenolol is more pronounced than from oxprenolol Oros at 2 and 5 hr.

  5. Simulation concept of NICA-MPD-SPD Tier0-Tier1 computing facilities

    NASA Astrophysics Data System (ADS)

    Korenkov, V. V.; Nechaevskiy, A. V.; Ososkov, G. A.; Pryahina, D. I.; Trofomov, V. V.; Uzhinskiy, A. V.

    2016-09-01

    The simulation concept for grid-cloud services of contemporary HENP experiments of the Big Data scale was formulated in practicing the simulation system developed in LIT JINR Dubna. This system is intended to improve the efficiency of the design and development of a wide class of grid-cloud structures by using the work quality indicators of some real system to design and predict its evolution. For these purposes the simulation program is combined with a real monitoring system of the grid-cloud service through a special database (DB). The DB accomplishes acquisition and analysis of monitoring data to carry out dynamical corrections of the simulation. Such an approach allows us to construct a general model pattern which should not depend on a specific simulated object, while the parameters describing this object can be used as input to run the pattern. The simulation of some processes of the NICA-MPD-SPD Tier0-Tier1 distributed computing is considered as an example of our approach applications.

  6. A new taxonomy for distributed computer systems based upon operating system structure

    NASA Technical Reports Server (NTRS)

    Foudriat, E. C.

    1985-01-01

    Characteristics of the resource structure found in the operating system are considered as a mechanism for classifying distributed computer systems. Since the operating system resources, themselves, are too diversified to provide a consistent classification, the structure upon which resources are built and shared are examined. The location and control character of this indivisibility provides the taxonomy for separating uniprocessors, computer networks, network computers (fully distributed processing systems or decentralized computers) and algorithm and/or data control multiprocessors. The taxonomy is important because it divides machines into a classification that is relevant or important to the client and not the hardware architect. It also defines the character of the kernel O/S structure needed for future computer systems. What constitutes an operating system for a fully distributed processor is discussed in detail.

  7. Results of computer calculations for a simulated distribution of kidney cells

    NASA Technical Reports Server (NTRS)

    Micale, F. J.

    1985-01-01

    The results of computer calculations for a simulated distribution of kidney cells are given. The calculations were made for different values of electroosmotic flow, U sub o, and the ratio of sample diameter to channel diameter, R.

  8. Intercommunications in Real Time, Redundant, Distributed Computer System

    NASA Technical Reports Server (NTRS)

    Zanger, H.

    1980-01-01

    An investigation into the applicability of fiber optic communication techniques to real time avionic control systems, in particular the total automatic flight control system used for the VSTOL aircraft is presented. The system consists of spatially distributed microprocessors. The overall control function is partitioned to yield a unidirectional data flow between the processing elements (PE). System reliability is enhanced by the use of triple redundancy. Some general overall system specifications are listed here to provide the necessary background for the requirements of the communications system.

  9. Testing SLURM open source batch system for a Tierl/Tier2 HEP computing facility

    NASA Astrophysics Data System (ADS)

    Donvito, Giacinto; Salomoni, Davide; Italiano, Alessandro

    2014-06-01

    In this work the testing activities that were carried on to verify if the SLURM batch system could be used as the production batch system of a typical Tier1/Tier2 HEP computing center are shown. SLURM (Simple Linux Utility for Resource Management) is an Open Source batch system developed mainly by the Lawrence Livermore National Laboratory, SchedMD, Linux NetworX, Hewlett-Packard, and Groupe Bull. Testing was focused both on verifying the functionalities of the batch system and the performance that SLURM is able to offer. We first describe our initial set of requirements. Functionally, we started configuring SLURM so that it replicates all the scheduling policies already used in production in the computing centers involved in the test, i.e. INFN-Bari and the INFN-Tier1 at CNAF, Bologna. Currently, the INFN-Tier1 is using IBM LSF (Load Sharing Facility), while INFN-Bari, an LHC Tier2 for both CMS and Alice, is using Torque as resource manager and MAUI as scheduler. We show how we configured SLURM in order to enable several scheduling functionalities such as Hierarchical FairShare, Quality of Service, user-based and group-based priority, limits on the number of jobs per user/group/queue, job age scheduling, job size scheduling, and scheduling of consumable resources. We then show how different job typologies, like serial, MPI, multi-thread, whole-node and interactive jobs can be managed. Tests on the use of ACLs on queues or in general other resources are then described. A peculiar SLURM feature we also verified is triggers on event, useful to configure specific actions on each possible event in the batch system. We also tested highly available configurations for the master node. This feature is of paramount importance since a mandatory requirement in our scenarios is to have a working farm cluster even in case of hardware failure of the server(s) hosting the batch system. Among our requirements there is also the possibility to deal with pre-execution and post

  10. Computer-Mediated Group Processes in Distributed Command and Control Systems: Dyad Shared Work

    DTIC Science & Technology

    1989-06-01

    effects of computer- mediated LofnuIiufi- cations on distributed command and control. To support collaboration among distributed re- mote command...terms of performance quality or speed when moving from face-to-face to computer- mediated communications with an auxiliary voice channel . There were... mediation as a viable alternative to face-to-face and voice-only communications. Acconnion For J 1NTJS *- 1 -Alcl D- . :. A I, AL~ D•"" , ý " ,t DiftrItr

  11. Research in Functionally Distributed Computer Systems Development. Volume XIX. Roll-Back and Recovery in Distributed Data Base Systems.

    DTIC Science & Technology

    1977-02-01

    both academic and industrial environments. However, many problems still require efficient solutions. One of these problem -areas that can have a...distribution of a data base system over several processors increases the complexity of the recovery problem. Just the interprocessor comunications ...DBMS over a computer network enormously complicates the data base administration function. If a recovery scheme similar to that proposed in this

  12. Survivable algorithms and redundancy management in NASA's distributed computing systems

    NASA Technical Reports Server (NTRS)

    Malek, Miroslaw

    1992-01-01

    The design of survivable algorithms requires a solid foundation for executing them. While hardware techniques for fault-tolerant computing are relatively well understood, fault-tolerant operating systems, as well as fault-tolerant applications (survivable algorithms), are, by contrast, little understood, and much more work in this field is required. We outline some of our work that contributes to the foundation of ultrareliable operating systems and fault-tolerant algorithm design. We introduce our consensus-based framework for fault-tolerant system design. This is followed by a description of a hierarchical partitioning method for efficient consensus. A scheduler for redundancy management is introduced, and application-specific fault tolerance is described. We give an overview of our hybrid algorithm technique, which is an alternative to the formal approach given.

  13. Survey and future directions of fault-tolerant distributed computing on board spacecraft

    NASA Astrophysics Data System (ADS)

    Fayyaz, Muhammad; Vladimirova, Tanya

    2016-12-01

    Current and future space missions demand highly reliable on-board computing systems, which are capable of carrying out high-performance data processing. At present, no single computing scheme satisfies both, the highly reliable operation requirement and the high-performance computing requirement. The aim of this paper is to review existing systems and offer a new approach to addressing the problem. In the first part of the paper, a detailed survey of fault-tolerant distributed computing systems for space applications is presented. Fault types and assessment criteria for fault-tolerant systems are introduced. Redundancy schemes for distributed systems are analyzed. A review of the state-of-the-art on fault-tolerant distributed systems is presented and limitations of current approaches are discussed. In the second part of the paper, a new fault-tolerant distributed computing platform with wireless links among the computing nodes is proposed. Novel algorithms, enabling important aspects of the architecture, such as time slot priority adaptive fault-tolerant channel access and fault-tolerant distributed computing using task migration are introduced.

  14. 26 CFR 1.1247-2 - Computation and distribution of taxable income.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... includible in the gross income of a shareholder of the foreign investment company for his taxable year in....1247-2 Computation and distribution of taxable income. (a) In general. Taxable income of a foreign investment company means taxable income as defined in section 63(a), computed without regard to subchapter...

  15. VLab: A Science Gateway for Distributed First Principles Calculations in Heterogeneous High Performance Computing Systems

    ERIC Educational Resources Information Center

    da Silveira, Pedro Rodrigo Castro

    2014-01-01

    This thesis describes the development and deployment of a cyberinfrastructure for distributed high-throughput computations of materials properties at high pressures and/or temperatures--the Virtual Laboratory for Earth and Planetary Materials--VLab. VLab was developed to leverage the aggregated computational power of grid systems to solve…

  16. Distributed Multimedia Computing: An Assessment of the State of the Art.

    ERIC Educational Resources Information Center

    Williams, Neil; And Others

    1991-01-01

    Describes multimedia computing and the characteristics of multimedia information. Trends in information technology are reviewed; distributed multimedia computing is explained; media types are described, including digital media; and multimedia applications are examined, including office systems, documents, information storage and retrieval,…

  17. Parallel computation of the SAR distribution in a 3D human head model

    NASA Astrophysics Data System (ADS)

    Walendziuk, Wojciech

    2008-01-01

    This work presents a way of parallel computation of the Specific Absorption Rate distribution. The parallel program used in the computation was based on the FDTD (Finite-Difference Time-Domain) method [1,2,3]. In order to establish communication among the computational nodes, the MPI (Message Passing Interface) standard was used [4,5,6]. The presented example of a human head numerical model was built with the use of MRI (Magnetic Resonance Image) pictures.

  18. Secure Large-Scale Airport Simulations Using Distributed Computational Resources

    NASA Technical Reports Server (NTRS)

    McDermott, William J.; Maluf, David A.; Gawdiak, Yuri; Tran, Peter; Clancy, Dan (Technical Monitor)

    2001-01-01

    To fully conduct research that will support the far-term concepts, technologies and methods required to improve the safety of Air Transportation a simulation environment of the requisite degree of fidelity must first be in place. The Virtual National Airspace Simulation (VNAS) will provide the underlying infrastructure necessary for such a simulation system. Aerospace-specific knowledge management services such as intelligent data-integration middleware will support the management of information associated with this complex and critically important operational environment. This simulation environment, in conjunction with a distributed network of supercomputers, and high-speed network connections to aircraft, and to Federal Aviation Administration (FAA), airline and other data-sources will provide the capability to continuously monitor and measure operational performance against expected performance. The VNAS will also provide the tools to use this performance baseline to obtain a perspective of what is happening today and of the potential impact of proposed changes before they are introduced into the system.

  19. A secure communications infrastructure for high-performance distributed computing

    SciTech Connect

    Foster, I.; Koenig, G.; Tuecke, S.

    1997-08-01

    Applications that use high-speed networks to connect geographically distributed supercomputers, databases, and scientific instruments may operate over open networks and access valuable resources. Hence, they can require mechanisms for ensuring integrity and confidentially of communications and for authenticating both users and resources. Security solutions developed for traditional client-server applications do not provide direct support for the program structures, programming tools, and performance requirements encountered in these applications. The authors address these requirements via a security-enhanced version of the Nexus communication library; which they use to provide secure versions of parallel libraries and languages, including the Message Passing Interface. These tools permit a fine degree of control over what, where, and when security mechanisms are applied. In particular, a single application can mix secure and nonsecure communication, allowing the programmer to make fine-grained security/performance tradeoffs. The authors present performance results that quantify the performance of their infrastructure.

  20. Pit Distribution Design for Computer-Generated Waveguide Holography

    NASA Astrophysics Data System (ADS)

    Yagi, Shogo; Imai, Tadayuki; Ueno, Masahiro; Ohtani, Yoshimitsu; Endo, Masahiro; Kurokawa, Yoshiaki; Yoshikawa, Hiroshi; Watanabe, Toshifumi; Fukuda, Makoto

    2008-02-01

    Multilayered waveguide holography (MWH) is one of a number of page-oriented data multiplexing holographies that will be applied to optical data storage and three-dimensional (3D) moving images. While conventional volumetric holography using photopolymer or photorefractive materials requires page-by-page light exposure for recording, MWH media can be made by employing stamping and laminating technologies that are suitable for mass production. This makes devising an economical mastering technique for replicating holograms a key issue. In this paper, we discuss an approach to pit distribution design that enables us to replace expensive electron beam mastering with economical laser beam mastering. We propose an algorithm that avoids the overlapping of even comparatively large adjacent pits when we employ laser beam mastering. We also compensate for the angular dependence of the diffraction power, which strongly depends on pit shape, by introducing an enhancement profile so that a diffracted image has uniform intensity.

  1. Execution models for mapping programs onto distributed memory parallel computers

    NASA Technical Reports Server (NTRS)

    Sussman, Alan

    1992-01-01

    The problem of exploiting the parallelism available in a program to efficiently employ the resources of the target machine is addressed. The problem is discussed in the context of building a mapping compiler for a distributed memory parallel machine. The paper describes using execution models to drive the process of mapping a program in the most efficient way onto a particular machine. Through analysis of the execution models for several mapping techniques for one class of programs, we show that the selection of the best technique for a particular program instance can make a significant difference in performance. On the other hand, the results of benchmarks from an implementation of a mapping compiler show that our execution models are accurate enough to select the best mapping technique for a given program.

  2. A European Federated Cloud: Innovative distributed computing solutions by EGI

    NASA Astrophysics Data System (ADS)

    Sipos, Gergely; Turilli, Matteo; Newhouse, Steven; Kacsuk, Peter

    2013-04-01

    The European Grid Infrastructure (EGI) is the result of pioneering work that has, over the last decade, built a collaborative production infrastructure of uniform services through the federation of national resource providers that supports multi-disciplinary science across Europe and around the world. This presentation will provide an overview of the recently established 'federated cloud computing services' that the National Grid Initiatives (NGIs), operators of EGI, offer to scientific communities. The presentation will explain the technical capabilities of the 'EGI Federated Cloud' and the processes whereby earth and space science researchers can engage with it. EGI's resource centres have been providing services for collaborative, compute- and data-intensive applications for over a decade. Besides the well-established 'grid services', several NGIs already offer privately run cloud services to their national researchers. Many of these researchers recently expressed the need to share these cloud capabilities within their international research collaborations - a model similar to the way the grid emerged through the federation of institutional batch computing and file storage servers. To facilitate the setup of a pan-European cloud service from the NGIs' resources, the EGI-InSPIRE project established a Federated Cloud Task Force in September 2011. The Task Force has a mandate to identify and test technologies for a multinational federated cloud that could be provisioned within EGI by the NGIs. A guiding principle for the EGI Federated Cloud is to remain technology neutral and flexible for both resource providers and users: • Resource providers are allowed to use any cloud hypervisor and management technology to join virtualised resources into the EGI Federated Cloud as long as the site is subscribed to the user-facing interfaces selected by the EGI community. • Users can integrate high level services - such as brokers, portals and customised Virtual Research

  3. Distributed design tools: Mapping targeted design tools onto a Web-based distributed architecture for high-performance computing

    SciTech Connect

    Holmes, V.P.; Linebarger, J.M.; Miller, D.J.; Poore, C.A.

    1999-11-30

    Design Tools use a Web-based Java interface to guide a product designer through the design-to-analysis cycle for a specific, well-constrained design problem. When these Design Tools are mapped onto a Web-based distributed architecture for high-performance computing, the result is a family of Distributed Design Tools (DDTs). The software components that enable this mapping consist of a Task Sequencer, a generic Script Execution Service, and the storage of both data and metadata in an active, object-oriented database called the Product Database Operator (PDO). The benefits of DDTs include improved security, reliability, scalability (in both problem size and computing hardware), robustness, and reusability. In addition, access to the PDO unlocks its wide range of services for distributed components, such as lookup and launch capability, persistent shared memory for communication between cooperating services, state management, event notification, and archival of design-to-analysis session data.

  4. Fast distributed large-pixel-count hologram computation using a GPU cluster.

    PubMed

    Pan, Yuechao; Xu, Xuewu; Liang, Xinan

    2013-09-10

    Large-pixel-count holograms are one essential part for big size holographic three-dimensional (3D) display, but the generation of such holograms is computationally demanding. In order to address this issue, we have built a graphics processing unit (GPU) cluster with 32.5 Tflop/s computing power and implemented distributed hologram computation on it with speed improvement techniques, such as shared memory on GPU, GPU level adaptive load balancing, and node level load distribution. Using these speed improvement techniques on the GPU cluster, we have achieved 71.4 times computation speed increase for 186M-pixel holograms. Furthermore, we have used the approaches of diffraction limits and subdivision of holograms to overcome the GPU memory limit in computing large-pixel-count holograms. 745M-pixel and 1.80G-pixel holograms were computed in 343 and 3326 s, respectively, for more than 2 million object points with RGB colors. Color 3D objects with 1.02M points were successfully reconstructed from 186M-pixel hologram computed in 8.82 s with all the above three speed improvement techniques. It is shown that distributed hologram computation using a GPU cluster is a promising approach to increase the computation speed of large-pixel-count holograms for large size holographic display.

  5. Applications of computer algebra to distributed parameter systems

    NASA Technical Reports Server (NTRS)

    Storch, Joel A.

    1993-01-01

    In the analysis of vibrations of continuous elastic systems, one often encounters complicated transcendental equations with roots directly related to the system's natural frequencies. Typically, these equations contain system parameters whose values must be specified before a numerical solution can be obtained. The present paper presents a method whereby the fundamental frequency can be obtained in analytical form to any desired degree of accuracy. The method is based upon truncation of rapidly converging series involving inverse powers of the system natural frequencies. A straightforward method to developing these series and summing them in closed form is presented. It is demonstrated how Computer Algebra can be exploited to perform the intricate analytical procedures which otherwise would render the technique difficult to apply in practice. We illustrate the method by developing two analytical approximations to the fundamental frequency of a vibrating cantilever carrying a rigid tip body. The results are compared to the numerical solution of the exact (transcendental) frequency equation over a range of system parameters.

  6. Development of Computer-Supported Collaborative Social Networks in a Distributed Learning Community

    ERIC Educational Resources Information Center

    Cho, H.; Lee, J.-S.; Stefanone, M.; Gay, G.

    2005-01-01

    This study examines the formation and change of collaborative learning social networks in a distributed learning community. A social network perspective is employed to understand how collaborative networks evolved over time when 31 distributed learners collaborated on a design project using a computer-mediated communication system during two…

  7. Computer program determines exact two-sided tolerance limits for normal distributions

    NASA Technical Reports Server (NTRS)

    Friedman, H. A.; Webb, S. R.

    1968-01-01

    Computer program determines by numerical integration the exact statistical two-sided tolerance limits, when the proportion between the limits is at least a specified number. The program is limited to situations in which the underlying probability distribution for the population sampled is the normal distribution with unknown mean and variance.

  8. A Hybrid Computer Simulation to Generate the DNA Distribution of a Cell Population.

    ERIC Educational Resources Information Center

    Griebling, John L.; Adams, William S.

    1981-01-01

    Described is a method of simulating the formation of a DNA distribution, on which statistical results and experimentally measured parameters from DNA distribution and percent-labeled mitosis studies are combined. An EAI-680 and DECSystem-10 Hybrid Computer configuration are used. (Author/CS)

  9. A distributed vortex method for computing the vortex field of a missile

    NASA Technical Reports Server (NTRS)

    Barger, R. L.

    1978-01-01

    Vortex sheet development in the flow field of a missile was investigated by approximating the sheets in the cross-flow plane with short straight-line segments having distributed vorticity. In contrast with the method that represents the sheets as lines of discrete vortices, this distributed vortex method produced calculations with a high degree of computational stability.

  10. DISTRIBUTION COEFICIENTS (KD) GENERATED FROM A CORE SAMPLE COLLECTED FROM THE SALTSTONE DISPOSAL FACILITY

    SciTech Connect

    Almond, P.; Kaplan, D.

    2011-04-25

    Core samples originating from Vault 4, Cell E of the Saltstone Disposal Facility (SDF) were collected in September of 2008 (Hansen and Crawford 2009, Smith 2008) and sent to SRNL to measure chemical and physical properties of the material including visual uniformity, mineralogy, microstructure, density, porosity, distribution coefficients (K{sub d}), and chemical composition. Some data from these experiments have been reported (Cozzi and Duncan 2010). In this study, leaching experiments were conducted with a single core sample under conditions that are representative of saltstone performance. In separate experiments, reducing and oxidizing environments were targeted to obtain solubility and Kd values from the measurable species identified in the solid and aqueous leachate. This study was designed to provide insight into how readily species immobilized in saltstone will leach from the saltstone under oxidizing conditions simulating the edge of a saltstone monolith and under reducing conditions, targeting conditions within the saltstone monolith. Core samples were taken from saltstone poured in December of 2007 giving a cure time of nine months in the cell and a total of thirty months before leaching experiments began in June 2010. The saltstone from Vault 4, Cell E is comprised of blast furnace slag, class F fly ash, portland cement, and Deliquification, Dissolution, and Adjustment (DDA) Batch 2 salt solution. The salt solution was previously analyzed from a sample of Tank 50 salt solution and characterized in the 4QCY07 Waste Acceptance Criteria (WAC) report (Zeigler and Bibler 2009). Subsequent to Tank 50 analysis, additional solution was added to the tank solution from the Effluent Treatment Project as well as from inleakage from Tank 50 pump bearings (Cozzi and Duncan 2010). Core samples were taken from three locations and at three depths at each location using a two-inch diameter concrete coring bit (1-1, 1-2, 1-3; 2-1, 2-2, 2-3; 3-1, 3-2, 3-3) (Hansen and

  11. Benchmark experiments at ASTRA facility on definition of space distribution of {sup 235}U fission reaction rate

    SciTech Connect

    Bobrov, A. A.; Boyarinov, V. F.; Glushkov, A. E.; Glushkov, E. S.; Kompaniets, G. V.; Moroz, N. P.; Nevinitsa, V. A.; Nosov, V. I.; Smirnov, O. N.; Fomichenko, P. A.; Zimin, A. A.

    2012-07-01

    Results of critical experiments performed at five ASTRA facility configurations modeling the high-temperature helium-cooled graphite-moderated reactors are presented. Results of experiments on definition of space distribution of {sup 235}U fission reaction rate performed at four from these five configurations are presented more detail. Analysis of available information showed that all experiments on criticality at these five configurations are acceptable for use them as critical benchmark experiments. All experiments on definition of space distribution of {sup 235}U fission reaction rate are acceptable for use them as physical benchmark experiments. (authors)

  12. A method for measuring the dose distribution of the radiotherapy domain using the computed radiography system.

    PubMed

    Homma, Mitsuhiko; Tabushi, Katsuyoshi; Obata, Yasunori; Tamiya, Tadashi; Koyama, Shuji; Ishigaki, Takeo

    2002-01-01

    Knowing the dose distribution in a tissue is as important as being able to measure exposure or absorbed dose in radiotherapy. Therefore, we have developed a measurement method for the dose distribution (CR dosimetry) in the phantom based on the imaging plate (IP) of the computed radiography (CR). The IP was applied for the dose measurement as a dosimeter instead of the film used for film dosimetry. The data from the irradiated IP were processed by a personal computer with 10 bits and were depicted as absorbed dose distributions in the phantom. The image of the dose distribution was obtained from the CR system using the DICOM form. The CR dosimetry is an application of CR system currently employed in medical examinations to dosimetry in radiotherapy. A dose distribution can be easily shown by the Dose Distribution Depiction System we developed this time. Moreover, the measurement method is simpler and a result is obtained more quickly compared with film dosimetry.

  13. Rocket Engine Turbine Blade Surface Pressure Distributions Experiment and Computations

    NASA Technical Reports Server (NTRS)

    Hudson, Susan T.; Zoladz, Thomas F.; Dorney, Daniel J.; Turner, James (Technical Monitor)

    2002-01-01

    Understanding the unsteady aspects of turbine rotor flow fields is critical to successful future turbine designs. A technology program was conducted at NASA's Marshall Space Flight Center to increase the understanding of unsteady environments for rocket engine turbines. The experimental program involved instrumenting turbine rotor blades with miniature surface mounted high frequency response pressure transducers. The turbine model was then tested to measure the unsteady pressures on the rotor blades. The data obtained from the experimental program is unique in two respects. First, much more unsteady data was obtained (several minutes per set point) than has been possible in the past. Also, an extensive steady performance database existed for the turbine model. This allowed an evaluation of the effect of the on-blade instrumentation on the turbine's performance. A three-dimensional unsteady Navier-Stokes analysis was also used to blindly predict the unsteady flow field in the turbine at the design operating conditions and at +15 degrees relative incidence to the first-stage rotor. The predicted time-averaged and unsteady pressure distributions show good agreement with the experimental data. This unique data set, the lessons learned for acquiring this type of data, and the improvements made to the data analysis and prediction tools are contributing significantly to current Space Launch Initiative turbine airflow test and blade surface pressure prediction efforts.

  14. SAMDIST: A Computer Code for Calculating Statistical Distributions for R-Matrix Resonance Parameters

    SciTech Connect

    Leal, L.C.

    1995-01-01

    The: SAMDIST computer code has been developed to calculate distribution of resonance parameters of the Reich-Moore R-matrix type. The program assumes the parameters are in the format compatible with that of the multilevel R-matrix code SAMMY. SAMDIST calculates the energy-level spacing distribution, the resonance width distribution, and the long-range correlation of the energy levels. Results of these calculations are presented in both graphic and tabular forms.

  15. A computational approach for the analysis of changes in polygon distributions

    NASA Astrophysics Data System (ADS)

    Sadahiro, Yukio; Umemura, Mitsuru

    This paper develops a computational method for analyzing changes in polygon distributions. Unmovable polygons that change discontinuously without explicit functional linkage information are discussed. Six types of primitive events are used to describe the change: 1) generation, 2) disappearance, 3) expansion, 4) shrinkage, 5) union, and 6) division. The change of polygon distributions is decomposed into a combination of these events. A computational procedure for deducing a set of events from polygon distributions of two times is proposed. The method is applied to the analysis of the spatial competition between the major and small chains of convenience stores in Tokyo, Japan. Some empirical findings are shown.

  16. Methods of computing vocabulary size for the two-parameter rank distribution

    NASA Technical Reports Server (NTRS)

    Edmundson, H. P.; Fostel, G.; Tung, I.; Underwood, W.

    1972-01-01

    A summation method is described for computing the vocabulary size for given parameter values in the 1- and 2-parameter rank distributions. Two methods of determining the asymptotes for the family of 2-parameter rank-distribution curves are also described. Tables are computed and graphs are drawn relating paris of parameter values to the vocabulary size. The partial product formula for the Riemann zeta function is investigated as an approximation to the partial sum formula for the Riemann zeta function. An error bound is established that indicates that the partial product should not be used to approximate the partial sum in calculating the vocabulary size for the 2-parameter rank distribution.

  17. A Latency-Tolerant Partitioner for Distributed Computing on the Information Power Grid

    NASA Technical Reports Server (NTRS)

    Das, Sajal K.; Harvey, Daniel J.; Biwas, Rupak; Kwak, Dochan (Technical Monitor)

    2001-01-01

    NASA's Information Power Grid (IPG) is an infrastructure designed to harness the power of graphically distributed computers, databases, and human expertise, in order to solve large-scale realistic computational problems. This type of a meta-computing environment is necessary to present a unified virtual machine to application developers that hides the intricacies of a highly heterogeneous environment and yet maintains adequate security. In this paper, we present a novel partitioning scheme. called MinEX, that dynamically balances processor workloads while minimizing data movement and runtime communication, for applications that are executed in a parallel distributed fashion on the IPG. We also analyze the conditions that are required for the IPG to be an effective tool for such distributed computations. Our results show that MinEX is a viable load balancer provided the nodes of the IPG are connected by a high-speed asynchronous interconnection network.

  18. Distributed computing methodology for training neural networks in an image-guided diagnostic application.

    PubMed

    Plagianakos, V P; Magoulas, G D; Vrahatis, M N

    2006-03-01

    Distributed computing is a process through which a set of computers connected by a network is used collectively to solve a single problem. In this paper, we propose a distributed computing methodology for training neural networks for the detection of lesions in colonoscopy. Our approach is based on partitioning the training set across multiple processors using a parallel virtual machine. In this way, interconnected computers of varied architectures can be used for the distributed evaluation of the error function and gradient values, and, thus, training neural networks utilizing various learning methods. The proposed methodology has large granularity and low synchronization, and has been implemented and tested. Our results indicate that the parallel virtual machine implementation of the training algorithms developed leads to considerable speedup, especially when large network architectures and training sets are used.

  19. Measurements over distributed high performance computing and storage systems

    NASA Technical Reports Server (NTRS)

    Williams, Elizabeth; Myers, Tom

    1993-01-01

    Requirements are carefully described in descriptions of systems to be acquired but often there is no requirement to provide measurements and performance monitoring to ensure that requirements are met over the long term after acceptance. A set of measurements for various UNIX-based systems will be available at the 1992 Goddard Conference on Mass Storage Systems and Technologies. The authors invite others to contribute to the set of measurements. The framework for presenting the measurements of supercomputers, workstations, file servers, mass storage systems, and the networks that interconnect them are given. Production control and database systems are also included. Though other applications and third party software systems are not addressed, it is important to measure them as well. The capability to integrate measurements from all these components from different vendors, and from the third party software systems was recognized and there are efforts to standardize a framework to do this. The measurement activity falls into the domain of management standards. Standards work is ongoing for Open Systems Interconnection (OSI) systems management; AT&T, Digital, and Hewlett-Packard are developing management systems based on this architecture even though it is not finished. Another effort is in the UNIX International Performance Management Working Group. In addition, there are the Open Systems Foundation's Distributed Management Environment and the Object Management Group. A paper comparing the OSI systems management model and the Object Management Group model has been written. The IBM world has had a capability for measurement for various IBM systems since the 1970's and different vendors were able to develop tools for analyzing and viewing these measurements. Since IBM was the only vendor, the user groups were able to lobby IBM for the kinds of measurements needed. In the UNIX world of multiple vendors, a common set of measurements will not be as easy to get.

  20. Development and Demonstration of a Computational Tool for the Analysis of Particle Vitiation Effects in Hypersonic Propulsion Test Facilities

    NASA Technical Reports Server (NTRS)

    Perkins, Hugh Douglas

    2010-01-01

    In order to improve the understanding of particle vitiation effects in hypersonic propulsion test facilities, a quasi-one dimensional numerical tool was developed to efficiently model reacting particle-gas flows over a wide range of conditions. Features of this code include gas-phase finite-rate kinetics, a global porous-particle combustion model, mass, momentum and energy interactions between phases, and subsonic and supersonic particle drag and heat transfer models. The basic capabilities of this tool were validated against available data or other validated codes. To demonstrate the capabilities of the code a series of computations were performed for a model hypersonic propulsion test facility and scramjet. Parameters studied were simulated flight Mach number, particle size, particle mass fraction and particle material.

  1. Development of Parallel Computing Framework to Enhance Radiation Transport Code Capabilities for Rare Isotope Beam Facility Design

    SciTech Connect

    Kostin, Mikhail; Mokhov, Nikolai; Niita, Koji

    2013-09-25

    A parallel computing framework has been developed to use with general-purpose radiation transport codes. The framework was implemented as a C++ module that uses MPI for message passing. It is intended to be used with older radiation transport codes implemented in Fortran77, Fortran 90 or C. The module is significantly independent of radiation transport codes it can be used with, and is connected to the codes by means of a number of interface functions. The framework was developed and tested in conjunction with the MARS15 code. It is possible to use it with other codes such as PHITS, FLUKA and MCNP after certain adjustments. Besides the parallel computing functionality, the framework offers a checkpoint facility that allows restarting calculations with a saved checkpoint file. The checkpoint facility can be used in single process calculations as well as in the parallel regime. The framework corrects some of the known problems with the scheduling and load balancing found in the original implementations of the parallel computing functionality in MARS15 and PHITS. The framework can be used efficiently on homogeneous systems and networks of workstations, where the interference from the other users is possible.

  2. An incentive for coordination in a decentralised service chain with a Weibull lifetime distributed facility

    NASA Astrophysics Data System (ADS)

    Lin, Yi-Fang; Yang, Gino K.; Yang, Chyn-Yng; Chu, Tu-Bin

    2013-10-01

    This article deals with a decentralised service chain consisting of a service provider and a facility owner. The revenue allocation and service price are, respectively, determined by the service provider and the facility owner in a non-cooperative manner. To model this decentralised operation, a Stackelberg game between the two parties is formulated. In the mathematical framework, the service system is assumed to be driven by Poisson customer arrivals and exponential service times. The most common log-linear service demand and Weibull facility lifetime are also adopted. Under these analytical conditions, the decentralised decisions in this game are investigated and then a unique optimal equilibrium is derived. Finally, a coordination mechanism is proposed to improve the efficiency of this decentralised system.

  3. System Design for On-line Distributed Computational Visualization and Steering

    SciTech Connect

    Wu, Qishi; Zhu, Mengxia; Rao, Nageswara S

    2006-01-01

    We propose a distributed computing framework for network-optimized visualization and steering of real-time scientific simulations and computations executed on a remote host, such as workstation, cluster or supercomputer. Unlike the conventional "batch" simulations, this system enables: (i) monitoring of an ongoing remote computation using visualization tools, and (ii) on-line specification of simulation parameters to interactively steer remote computations. Using performance models for transport channels and visualization modules, we develop a dynamic programming method to optimize the realization of the visualization pipeline over a wide-area network to maximize the frame rate. We present experimental results to illustrate the effectiveness of this system.

  4. Probability Distributome: A Web Computational Infrastructure for Exploring the Properties, Interrelations, and Applications of Probability Distributions.

    PubMed

    Dinov, Ivo D; Siegrist, Kyle; Pearl, Dennis K; Kalinin, Alexandr; Christou, Nicolas

    2016-06-01

    Probability distributions are useful for modeling, simulation, analysis, and inference on varieties of natural processes and physical phenomena. There are uncountably many probability distributions. However, a few dozen families of distributions are commonly defined and are frequently used in practice for problem solving, experimental applications, and theoretical studies. In this paper, we present a new computational and graphical infrastructure, the Distributome, which facilitates the discovery, exploration and application of diverse spectra of probability distributions. The extensible Distributome infrastructure provides interfaces for (human and machine) traversal, search, and navigation of all common probability distributions. It also enables distribution modeling, applications, investigation of inter-distribution relations, as well as their analytical representations and computational utilization. The entire Distributome framework is designed and implemented as an open-source, community-built, and Internet-accessible infrastructure. It is portable, extensible and compatible with HTML5 and Web2.0 standards (http://Distributome.org). We demonstrate two types of applications of the probability Distributome resources: computational research and science education. The Distributome tools may be employed to address five complementary computational modeling applications (simulation, data-analysis and inference, model-fitting, examination of the analytical, mathematical and computational properties of specific probability distributions, and exploration of the inter-distributional relations). Many high school and college science, technology, engineering and mathematics (STEM) courses may be enriched by the use of modern pedagogical approaches and technology-enhanced methods. The Distributome resources provide enhancements for blended STEM education by improving student motivation, augmenting the classical curriculum with interactive webapps, and overhauling the

  5. A Computer Simulation Model for Planning Instructional Facilities at the University of Toronto.

    ERIC Educational Resources Information Center

    Sceviour, W. F.

    A computer model for providing information to assist space administrators at the University of Toronto in planning classroom requirements is presented in this thesis. The requirements generated are compared against available rooms and measures of utilization computed. The model reacts to changes in parameters describing the system which allows the…

  6. Distributed Problem Solving: Adaptive Networks with a Computer Intermediary Resource. Intelligent Executive Computer Communication

    DTIC Science & Technology

    1991-06-01

    Alto Research Center, August 1982. [82] Ernst W. Mayr . Well Structured Parallel Programs Are Not Easier to Schedule. Technical Report No. STAN-CS-81...articles on scheduling) [Dolev, 80; Graham, 69; Helmbold and Mayr , 84; Mayr , 81], in systems [Ackerman, 82] and in artificial intelligence [Rosenschein...Flight Control. NASA Technical Memorandum 58258, May 1984. [60] D. Helmbold and E. Mayr . Fast Scheduling Algorithms on Parallel Computers. Technical

  7. Sources and distribution of polychlorinated terphenyls at a major US aeronautics research facility

    SciTech Connect

    Hale, R.C.; Enos, C.; Gallagher, K.

    1998-11-01

    High concentrations of an unusual, complex mixture of chlorinated compounds were discovered in sediments and oysters near a federal aeronautics facility during implementation of a pollutant screening protocol. The mixture was identified as Aroclor 5432, a polychlorinated terphenyl (PCT) formulation, produced in the US until 1972. PCTs, particularly low chlorinated mixtures, have rarely been reported in the environment, despite significant manufacture and usage. PCBs, and mercury were also detected in storm drain lines entering these outfalls. The lines received input from both storm water and research buildings. Historical hydraulic fluid leaks and in-service compressor fluids in some buildings contained PCTs and PCBs. Contaminated materials on-site were removed to minimize pollutant spread. Aroclor 5432 usage, most likely as compressor/hydraulic fluid additives, probably ended about ten years prior to its on-site detection, in terms of biological effects, intraperitoneal injection of fish with Aroclor 5432 induced cytochrome P-4501A (CYP1A) and ethoxyresorufin O-deethylase (EROD) activity to a similar degree as PCB Aroclor 1254 and to a greater extent than PCT Aroclor 5460. The presence of high concentrations of PCTs contributed to the facility being included on the National Priorities List. It subsequently became the first US federal facility to sign a Federal Facility Agreement, identifying cleanup responsibilities, prior to formal listing.

  8. Effects of wind-energy facilities on breeding grassland bird distributions.

    PubMed

    Shaffer, Jill A; Buhl, Deborah A

    2016-02-01

    The contribution of renewable energy to meet worldwide demand continues to grow. Wind energy is one of the fastest growing renewable sectors, but new wind facilities are often placed in prime wildlife habitat. Long-term studies that incorporate a rigorous statistical design to evaluate the effects of wind facilities on wildlife are rare. We conducted a before-after-control-impact (BACI) assessment to determine if wind facilities placed in native mixed-grass prairies displaced breeding grassland birds. During 2003-2012, we monitored changes in bird density in 3 study areas in North Dakota and South Dakota (U.S.A.). We examined whether displacement or attraction occurred 1 year after construction (immediate effect) and the average displacement or attraction 2-5 years after construction (delayed effect). We tested for these effects overall and within distance bands of 100, 200, 300, and >300 m from turbines. We observed displacement for 7 of 9 species. One species was unaffected by wind facilities and one species exhibited attraction. Displacement and attraction generally occurred within 100 m and often extended up to 300 m. In a few instances, displacement extended beyond 300 m. Displacement and attraction occurred 1 year after construction and persisted at least 5 years. Our research provides a framework for applying a BACI design to displacement studies and highlights the erroneous conclusions that can be made without the benefit of adopting such a design. More broadly, species-specific behaviors can be used to inform management decisions about turbine placement and the potential impact to individual species. Additionally, the avoidance distance metrics we estimated can facilitate future development of models evaluating impacts of wind facilities under differing land-use scenarios.

  9. A computational method for planning complex compound distributions under container, liquid handler, and assay constraints.

    PubMed

    Russo, Mark F; Wild, Daniel; Hoffman, Steve; Paulson, James; Neil, William; Nirschl, David S

    2013-10-01

    A systematic method for assembling and solving complex compound distribution problems is presented in detail. The method is based on a model problem that enumerates the mathematical equations and constraints describing a source container, liquid handler, and three types of destination containers involved in a set of compound distributions. One source container and one liquid handler are permitted in any given problem formulation, although any number of compound distributions may be specified. The relative importance of all distributions is expressed by assigning weights, which are factored into the final mathematical problem specification. A computer program was created that automatically assembles and solves a complete compound distribution problem given the parameters that describe the source container, liquid handler, and any number and type of compound distributions. Business rules are accommodated by adjusting weighting factors assigned to each distribution. An example problem, presented and explored in detail, demonstrates complex and nonintuitive solution behavior.

  10. Computing multiple aggregation levels and contextual features for road facilities recognition using mobile laser scanning data

    NASA Astrophysics Data System (ADS)

    Yang, Bisheng; Dong, Zhen; Liu, Yuan; Liang, Fuxun; Wang, Yongjun

    2017-04-01

    In recent years, updating the inventory of road infrastructures based on field work is labor intensive, time consuming, and costly. Fortunately, vehicle-based mobile laser scanning (MLS) systems provide an efficient solution to rapidly capture three-dimensional (3D) point clouds of road environments with high flexibility and precision. However, robust recognition of road facilities from huge volumes of 3D point clouds is still a challenging issue because of complicated and incomplete structures, occlusions and varied point densities. Most existing methods utilize point or object based features to recognize object candidates, and can only extract limited types of objects with a relatively low recognition rate, especially for incomplete and small objects. To overcome these drawbacks, this paper proposes a semantic labeling framework by combing multiple aggregation levels (point-segment-object) of features and contextual features to recognize road facilities, such as road surfaces, road boundaries, buildings, guardrails, street lamps, traffic signs, roadside-trees, power lines, and cars, for highway infrastructure inventory. The proposed method first identifies ground and non-ground points, and extracts road surfaces facilities from ground points. Non-ground points are segmented into individual candidate objects based on the proposed multi-rule region growing method. Then, the multiple aggregation levels of features and the contextual features (relative positions, relative directions, and spatial patterns) associated with each candidate object are calculated and fed into a SVM classifier to label the corresponding candidate object. The recognition performance of combining multiple aggregation levels and contextual features was compared with single level (point, segment, or object) based features using large-scale highway scene point clouds. Comparative studies demonstrated that the proposed semantic labeling framework significantly improves road facilities recognition

  11. Computational Studies of X-ray Framing Cameras for the National Ignition Facility

    DTIC Science & Technology

    2013-06-01

    Livermore National Laboratory 7000 East Avenue Livermore, CA 94550 USA Abstract The NIF is the world’s most powerful laser facility and is...a phosphor screen where the output is recorded. The x-ray framing cameras have provided excellent information. As the yields at NIF have increased...experiments on the NIF . The basic operation of these cameras is shown in Fig. 1. Incident photons generate photoelectrons both in the pores of the MCP and

  12. Distributed Computing for Signal Processing: Modeling of Asynchronous Parallel Computation. Appendix A.

    DTIC Science & Technology

    1983-03-01

    Modeling of Asynchronous Parallel Computation 1983 Progress Report L.J. Siegel, H.J. Siegel, PMH . Swain, G.B. Adams 111, W.E. Kuhn III, R .J...used in reduction machines), and vector. A complete and very detailed taxonomy based on these concepts is presented in Ji181]. Its length is too great...representation [(1oL731. A banyan is a directed graph composed of vertices and edges or arcs such that. it is irreflexive, asymmetric , and intransitive (a

  13. An efficient numerical algorithm for computing densely distributed positive interior transmission eigenvalues

    NASA Astrophysics Data System (ADS)

    Li, Tiexiang; Huang, Tsung-Ming; Lin, Wen-Wei; Wang, Jenn-Nan

    2017-03-01

    We propose an efficient eigensolver for computing densely distributed spectra of the two-dimensional transmission eigenvalue problem (TEP), which is derived from Maxwell’s equations with Tellegen media and the transverse magnetic mode. The governing equations, when discretized by the standard piecewise linear finite element method, give rise to a large-scale quadratic eigenvalue problem (QEP). Our numerical simulation shows that half of the positive eigenvalues of the QEP are densely distributed in some interval near the origin. The quadratic Jacobi–Davidson method with a so-called non-equivalence deflation technique is proposed to compute the dense spectrum of the QEP. Extensive numerical simulations show that our proposed method processes the convergence efficiently, even when it needs to compute more than 5000 desired eigenpairs. Numerical results also illustrate that the computed eigenvalue curves can be approximated by nonlinear functions, which can be applied to estimate the denseness of the eigenvalues for the TEP.

  14. Distributed Computation of the knn Graph for Large High-Dimensional Point Sets

    PubMed Central

    Plaku, Erion; Kavraki, Lydia E.

    2009-01-01

    High-dimensional problems arising from robot motion planning, biology, data mining, and geographic information systems often require the computation of k nearest neighbor (knn) graphs. The knn graph of a data set is obtained by connecting each point to its k closest points. As the research in the above-mentioned fields progressively addresses problems of unprecedented complexity, the demand for computing knn graphs based on arbitrary distance metrics and large high-dimensional data sets increases, exceeding resources available to a single machine. In this work we efficiently distribute the computation of knn graphs for clusters of processors with message passing. Extensions to our distributed framework include the computation of graphs based on other proximity queries, such as approximate knn or range queries. Our experiments show nearly linear speedup with over one hundred processors and indicate that similar speedup can be obtained with several hundred processors. PMID:19847318

  15. Approximation modeling for the online performance management of distributed computing systems.

    PubMed

    Kusic, Dara; Kandasamy, Nagarajan; Jiang, Guofei

    2008-10-01

    A promising method of automating management tasks in computing systems is to formulate them as control or optimization problems in terms of performance metrics. For an online optimization scheme to be of practical value in a distributed setting, however, it must successfully tackle the curses of dimensionality and modeling. This paper develops a hierarchical control framework to solve performance management problems in distributed computing systems operating in a data center. Concepts from approximation theory are used to reduce the computational burden of controlling such large-scale systems. The relevant approximations are made in the construction of the dynamical models to predict system behavior and in the solution of the associated control equations. Using a dynamic resource-provisioning problem as a case study, we show that a computing system managed by the proposed control framework with approximation models realizes profit gains that are, in the best case, within 1% of a controller using an explicit model of the system.

  16. Sources and Distribution of Polychlorinated Terphenyls at a Major US Aeronautics Research Facility.

    PubMed

    HALE; ENOS; GALLAGHER

    1998-11-01

    / High concentrations of an unusual, complex mixture of chlorinated compounds were discovered in sediments and oysters near a federal aeronautics facility during implementation of a pollutant screening protocol. The mixture was identified as Aroclor 5432, a polychlorinated terphenyl (PCT) formulation, produced in the US until 1972. PCTs, particularly low chlorinated mixtures, have rarely been reported in the environment, despite significant manufacture and usage. Releases were traced to two outfalls. Creek sediments downstream of one contained concentrations as high as 200,000 |gmg/kg (dry weight basis); those in indigenous oysters reached 35,000 |gmg/kg, indicating significant bioavailability and bioaccumulation potential. Subsequent work showed that PCTs were widely disseminated in marsh grass, crabs, and fish. PCTs, PCBs, and mercury were also detected in storm drain lines entering these outfalls. The lines received input from both storm water and research buildings. Historical hydraulic fluid leaks and in-service compressor fluids in some buildings contained PCTs and PCBs. Contaminated materials on-site were removed to minimize pollutant spread. Aroclor 5432 usage, most likely as compressor/hydraulic fluid additives, probably ended about ten years prior to its on-site detection. In terms of biological effects, intraperitoneal injection of fish with Aroclor 5432 induced cytochrome P-4501A (CYP1A) and ethoxyresorufin O-deethylase (EROD) activity to a similar degree as PCB Aroclor 1254 and to a greater extent than PCT Aroclor 5460. The presence of high concentrations of PCTs contributed to the facility being included on the National Priorities List. It subsequently became the first US federal facility to sign a Federal Facility Agreement, identifying cleanup responsibilities, prior to formal listing.KEY WORDS: Polychlorinated terphenyls; Aroclor; Contaminated sediments; Hydraulic fluid; Enzyme induction; Polychlorinated biphenyls

  17. The influence of facility agriculture production on phthalate esters distribution in black soils of northeast China.

    PubMed

    Zhang, Ying; Wang, Pengjie; Wang, Lei; Sun, Guoqiang; Zhao, Jiaying; Zhang, Hui; Du, Na

    2015-02-15

    The current study investigates the existence of 15 phthalate esters (PAEs) in surface soils (27 samples) collected from 9 different facility agriculture sites in the black soil region of northeast China, during the process of agricultural production (comprising only three seasons spring, summer and autumn). Concentrations of the 15 PAEs detected significantly varied from spring to autumn and their values ranged from 1.37 to 4.90 mg/kg-dw, with a median value of 2.83 mg/kg-dw. The highest concentration of the 15 PAEs (4.90 mg/kg-dw) was determined in summer when mulching film was used in the greenhouses. Probably an increase in environmental temperature was a major reason for PAE transfer from the mulching film into the soil and coupled with the increased usage of chemical fertilizers in greenhouses. Results showed that of the 15 PAEs, di(2-ethylhexyl) phthalate(DEHP), di-n-butyl phthalate (DBP), diethyl phthalate (DEP) and dimethyl phthalate (DMP) were in abundance with the mean value of 1.12 ± 0.22, 0.46 ± 0.05, 0.36 ± 0.04, and 0.17 ± 0.01 mg/kg-dw, respectively; and their average contributions in spring, summer, and autumn ranged between 64.08 and 90.51% among the 15 PAEs. The results of Principal Component Analysis (PCA) indicated the concentration of these four main PAEs significantly differed among the facility agricultures investigated, during the process of agricultural production. In comparison with foreign and domestic results of previous researches, it is proved that the black soils of facility agriculture in northeast China show higher pollution situation comparing with non-facility agriculture soils.

  18. A method for computing random chord length distributions in geometrical objects.

    PubMed

    Borak, T B

    1994-03-01

    A method is described that uses a Monte Carlo approach for computing the distribution of random chord lengths in objects traversed by rays originating uniformly in space (mu-randomness). The resulting distributions converge identically to the analytical solutions for a sphere and satisfy the Cauchy relationship for mean chord lengths in circular cylinders. The method can easily be applied to geometrical shapes that are not convex such as the region between nested cylinders to simulate the sensitive volume of a detector. Comparisons with other computational methods are presented.

  19. Experiences on integration of network management and a distributed computing platform

    NASA Astrophysics Data System (ADS)

    Rahkila, Sakari; Stenberg, Susanne

    1997-09-01

    The integration of the two recognized network management protocol standards, common management information protocol, and simple network management protocol, and common object request broker architecture (CORBA) technology, allows management applications to take advantage of distributed object computing as well as the standardized network management protocols. This paper describes the distributed computing platform (DCP) prototype developed at the Nokia Research Center. The DCP prototype is a framework, including tools, compilers and gateways, built to support both Internet and open systems interconnection management through a CORBA infrastructure.

  20. Efficient computation of stress and load distribution for external cylindrical gears

    SciTech Connect

    Zhang, J.J.; Esat, I.I.; Shi, Y.H.

    1996-12-31

    It has been extensively realized that tooth flank correction is an effective technique to improve load carrying capacity and running behavior of gears. However, the existing analytical methods of load distribution are not very satisfactory. They are either too simplified to produce accurate results or computationally too expensive. In this paper, we propose a new approach which computes the load and stress distribution of external involute gears efficiently and accurately. It adopts the {open_quotes}thin-slice{close_quotes} model and 2D FEA technique and takes into account the varying meshing stiffness.

  1. MultiPhyl: a high-throughput phylogenomics webserver using distributed computing.

    PubMed

    Keane, Thomas M; Naughton, Thomas J; McInerney, James O

    2007-07-01

    With the number of fully sequenced genomes increasing steadily, there is greater interest in performing large-scale phylogenomic analyses from large numbers of individual gene families. Maximum likelihood (ML) has been shown repeatedly to be one of the most accurate methods for phylogenetic construction. Recently, there have been a number of algorithmic improvements in maximum-likelihood-based tree search methods. However, it can still take a long time to analyse the evolutionary history of many gene families using a single computer. Distributed computing refers to a method of combining the computing power of multiple computers in order to perform some larger overall calculation. In this article, we present the first high-throughput implementation of a distributed phylogenetics platform, MultiPhyl, capable of using the idle computational resources of many heterogeneous non-dedicated machines to form a phylogenetics supercomputer. MultiPhyl allows a user to upload hundreds or thousands of amino acid or nucleotide alignments simultaneously and perform computationally intensive tasks such as model selection, tree searching and bootstrapping of each of the alignments using many desktop machines. The program implements a set of 88 amino acid models and 56 nucleotide maximum likelihood models and a variety of statistical methods for choosing between alternative models. A MultiPhyl webserver is available for public use at: http://www.cs.nuim.ie/distributed/multiphyl.php.

  2. Reconciling fault-tolerant distributed algorithms and real-time computing.

    PubMed

    Moser, Heinrich; Schmid, Ulrich

    We present generic transformations, which allow to translate classic fault-tolerant distributed algorithms and their correctness proofs into a real-time distributed computing model (and vice versa). Owing to the non-zero-time, non-preemptible state transitions employed in our real-time model, scheduling and queuing effects (which are inherently abstracted away in classic zero step-time models, sometimes leading to overly optimistic time complexity results) can be accurately modeled. Our results thus make fault-tolerant distributed algorithms amenable to a sound real-time analysis, without sacrificing the wealth of algorithms and correctness proofs established in classic distributed computing research. By means of an example, we demonstrate that real-time algorithms generated by transforming classic algorithms can be competitive even w.r.t. optimal real-time algorithms, despite their comparatively simple real-time analysis.

  3. DISTRIBUTED CONTAINER FAILURE MODELS FOR THE DUST-MS COMPUTER CODE.

    SciTech Connect

    SULLIVAN,T.; DE LEMOS,F.

    2001-02-24

    Improvements to the DUST-MS computer code have been made that permit simulation of distributed container failure rates. The new models permit instant failure of all containers within a computational volume, uniform failure of these containers over time, or a normal distribution in container failures. Incorporation of a distributed failure model requires wasteform releases to be calculated using a convolution integral. In addition, the models permit a unique time of emplacement for each modeled container and allow a fraction of the containers to fail at emplacement. Implementation of these models, verification testing, and an example problem comparing releases from a wasteform with a two-species decay chain as a function of failure distribution are presented in the paper.

  4. SU-E-T-531: Performance Evaluation of Multithreaded Geant4 for Proton Therapy Dose Calculations in a High Performance Computing Facility

    SciTech Connect

    Shin, J; Coss, D; McMurry, J; Farr, J; Faddegon, B

    2014-06-01

    Purpose: To evaluate the efficiency of multithreaded Geant4 (Geant4-MT, version 10.0) for proton Monte Carlo dose calculations using a high performance computing facility. Methods: Geant4-MT was used to calculate 3D dose distributions in 1×1×1 mm3 voxels in a water phantom and patient's head with a 150 MeV proton beam covering approximately 5×5 cm2 in the water phantom. Three timestamps were measured on the fly to separately analyze the required time for initialization (which cannot be parallelized), processing time of individual threads, and completion time. Scalability of averaged processing time per thread was calculated as a function of thread number (1, 100, 150, and 200) for both 1M and 50 M histories. The total memory usage was recorded. Results: Simulations with 50 M histories were fastest with 100 threads, taking approximately 1.3 hours and 6 hours for the water phantom and the CT data, respectively with better than 1.0 % statistical uncertainty. The calculations show 1/N scalability in the event loops for both cases. The gains from parallel calculations started to decrease with 150 threads. The memory usage increases linearly with number of threads. No critical failures were observed during the simulations. Conclusion: Multithreading in Geant4-MT decreased simulation time in proton dose distribution calculations by a factor of 64 and 54 at a near optimal 100 threads for water phantom and patient's data respectively. Further simulations will be done to determine the efficiency at the optimal thread number. Considering the trend of computer architecture development, utilizing Geant4-MT for radiotherapy simulations is an excellent cost-effective alternative for a distributed batch queuing system. However, because the scalability depends highly on simulation details, i.e., the ratio of the processing time of one event versus waiting time to access for the shared event queue, a performance evaluation as described is recommended.

  5. On Developing a Theory of Distributed Computing: Summary of Current Research.

    DTIC Science & Technology

    1980-09-01

    The paradigms of theory can be applied to the problems of concurrency and distribution to yield a rich mathematical theory which will provide a solid framework for practitioner and theoretician alike to use in gaining greater understanding of the exciting and important area of distributed computing . The author is currently engaged in an effort to develop such a theory. This paper summarizes work to date and indicates directions for further research. (Author)

  6. ClustalW-MPI: ClustalW analysis using distributed and parallel computing.

    PubMed

    Li, Kuo-Bin

    2003-08-12

    ClustalW is a tool for aligning multiple protein or nucleotide sequences. The alignment is achieved via three steps: pairwise alignment, guide-tree generation and progressive alignment. ClustalW-MPI is a distributed and parallel implementation of ClustalW. All three steps have been parallelized to reduce the execution time. The software uses a message-passing library called MPI (Message Passing Interface) and runs on distributed workstation clusters as well as on traditional parallel computers.

  7. Computation of pair distribution functions and three-dimensional densities with a reduced variance principle

    NASA Astrophysics Data System (ADS)

    Borgis, Daniel; Assaraf, Roland; Rotenberg, Benjamin; Vuilleumier, Rodolphe

    2013-12-01

    No fancy statistical objects here, we go back to the computation of one of the most basic and fundamental quantities in the statistical mechanics of fluids, namely the pair distribution functions. Those functions are usually computed in molecular simulations by using histogram techniques. We show here that they can be estimated using a global information on the instantaneous forces acting on the particles, and that this leads to a reduced variance compared to the standard histogram estimators. The technique is extended successfully to the computation of three-dimensional solvent densities around tagged molecular solutes, quantities that are noisy and very long to converge, using histograms.

  8. Distributed computing architecture for image-based wavefront sensing and 2D FFTs

    NASA Astrophysics Data System (ADS)

    Smith, Jeffrey S.; Dean, Bruce H.; Haghani, Shadan

    2006-06-01

    Image-based wavefront sensing provides significant advantages over interferometric-based wavefront sensors such as optical design simplicity and stability. However, the image-based approach is computationally intensive, and therefore, applications utilizing the image-based approach gain substantial benefits using specialized high-performance computing architectures. The development and testing of these computing architectures are essential to missions such as James Webb Space Telescope (JWST), Terrestrial Planet Finder-Coronagraph (TPF-C and CorSpec), and the Spherical Primary Optical Telescope (SPOT). The algorithms implemented on these specialized computing architectures make use of numerous two-dimensional Fast Fourier Transforms (FFTs) which necessitate an all-to-all communication when applied on a distributed computational architecture. Several solutions for distributed computing are presented with an emphasis on a 64 Node cluster of digital signal processors (DSPs) and multiple DSP field programmable gate arrays (FPGAs), offering a novel application of low-diameter graph theory. Timing results and performance analysis are presented. The solutions offered could be applied to other computationally complex all-to-all communication problems.

  9. Distributed Computing Architecture for Image-Based Wavefront Sensing and 2 D FFTs

    NASA Technical Reports Server (NTRS)

    Smith, Jeffrey S.; Dean, Bruce H.; Haghani, Shadan

    2006-01-01

    Image-based wavefront sensing (WFS) provides significant advantages over interferometric-based wavefi-ont sensors such as optical design simplicity and stability. However, the image-based approach is computational intensive, and therefore, specialized high-performance computing architectures are required in applications utilizing the image-based approach. The development and testing of these high-performance computing architectures are essential to such missions as James Webb Space Telescope (JWST), Terrestial Planet Finder-Coronagraph (TPF-C and CorSpec), and Spherical Primary Optical Telescope (SPOT). The development of these specialized computing architectures require numerous two-dimensional Fourier Transforms, which necessitate an all-to-all communication when applied on a distributed computational architecture. Several solutions for distributed computing are presented with an emphasis on a 64 Node cluster of DSPs, multiple DSP FPGAs, and an application of low-diameter graph theory. Timing results and performance analysis will be presented. The solutions offered could be applied to other all-to-all communication and scientifically computationally complex problems.

  10. Development of MCNPX-ESUT computer code for simulation of neutron/gamma pulse height distribution

    NASA Astrophysics Data System (ADS)

    Abolfazl Hosseini, Seyed; Vosoughi, Naser; Zangian, Mehdi

    2015-05-01

    In this paper, the development of the MCNPX-ESUT (MCNPX-Energy Engineering of Sharif University of Technology) computer code for simulation of neutron/gamma pulse height distribution is reported. Since liquid organic scintillators like NE-213 are well suited and routinely used for spectrometry in mixed neutron/gamma fields, this type of detectors is selected for simulation in the present study. The proposed algorithm for simulation includes four main steps. The first step is the modeling of the neutron/gamma particle transport and their interactions with the materials in the environment and detector volume. In the second step, the number of scintillation photons due to charged particles such as electrons, alphas, protons and carbon nuclei in the scintillator material is calculated. In the third step, the transport of scintillation photons in the scintillator and lightguide is simulated. Finally, the resolution corresponding to the experiment is considered in the last step of the simulation. Unlike the similar computer codes like SCINFUL, NRESP7 and PHRESP, the developed computer code is applicable to both neutron and gamma sources. Hence, the discrimination of neutron and gamma in the mixed fields may be performed using the MCNPX-ESUT computer code. The main feature of MCNPX-ESUT computer code is that the neutron/gamma pulse height simulation may be performed without needing any sort of post processing. In the present study, the pulse height distributions due to a monoenergetic neutron/gamma source in NE-213 detector using MCNPX-ESUT computer code is simulated. The simulated neutron pulse height distributions are validated through comparing with experimental data (Gohil et al. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 664 (2012) 304-309.) and the results obtained from similar computer codes like SCINFUL, NRESP7 and Geant4. The simulated gamma pulse height distribution for a 137Cs

  11. Planning for distributed workflows: constraint-based coscheduling of computational jobs and data placement in distributed environments

    NASA Astrophysics Data System (ADS)

    Makatun, Dzmitry; Lauret, Jérôme; Rudová, Hana; Šumbera, Michal

    2015-05-01

    When running data intensive applications on distributed computational resources long I/O overheads may be observed as access to remotely stored data is performed. Latencies and bandwidth can become the major limiting factor for the overall computation performance and can reduce the CPU/WallTime ratio to excessive IO wait. Reusing the knowledge of our previous research, we propose a constraint programming based planner that schedules computational jobs and data placements (transfers) in a distributed environment in order to optimize resource utilization and reduce the overall processing completion time. The optimization is achieved by ensuring that none of the resources (network links, data storages and CPUs) are oversaturated at any moment of time and either (a) that the data is pre-placed at the site where the job runs or (b) that the jobs are scheduled where the data is already present. Such an approach eliminates the idle CPU cycles occurring when the job is waiting for the I/O from a remote site and would have wide application in the community. Our planner was evaluated and simulated based on data extracted from log files of batch and data management systems of the STAR experiment. The results of evaluation and estimation of performance improvements are discussed in this paper.

  12. The Use of Public Computing Facilities by Library Patrons: Demography, Motivations, and Barriers

    ERIC Educational Resources Information Center

    DeMaagd, Kurt; Chew, Han Ei; Huang, Guanxiong; Khan, M. Laeeq; Sreenivasan, Akshaya; LaRose, Robert

    2013-01-01

    Public libraries play an important part in the development of a community. Today, they are seen as more than store houses of books; they are also responsible for the dissemination of online, and offline information. Public access computers are becoming increasingly popular as more and more people understand the need for internet access. Using a…

  13. Computer Skills Development by Children Using "Hole in the Wall" Facilities in Rural India

    ERIC Educational Resources Information Center

    Inamdar, Parimala

    2004-01-01

    Earlier work often referred to as the "hole in the wall" experiments has shown that groups of children can learn to use public computers on their own. This paper presents the method and results of an experiment conducted to investigate whether such unsupervised group learning in shared public spaces can improve children's performance in…

  14. Distribution Coefficients (Kd Values) for Waste Resins Generated from the K and L Disassembly Basin Facilities

    SciTech Connect

    Kaplan, D.I.

    2002-12-02

    The objective of this study was to measure 14C, 129I, and 99Tc Kd values of spent resin generated from the K and L Disassembly Basin Facilities. The scope of the work was to conduct Kd measurements of resins combined in the ratio that they are disposed, 42:58 cation:anion. Because it was not known how these spent resins would be buried, it was necessary to measure the Kd values in such a manner as to simulate both trench and vault disposal. This was accomplished by using an acid-rain simulant (a standard U.S. Environmental Protection Agency protocol) and a cement leachate simulant .

  15. Linking and Combining Distributed Operations Facilities using NASA's "GMSEC" Systems Architectures

    NASA Technical Reports Server (NTRS)

    Smith, Danford; Grubb, Thomas; Esper, Jaime

    2008-01-01

    NASA's Goddard Mission Services Evolution Center (GMSEC) ground system architecture has been in development since late 2001, has successfully supported eight orbiting satellites and is being applied to many of NASA's future missions. GMSEC can be considered an event-driven service-oriented architecture built around a publish/subscribe message bus middleware. This paper briefly discusses the GMSEC technical approaches which have led to significant cost savings and risk reduction for NASA missions operated at the Goddard Space Flight Center (GSFC). The paper then focuses on the development and operational impacts of extending the architecture across multiple mission operations facilities.

  16. Analysis and synthesis of distributed-lumped-active networks by digital computer

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The use of digital computational techniques in the analysis and synthesis of DLA (distributed lumped active) networks is considered. This class of networks consists of three distinct types of elements, namely, distributed elements (modeled by partial differential equations), lumped elements (modeled by algebraic relations and ordinary differential equations), and active elements (modeled by algebraic relations). Such a characterization is applicable to a broad class of circuits, especially including those usually referred to as linear integrated circuits, since the fabrication techniques for such circuits readily produce elements which may be modeled as distributed, as well as the more conventional lumped and active ones.

  17. Scheduling of distributed applications for high performance computing as a service

    NASA Astrophysics Data System (ADS)

    Båk, Slawomir; Czarnecki, Radosław; Deniziak, Stanislaw

    2016-12-01

    In this paper we propose the method for scheduling parallel applications in HPCaaS cloud. Applications are specified as distributed algorithms. The goal of our method is to optimize the cost of resource hiring and minimize the execution time of all incoming applications. Experimental results showed that our method gives significantly better utilization of computational resources than classical scheduling methods.

  18. Variable-Length Message Transmission for Distributed Loop Computer Networks (Part I).

    ERIC Educational Resources Information Center

    Reames, C. C.; Liu, M. T.

    An introduction to the problems of variable-length message transmission in distributed loop computer networks, with a summary of previous accomplishments in the area, begins this technically-oriented document. An improved technique, overcoming some of the inadequacies in presently used techniques, is proposed together with a conceptual model of…

  19. A Survey of Knowledge Management Skills Acquisition in an Online Team-Based Distributed Computing Course

    ERIC Educational Resources Information Center

    Thomas, Jennifer D. E.

    2007-01-01

    This paper investigates students' perceptions of their acquisition of knowledge management skills, namely thinking and team-building skills, resulting from the integration of various resources and technologies into an entirely team-based, online upper level distributed computing (DC) information systems (IS) course. Results seem to indicate that…

  20. Integrating Computing Resources: A Shared Distributed Architecture for Academics and Administrators.

    ERIC Educational Resources Information Center

    Beltrametti, Monica; English, Will

    1994-01-01

    Development and implementation of a shared distributed computing architecture at the University of Alberta (Canada) are described. Aspects discussed include design of the architecture, users' views of the electronic environment, technical and managerial challenges, and the campuswide human infrastructures needed to manage such an integrated…

  1. Challenges and Opportunities of Information Technology in the 90s. Track VIII: Managing Distributed Computing Services.

    ERIC Educational Resources Information Center

    CAUSE, Boulder, CO.

    Six papers from the 1990 CAUSE Conference Track VIII: Managing Distributed Computing are presented. Authors discuss the challenges and opportunities involved in providing user managers with direct access to institutional databases to support their decision making and planning activities. Papers and their authors are as follows: "Rendering an…

  2. Determination and distribution of diesel components in igneous rock surrounding underground diesel storage facilities in Sweden.

    PubMed

    Loren, A; Hallbeck, L; Pedersen, K; Abrahamsson, K

    2001-01-15

    In Sweden, a preliminary investigation of the contamination situation of igneous rock surrounding underground storage facilities of diesel showed that the situation was severe. The diesel was believed to have penetrated into the rock as far as 50 m from the walls of the vaults. Consequently, the risk for contamination of groundwater and recipients could not be neglected. To be able to assess the fate of diesel components in rock, both a suitable drilling method and a method for the determination of a wide range of diesel components were needed. The analytical method presented made it possible to quantify a number of hydrocarbons in rock samples collected with triple-tube core drilling. The samples were dissolved in hydrofluoric acid (HF) with hexane in Teflon centrifuge tubes. After digestion of the rock, extraction of the analytes with hexane was performed. Determination of the individual hydrocarbons present was done with gas chromatography-mass spectrometry (GC-MS). The method was used to study the environmental impact of the underground storage of diesel. The drilling method enabled sampling without contamination risks. Our data show that the major transport of diesel components in rock occurs through fracture systems and that diffusion of diesel through the rock is of minor importance. The results have drastically changed the view of the contamination situation of diesel in the vicinity of storage facilities in hard rock in Sweden.

  3. Distributed Feedback Fiber Laser The Heart of the National Ignition Facility

    SciTech Connect

    Browning, D F; Erbert, G V

    2003-12-01

    The National Ignition Facility (NIF) is a world-class laser fusion machine that is currently under construction at Lawrence Livermore National Laboratory (LLNL). The 192 laser beams that converge on the target at the output of the NIF laser system originate from a low power fiber laser in the Master Oscillator Room (MOR). The MOR is responsible for generating the single pulse that seeds the entire NIF laser system. This single pulse is phase-modulated to add bandwidth, and then amplified and split into 48 separate beam lines all in single-mode polarizing fiber. Before leaving the MOR, each of the 48 output beams are temporally sculpted into high contrast shapes using Arbitrary Waveform Generators. The 48 output beams of the MOR are amplified in the Preamplifier Modules (PAMs), split and amplified again to generate 192 laser beams. The 192 laser beams are frequency converted to the third harmonic and then focused at the center of a 10-meter diameter target chamber. The MOR is an all fiber-based system utilizing highly reliable Telecom-Industry type hardware. The nearly 2,000,000 joules of energy at the output of the NIF laser system starts from a single fiber oscillator that fits in the palm of your hand. This paper describes the design and performance of the laser source that provides the precision light to the National Ignition Facility. Shown below is a simplified diagram illustrating the MOR's basic functions.

  4. Liquid rocket combustion computer model with distributed energy release. DER computer program documentation and user's guide, volume 1

    NASA Technical Reports Server (NTRS)

    Combs, L. P.

    1974-01-01

    A computer program for analyzing rocket engine performance was developed. The program is concerned with the formation, distribution, flow, and combustion of liquid sprays and combustion product gases in conventional rocket combustion chambers. The capabilities of the program to determine the combustion characteristics of the rocket engine are described. Sample data code sheets show the correct sequence and formats for variable values and include notes concerning options to bypass the input of certain data. A seperate list defines the variables and indicates their required dimensions.

  5. Distributed Computing for Signal Processing: Modeling of Asynchronous Parallel Computation. Appendix F. Studies in Parallel Image Processing.

    DTIC Science & Technology

    1984-08-01

    represented in the iimage , tie greater the potential benefits to be derived from SIMI)’ implementation of the process . This section begins with an...AD0A167 317 DISTRIBUTED COMPUTING FOR SIGNRL PROCESSING : MODELING 1.12 OF ASYNCHRONOUS PAR.. (U) PURDUE UNIV LAFAYETTE IN SCHOOL OF ELECTRICRL...Sffllffllflflflf lllI ..hhmhmhmhmh. II.LP NA -. II ’** -u 118 U2- miT 11111125 .h 4 6 MICR ACP’ CHART .............. 71Ph.D. Thesis by: Gie-Hing Lin

  6. Computer simulated building energy consumption for verification of energy conservation measures in network facilities

    NASA Technical Reports Server (NTRS)

    Plankey, B.

    1981-01-01

    A computer program called ECPVER (Energy Consumption Program - Verification) was developed to simulate all energy loads for any number of buildings. The program computes simulated daily, monthly, and yearly energy consumption which can be compared with actual meter readings for the same time period. Such comparison can lead to validation of the model under a variety of conditions, which allows it to be used to predict future energy saving due to energy conservation measures. Predicted energy saving can then be compared with actual saving to verify the effectiveness of those energy conservation changes. This verification procedure is planned to be an important advancement in the Deep Space Network Energy Project, which seeks to reduce energy cost and consumption at all DSN Deep Space Stations.

  7. International seismological datacenter. Database structure, computer facilities, automatic and interactive analysis

    NASA Astrophysics Data System (ADS)

    Barkeby, G.

    1980-11-01

    A data base and data analysis system were designed for receiving and processing seismological data from the WMO Global Telecommunications System. The interface with the system uses a PDP 11/34 computer. Data from the seismic bulletins can be analyzed online or stored for later use. The data base is constructed on a list basis and is a set of seismological data consisting of either reported or calculated parameters. Each parameter is accessible to the user. Programming for the system is in standard FORTRAN except for the communications interface. Record structure is shown with examples of the command language. Computer equipment includes an Amdahl 470/V7, a DEC 10, and a CDC 170-720

  8. Reliability Lessons Learned From GPU Experience With The Titan Supercomputer at Oak Ridge Leadership Computing Facility

    SciTech Connect

    Gallarno, George; Rogers, James H; Maxwell, Don E

    2015-01-01

    The high computational capability of graphics processing units (GPUs) is enabling and driving the scientific discovery process at large-scale. The world s second fastest supercomputer for open science, Titan, has more than 18,000 GPUs that computational scientists use to perform scientific simu- lations and data analysis. Understanding of GPU reliability characteristics, however, is still in its nascent stage since GPUs have only recently been deployed at large-scale. This paper presents a detailed study of GPU errors and their impact on system operations and applications, describing experiences with the 18,688 GPUs on the Titan supercom- puter as well as lessons learned in the process of efficient operation of GPUs at scale. These experiences are helpful to HPC sites which already have large-scale GPU clusters or plan to deploy GPUs in the future.

  9. Methods and apparatuses for information analysis on shared and distributed computing systems

    DOEpatents

    Bohn, Shawn J [Richland, WA; Krishnan, Manoj Kumar [Richland, WA; Cowley, Wendy E [Richland, WA; Nieplocha, Jarek [Richland, WA

    2011-02-22

    Apparatuses and computer-implemented methods for analyzing, on shared and distributed computing systems, information comprising one or more documents are disclosed according to some aspects. In one embodiment, information analysis can comprise distributing one or more distinct sets of documents among each of a plurality of processes, wherein each process performs operations on a distinct set of documents substantially in parallel with other processes. Operations by each process can further comprise computing term statistics for terms contained in each distinct set of documents, thereby generating a local set of term statistics for each distinct set of documents. Still further, operations by each process can comprise contributing the local sets of term statistics to a global set of term statistics, and participating in generating a major term set from an assigned portion of a global vocabulary.

  10. NASA's Information Power Grid: Large Scale Distributed Computing and Data Management

    NASA Technical Reports Server (NTRS)

    Johnston, William E.; Vaziri, Arsi; Hinke, Tom; Tanner, Leigh Ann; Feiereisen, William J.; Thigpen, William; Tang, Harry (Technical Monitor)

    2001-01-01

    Large-scale science and engineering are done through the interaction of people, heterogeneous computing resources, information systems, and instruments, all of which are geographically and organizationally dispersed. The overall motivation for Grids is to facilitate the routine interactions of these resources in order to support large-scale science and engineering. Multi-disciplinary simulations provide a good example of a class of applications that are very likely to require aggregation of widely distributed computing, data, and intellectual resources. Such simulations - e.g. whole system aircraft simulation and whole system living cell simulation - require integrating applications and data that are developed by different teams of researchers frequently in different locations. The research team's are the only ones that have the expertise to maintain and improve the simulation code and/or the body of experimental data that drives the simulations. This results in an inherently distributed computing and data management environment.

  11. PROFEAT Update: A Protein Features Web Server with Added Facility to Compute Network Descriptors for Studying Omics-Derived Networks.

    PubMed

    Zhang, P; Tao, L; Zeng, X; Qin, C; Chen, S Y; Zhu, F; Yang, S Y; Li, Z R; Chen, W P; Chen, Y Z

    2017-02-03

    The studies of biological, disease, and pharmacological networks are facilitated by the systems-level investigations using computational tools. In particular, the network descriptors developed in other disciplines have found increasing applications in the study of the protein, gene regulatory, metabolic, disease, and drug-targeted networks. Facilities are provided by the public web servers for computing network descriptors, but many descriptors are not covered, including those used or useful for biological studies. We upgraded the PROFEAT web server http://bidd2.nus.edu.sg/cgi-bin/profeat2016/main.cgi for computing up to 329 network descriptors and protein-protein interaction descriptors. PROFEAT network descriptors comprehensively describe the topological and connectivity characteristics of unweighted (uniform binding constants and molecular levels), edge-weighted (varying binding constants), node-weighted (varying molecular levels), edge-node-weighted (varying binding constants and molecular levels), and directed (oriented processes) networks. The usefulness of the network descriptors is illustrated by the literature-reported studies of the biological networks derived from the genome, interactome, transcriptome, metabolome, and diseasome profiles.

  12. Computer simulation of random variables and vectors with arbitrary probability distribution laws

    NASA Technical Reports Server (NTRS)

    Bogdan, V. M.

    1981-01-01

    Assume that there is given an arbitrary n-dimensional probability distribution F. A recursive construction is found for a sequence of functions x sub 1 = f sub 1 (U sub 1, ..., U sub n), ..., x sub n = f sub n (U sub 1, ..., U sub n) such that if U sub 1, ..., U sub n are independent random variables having uniform distribution over the open interval (0,1), then the joint distribution of the variables x sub 1, ..., x sub n coincides with the distribution F. Since uniform independent random variables can be well simulated by means of a computer, this result allows one to simulate arbitrary n-random variables if their joint probability distribution is known.

  13. Measurement and simulation of lineal energy distribution at the CERN high energy facility with a tissue equivalent proportional counter.

    PubMed

    Rollet, S; Autischer, M; Beck, P; Latocha, M

    2007-01-01

    The response of a tissue equivalent proportional counter (TEPC) in a mixed radiation field with a neutron energy distribution similar to the radiation field at commercial flight altitudes has been studied. The measurements have been done at the CERN-EU High-Energy Reference Field (CERF) facility where a well-characterised radiation field is available for intercomparison. The TEPC instrument used by the ARC Seibersdorf Research is filled with pure propane gas at low pressure and can be used to determine the lineal energy distribution of the energy deposition in a mass of gas equivalent to a 2 microm diameter volume of unit density tissue, of similar size to the nuclei of biological cells. The linearity of the detector response was checked both in term of dose and dose rate. The effect of dead-time has been corrected. The influence of the detector exposure location and orientation in the radiation field on the dose distribution was also studied as a function of the total dose. The microdosimetric distribution of the absorbed dose as a function of the lineal energy has been obtained and compared with the same distribution simulated with the FLUKA Monte Carlo transport code. The dose equivalent was calculated by folding this distribution with the quality factor as a function of linear energy transfer. The comparison between the measured and simulated distributions show that they are in good agreement. As a result of this study the detector is well characterised, thanks also to the numerical simulations the instrument response is well understood, and it's currently being used onboard the aircrafts to evaluate the dose to aircraft crew caused by cosmic radiation.

  14. Using molecular visualization to explore protein structure and function and enhance student facility with computational tools.

    PubMed

    Terrell, Cassidy R; Listenberger, Laura L

    2017-02-01

    Recognizing that undergraduate students can benefit from analysis of 3D protein structure and function, we have developed a multiweek, inquiry-based molecular visualization project for Biochemistry I students. This project uses a virtual model of cyclooxygenase-1 (COX-1) to guide students through multiple levels of protein structure analysis. The first assignment explores primary structure by generating and examining a protein sequence alignment. Subsequent assignments introduce 3D visualization software to explore secondary, tertiary, and quaternary structure. Students design an inhibitor, based on scrutiny of the enzyme active site, and evaluate the fit of the molecule using computed binding energies. In the last assignment, students introduce a point mutation to model the active site of the related COX-2 enzyme and analyze the impact of the mutation on inhibitor binding. With this project we aim to increase knowledge about, and confidence in using, online databases and computational tools. Here, we share results of our mixed methods pre- and postsurvey demonstrating student gains in knowledge about, and confidence using, online databases and computational tools. © 2017 by The International Union of Biochemistry and Molecular Biology, 2017.

  15. Dynamic Load-Balancing for Distributed Heterogeneous Computing of Parallel CFD Problems

    NASA Technical Reports Server (NTRS)

    Ecer, A.; Chien, Y. P.; Boenisch, T.; Akay, H. U.

    2000-01-01

    The developed methodology is aimed at improving the efficiency of executing block-structured algorithms on parallel, distributed, heterogeneous computers. The basic approach of these algorithms is to divide the flow domain into many sub- domains called blocks, and solve the governing equations over these blocks. Dynamic load balancing problem is defined as the efficient distribution of the blocks among the available processors over a period of several hours of computations. In environments with computers of different architecture, operating systems, CPU speed, memory size, load, and network speed, balancing the loads and managing the communication between processors becomes crucial. Load balancing software tools for mutually dependent parallel processes have been created to efficiently utilize an advanced computation environment and algorithms. These tools are dynamic in nature because of the chances in the computer environment during execution time. More recently, these tools were extended to a second operating system: NT. In this paper, the problems associated with this application will be discussed. Also, the developed algorithms were combined with the load sharing capability of LSF to efficiently utilize workstation clusters for parallel computing. Finally, results will be presented on running a NASA based code ADPAC to demonstrate the developed tools for dynamic load balancing.

  16. Intra-Beam and Touschek Scattering Computations for Beam with Non-Gaussian Longitudinal Distributions

    SciTech Connect

    Xiao, A.; Borland, M.

    2015-01-01

    Both intra-beamscattering (IBS) and the Touschek effect become prominent formulti-bend-achromat- (MBA-) based ultra-low-emittance storage rings. To mitigate the transverse emittance degradation and obtain a reasonably long beam lifetime, a higher harmonic rf cavity (HHC) is often proposed to lengthen the bunch. The use of such a cavity results in a non-gaussian longitudinal distribution. However, common methods for computing IBS and Touschek scattering assume Gaussian distributions. Modifications have been made to several simulation codes that are part of the elegant [1] toolkit to allow these computations for arbitrary longitudinal distributions. After describing thesemodifications, we review the results of detailed simulations for the proposed hybrid seven-bend-achromat (H7BA) upgrade lattice [2] for the Advanced Photon Source.

  17. Application of the Open Software Foundation (OSF)distributed computing environment to global PACS

    NASA Astrophysics Data System (ADS)

    Martinez, Ralph; Alsafadi, Yasser H.; Kim, Jinman

    1994-05-01

    In this paper, we present our approach to developing Global Picture Archiving and Communication System (GPACS) applications using the Open Software Foundation (OSF) Distributed Computing Environment (DCE) services and toolkits. The OSF DCE services include remote procedure calls, naming service, threads service, time service, file management services, and security service. Several OSF DCE toolkits are currently available from computer and software vendors. Designing distributed Global PACS applications using the OSF DCE approach will feature an open architecture, heterogeneity, and technology independence for GPACS remote consultation and diagnosis applications, including synchronized image annotation, and system privacy and security. The applications can communicate through various transport services and communications networks in a Global PACS environment. The use of OSF DCE services for Global PACS will enable us to develop a robust distributed structure and new user services which feature reliability and scalability for Global PACS environments.

  18. Evolution of the ATLAS distributed computing system during the LHC long shutdown

    NASA Astrophysics Data System (ADS)

    Campana, S.; Atlas Collaboration

    2014-06-01

    The ATLAS Distributed Computing project (ADC) was established in 2007 to develop and operate a framework, following the ATLAS computing model, to enable data storage, processing and bookkeeping on top of the Worldwide LHC Computing Grid (WLCG) distributed infrastructure. ADC development has always been driven by operations and this contributed to its success. The system has fulfilled the demanding requirements of ATLAS, daily consolidating worldwide up to 1 PB of data and running more than 1.5 million payloads distributed globally, supporting almost one thousand concurrent distributed analysis users. Comprehensive automation and monitoring minimized the operational manpower required. The flexibility of the system to adjust to operational needs has been important to the success of the ATLAS physics program. The LHC shutdown in 2013-2015 affords an opportunity to improve the system in light of operational experience and scale it to cope with the demanding requirements of 2015 and beyond, most notably a much higher trigger rate and event pileup. We will describe the evolution of the ADC software foreseen during this period. This includes consolidating the existing Production and Distributed Analysis framework (PanDA) and ATLAS Grid Information System (AGIS), together with the development and commissioning of next generation systems for distributed data management (DDM/Rucio) and production (Prodsys-2). We will explain how new technologies such as Cloud Computing and NoSQL databases, which ATLAS investigated as R&D projects in past years, will be integrated in production. Finally, we will describe more fundamental developments such as breaking job-to-data locality by exploiting storage federations and caches, and event level (rather than file or dataset level) workload engines.

  19. A computer code to estimate accidental fire and radioactive airborne releases in nuclear fuel cycle facilities: User's manual for FIRIN

    SciTech Connect

    Chan, M.K.; Ballinger, M.Y.; Owczarski, P.C.

    1989-02-01

    This manual describes the technical bases and use of the computer code FIRIN. This code was developed to estimate the source term release of smoke and radioactive particles from potential fires in nuclear fuel cycle facilities. FIRIN is a product of a broader study, Fuel Cycle Accident Analysis, which Pacific Northwest Laboratory conducted for the US Nuclear Regulatory Commission. The technical bases of FIRIN consist of a nonradioactive fire source term model, compartment effects modeling, and radioactive source term models. These three elements interact with each other in the code affecting the course of the fire. This report also serves as a complete FIRIN user's manual. Included are the FIRIN code description with methods/algorithms of calculation and subroutines, code operating instructions with input requirements, and output descriptions. 40 refs., 5 figs., 31 tabs.

  20. A grid-enabled MPI : message passing in heterogeneous distributed computing systems.

    SciTech Connect

    Foster, I.; Karonis, N. T.

    2000-11-30

    Application development for high-performance distributed computing systems, or computational grids as they are sometimes called, requires grid-enabled tools that hide mundate aspects of the heterogeneous grid environment without compromising performance. As part of an investigation of these issues, they have developed MPICH-G, a grid-enabled implementation of the Message Passing Interface (MPI) that allows a user to run MPI programs across multiple computers at different sites using the same commands that would be used on a parallel computer. This library extends the Argonne MPICH implementation of MPI to use services provided by the globus grid toolkit. In this paper, they describe the MPICH-G implementation and present preliminary performance results.

  1. Can nursing facility staff with minimal education be successfully trained with computer-based training?

    PubMed

    Walker, Bonnie L; Harrington, Susan S

    2004-05-01

    This study compares the effects of computer-based and instructor-led training on long-term care staff with a high school education or less on fire safety knowledge, attitudes, and practices. Findings show that both methods of instruction were effective in increasing staff tests scores from pre- to posttest. Scores of both groups were lower at follow-up three months later but continued to be higher than at pretest. Staff with a high school education increased scores more than those without a high school diploma.

  2. IEEE 1547 National Standard for Interconnecting Distributed Generation: How Could It Help My Facility? Preprint

    SciTech Connect

    Basso, T.; Friedman, N. R.

    2003-11-01

    This article summarizes the purpose, development, and impact of the Institute of Electrical and Electronics Engineers 1547 Standard for Interconnecting Distributed Resources With Electric Power Systems. Also included is a short explanation of supporting standards IEEE P1547.1, P1547.2, and P1547.3.

  3. Facile identification of dual FLT3-Aurora A inhibitors: a computer-guided drug design approach.

    PubMed

    Chang Hsu, Yung; Ke, Yi-Yu; Shiao, Hui-Yi; Lee, Chieh-Chien; Lin, Wen-Hsing; Chen, Chun-Hwa; Yen, Kuei-Jung; Hsu, John T-A; Chang, Chungming; Hsieh, Hsing-Pang

    2014-05-01

    Computer-guided drug design is a powerful tool for drug discovery. Herein we disclose the use of this approach for the discovery of dual FMS-like receptor tyrosine kinase-3 (FLT3)-Aurora A inhibitors against cancer. An Aurora hit compound was selected as a starting point, from which 288 virtual molecules were screened. Subsequently, some of these were synthesized and evaluated for their capacity to inhibit FLT3 and Aurora kinase A. To further enhance FLT3 inhibition, structure-activity relationship studies of the lead compound were conducted through a simplification strategy and bioisosteric replacement, followed by the use of computer-guided drug design to prioritize molecules bearing a variety of different terminal groups in terms of favorable binding energy. Selected compounds were then synthesized, and their bioactivity was evaluated. Of these, one novel inhibitor was found to exhibit excellent inhibition of FLT3 and Aurora kinase A and exert a dramatic antiproliferative effect on MOLM-13 and MV4-11 cells, with an IC50 value of 7 nM. Accordingly, it is considered a highly promising candidate for further development.

  4. CBRAIN: a web-based, distributed computing platform for collaborative neuroimaging research

    PubMed Central

    Sherif, Tarek; Rioux, Pierre; Rousseau, Marc-Etienne; Kassis, Nicolas; Beck, Natacha; Adalat, Reza; Das, Samir; Glatard, Tristan; Evans, Alan C.

    2014-01-01

    The Canadian Brain Imaging Research Platform (CBRAIN) is a web-based collaborative research platform developed in response to the challenges raised by data-heavy, compute-intensive neuroimaging research. CBRAIN offers transparent access to remote data sources, distributed computing sites, and an array of processing and visualization tools within a controlled, secure environment. Its web interface is accessible through any modern browser and uses graphical interface idioms to reduce the technical expertise required to perform large-scale computational analyses. CBRAIN's flexible meta-scheduling has allowed the incorporation of a wide range of heterogeneous computing sites, currently including nine national research High Performance Computing (HPC) centers in Canada, one in Korea, one in Germany, and several local research servers. CBRAIN leverages remote computing cycles and facilitates resource-interoperability in a transparent manner for the end-user. Compared with typical grid solutions available, our architecture was designed to be easily extendable and deployed on existing remote computing sites with no tool modification, administrative intervention, or special software/hardware configuration. As October 2013, CBRAIN serves over 200 users spread across 53 cities in 17 countries. The platform is built as a generic framework that can accept data and analysis tools from any discipline. However, its current focus is primarily on neuroimaging research and studies of neurological diseases such as Autism, Parkinson's and Alzheimer's diseases, Multiple Sclerosis as well as on normal brain structure and development. This technical report presents the CBRAIN Platform, its current deployment and usage and future direction. PMID:24904400

  5. CBRAIN: a web-based, distributed computing platform for collaborative neuroimaging research.

    PubMed

    Sherif, Tarek; Rioux, Pierre; Rousseau, Marc-Etienne; Kassis, Nicolas; Beck, Natacha; Adalat, Reza; Das, Samir; Glatard, Tristan; Evans, Alan C

    2014-01-01

    The Canadian Brain Imaging Research Platform (CBRAIN) is a web-based collaborative research platform developed in response to the challenges raised by data-heavy, compute-intensive neuroimaging research. CBRAIN offers transparent access to remote data sources, distributed computing sites, and an array of processing and visualization tools within a controlled, secure environment. Its web interface is accessible through any modern browser and uses graphical interface idioms to reduce the technical expertise required to perform large-scale computational analyses. CBRAIN's flexible meta-scheduling has allowed the incorporation of a wide range of heterogeneous computing sites, currently including nine national research High Performance Computing (HPC) centers in Canada, one in Korea, one in Germany, and several local research servers. CBRAIN leverages remote computing cycles and facilitates resource-interoperability in a transparent manner for the end-user. Compared with typical grid solutions available, our architecture was designed to be easily extendable and deployed on existing remote computing sites with no tool modification, administrative intervention, or special software/hardware configuration. As October 2013, CBRAIN serves over 200 users spread across 53 cities in 17 countries. The platform is built as a generic framework that can accept data and analysis tools from any discipline. However, its current focus is primarily on neuroimaging research and studies of neurological diseases such as Autism, Parkinson's and Alzheimer's diseases, Multiple Sclerosis as well as on normal brain structure and development. This technical report presents the CBRAIN Platform, its current deployment and usage and future direction.

  6. A distributed, dynamic, parallel computational model: the role of noise in velocity storage

    PubMed Central

    Merfeld, Daniel M.

    2012-01-01

    Networks of neurons perform complex calculations using distributed, parallel computation, including dynamic “real-time” calculations required for motion control. The brain must combine sensory signals to estimate the motion of body parts using imperfect information from noisy neurons. Models and experiments suggest that the brain sometimes optimally minimizes the influence of noise, although it remains unclear when and precisely how neurons perform such optimal computations. To investigate, we created a model of velocity storage based on a relatively new technique–“particle filtering”–that is both distributed and parallel. It extends existing observer and Kalman filter models of vestibular processing by simulating the observer model many times in parallel with noise added. During simulation, the variance of the particles defining the estimator state is used to compute the particle filter gain. We applied our model to estimate one-dimensional angular velocity during yaw rotation, which yielded estimates for the velocity storage time constant, afferent noise, and perceptual noise that matched experimental data. We also found that the velocity storage time constant was Bayesian optimal by comparing the estimate of our particle filter with the estimate of the Kalman filter, which is optimal. The particle filter demonstrated a reduced velocity storage time constant when afferent noise increased, which mimics what is known about aminoglycoside ablation of semicircular canal hair cells. This model helps bridge the gap between parallel distributed neural computation and systems-level behavioral responses like the vestibuloocular response and perception. PMID:22514288

  7. Distributed dynamical computation in neural circuits with propagating coherent activity patterns.

    PubMed

    Gong, Pulin; van Leeuwen, Cees

    2009-12-01

    Activity in neural circuits is spatiotemporally organized. Its spatial organization consists of multiple, localized coherent patterns, or patchy clusters. These patterns propagate across the circuits over time. This type of collective behavior has ubiquitously been observed, both in spontaneous activity and evoked responses; its function, however, has remained unclear. We construct a spatially extended, spiking neural circuit that generates emergent spatiotemporal activity patterns, thereby capturing some of the complexities of the patterns observed empirically. We elucidate what kind of fundamental function these patterns can serve by showing how they process information. As self-sustained objects, localized coherent patterns can signal information by propagating across the neural circuit. Computational operations occur when these emergent patterns interact, or collide with each other. The ongoing behaviors of these patterns naturally embody both distributed, parallel computation and cascaded logical operations. Such distributed computations enable the system to work in an inherently flexible and efficient way. Our work leads us to propose that propagating coherent activity patterns are the underlying primitives with which neural circuits carry out distributed dynamical computation.

  8. Atomistic protein folding simulations on the submillisecond time scale using worldwide distributed computing.

    PubMed

    Pande, Vijay S; Baker, Ian; Chapman, Jarrod; Elmer, Sidney P; Khaliq, Siraj; Larson, Stefan M; Rhee, Young Min; Shirts, Michael R; Snow, Christopher D; Sorin, Eric J; Zagrovic, Bojan

    2003-01-01

    Atomistic simulations of protein folding have the potential to be a great complement to experimental studies, but have been severely limited by the time scales accessible with current computer hardware and algorithms. By employing a worldwide distributed computing network of tens of thousands of PCs and algorithms designed to efficiently utilize this new many-processor, highly heterogeneous, loosely coupled distributed computing paradigm, we have been able to simulate hundreds of microseconds of atomistic molecular dynamics. This has allowed us to directly simulate the folding mechanism and to accurately predict the folding rate of several fast-folding proteins and polymers, including a nonbiological helix, polypeptide alpha-helices, a beta-hairpin, and a three-helix bundle protein from the villin headpiece. Our results demonstrate that one can reach the time scales needed to simulate fast folding using distributed computing, and that potential sets used to describe interatomic interactions are sufficiently accurate to reach the folded state with experimentally validated rates, at least for small proteins.

  9. Microdot - A Four-Bit Microcontroller Designed for Distributed Low-End Computing in Satellites

    NASA Astrophysics Data System (ADS)

    2002-03-01

    Many satellites are an integrated collection of sensors and actuators that require dedicated real-time control. For single processor systems, additional sensors require an increase in computing power and speed to provide the multi-tasking capability needed to service each sensor. Faster processors cost more and consume more power, which taxes a satellite's power resources and may lead to shorter satellite lifetimes. An alternative design approach is a distributed network of small and low power microcontrollers designed for space that handle the computing requirements of each individual sensor and actuator. The design of microdot, a four-bit microcontroller for distributed low-end computing, is presented. The design is based on previous research completed at the Space Electronics Branch, Air Force Research Laboratory (AFRL/VSSE) at Kirtland AFB, NM, and the Air Force Institute of Technology at Wright-Patterson AFB, OH. The Microdot has 29 instructions and a 1K x 4 instruction memory. The distributed computing architecture is based on the Philips Semiconductor I2C Serial Bus Protocol. A prototype was implemented and tested using an Altera Field Programmable Gate Array (FPGA). The prototype was operable to 9.1 MHz. The design was targeted for fabrication in a radiation-hardened-by-design gate-array cell library for the TSMC 0.35 micrometer CMOS process.

  10. Experience of BESIII data production with local cluster and distributed computing model

    NASA Astrophysics Data System (ADS)

    Deng, Z. Y.; Li, W. D.; Lin, L.; Liu, H. M.; Nicholson, C.; Sun, Y. Z.; Zhang, X. M.; Zhemchugov, A.

    2012-12-01

    The BES III detector is a new spectrometer which works on the upgraded high-luminosity collider, BEPCII. The BES III experiment studies physics in the tau-charm energy region from 2 GeV to 4.6 GeV . From 2009 to 2011, BEPCII has produced 106M ψ(2S) events, 225M J/ψ events, 2.8 fb-1 ψ(3770) data, and 500 pb-1 data at 4.01 GeV. All the data samples were processed successfully and many important physics results have been achieved based on these samples. Doing data production correctly and efficiently with limited CPU and storage resources is a big challenge. This paper will describe the implementation of the experiment-specific data production for BESIII in detail, including data calibration with event-level parallel computing model, data reconstruction, inclusive Monte Carlo generation, random trigger background mixing and multi-stream data skimming. Now, with the data sample increasing rapidly, there is a growing demand to move from solely using a local cluster to a more distributed computing model. A distributed computing environment is being set up and expected to go into production use in 2012. The experience of BESIII data production, both with a local cluster and with a distributed computing model, is presented here.

  11. A configurable distributed high-performance computing framework for satellite's TDI-CCD imaging simulation

    NASA Astrophysics Data System (ADS)

    Xue, Bo; Mao, Bingjing; Chen, Xiaomei; Ni, Guoqiang

    2010-11-01

    This paper renders a configurable distributed high performance computing(HPC) framework for TDI-CCD imaging simulation. It uses strategy pattern to adapt multi-algorithms. Thus, this framework help to decrease the simulation time with low expense. Imaging simulation for TDI-CCD mounted on satellite contains four processes: 1) atmosphere leads degradation, 2) optical system leads degradation, 3) electronic system of TDI-CCD leads degradation and re-sampling process, 4) data integration. Process 1) to 3) utilize diversity data-intensity algorithms such as FFT, convolution and LaGrange Interpol etc., which requires powerful CPU. Even uses Intel Xeon X5550 processor, regular series process method takes more than 30 hours for a simulation whose result image size is 1500 * 1462. With literature study, there isn't any mature distributing HPC framework in this field. Here we developed a distribute computing framework for TDI-CCD imaging simulation, which is based on WCF[1], uses Client/Server (C/S) layer and invokes the free CPU resources in LAN. The server pushes the process 1) to 3) tasks to those free computing capacity. Ultimately we rendered the HPC in low cost. In the computing experiment with 4 symmetric nodes and 1 server , this framework reduced about 74% simulation time. Adding more asymmetric nodes to the computing network, the time decreased namely. In conclusion, this framework could provide unlimited computation capacity in condition that the network and task management server are affordable. And this is the brand new HPC solution for TDI-CCD imaging simulation and similar applications.

  12. Advances in the design of a thermomechanical analyzer for fibers. II. Computer facilities and software

    NASA Astrophysics Data System (ADS)

    Noui, L.; Hearle, J. W. S.

    1995-06-01

    PC-based software for the full control of the flexible thermomechanical analyzer (FTMA) for yarns and fibers is described. The software permits a flexible procedure to control three essential parameters of the FTMA, namely tension, twist, and temperature. The computer program allows data acquisition at a programmable rate of up to 62.5 ksamples/s, on-line data display, and on-line data storage. Up to eight channels can be monitored. A circular buffer was used to store unlimited amount of data. For FTMA applications, data were calibrated in terms of Newtons for the tension, degree Celsius for the temperature, and Newton-meter for the torque and can be saved in three different formats, ASCII, LOTUS, or binary. The software is user friendly as it makes use of graphical user interface for motor control and data display. The software is also capable of controlling thermomechanical tests at constant force.

  13. Computer Augmented Video Education.

    ERIC Educational Resources Information Center

    Sousa, M. B.

    1979-01-01

    Describes project CAVE (Computer Augmented Video Education), an ongoing effort at the U.S. Naval Academy to present lecture material on videocassette tape, reinforced by drill and practice through an interactive computer system supported by a 12 channel closed circuit television distribution and production facility. (RAO)

  14. Lilith: A software framework for the rapid development of scalable tools for distributed computing

    SciTech Connect

    Gentile, A.C.; Evensky, D.A.; Armstrong, R.C.

    1997-12-31

    Lilith is a general purpose tool that provides a highly scalable, easy distribution of user code across a heterogeneous computing platform. By handling the details of code distribution and communication, such a framework allows for the rapid development of tools for the use and management of large distributed systems. This speed-up in development not only enables the easy creation of tools as needed but also facilitates the ultimate development of more refined, hard-coded tools as well. Lilith is written in Java, providing platform independence and further facilitating rapid tool development through Object reuse and ease of development. The authors present the user-involved objects in the Lilith Distributed Object System and the Lilith User API. They present an example of tool development, illustrating the user calls, and present results demonstrating Lilith`s scalability.

  15. Hardware Acquisition for the Enhancement of a Fault Tolerance/Distributed Computing Laboratory.

    DTIC Science & Technology

    2014-09-26

    8217.).-..-e:j N/A N/A 4. TITLE (rn Subtitle) S. TYPE OF REPORT & PERIOD COVERED Hardware Acquisition for the Enhancement of aFMa 1 92 a 4 9 Fault Tolerance...Identify by block number) -. Fault tolerance, multiprocessor, distributed data processing, software support, testbed, computer-aided design. R0 A*TRACT r(c...m - evwao lf i ceeawuy and Identify by block number) A VAX 11/780 computer was obtained to provide a software development envi- ronment for the Fault

  16. Distributed-Memory Computing With the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA)

    NASA Technical Reports Server (NTRS)

    Riley, Christopher J.; Cheatwood, F. McNeil

    1997-01-01

    The Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA), a Navier-Stokes solver, has been modified for use in a parallel, distributed-memory environment using the Message-Passing Interface (MPI) standard. A standard domain decomposition strategy is used in which the computational domain is divided into subdomains with each subdomain assigned to a processor. Performance is examined on dedicated parallel machines and a network of desktop workstations. The effect of domain decomposition and frequency of boundary updates on performance and convergence is also examined for several realistic configurations and conditions typical of large-scale computational fluid dynamic analysis.

  17. Evaluation of a computational model used to predict the patellofemoral contact pressure distribution.

    PubMed

    Elias, John J; Wilson, David R; Adamson, Robert; Cosgarea, Andrew J

    2004-03-01

    One possible cause of patellofemoral pain syndrome is excessive lateral force acting on the patella. Although several treatment methods focus on decreasing the lateral force acting on the patella, the relationship between the lateral force and the patellofemoral contact pressure distribution is unclear. A computational model has been developed to determine how loading variations alter the patellofemoral force and pressure distributions for individual knees. The model allows variation in the quadriceps and patella tendon forces, and calculates the predicted contact pressure distribution using the discrete element analysis technique. To characterize the accuracy of the model, four cadaver knees were flexed on a knee simulator with three initial Q-angles, while recording the force and pressure distributions with a pressure sensor. A model of each knee was created from CT data. Using the external force applied to the knee, the geometry of the knee, and the quadriceps origin as input, the pressure distribution was calculated during flexion. Similar trends were noted for the computational and experimental results. The percentage of the total force applied to the lateral cartilage increased with the Q-angle. The maximum contact pressure increased during flexion. The maximum lateral contact pressure increased with the Q-angle for three knees. For the other knee, increasing the Q-angle decreased the maximum lateral pressure. The maximum medial contact pressure decreased as the Q-angle increased. By characterizing the influence of patellofemoral loading on the force and pressure distributions, the computational model could be used to evaluate treatment methods prescribed for patellofemoral pain.

  18. A study of coupled rotor-fuselage vibration with higher harmonic control using a symbolic computing facility

    NASA Technical Reports Server (NTRS)

    Papavassiliou, I.; Venkatesan, C.; Friedmann, P. P.

    1990-01-01

    A fundamental study of vibration prediction and vibration reduction in helicopters using active controls was performed. The nonlinear equations of motion for a coupled rotor/flexible fuselage system have been derived using computer algebra on a special purpose symbolic computing facility. The details of the derivation using the MACSYMA program are described. The trim state and vibratory response of the helicopter are obtained in a single pass by applying the harmonic balance technique and simultaneously satisfying the trim and the vibratory response of the helicopter for all rotor and fuselage degrees of freedom. The influence of the fuselage flexibility on the vibratory response is studied. It is shown that the conventional single frequency higher harmonic control (HHC) capable of reducing either the hub loads or only the fuselage vibrations but not both simultaneously. It is demonstrated that for simultaneous reduction of hub shears and fuselage vibrations a new scheme called multiple higher harmonic control (MHHC) is required. The fundamental aspects of this scheme and its uniqueness are described in detail, providing new insight on vibration reduction in helicopters using HHC.

  19. Lilith: A Java framework for the development of scalable tools for high performance distributed computing platforms

    SciTech Connect

    Evensky, D.A.; Gentile, A.C.; Armstrong, R.C.

    1998-03-19

    Increasingly, high performance computing constitutes the use of very large heterogeneous clusters of machines. The use and maintenance of such clusters are subject to complexities of communication between the machines in a time efficient and secure manner. Lilith is a general purpose tool that provides a highly scalable, secure, and easy distribution of user code across a heterogeneous computing platform. By handling the details of code distribution and communication, such a framework allows for the rapid development of tools for the use and management of large distributed systems. Lilith is written in Java, taking advantage of Java`s unique features of loading and distributing code dynamically, its platform independence, its thread support, and its provision of graphical components to facilitate easy to use resultant tools. The authors describe the use of Lilith in a tool developed for the maintenance of the large distributed cluster at their institution and present details of the Lilith architecture and user API for the general user development of scalable tools.

  20. Computer simulation study of grain boundary and triple junction distributions in microstructures formed by multiple twinning

    SciTech Connect

    Gertsman, V.Y. |; Tangri, K.

    1995-06-01

    Microstructures formed as a result of multiple twinning have been simulated by means of computer modeling. Grain boundary misorientation (character) and triple junction distributions have been studied with the emphasis on the effect of initial texture and multiple twinning process. Although grain boundary distributions are similar in all the microstructures modeled, sharp initial texture leads to a somewhat enhanced amount of {Sigma}3 boundaries and to a considerable increase in the number of triple junctions containing two {Sigma}3 boundaries. The impact of these parameters on the material susceptibility to intergranular crack propagation has been analyzed and implications for grain boundary engineering has been discussed.