Implementing TCP/IP and a socket interface as a server in a message-passing operating system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hipp, E.; Wiltzius, D.

1990-03-01

The UNICOS 4.3BSD network code and socket transport interface are the basis of an explicit network server for NLTSS, a message passing operating system on the Cray YMP. A BSD socket user library provides access to the network server using an RPC mechanism. The advantages of this server methodology are its modularity and extensibility to migrate to future protocol suites (e.g. OSI) and transport interfaces. In addition, the network server is implemented in an explicit multi-tasking environment to take advantage of the Cray YMP multi-processor platform. 19 refs., 5 figs.

Public-channel cryptography based on mutual chaos pass filters.

PubMed

Klein, Einat; Gross, Noam; Kopelowitz, Evi; Rosenbluh, Michael; Khaykovich, Lev; Kinzel, Wolfgang; Kanter, Ido

2006-10-01

We study the mutual coupling of chaotic lasers and observe both experimentally and in numeric simulations that there exists a regime of parameters for which two mutually coupled chaotic lasers establish isochronal synchronization, while a third laser coupled unidirectionally to one of the pair does not synchronize. We then propose a cryptographic scheme, based on the advantage of mutual coupling over unidirectional coupling, where all the parameters of the system are public knowledge. We numerically demonstrate that in such a scheme the two communicating lasers can add a message signal (compressed binary message) to the transmitted coupling signal and recover the message in both directions with high fidelity by using a mutual chaos pass filter procedure. An attacker, however, fails to recover an errorless message even if he amplifies the coupling signal.

Performance analysis of distributed applications using automatic classification of communication inefficiencies

DOEpatents

Vetter, Jeffrey S.

2005-02-01

The method and system described herein presents a technique for performance analysis that helps users understand the communication behavior of their message passing applications. The method and system described herein may automatically classifies individual communication operations and reveal the cause of communication inefficiencies in the application. This classification allows the developer to quickly focus on the culprits of truly inefficient behavior, rather than manually foraging through massive amounts of performance data. Specifically, the method and system described herein trace the message operations of Message Passing Interface (MPI) applications and then classify each individual communication event using a supervised learning technique: decision tree classification. The decision tree may be trained using microbenchmarks that demonstrate both efficient and inefficient communication. Since the method and system described herein adapt to the target system's configuration through these microbenchmarks, they simultaneously automate the performance analysis process and improve classification accuracy. The method and system described herein may improve the accuracy of performance analysis and dramatically reduce the amount of data that users must encounter.

Design and Implementation of an Operations Module for the ARGOS paperless Ship System

DTIC Science & Technology

1989-06-01

A. OPERATIONS STACK SCRIPTS SCRIPTS FOR STACK: operations * BACKGROUND #1: Operations * on openStack hide message box show menuBar pass openStack end... openStack ** CARD #1, BUTTON #1: Up ***** on mouseUp visual effect zoom out go to card id 10931 of stack argos end mouseUp ** CARD #1, BUTTON #2...STACK SCRIPTS SCRIPTS FOR STACK: Reports ** BACKGROUND #1: Operations * on openStack hie message box show menuBar pass openStack end openStack ** CARD #1

Experiences Using OpenMP Based on Compiler Directed Software DSM on a PC Cluster

NASA Technical Reports Server (NTRS)

Hess, Matthias; Jost, Gabriele; Mueller, Matthias; Ruehle, Roland; Biegel, Bryan (Technical Monitor)

2002-01-01

In this work we report on our experiences running OpenMP (message passing) programs on a commodity cluster of PCs (personal computers) running a software distributed shared memory (DSM) system. We describe our test environment and report on the performance of a subset of the NAS (NASA Advanced Supercomputing) Parallel Benchmarks that have been automatically parallelized for OpenMP. We compare the performance of the OpenMP implementations with that of their message passing counterparts and discuss performance differences.

Space Reclamation for Uncoordinated Checkpointing in Message-Passing Systems. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Wang, Yi-Min

1993-01-01

Checkpointing and rollback recovery are techniques that can provide efficient recovery from transient process failures. In a message-passing system, the rollback of a message sender may cause the rollback of the corresponding receiver, and the system needs to roll back to a consistent set of checkpoints called recovery line. If the processes are allowed to take uncoordinated checkpoints, the above rollback propagation may result in the domino effect which prevents recovery line progression. Traditionally, only obsolete checkpoints before the global recovery line can be discarded, and the necessary and sufficient condition for identifying all garbage checkpoints has remained an open problem. A necessary and sufficient condition for achieving optimal garbage collection is derived and it is proved that the number of useful checkpoints is bounded by N(N+1)/2, where N is the number of processes. The approach is based on the maximum-sized antichain model of consistent global checkpoints and the technique of recovery line transformation and decomposition. It is also shown that, for systems requiring message logging to record in-transit messages, the same approach can be used to achieve optimal message log reclamation. As a final topic, a unifying framework is described by considering checkpoint coordination and exploiting piecewise determinism as mechanisms for bounding rollback propagation, and the applicability of the optimal garbage collection algorithm to domino-free recovery protocols is demonstrated.

TravelAid : in-vehicle signing and variable speed limit evaluation

DOT National Transportation Integrated Search

2001-12-01

This report discusses the effectiveness of using variable message signs (VMSs) and in-vehicle traffic advisory systems (IVUs) on a mountainous pass (Snoqualmie Pass on Interstate 90 in Washington State) for changing driver behavior. As part of this p...

Three-pass protocol scheme for bitmap image security by using vernam cipher algorithm

NASA Astrophysics Data System (ADS)

Rachmawati, D.; Budiman, M. A.; Aulya, L.

2018-02-01

Confidentiality, integrity, and efficiency are the crucial aspects of data security. Among the other digital data, image data is too prone to abuse of operation like duplication, modification, etc. There are some data security techniques, one of them is cryptography. The security of Vernam Cipher cryptography algorithm is very dependent on the key exchange process. If the key is leaked, security of this algorithm will collapse. Therefore, a method that minimizes key leakage during the exchange of messages is required. The method which is used, is known as Three-Pass Protocol. This protocol enables message delivery process without the key exchange. Therefore, the sending messages process can reach the receiver safely without fear of key leakage. The system is built by using Java programming language. The materials which are used for system testing are image in size 200×200 pixel, 300×300 pixel, 500×500 pixel, 800×800 pixel and 1000×1000 pixel. The result of experiments showed that Vernam Cipher algorithm in Three-Pass Protocol scheme could restore the original image.

Quantum cluster variational method and message passing algorithms revisited

NASA Astrophysics Data System (ADS)

Domínguez, E.; Mulet, Roberto

2018-02-01

We present a general framework to study quantum disordered systems in the context of the Kikuchi's cluster variational method (CVM). The method relies in the solution of message passing-like equations for single instances or in the iterative solution of complex population dynamic algorithms for an average case scenario. We first show how a standard application of the Kikuchi's CVM can be easily translated to message passing equations for specific instances of the disordered system. We then present an "ad hoc" extension of these equations to a population dynamic algorithm representing an average case scenario. At the Bethe level, these equations are equivalent to the dynamic population equations that can be derived from a proper cavity ansatz. However, at the plaquette approximation, the interpretation is more subtle and we discuss it taking also into account previous results in classical disordered models. Moreover, we develop a formalism to properly deal with the average case scenario using a replica-symmetric ansatz within this CVM for quantum disordered systems. Finally, we present and discuss numerical solutions of the different approximations for the quantum transverse Ising model and the quantum random field Ising model in two-dimensional lattices.

Gene-network inference by message passing

NASA Astrophysics Data System (ADS)

Braunstein, A.; Pagnani, A.; Weigt, M.; Zecchina, R.

2008-01-01

The inference of gene-regulatory processes from gene-expression data belongs to the major challenges of computational systems biology. Here we address the problem from a statistical-physics perspective and develop a message-passing algorithm which is able to infer sparse, directed and combinatorial regulatory mechanisms. Using the replica technique, the algorithmic performance can be characterized analytically for artificially generated data. The algorithm is applied to genome-wide expression data of baker's yeast under various environmental conditions. We find clear cases of combinatorial control, and enrichment in common functional annotations of regulated genes and their regulators.

Optimal mapping of neural-network learning on message-passing multicomputers

NASA Technical Reports Server (NTRS)

Chu, Lon-Chan; Wah, Benjamin W.

1992-01-01

A minimization of learning-algorithm completion time is sought in the present optimal-mapping study of the learning process in multilayer feed-forward artificial neural networks (ANNs) for message-passing multicomputers. A novel approximation algorithm for mappings of this kind is derived from observations of the dominance of a parallel ANN algorithm over its communication time. Attention is given to both static and dynamic mapping schemes for systems with static and dynamic background workloads, as well as to experimental results obtained for simulated mappings on multicomputers with dynamic background workloads.

Trace-Driven Debugging of Message Passing Programs

NASA Technical Reports Server (NTRS)

Frumkin, Michael; Hood, Robert; Lopez, Louis; Bailey, David (Technical Monitor)

1998-01-01

In this paper we report on features added to a parallel debugger to simplify the debugging of parallel message passing programs. These features include replay, setting consistent breakpoints based on interprocess event causality, a parallel undo operation, and communication supervision. These features all use trace information collected during the execution of the program being debugged. We used a number of different instrumentation techniques to collect traces. We also implemented trace displays using two different trace visualization systems. The implementation was tested on an SGI Power Challenge cluster and a network of SGI workstations.

Advanced Numerical Techniques of Performance Evaluation. Volume 2

DTIC Science & Technology

1990-06-01

multiprocessor environment. This factor is determined by the overhead of the primitives available in the system ( semaphore , monitor , or message... semaphore , monitor , or message passing primitives ) and U the programming ability of the user who implements the simulation. " t,: the sequential...Warp Operating System . i Pro" lftevcnth ACM Symposum on Operating Systems Princlplcs, pages 77 9:3, Auslin, TX, Nov wicr 1987. ACM. [121 D.R. Jefferson

Message passing with a limited number of DMA byte counters

DOEpatents

Blocksome, Michael [Rochester, MN; Chen, Dong [Croton on Hudson, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Kumar, Sameer [White Plains, NY; Parker, Jeffrey J [Rochester, MN

2011-10-04

A method for passing messages in a parallel computer system constructed as a plurality of compute nodes interconnected as a network where each compute node includes a DMA engine but includes only a limited number of byte counters for tracking a number of bytes that are sent or received by the DMA engine, where the byte counters may be used in shared counter or exclusive counter modes of operation. The method includes using rendezvous protocol, a source compute node deterministically sending a request to send (RTS) message with a single RTS descriptor using an exclusive injection counter to track both the RTS message and message data to be sent in association with the RTS message, to a destination compute node such that the RTS descriptor indicates to the destination compute node that the message data will be adaptively routed to the destination node. Using one DMA FIFO at the source compute node, the RTS descriptors are maintained for rendezvous messages destined for the destination compute node to ensure proper message data ordering thereat. Using a reception counter at a DMA engine, the destination compute node tracks reception of the RTS and associated message data and sends a clear to send (CTS) message to the source node in a rendezvous protocol form of a remote get to accept the RTS message and message data and processing the remote get (CTS) by the source compute node DMA engine to provide the message data to be sent.

Passing crisis and emergency risk communications: the effects of communication channel, information type, and repetition.

PubMed

Edworthy, Judy; Hellier, Elizabeth; Newbold, Lex; Titchener, Kirsteen

2015-05-01

Three experiments explore several factors which influence information transmission when warning messages are passed from person to person. In Experiment 1, messages were passed down chains of participants using five different modes of communication. Written communication channels resulted in more accurate message transmission than verbal. In addition, some elements of the message endured further down the chain than others. Experiment 2 largely replicated these effects and also demonstrated that simple repetition of a message eliminated differences between written and spoken communication. In a final field experiment, chains of participants passed information however they wanted to, with the proviso that half of the chains could not use telephones. Here, the lack of ability to use a telephone did not affect accuracy, but did slow down the speed of transmission from the recipient of the message to the last person in the chain. Implications of the findings for crisis and emergency risk communication are discussed. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

The serial message-passing schedule for LDPC decoding algorithms

NASA Astrophysics Data System (ADS)

Liu, Mingshan; Liu, Shanshan; Zhou, Yuan; Jiang, Xue

2015-12-01

The conventional message-passing schedule for LDPC decoding algorithms is the so-called flooding schedule. It has the disadvantage that the updated messages cannot be used until next iteration, thus reducing the convergence speed . In this case, the Layered Decoding algorithm (LBP) based on serial message-passing schedule is proposed. In this paper the decoding principle of LBP algorithm is briefly introduced, and then proposed its two improved algorithms, the grouped serial decoding algorithm (Grouped LBP) and the semi-serial decoding algorithm .They can improve LBP algorithm's decoding speed while maintaining a good decoding performance.

A real-time MPEG software decoder using a portable message-passing library

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwong, Man Kam; Tang, P.T. Peter; Lin, Biquan

1995-12-31

We present a real-time MPEG software decoder that uses message-passing libraries such as MPL, p4 and MPI. The parallel MPEG decoder currently runs on the IBM SP system but can be easil ported to other parallel machines. This paper discusses our parallel MPEG decoding algorithm as well as the parallel programming environment under which it uses. Several technical issues are discussed, including balancing of decoding speed, memory limitation, 1/0 capacities, and optimization of MPEG decoding components. This project shows that a real-time portable software MPEG decoder is feasible in a general-purpose parallel machine.

Performance Comparison of a Matrix Solver on a Heterogeneous Network Using Two Implementations of MPI: MPICH and LAM

NASA Technical Reports Server (NTRS)

Phillips, Jennifer K.

1995-01-01

Two of the current and most popular implementations of the Message-Passing Standard, Message Passing Interface (MPI), were contrasted: MPICH by Argonne National Laboratory, and LAM by the Ohio Supercomputer Center at Ohio State University. A parallel skyline matrix solver was adapted to be run in a heterogeneous environment using MPI. The Message-Passing Interface Forum was held in May 1994 which lead to a specification of library functions that implement the message-passing model of parallel communication. LAM, which creates it's own environment, is more robust in a highly heterogeneous network. MPICH uses the environment native to the machine architecture. While neither of these free-ware implementations provides the performance of native message-passing or vendor's implementations, MPICH begins to approach that performance on the SP-2. The machines used in this study were: IBM RS6000, 3 Sun4, SGI, and the IBM SP-2. Each machine is unique and a few machines required specific modifications during the installation. When installed correctly, both implementations worked well with only minor problems.

Extensions to the Parallel Real-Time Artificial Intelligence System (PRAIS) for fault-tolerant heterogeneous cycle-stealing reasoning

NASA Technical Reports Server (NTRS)

Goldstein, David

1991-01-01

Extensions to an architecture for real-time, distributed (parallel) knowledge-based systems called the Parallel Real-time Artificial Intelligence System (PRAIS) are discussed. PRAIS strives for transparently parallelizing production (rule-based) systems, even under real-time constraints. PRAIS accomplished these goals (presented at the first annual C Language Integrated Production System (CLIPS) conference) by incorporating a dynamic task scheduler, operating system extensions for fact handling, and message-passing among multiple copies of CLIPS executing on a virtual blackboard. This distributed knowledge-based system tool uses the portability of CLIPS and common message-passing protocols to operate over a heterogeneous network of processors. Results using the original PRAIS architecture over a network of Sun 3's, Sun 4's and VAX's are presented. Mechanisms using the producer-consumer model to extend the architecture for fault-tolerance and distributed truth maintenance initiation are also discussed.

Multiple node remote messaging

DOEpatents

Blumrich, Matthias A.; Chen, Dong; Gara, Alan G.; Giampapa, Mark E.; Heidelberger, Philip; Ohmacht, Martin; Salapura, Valentina; Steinmacher-Burow, Burkhard; Vranas, Pavlos

2010-08-31

A method for passing remote messages in a parallel computer system formed as a network of interconnected compute nodes includes that a first compute node (A) sends a single remote message to a remote second compute node (B) in order to control the remote second compute node (B) to send at least one remote message. The method includes various steps including controlling a DMA engine at first compute node (A) to prepare the single remote message to include a first message descriptor and at least one remote message descriptor for controlling the remote second compute node (B) to send at least one remote message, including putting the first message descriptor into an injection FIFO at the first compute node (A) and sending the single remote message and the at least one remote message descriptor to the second compute node (B).

Benchmarking hypercube hardware and software

NASA Technical Reports Server (NTRS)

Grunwald, Dirk C.; Reed, Daniel A.

1986-01-01

It was long a truism in computer systems design that balanced systems achieve the best performance. Message passing parallel processors are no different. To quantify the balance of a hypercube design, an experimental methodology was developed and the associated suite of benchmarks was applied to several existing hypercubes. The benchmark suite includes tests of both processor speed in the absence of internode communication and message transmission speed as a function of communication patterns.

Asbestos: Securing Untrusted Software with Interposition

DTIC Science & Technology

2005-09-01

consistent intelligible interfaces to different types of resource. Message-based operating systems, such as Accent, Amoeba, Chorus, L4 , Spring...control on self-authenticating capabilities, precluding policies that restrict delegation. L4 uses a strict hierarchy of interpositions, useful for...the OS de- sign space amenable to secure application construction. Similar effects might be possible with message-passing microkernels , or unwieldy

Message Passing on GPUs

NASA Astrophysics Data System (ADS)

Stuart, J. A.

2011-12-01

This paper explores the challenges in implementing a message passing interface usable on systems with data-parallel processors, and more specifically GPUs. As a case study, we design and implement the ``DCGN'' API on NVIDIA GPUs that is similar to MPI and allows full access to the underlying architecture. We introduce the notion of data-parallel thread-groups as a way to map resources to MPI ranks. We use a method that also allows the data-parallel processors to run autonomously from user-written CPU code. In order to facilitate communication, we use a sleep-based polling system to store and retrieve messages. Unlike previous systems, our method provides both performance and flexibility. By running a test suite of applications with different communication requirements, we find that a tolerable amount of overhead is incurred, somewhere between one and five percent depending on the application, and indicate the locations where this overhead accumulates. We conclude that with innovations in chipsets and drivers, this overhead will be mitigated and provide similar performance to typical CPU-based MPI implementations while providing fully-dynamic communication.

Principles for problem aggregation and assignment in medium scale multiprocessors

NASA Technical Reports Server (NTRS)

Nicol, David M.; Saltz, Joel H.

1987-01-01

One of the most important issues in parallel processing is the mapping of workload to processors. This paper considers a large class of problems having a high degree of potential fine grained parallelism, and execution requirements that are either not predictable, or are too costly to predict. The main issues in mapping such a problem onto medium scale multiprocessors are those of aggregation and assignment. We study a method of parameterized aggregation that makes few assumptions about the workload. The mapping of aggregate units of work onto processors is uniform, and exploits locality of workload intensity to balance the unknown workload. In general, a finer aggregate granularity leads to a better balance at the price of increased communication/synchronization costs; the aggregation parameters can be adjusted to find a reasonable granularity. The effectiveness of this scheme is demonstrated on three model problems: an adaptive one-dimensional fluid dynamics problem with message passing, a sparse triangular linear system solver on both a shared memory and a message-passing machine, and a two-dimensional time-driven battlefield simulation employing message passing. Using the model problems, the tradeoffs are studied between balanced workload and the communication/synchronization costs. Finally, an analytical model is used to explain why the method balances workload and minimizes the variance in system behavior.

Parallel and fault-tolerant algorithms for hypercube multiprocessors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aykanat, C.

1988-01-01

Several techniques for increasing the performance of parallel algorithms on distributed-memory message-passing multi-processor systems are investigated. These techniques are effectively implemented for the parallelization of the Scaled Conjugate Gradient (SCG) algorithm on a hypercube connected message-passing multi-processor. Significant performance improvement is achieved by using these techniques. The SCG algorithm is used for the solution phase of an FE modeling system. Almost linear speed-up is achieved, and it is shown that hypercube topology is scalable for an FE class of problem. The SCG algorithm is also shown to be suitable for vectorization, and near supercomputer performance is achieved on a vectormore » hypercube multiprocessor by exploiting both parallelization and vectorization. Fault-tolerance issues for the parallel SCG algorithm and for the hypercube topology are also addressed.« less

Message passing with parallel queue traversal

DOEpatents

Underwood, Keith D [Albuquerque, NM; Brightwell, Ronald B [Albuquerque, NM; Hemmert, K Scott [Albuquerque, NM

2012-05-01

In message passing implementations, associative matching structures are used to permit list entries to be searched in parallel fashion, thereby avoiding the delay of linear list traversal. List management capabilities are provided to support list entry turnover semantics and priority ordering semantics.

Gauge-free cluster variational method by maximal messages and moment matching.

PubMed

Domínguez, Eduardo; Lage-Castellanos, Alejandro; Mulet, Roberto; Ricci-Tersenghi, Federico

2017-04-01

We present an implementation of the cluster variational method (CVM) as a message passing algorithm. The kind of message passing algorithm used for CVM, usually named generalized belief propagation (GBP), is a generalization of the belief propagation algorithm in the same way that CVM is a generalization of the Bethe approximation for estimating the partition function. However, the connection between fixed points of GBP and the extremal points of the CVM free energy is usually not a one-to-one correspondence because of the existence of a gauge transformation involving the GBP messages. Our contribution is twofold. First, we propose a way of defining messages (fields) in a generic CVM approximation, such that messages arrive on a given region from all its ancestors, and not only from its direct parents, as in the standard parent-to-child GBP. We call this approach maximal messages. Second, we focus on the case of binary variables, reinterpreting the messages as fields enforcing the consistency between the moments of the local (marginal) probability distributions. We provide a precise rule to enforce all consistencies, avoiding any redundancy, that would otherwise lead to a gauge transformation on the messages. This moment matching method is gauge free, i.e., it guarantees that the resulting GBP is not gauge invariant. We apply our maximal messages and moment matching GBP to obtain an analytical expression for the critical temperature of the Ising model in general dimensions at the level of plaquette CVM. The values obtained outperform Bethe estimates, and are comparable with loop corrected belief propagation equations. The method allows for a straightforward generalization to disordered systems.

Gauge-free cluster variational method by maximal messages and moment matching

NASA Astrophysics Data System (ADS)

Domínguez, Eduardo; Lage-Castellanos, Alejandro; Mulet, Roberto; Ricci-Tersenghi, Federico

2017-04-01

We present an implementation of the cluster variational method (CVM) as a message passing algorithm. The kind of message passing algorithm used for CVM, usually named generalized belief propagation (GBP), is a generalization of the belief propagation algorithm in the same way that CVM is a generalization of the Bethe approximation for estimating the partition function. However, the connection between fixed points of GBP and the extremal points of the CVM free energy is usually not a one-to-one correspondence because of the existence of a gauge transformation involving the GBP messages. Our contribution is twofold. First, we propose a way of defining messages (fields) in a generic CVM approximation, such that messages arrive on a given region from all its ancestors, and not only from its direct parents, as in the standard parent-to-child GBP. We call this approach maximal messages. Second, we focus on the case of binary variables, reinterpreting the messages as fields enforcing the consistency between the moments of the local (marginal) probability distributions. We provide a precise rule to enforce all consistencies, avoiding any redundancy, that would otherwise lead to a gauge transformation on the messages. This moment matching method is gauge free, i.e., it guarantees that the resulting GBP is not gauge invariant. We apply our maximal messages and moment matching GBP to obtain an analytical expression for the critical temperature of the Ising model in general dimensions at the level of plaquette CVM. The values obtained outperform Bethe estimates, and are comparable with loop corrected belief propagation equations. The method allows for a straightforward generalization to disordered systems.

Interprocess Communication in Highly Distributed Systems - A Workshop Report - 20 to 22, November 1978.

DTIC Science & Technology

1979-12-01

Links between processes can be aLlocated strictLy to controL functions. In fact, the degree of separation of control and data is an important research is...delays or Loss of control messages. Cognoscienti agree that message-passing IPC schemes are equivalent in "power" to schemes which employ shared...THEORETICAL WORK Page 55 SECTION 6 THEORETICAL WORK 6.1 WORKING GRUP JIM REP.OR STRUCTURE of Discussion: Distributed system without central (or any) control

Chaos synchronization communication using extremely unsymmetrical bidirectional injections.

PubMed

Zhang, Wei Li; Pan, Wei; Luo, Bin; Zou, Xi Hua; Wang, Meng Yao; Zhou, Zhi

2008-02-01

Chaos synchronization and message transmission between two semiconductor lasers with extremely unsymmetrical bidirectional injections (EUBIs) are discussed. By using EUBIs, synchronization is realized through injection locking. Numerical results show that if the laser subjected to strong injection serves as the receiver, chaos pass filtering (CPF) of the system is similar to that of unidirectional coupled systems. Moreover, if the other laser serves as the receiver, a stronger CPF can be obtained. Finally, we demonstrate that messages can be extracted successfully from either of the two transmission directions of the system.

Neighbourhood-consensus message passing and its potentials in image processing applications

NASA Astrophysics Data System (ADS)

Ružic, Tijana; Pižurica, Aleksandra; Philips, Wilfried

2011-03-01

In this paper, a novel algorithm for inference in Markov Random Fields (MRFs) is presented. Its goal is to find approximate maximum a posteriori estimates in a simple manner by combining neighbourhood influence of iterated conditional modes (ICM) and message passing of loopy belief propagation (LBP). We call the proposed method neighbourhood-consensus message passing because a single joint message is sent from the specified neighbourhood to the central node. The message, as a function of beliefs, represents the agreement of all nodes within the neighbourhood regarding the labels of the central node. This way we are able to overcome the disadvantages of reference algorithms, ICM and LBP. On one hand, more information is propagated in comparison with ICM, while on the other hand, the huge amount of pairwise interactions is avoided in comparison with LBP by working with neighbourhoods. The idea is related to the previously developed iterated conditional expectations algorithm. Here we revisit it and redefine it in a message passing framework in a more general form. The results on three different benchmarks demonstrate that the proposed technique can perform well both for binary and multi-label MRFs without any limitations on the model definition. Furthermore, it manifests improved performance over related techniques either in terms of quality and/or speed.

Foundations for a healthy future.

PubMed

Riley, R; Green, J; Willis, S; Soden, E; Rushby, C; Postle, D; Wakeling, S

1998-01-01

Health promotion activities with children and young people are important as they take messages about health seriously and can be influential in spreading messages about healthy living to their friends and families. Child health professionals have an important role to play in passing on messages of positive health to children and young people. Peer education is a useful way of passing on messages about health to young people. This article shares examples of three health promotion projects with children in a community trust, looking at asthma, sex education and testicular examination.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Painter, J.; McCormick, P.; Krogh, M.

This paper presents the ACL (Advanced Computing Lab) Message Passing Library. It is a high throughput, low latency communications library, based on Thinking Machines Corp.`s CMMD, upon which message passing applications can be built. The library has been implemented on the Cray T3D, Thinking Machines CM-5, SGI workstations, and on top of PVM.

Parallelization of KENO-Va Monte Carlo code

NASA Astrophysics Data System (ADS)

Ramón, Javier; Peña, Jorge

1995-07-01

KENO-Va is a code integrated within the SCALE system developed by Oak Ridge that solves the transport equation through the Monte Carlo Method. It is being used at the Consejo de Seguridad Nuclear (CSN) to perform criticality calculations for fuel storage pools and shipping casks. Two parallel versions of the code: one for shared memory machines and other for distributed memory systems using the message-passing interface PVM have been generated. In both versions the neutrons of each generation are tracked in parallel. In order to preserve the reproducibility of the results in both versions, advanced seeds for random numbers were used. The CONVEX C3440 with four processors and shared memory at CSN was used to implement the shared memory version. A FDDI network of 6 HP9000/735 was employed to implement the message-passing version using proprietary PVM. The speedup obtained was 3.6 in both cases.

A Down-to-Earth Educational Operating System for Up-in-the-Cloud Many-Core Architectures

ERIC Educational Resources Information Center

Ziwisky, Michael; Persohn, Kyle; Brylow, Dennis

2013-01-01

We present "Xipx," the first port of a major educational operating system to a processor in the emerging class of many-core architectures. Through extensions to the proven Embedded Xinu operating system, Xipx gives students hands-on experience with system programming in a distributed message-passing environment. We expose the software primitives…

WinHPC System Programming | High-Performance Computing | NREL

Science.gov Websites

Programming WinHPC System Programming Learn how to build and run an MPI (message passing interface (mpi.h) and library (msmpi.lib) are. To build from the command line, run... Start > Intel Software Development Tools > Intel C++ Compiler Professional... > C++ Build Environment for applications running

Commanding and Controlling Satellite Clusters (IEEE Intelligent Systems, November/December 2000)

DTIC Science & Technology

2000-01-01

real - time operating system , a message-passing OS well suited for distributed...ground Flight processors ObjectAgent RTOS SCL RTOS RDMS Space command language Real - time operating system Rational database management system TS-21 RDMS...engineer with Princeton Satellite Systems. She is working with others to develop ObjectAgent software to run on the OSE Real Time Operating System .

Ultrascalable petaflop parallel supercomputer

DOEpatents

Blumrich, Matthias A [Ridgefield, CT; Chen, Dong [Croton On Hudson, NY; Chiu, George [Cross River, NY; Cipolla, Thomas M [Katonah, NY; Coteus, Paul W [Yorktown Heights, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Hall, Shawn [Pleasantville, NY; Haring, Rudolf A [Cortlandt Manor, NY; Heidelberger, Philip [Cortlandt Manor, NY; Kopcsay, Gerard V [Yorktown Heights, NY; Ohmacht, Martin [Yorktown Heights, NY; Salapura, Valentina [Chappaqua, NY; Sugavanam, Krishnan [Mahopac, NY; Takken, Todd [Brewster, NY

2010-07-20

A massively parallel supercomputer of petaOPS-scale includes node architectures based upon System-On-a-Chip technology, where each processing node comprises a single Application Specific Integrated Circuit (ASIC) having up to four processing elements. The ASIC nodes are interconnected by multiple independent networks that optimally maximize the throughput of packet communications between nodes with minimal latency. The multiple networks may include three high-speed networks for parallel algorithm message passing including a Torus, collective network, and a Global Asynchronous network that provides global barrier and notification functions. These multiple independent networks may be collaboratively or independently utilized according to the needs or phases of an algorithm for optimizing algorithm processing performance. The use of a DMA engine is provided to facilitate message passing among the nodes without the expenditure of processing resources at the node.

Reducing Interprocessor Dependence in Recoverable Distributed Shared Memory

NASA Technical Reports Server (NTRS)

Janssens, Bob; Fuchs, W. Kent

1994-01-01

Checkpointing techniques in parallel systems use dependency tracking and/or message logging to ensure that a system rolls back to a consistent state. Traditional dependency tracking in distributed shared memory (DSM) systems is expensive because of high communication frequency. In this paper we show that, if designed correctly, a DSM system only needs to consider dependencies due to the transfer of blocks of data, resulting in reduced dependency tracking overhead and reduced potential for rollback propagation. We develop an ownership timestamp scheme to tolerate the loss of block state information and develop a passive server model of execution where interactions between processors are considered atomic. With our scheme, dependencies are significantly reduced compared to the traditional message-passing model.

Information Management and Learning in Computer Conferences: Coping with Irrelevant and Unconnected Messages.

ERIC Educational Resources Information Center

Schwan, Stephan; Straub, Daniela; Hesse, Friedrich W.

2002-01-01

Describes a study of computer conferencing where learners interacted over the course of four log-in sessions to acquire the knowledge sufficient to pass a learning test. Studied the number of messages irrelevant to the topic, explicit threading of messages, reading times of relevant messages, and learning outcomes. (LRW)

Identifying an influential spreader from a single seed in complex networks via a message-passing approach

NASA Astrophysics Data System (ADS)

Min, Byungjoon

2018-01-01

Identifying the most influential spreaders is one of outstanding problems in physics of complex systems. So far, many approaches have attempted to rank the influence of nodes but there is still the lack of accuracy to single out influential spreaders. Here, we directly tackle the problem of finding important spreaders by solving analytically the expected size of epidemic outbreaks when spreading originates from a single seed. We derive and validate a theory for calculating the size of epidemic outbreaks with a single seed using a message-passing approach. In addition, we find that the probability to occur epidemic outbreaks is highly dependent on the location of the seed but the size of epidemic outbreaks once it occurs is insensitive to the seed. We also show that our approach can be successfully adapted into weighted networks.

The design of multi-core DSP parallel model based on message passing and multi-level pipeline

NASA Astrophysics Data System (ADS)

Niu, Jingyu; Hu, Jian; He, Wenjing; Meng, Fanrong; Li, Chuanrong

2017-10-01

Currently, the design of embedded signal processing system is often based on a specific application, but this idea is not conducive to the rapid development of signal processing technology. In this paper, a parallel processing model architecture based on multi-core DSP platform is designed, and it is mainly suitable for the complex algorithms which are composed of different modules. This model combines the ideas of multi-level pipeline parallelism and message passing, and summarizes the advantages of the mainstream model of multi-core DSP (the Master-Slave model and the Data Flow model), so that it has better performance. This paper uses three-dimensional image generation algorithm to validate the efficiency of the proposed model by comparing with the effectiveness of the Master-Slave and the Data Flow model.

Generalized hypercube structures and hyperswitch communication network

NASA Technical Reports Server (NTRS)

Young, Steven D.

1992-01-01

This paper discusses an ongoing study that uses a recent development in communication control technology to implement hybrid hypercube structures. These architectures are similar to binary hypercubes, but they also provide added connectivity between the processors. This added connectivity increases communication reliability while decreasing the latency of interprocessor message passing. Because these factors directly determine the speed that can be obtained by multiprocessor systems, these architectures are attractive for applications such as remote exploration and experimentation, where high performance and ultrareliability are required. This paper describes and enumerates these architectures and discusses how they can be implemented with a modified version of the hyperswitch communication network (HCN). The HCN is analyzed because it has three attractive features that enable these architectures to be effective: speed, fault tolerance, and the ability to pass multiple messages simultaneously through the same hyperswitch controller.

What it Takes to Get Passed On: Message Content, Style, and Structure as Predictors of Retransmission in the Boston Marathon Bombing Response

PubMed Central

Sutton, Jeannette; Gibson, C. Ben; Spiro, Emma S.; League, Cedar; Fitzhugh, Sean M.; Butts, Carter T.

2015-01-01

Message retransmission is a central aspect of information diffusion. In a disaster context, the passing on of official warning messages by members of the public also serves as a behavioral indicator of message salience, suggesting that particular messages are (or are not) perceived by the public to be both noteworthy and valuable enough to share with others. This study provides the first examination of terse message retransmission of official warning messages in response to a domestic terrorist attack, the Boston Marathon Bombing in 2013. Using messages posted from public officials’ Twitter accounts that were active during the period of the Boston Marathon bombing and manhunt, we examine the features of messages that are associated with their retransmission. We focus on message content, style, and structure, as well as the networked relationships of message senders to answer the question: what characteristics of a terse message sent under conditions of imminent threat predict its retransmission among members of the public? We employ a negative binomial model to examine how message characteristics affect message retransmission. We find that, rather than any single effect dominating the process, retransmission of official Tweets during the Boston bombing response was jointly influenced by various message content, style, and sender characteristics. These findings suggest the need for more work that investigates impact of multiple factors on the allocation of attention and on message retransmission during hazard events. PMID:26295584

The Edge-Disjoint Path Problem on Random Graphs by Message-Passing.

PubMed

Altarelli, Fabrizio; Braunstein, Alfredo; Dall'Asta, Luca; De Bacco, Caterina; Franz, Silvio

2015-01-01

We present a message-passing algorithm to solve a series of edge-disjoint path problems on graphs based on the zero-temperature cavity equations. Edge-disjoint paths problems are important in the general context of routing, that can be defined by incorporating under a unique framework both traffic optimization and total path length minimization. The computation of the cavity equations can be performed efficiently by exploiting a mapping of a generalized edge-disjoint path problem on a star graph onto a weighted maximum matching problem. We perform extensive numerical simulations on random graphs of various types to test the performance both in terms of path length minimization and maximization of the number of accommodated paths. In addition, we test the performance on benchmark instances on various graphs by comparison with state-of-the-art algorithms and results found in the literature. Our message-passing algorithm always outperforms the others in terms of the number of accommodated paths when considering non trivial instances (otherwise it gives the same trivial results). Remarkably, the largest improvement in performance with respect to the other methods employed is found in the case of benchmarks with meshes, where the validity hypothesis behind message-passing is expected to worsen. In these cases, even though the exact message-passing equations do not converge, by introducing a reinforcement parameter to force convergence towards a sub optimal solution, we were able to always outperform the other algorithms with a peak of 27% performance improvement in terms of accommodated paths. On random graphs, we numerically observe two separated regimes: one in which all paths can be accommodated and one in which this is not possible. We also investigate the behavior of both the number of paths to be accommodated and their minimum total length.

The Edge-Disjoint Path Problem on Random Graphs by Message-Passing

PubMed Central

2015-01-01

We present a message-passing algorithm to solve a series of edge-disjoint path problems on graphs based on the zero-temperature cavity equations. Edge-disjoint paths problems are important in the general context of routing, that can be defined by incorporating under a unique framework both traffic optimization and total path length minimization. The computation of the cavity equations can be performed efficiently by exploiting a mapping of a generalized edge-disjoint path problem on a star graph onto a weighted maximum matching problem. We perform extensive numerical simulations on random graphs of various types to test the performance both in terms of path length minimization and maximization of the number of accommodated paths. In addition, we test the performance on benchmark instances on various graphs by comparison with state-of-the-art algorithms and results found in the literature. Our message-passing algorithm always outperforms the others in terms of the number of accommodated paths when considering non trivial instances (otherwise it gives the same trivial results). Remarkably, the largest improvement in performance with respect to the other methods employed is found in the case of benchmarks with meshes, where the validity hypothesis behind message-passing is expected to worsen. In these cases, even though the exact message-passing equations do not converge, by introducing a reinforcement parameter to force convergence towards a sub optimal solution, we were able to always outperform the other algorithms with a peak of 27% performance improvement in terms of accommodated paths. On random graphs, we numerically observe two separated regimes: one in which all paths can be accommodated and one in which this is not possible. We also investigate the behavior of both the number of paths to be accommodated and their minimum total length. PMID:26710102

Scalable Optical-Fiber Communication Networks

NASA Technical Reports Server (NTRS)

Chow, Edward T.; Peterson, John C.

1993-01-01

Scalable arbitrary fiber extension network (SAFEnet) is conceptual fiber-optic communication network passing digital signals among variety of computers and input/output devices at rates from 200 Mb/s to more than 100 Gb/s. Intended for use with very-high-speed computers and other data-processing and communication systems in which message-passing delays must be kept short. Inherent flexibility makes it possible to match performance of network to computers by optimizing configuration of interconnections. In addition, interconnections made redundant to provide tolerance to faults.

Belief propagation decoding of quantum channels by passing quantum messages

NASA Astrophysics Data System (ADS)

Renes, Joseph M.

2017-07-01

The belief propagation (BP) algorithm is a powerful tool in a wide range of disciplines from statistical physics to machine learning to computational biology, and is ubiquitous in decoding classical error-correcting codes. The algorithm works by passing messages between nodes of the factor graph associated with the code and enables efficient decoding of the channel, in some cases even up to the Shannon capacity. Here we construct the first BP algorithm which passes quantum messages on the factor graph and is capable of decoding the classical-quantum channel with pure state outputs. This gives explicit decoding circuits whose number of gates is quadratic in the code length. We also show that this decoder can be modified to work with polar codes for the pure state channel and as part of a decoder for transmitting quantum information over the amplitude damping channel. These represent the first explicit capacity-achieving decoders for non-Pauli channels.

LCAMP: Location Constrained Approximate Message Passing for Compressed Sensing MRI

PubMed Central

Sung, Kyunghyun; Daniel, Bruce L; Hargreaves, Brian A

2016-01-01

Iterative thresholding methods have been extensively studied as faster alternatives to convex optimization methods for solving large-sized problems in compressed sensing. A novel iterative thresholding method called LCAMP (Location Constrained Approximate Message Passing) is presented for reducing computational complexity and improving reconstruction accuracy when a nonzero location (or sparse support) constraint can be obtained from view shared images. LCAMP modifies the existing approximate message passing algorithm by replacing the thresholding stage with a location constraint, which avoids adjusting regularization parameters or thresholding levels. This work is first compared with other conventional reconstruction methods using random 1D signals and then applied to dynamic contrast-enhanced breast MRI to demonstrate the excellent reconstruction accuracy (less than 2% absolute difference) and low computation time (5 - 10 seconds using Matlab) with highly undersampled 3D data (244 × 128 × 48; overall reduction factor = 10). PMID:23042658

Efficient Tracing for On-the-Fly Space-Time Displays in a Debugger for Message Passing Programs

NASA Technical Reports Server (NTRS)

Hood, Robert; Matthews, Gregory

2001-01-01

In this work we describe the implementation of a practical mechanism for collecting and displaying trace information in a debugger for message passing programs. We introduce a trace format that is highly compressible while still providing information adequate for debugging purposes. We make the mechanism convenient for users to access by incorporating the trace collection in a set of wrappers for the MPI (message passing interface) communication library. We implement several debugger operations that use the trace display: consistent stoplines, undo, and rollback. They all are implemented using controlled replay, which executes at full speed in target processes until the appropriate position in the computation is reached. They provide convenient mechanisms for getting to places in the execution where the full power of a state-based debugger can be brought to bear on isolating communication errors.

Statistical analysis of loopy belief propagation in random fields

NASA Astrophysics Data System (ADS)

Yasuda, Muneki; Kataoka, Shun; Tanaka, Kazuyuki

2015-10-01

Loopy belief propagation (LBP), which is equivalent to the Bethe approximation in statistical mechanics, is a message-passing-type inference method that is widely used to analyze systems based on Markov random fields (MRFs). In this paper, we propose a message-passing-type method to analytically evaluate the quenched average of LBP in random fields by using the replica cluster variation method. The proposed analytical method is applicable to general pairwise MRFs with random fields whose distributions differ from each other and can give the quenched averages of the Bethe free energies over random fields, which are consistent with numerical results. The order of its computational cost is equivalent to that of standard LBP. In the latter part of this paper, we describe the application of the proposed method to Bayesian image restoration, in which we observed that our theoretical results are in good agreement with the numerical results for natural images.

High Performance Programming Using Explicit Shared Memory Model on Cray T3D1

NASA Technical Reports Server (NTRS)

Simon, Horst D.; Saini, Subhash; Grassi, Charles

1994-01-01

The Cray T3D system is the first-phase system in Cray Research, Inc.'s (CRI) three-phase massively parallel processing (MPP) program. This system features a heterogeneous architecture that closely couples DEC's Alpha microprocessors and CRI's parallel-vector technology, i.e., the Cray Y-MP and Cray C90. An overview of the Cray T3D hardware and available programming models is presented. Under Cray Research adaptive Fortran (CRAFT) model four programming methods (data parallel, work sharing, message-passing using PVM, and explicit shared memory model) are available to the users. However, at this time data parallel and work sharing programming models are not available to the user community. The differences between standard PVM and CRI's PVM are highlighted with performance measurements such as latencies and communication bandwidths. We have found that the performance of neither standard PVM nor CRI s PVM exploits the hardware capabilities of the T3D. The reasons for the bad performance of PVM as a native message-passing library are presented. This is illustrated by the performance of NAS Parallel Benchmarks (NPB) programmed in explicit shared memory model on Cray T3D. In general, the performance of standard PVM is about 4 to 5 times less than obtained by using explicit shared memory model. This degradation in performance is also seen on CM-5 where the performance of applications using native message-passing library CMMD on CM-5 is also about 4 to 5 times less than using data parallel methods. The issues involved (such as barriers, synchronization, invalidating data cache, aligning data cache etc.) while programming in explicit shared memory model are discussed. Comparative performance of NPB using explicit shared memory programming model on the Cray T3D and other highly parallel systems such as the TMC CM-5, Intel Paragon, Cray C90, IBM-SP1, etc. is presented.

Low-pass filtering of noisy Schlumberger sounding curves. Part I: Theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patella, D.

1986-02-01

A contribution is given to the solution of the problem of filtering noise-degraded Schlumberger sounding curves. It is shown that the transformation to the pole-pole system is actually a smoothing operation that filters high-frequency noise. In the case of residual noise contamination in the transformed pole-pole curve, it is demonstrated that a subsequent application of a conventional rectangular low-pass filter, with cut-off frequency not less than the right-hand frequency limit of the main message pass-band, may satisfactorily solve the problem by leaving a pole-pole curve available for interpretation. An attempt is also made to understand the essential peculiarities of themore » pole-pole system as far as penetration depth, resolving power and selectivity power are concerned.« less

Interactive Supercomputing’s Star-P Platform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edelman, Alan; Husbands, Parry; Leibman, Steve

2006-09-19

The thesis of this extended abstract is simple. High productivity comes from high level infrastructures. To measure this, we introduce a methodology that goes beyond the tradition of timing software in serial and tuned parallel modes. We perform a classroom productivity study involving 29 students who have written a homework exercise in a low level language (MPI message passing) and a high level language (Star-P with MATLAB client). Our conclusions indicate what perhaps should be of little surprise: (1) the high level language is always far easier on the students than the low level language. (2) The early versions ofmore » the high level language perform inadequately compared to the tuned low level language, but later versions substantially catch up. Asymptotically, the analogy must hold that message passing is to high level language parallel programming as assembler is to high level environments such as MATLAB, Mathematica, Maple, or even Python. We follow the Kepner method that correctly realizes that traditional speedup numbers without some discussion of the human cost of reaching these numbers can fail to reflect the true human productivity cost of high performance computing. Traditional data compares low level message passing with serial computation. With the benefit of a high level language system in place, in our case Star-P running with MATLAB client, and with the benefit of a large data pool: 29 students, each running the same code ten times on three evolutions of the same platform, we can methodically demonstrate the productivity gains. To date we are not aware of any high level system as extensive and interoperable as Star-P, nor are we aware of an experiment of this kind performed with this volume of data.« less

The Raid distributed database system

NASA Technical Reports Server (NTRS)

Bhargava, Bharat; Riedl, John

1989-01-01

Raid, a robust and adaptable distributed database system for transaction processing (TP), is described. Raid is a message-passing system, with server processes on each site to manage concurrent processing, consistent replicated copies during site failures, and atomic distributed commitment. A high-level layered communications package provides a clean location-independent interface between servers. The latest design of the package delivers messages via shared memory in a configuration with several servers linked into a single process. Raid provides the infrastructure to investigate various methods for supporting reliable distributed TP. Measurements on TP and server CPU time are presented, along with data from experiments on communications software, consistent replicated copy control during site failures, and concurrent distributed checkpointing. A software tool for evaluating the implementation of TP algorithms in an operating-system kernel is proposed.

Increasing the Operational Value of Event Messages

NASA Technical Reports Server (NTRS)

Li, Zhenping; Savkli, Cetin; Smith, Dan

2003-01-01

Assessing the health of a space mission has traditionally been performed using telemetry analysis tools. Parameter values are compared to known operational limits and are plotted over various time periods. This presentation begins with the notion that there is an incredible amount of untapped information contained within the mission s event message logs. Through creative advancements in message handling tools, the event message logs can be used to better assess spacecraft and ground system status and to highlight and report on conditions not readily apparent when messages are evaluated one-at-a-time during a real-time pass. Work in this area is being funded as part of a larger NASA effort at the Goddard Space Flight Center to create component-based, middleware-based, standards-based general purpose ground system architecture referred to as GMSEC - the GSFC Mission Services Evolution Center. The new capabilities and operational concepts for event display, event data analyses and data mining are being developed by Lockheed Martin and the new subsystem has been named GREAT - the GMSEC Reusable Event Analysis Toolkit. Planned for use on existing and future missions, GREAT has the potential to increase operational efficiency in areas of problem detection and analysis, general status reporting, and real-time situational awareness.

The graphical brain: Belief propagation and active inference

PubMed Central

Friston, Karl J.; Parr, Thomas; de Vries, Bert

2018-01-01

This paper considers functional integration in the brain from a computational perspective. We ask what sort of neuronal message passing is mandated by active inference—and what implications this has for context-sensitive connectivity at microscopic and macroscopic levels. In particular, we formulate neuronal processing as belief propagation under deep generative models. Crucially, these models can entertain both discrete and continuous states, leading to distinct schemes for belief updating that play out on the same (neuronal) architecture. Technically, we use Forney (normal) factor graphs to elucidate the requisite message passing in terms of its form and scheduling. To accommodate mixed generative models (of discrete and continuous states), one also has to consider link nodes or factors that enable discrete and continuous representations to talk to each other. When mapping the implicit computational architecture onto neuronal connectivity, several interesting features emerge. For example, Bayesian model averaging and comparison, which link discrete and continuous states, may be implemented in thalamocortical loops. These and other considerations speak to a computational connectome that is inherently state dependent and self-organizing in ways that yield to a principled (variational) account. We conclude with simulations of reading that illustrate the implicit neuronal message passing, with a special focus on how discrete (semantic) representations inform, and are informed by, continuous (visual) sampling of the sensorium. Author Summary This paper considers functional integration in the brain from a computational perspective. We ask what sort of neuronal message passing is mandated by active inference—and what implications this has for context-sensitive connectivity at microscopic and macroscopic levels. In particular, we formulate neuronal processing as belief propagation under deep generative models that can entertain both discrete and continuous states. This leads to distinct schemes for belief updating that play out on the same (neuronal) architecture. Technically, we use Forney (normal) factor graphs to characterize the requisite message passing, and link this formal characterization to canonical microcircuits and extrinsic connectivity in the brain. PMID:29417960

Parallelized direct execution simulation of message-passing parallel programs

NASA Technical Reports Server (NTRS)

Dickens, Phillip M.; Heidelberger, Philip; Nicol, David M.

1994-01-01

As massively parallel computers proliferate, there is growing interest in findings ways by which performance of massively parallel codes can be efficiently predicted. This problem arises in diverse contexts such as parallelizing computers, parallel performance monitoring, and parallel algorithm development. In this paper we describe one solution where one directly executes the application code, but uses a discrete-event simulator to model details of the presumed parallel machine such as operating system and communication network behavior. Because this approach is computationally expensive, we are interested in its own parallelization specifically the parallelization of the discrete-event simulator. We describe methods suitable for parallelized direct execution simulation of message-passing parallel programs, and report on the performance of such a system, Large Application Parallel Simulation Environment (LAPSE), we have built on the Intel Paragon. On all codes measured to date, LAPSE predicts performance well typically within 10 percent relative error. Depending on the nature of the application code, we have observed low slowdowns (relative to natively executing code) and high relative speedups using up to 64 processors.

CSlib, a library to couple codes via Client/Server messaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plimpton, Steve

The CSlib is a small, portable library which enables two (or more) independent simulation codes to be coupled, by exchanging messages with each other. Both codes link to the library when they are built, and can them communicate with each other as they run. The messages contain data or instructions that the two codes send back-and-forth to each other. The messaging can take place via files, sockets, or MPI. The latter is a standard distributed-memory message-passing library.

Evaluation Metrics for the Paragon XP/S-15

NASA Technical Reports Server (NTRS)

Traversat, Bernard; McNab, David; Nitzberg, Bill; Fineberg, Sam; Blaylock, Bruce T. (Technical Monitor)

1993-01-01

On February 17th 1993, the Numerical Aerodynamic Simulation (NAS) facility located at the NASA Ames Research Center installed a 224 node Intel Paragon XP/S-15 system. After its installation, the Paragon was found to be in a very immature state and was unable to support a NAS users' workload, composed of a wide range of development and production activities. As a first step towards addressing this problem, we implemented a set of metrics to objectively monitor the system as operating system and hardware upgrades were installed. The metrics were designed to measure four aspects of the system that we consider essential to support our workload: availability, utilization, functionality, and performance. This report presents the metrics collected from February 1993 to August 1993. Since its installation, the Paragon availability has improved from a low of 15% uptime to a high of 80%, while its utilization has remained low. Functionality and performance have improved from merely running one of the NAS Parallel Benchmarks to running all of them faster (between 1 and 2 times) than on the iPSC/860. In spite of the progress accomplished, fundamental limitations of the Paragon operating system are restricting the Paragon from supporting the NAS workload. The maximum operating system message passing (NORMA IPC) bandwidth was measured at 11 Mbytes/s, well below the peak hardware bandwidth (175 Mbytes/s), limiting overall virtual memory and Unix services (i.e. Disk and HiPPI I/O) performance. The high NX application message passing latency (184 microns), three times than on the iPSC/860, was found to significantly degrade performance of applications relying on small message sizes. The amount of memory available for an application was found to be approximately 10 Mbytes per node, indicating that the OS is taking more space than anticipated (6 Mbytes per node).

Six degrees of depolarization. Comment on "Network science of biological systems at different scales: A review" by Marko Gosak et al.

NASA Astrophysics Data System (ADS)

Wedgwood, Kyle C. A.; Satin, Leslie S.

2018-03-01

In 1967, the social psychologist Stanley Milgram asked how many intermediates would be required for a letter from participants in various U.S. states to be received by a contact in Boston, given that participants were given only basic information about the contact, and were instructed only to pass along the message to someone that might know the intended recipient [27]. The surprising answer was that, in spite of the social and geographical distances covered, on average, only 6 people were required for the message to reach its intended target.

A distributed infrastructure for publishing VO services: an implementation

NASA Astrophysics Data System (ADS)

Cepparo, Francesco; Scagnetto, Ivan; Molinaro, Marco; Smareglia, Riccardo

2016-07-01

This contribution describes both the design and the implementation details of a new solution for publishing VO services, enlightening its maintainable, distributed, modular and scalable architecture. Indeed, the new publisher is multithreaded and multiprocess. Multiple instances of the modules can run on different machines to ensure high performance and high availability, and this will be true both for the interface modules of the services and the back end data access ones. The system uses message passing to let its components communicate through an AMQP message broker that can itself be distributed to provide better scalability and availability.

Charon Message-Passing Toolkit for Scientific Computations

NASA Technical Reports Server (NTRS)

VanderWijngaart, Rob F.; Yan, Jerry (Technical Monitor)

2000-01-01

Charon is a library, callable from C and Fortran, that aids the conversion of structured-grid legacy codes-such as those used in the numerical computation of fluid flows-into parallel, high- performance codes. Key are functions that define distributed arrays, that map between distributed and non-distributed arrays, and that allow easy specification of common communications on structured grids. The library is based on the widely accepted MPI message passing standard. We present an overview of the functionality of Charon, and some representative results.

A new control system hardware architecture for the Hobby-Eberly Telescope prime focus instrument package

NASA Astrophysics Data System (ADS)

Ramiller, Chuck; Taylor, Trey; Rafferty, Tom H.; Cornell, Mark E.; Rafal, Marc; Savage, Richard

2010-07-01

The Hobby-Eberly Telescope (HET) will be undergoing a major upgrade as a precursor to the HET Dark Energy Experiment (HETDEX‡). As part of this upgrade, the Prime Focus Instrument Package (PFIP) will be replaced with a new design that supports the HETDEX requirements along with the existing suite of instruments and anticipated future additions. This paper describes the new PFIP control system hardware plus the physical constraints and other considerations driving its design. Because of its location at the top end of the telescope, the new PFIP is essentially a stand-alone remote automation island containing over a dozen subsystems. Within the PFIP, motion controllers and modular IO systems are interconnected using a local Controller Area Network (CAN) bus and the CANOpen messaging protocol. CCD cameras that are equipped only with USB 2.0 interfaces are connected to a local Ethernet network via small microcontroller boards running embedded Linux. Links to ground-level systems pass through a 100 m cable bundle and use Ethernet over fiber optic cable exclusively; communications are either direct or through Ethernet/CAN gateways that pass CANOpen messages transparently. All of the control system hardware components are commercially available, designed for rugged industrial applications, and rated for extended temperature operation down to -10 °C.

Performance of hybrid programming models for multiscale cardiac simulations: preparing for petascale computation.

PubMed

Pope, Bernard J; Fitch, Blake G; Pitman, Michael C; Rice, John J; Reumann, Matthias

2011-10-01

Future multiscale and multiphysics models that support research into human disease, translational medical science, and treatment can utilize the power of high-performance computing (HPC) systems. We anticipate that computationally efficient multiscale models will require the use of sophisticated hybrid programming models, mixing distributed message-passing processes [e.g., the message-passing interface (MPI)] with multithreading (e.g., OpenMP, Pthreads). The objective of this study is to compare the performance of such hybrid programming models when applied to the simulation of a realistic physiological multiscale model of the heart. Our results show that the hybrid models perform favorably when compared to an implementation using only the MPI and, furthermore, that OpenMP in combination with the MPI provides a satisfactory compromise between performance and code complexity. Having the ability to use threads within MPI processes enables the sophisticated use of all processor cores for both computation and communication phases. Considering that HPC systems in 2012 will have two orders of magnitude more cores than what was used in this study, we believe that faster than real-time multiscale cardiac simulations can be achieved on these systems.

Simulated Raman Spectral Analysis of Organic Molecules

NASA Astrophysics Data System (ADS)

Lu, Lu

The advent of the laser technology in the 1960s solved the main difficulty of Raman spectroscopy, resulted in simplified Raman spectroscopy instruments and also boosted the sensitivity of the technique. Up till now, Raman spectroscopy is commonly used in chemistry and biology. As vibrational information is specific to the chemical bonds, Raman spectroscopy provides fingerprints to identify the type of molecules in the sample. In this thesis, we simulate the Raman Spectrum of organic and inorganic materials by General Atomic and Molecular Electronic Structure System (GAMESS) and Gaussian, two computational codes that perform several general chemistry calculations. We run these codes on our CPU-based high-performance cluster (HPC). Through the message passing interface (MPI), a standardized and portable message-passing system which can make the codes run in parallel, we are able to decrease the amount of time for computation and increase the sizes and capacities of systems simulated by the codes. From our simulations, we will set up a database that allows search algorithm to quickly identify N-H and O-H bonds in different materials. Our ultimate goal is to analyze and identify the spectra of organic matter compositions from meteorites and compared these spectra with terrestrial biologically-produced amino acids and residues.

Petascale computation performance of lightweight multiscale cardiac models using hybrid programming models.

PubMed

Pope, Bernard J; Fitch, Blake G; Pitman, Michael C; Rice, John J; Reumann, Matthias

2011-01-01

Future multiscale and multiphysics models must use the power of high performance computing (HPC) systems to enable research into human disease, translational medical science, and treatment. Previously we showed that computationally efficient multiscale models will require the use of sophisticated hybrid programming models, mixing distributed message passing processes (e.g. the message passing interface (MPI)) with multithreading (e.g. OpenMP, POSIX pthreads). The objective of this work is to compare the performance of such hybrid programming models when applied to the simulation of a lightweight multiscale cardiac model. Our results show that the hybrid models do not perform favourably when compared to an implementation using only MPI which is in contrast to our results using complex physiological models. Thus, with regards to lightweight multiscale cardiac models, the user may not need to increase programming complexity by using a hybrid programming approach. However, considering that model complexity will increase as well as the HPC system size in both node count and number of cores per node, it is still foreseeable that we will achieve faster than real time multiscale cardiac simulations on these systems using hybrid programming models.

Couriers in the Inca Empire: Getting Your Message Across. [Lesson Plan].

ERIC Educational Resources Information Center

2002

This lesson shows how the Inca communicated across the vast stretches of their mountain realm, the largest empire of the pre-industrial world. The lesson explains how couriers carried messages along mountain-ridge roads, up and down stone steps, and over chasm-spanning footbridges. It states that couriers could pass a message from Quito (Ecuador)…

Object-oriented knowledge representation for expert systems

NASA Technical Reports Server (NTRS)

Scott, Stephen L.

1991-01-01

Object oriented techniques have generated considerable interest in the Artificial Intelligence (AI) community in recent years. This paper discusses an approach for representing expert system knowledge using classes, objects, and message passing. The implementation is in version 4.3 of NASA's C Language Integrated Production System (CLIPS), an expert system tool that does not provide direct support for object oriented design. The method uses programmer imposed conventions and keywords to structure facts, and rules to provide object oriented capabilities.

Inference in the brain: Statistics flowing in redundant population codes

PubMed Central

Pitkow, Xaq; Angelaki, Dora E

2017-01-01

It is widely believed that the brain performs approximate probabilistic inference to estimate causal variables in the world from ambiguous sensory data. To understand these computations, we need to analyze how information is represented and transformed by the actions of nonlinear recurrent neural networks. We propose that these probabilistic computations function by a message-passing algorithm operating at the level of redundant neural populations. To explain this framework, we review its underlying concepts, including graphical models, sufficient statistics, and message-passing, and then describe how these concepts could be implemented by recurrently connected probabilistic population codes. The relevant information flow in these networks will be most interpretable at the population level, particularly for redundant neural codes. We therefore outline a general approach to identify the essential features of a neural message-passing algorithm. Finally, we argue that to reveal the most important aspects of these neural computations, we must study large-scale activity patterns during moderately complex, naturalistic behaviors. PMID:28595050

Parallel Ray Tracing Using the Message Passing Interface

DTIC Science & Technology

2007-09-01

software is available for lens design and for general optical systems modeling. It tends to be designed to run on a single processor and can be very...Cameron, Senior Member, IEEE Abstract—Ray-tracing software is available for lens design and for general optical systems modeling. It tends to be designed to...National Aeronautics and Space Administration (NASA), optical ray tracing, parallel computing, parallel pro- cessing, prime numbers, ray tracing

Control Transfer in Operating System Kernels

DTIC Science & Technology

1994-05-13

microkernel system that runs less code in the kernel address space. To realize the performance benefit of allocating stacks in unmapped kseg0 memory, the...review how I modified the Mach 3.0 kernel to use continuations. Because of Mach’s message-passing microkernel structure, interprocess communication was...critical control transfer paths, deeply- nested call chains are undesirable in any case because of the function call overhead. 4.1.3 Microkernel Operating

Cooperative Data Sharing: Simple Support for Clusters of SMP Nodes

NASA Technical Reports Server (NTRS)

DiNucci, David C.; Balley, David H. (Technical Monitor)

1997-01-01

Libraries like PVM and MPI send typed messages to allow for heterogeneous cluster computing. Lower-level libraries, such as GAM, provide more efficient access to communication by removing the need to copy messages between the interface and user space in some cases. still lower-level interfaces, such as UNET, get right down to the hardware level to provide maximum performance. However, these are all still interfaces for passing messages from one process to another, and have limited utility in a shared-memory environment, due primarily to the fact that message passing is just another term for copying. This drawback is made more pertinent by today's hybrid architectures (e.g. clusters of SMPs), where it is difficult to know beforehand whether two communicating processes will share memory. As a result, even portable language tools (like HPF compilers) must either map all interprocess communication, into message passing with the accompanying performance degradation in shared memory environments, or they must check each communication at run-time and implement the shared-memory case separately for efficiency. Cooperative Data Sharing (CDS) is a single user-level API which abstracts all communication between processes into the sharing and access coordination of memory regions, in a model which might be described as "distributed shared messages" or "large-grain distributed shared memory". As a result, the user programs to a simple latency-tolerant abstract communication specification which can be mapped efficiently to either a shared-memory or message-passing based run-time system, depending upon the available architecture. Unlike some distributed shared memory interfaces, the user still has complete control over the assignment of data to processors, the forwarding of data to its next likely destination, and the queuing of data until it is needed, so even the relatively high latency present in clusters can be accomodated. CDS does not require special use of an MMU, which can add overhead to some DSM systems, and does not require an SPMD programming model. unlike some message-passing interfaces, CDS allows the user to implement efficient demand-driven applications where processes must "fight" over data, and does not perform copying if processes share memory and do not attempt concurrent writes. CDS also supports heterogeneous computing, dynamic process creation, handlers, and a very simple thread-arbitration mechanism. Additional support for array subsections is currently being considered. The CDS1 API, which forms the kernel of CDS, is built primarily upon only 2 communication primitives, one process initiation primitive, and some data translation (and marshalling) routines, memory allocation routines, and priority control routines. The entire current collection of 28 routines provides enough functionality to implement most (or all) of MPI 1 and 2, which has a much larger interface consisting of hundreds of routines. still, the API is small enough to consider integrating into standard os interfaces for handling inter-process communication in a network-independent way. This approach would also help to solve many of the problems plaguing other higher-level standards such as MPI and PVM which must, in some cases, "play OS" to adequately address progress and process control issues. The CDS2 API, a higher level of interface roughly equivalent in functionality to MPI and to be built entirely upon CDS1, is still being designed. It is intended to add support for the equivalent of communicators, reduction and other collective operations, process topologies, additional support for process creation, and some automatic memory management. CDS2 will not exactly match MPI, because the copy-free semantics of communication from CDS1 will be supported. CDS2 application programs will be free to carefully also use CDS1. CDS1 has been implemented on networks of workstations running unmodified Unix-based operating systems, using UDP/IP and vendor-supplied high- performance locks. Although its inter-node performance is currently unimpressive due to rudimentary implementation technique, it even now outperforms highly-optimized MPI implementation on intra-node communication due to its support for non-copy communication. The similarity of the CDS1 architecture to that of other projects such as UNET and TRAP suggests that the inter-node performance can be increased significantly to surpass MPI or PVM, and it may be possible to migrate some of its functionality to communication controllers.

Approximate message passing for nonconvex sparse regularization with stability and asymptotic analysis

NASA Astrophysics Data System (ADS)

Sakata, Ayaka; Xu, Yingying

2018-03-01

We analyse a linear regression problem with nonconvex regularization called smoothly clipped absolute deviation (SCAD) under an overcomplete Gaussian basis for Gaussian random data. We propose an approximate message passing (AMP) algorithm considering nonconvex regularization, namely SCAD-AMP, and analytically show that the stability condition corresponds to the de Almeida-Thouless condition in spin glass literature. Through asymptotic analysis, we show the correspondence between the density evolution of SCAD-AMP and the replica symmetric (RS) solution. Numerical experiments confirm that for a sufficiently large system size, SCAD-AMP achieves the optimal performance predicted by the replica method. Through replica analysis, a phase transition between replica symmetric and replica symmetry breaking (RSB) region is found in the parameter space of SCAD. The appearance of the RS region for a nonconvex penalty is a significant advantage that indicates the region of smooth landscape of the optimization problem. Furthermore, we analytically show that the statistical representation performance of the SCAD penalty is better than that of \

Temporal Proof Methodologies for Real-Time Systems,

DTIC Science & Technology

1990-09-01

real time systems that communicate either through shared variables or by message passing and real time issues such as time-outs, process priorities (interrupts) and process scheduling. The authors exhibit two styles for the specification of real - time systems . While the first approach uses bounded versions of temporal operators the second approach allows explicit references to time through a special clock variable. Corresponding to two styles of specification the authors present and compare two fundamentally different proof

Parallel-Processing Test Bed For Simulation Software

NASA Technical Reports Server (NTRS)

Blech, Richard; Cole, Gary; Townsend, Scott

1996-01-01

Second-generation Hypercluster computing system is multiprocessor test bed for research on parallel algorithms for simulation in fluid dynamics, electromagnetics, chemistry, and other fields with large computational requirements but relatively low input/output requirements. Built from standard, off-shelf hardware readily upgraded as improved technology becomes available. System used for experiments with such parallel-processing concepts as message-passing algorithms, debugging software tools, and computational steering. First-generation Hypercluster system described in "Hypercluster Parallel Processor" (LEW-15283).

Concurrent hypercube system with improved message passing

NASA Technical Reports Server (NTRS)

Peterson, John C. (Inventor); Tuazon, Jesus O. (Inventor); Lieberman, Don (Inventor); Pniel, Moshe (Inventor)

1989-01-01

A network of microprocessors, or nodes, are interconnected in an n-dimensional cube having bidirectional communication links along the edges of the n-dimensional cube. Each node's processor network includes an I/O subprocessor dedicated to controlling communication of message packets along a bidirectional communication link with each end thereof terminating at an I/O controlled transceiver. Transmit data lines are directly connected from a local FIFO through each node's communication link transceiver. Status and control signals from the neighboring nodes are delivered over supervisory lines to inform the local node that the neighbor node's FIFO is empty and the bidirectional link between the two nodes is idle for data communication. A clocking line between neighbors, clocks a message into an empty FIFO at a neighbor's node and vica versa. Either neighbor may acquire control over the bidirectional communication link at any time, and thus each node has circuitry for checking whether or not the communication link is busy or idle, and whether or not the receive FIFO is empty. Likewise, each node can empty its own FIFO and in turn deliver a status signal to a neighboring node indicating that the local FIFO is empty. The system includes features of automatic message rerouting, block message transfer and automatic parity checking and generation.

Mark 4A antenna control system data handling architecture study

NASA Technical Reports Server (NTRS)

Briggs, H. C.; Eldred, D. B.

1991-01-01

A high-level review was conducted to provide an analysis of the existing architecture used to handle data and implement control algorithms for NASA's Deep Space Network (DSN) antennas and to make system-level recommendations for improving this architecture so that the DSN antennas can support the ever-tightening requirements of the next decade and beyond. It was found that the existing system is seriously overloaded, with processor utilization approaching 100 percent. A number of factors contribute to this overloading, including dated hardware, inefficient software, and a message-passing strategy that depends on serial connections between machines. At the same time, the system has shortcomings and idiosyncrasies that require extensive human intervention. A custom operating system kernel and an obscure programming language exacerbate the problems and should be modernized. A new architecture is presented that addresses these and other issues. Key features of the new architecture include a simplified message passing hierarchy that utilizes a high-speed local area network, redesign of particular processing function algorithms, consolidation of functions, and implementation of the architecture in modern hardware and software using mainstream computer languages and operating systems. The system would also allow incremental hardware improvements as better and faster hardware for such systems becomes available, and costs could potentially be low enough that redundancy would be provided economically. Such a system could support DSN requirements for the foreseeable future, though thorough consideration must be given to hard computational requirements, porting existing software functionality to the new system, and issues of fault tolerance and recovery.

VAC: Versatile Advection Code

NASA Astrophysics Data System (ADS)

Tóth, Gábor; Keppens, Rony

2012-07-01

The Versatile Advection Code (VAC) is a freely available general hydrodynamic and magnetohydrodynamic simulation software that works in 1, 2 or 3 dimensions on Cartesian and logically Cartesian grids. VAC runs on any Unix/Linux system with a Fortran 90 (or 77) compiler and Perl interpreter. VAC can run on parallel machines using either the Message Passing Interface (MPI) library or a High Performance Fortran (HPF) compiler.

EMPIRE and pyenda: Two ensemble-based data assimilation systems written in Fortran and Python

NASA Astrophysics Data System (ADS)

Geppert, Gernot; Browne, Phil; van Leeuwen, Peter Jan; Merker, Claire

2017-04-01

We present and compare the features of two ensemble-based data assimilation frameworks, EMPIRE and pyenda. Both frameworks allow to couple models to the assimilation codes using the Message Passing Interface (MPI), leading to extremely efficient and fast coupling between models and the data-assimilation codes. The Fortran-based system EMPIRE (Employing Message Passing Interface for Researching Ensembles) is optimized for parallel, high-performance computing. It currently includes a suite of data assimilation algorithms including variants of the ensemble Kalman and several the particle filters. EMPIRE is targeted at models of all kinds of complexity and has been coupled to several geoscience models, eg. the Lorenz-63 model, a barotropic vorticity model, the general circulation model HadCM3, the ocean model NEMO, and the land-surface model JULES. The Python-based system pyenda (Python Ensemble Data Assimilation) allows Fortran- and Python-based models to be used for data assimilation. Models can be coupled either using MPI or by using a Python interface. Using Python allows quick prototyping and pyenda is aimed at small to medium scale models. pyenda currently includes variants of the ensemble Kalman filter and has been coupled to the Lorenz-63 model, an advection-based precipitation nowcasting scheme, and the dynamic global vegetation model JSBACH.

Ordering Traces Logically to Identify Lateness in Message Passing Programs

DOE PAGES

Isaacs, Katherine E.; Gamblin, Todd; Bhatele, Abhinav; ...

2015-03-30

Event traces are valuable for understanding the behavior of parallel programs. However, automatically analyzing a large parallel trace is difficult, especially without a specific objective. We aid this endeavor by extracting a trace's logical structure, an ordering of trace events derived from happened-before relationships, while taking into account developer intent. Using this structure, we can calculate an operation's delay relative to its peers on other processes. The logical structure also serves as a platform for comparing and clustering processes as well as highlighting communication patterns in a trace visualization. We present an algorithm for determining this idealized logical structure frommore » traces of message passing programs, and we develop metrics to quantify delays and differences among processes. We implement our techniques in Ravel, a parallel trace visualization tool that displays both logical and physical timelines. Rather than showing the duration of each operation, we display where delays begin and end, and how they propagate. As a result, we apply our approach to the traces of several message passing applications, demonstrating the accuracy of our extracted structure and its utility in analyzing these codes.« less

Dust Dynamics in Protoplanetary Disks: Parallel Computing with PVM

NASA Astrophysics Data System (ADS)

de La Fuente Marcos, Carlos; Barge, Pierre; de La Fuente Marcos, Raúl

2002-03-01

We describe a parallel version of our high-order-accuracy particle-mesh code for the simulation of collisionless protoplanetary disks. We use this code to carry out a massively parallel, two-dimensional, time-dependent, numerical simulation, which includes dust particles, to study the potential role of large-scale, gaseous vortices in protoplanetary disks. This noncollisional problem is easy to parallelize on message-passing multicomputer architectures. We performed the simulations on a cache-coherent nonuniform memory access Origin 2000 machine, using both the parallel virtual machine (PVM) and message-passing interface (MPI) message-passing libraries. Our performance analysis suggests that, for our problem, PVM is about 25% faster than MPI. Using PVM and MPI made it possible to reduce CPU time and increase code performance. This allows for simulations with a large number of particles (N ~ 105-106) in reasonable CPU times. The performances of our implementation of the pa! rallel code on an Origin 2000 supercomputer are presented and discussed. They exhibit very good speedup behavior and low load unbalancing. Our results confirm that giant gaseous vortices can play a dominant role in giant planet formation.

Complexity of parallel implementation of domain decomposition techniques for elliptic partial differential equations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gropp, W.D.; Keyes, D.E.

1988-03-01

The authors discuss the parallel implementation of preconditioned conjugate gradient (PCG)-based domain decomposition techniques for self-adjoint elliptic partial differential equations in two dimensions on several architectures. The complexity of these methods is described on a variety of message-passing parallel computers as a function of the size of the problem, number of processors and relative communication speeds of the processors. They show that communication startups are very important, and that even the small amount of global communication in these methods can significantly reduce the performance of many message-passing architectures.

n-body simulations using message passing parallel computers.

NASA Astrophysics Data System (ADS)

Grama, A. Y.; Kumar, V.; Sameh, A.

The authors present new parallel formulations of the Barnes-Hut method for n-body simulations on message passing computers. These parallel formulations partition the domain efficiently incurring minimal communication overhead. This is in contrast to existing schemes that are based on sorting a large number of keys or on the use of global data structures. The new formulations are augmented by alternate communication strategies which serve to minimize communication overhead. The impact of these communication strategies is experimentally studied. The authors report on experimental results obtained from an astrophysical simulation on an nCUBE2 parallel computer.

Learning classifier systems for single and multiple mobile robots in unstructured environments

NASA Astrophysics Data System (ADS)

Bay, John S.

1995-12-01

The learning classifier system (LCS) is a learning production system that generates behavioral rules via an underlying discovery mechanism. The LCS architecture operates similarly to a blackboard architecture; i.e., by posted-message communications. But in the LCS, the message board is wiped clean at every time interval, thereby requiring no persistent shared resource. In this paper, we adapt the LCS to the problem of mobile robot navigation in completely unstructured environments. We consider the model of the robot itself, including its sensor and actuator structures, to be part of this environment, in addition to the world-model that includes a goal and obstacles at unknown locations. This requires a robot to learn its own I/O characteristics in addition to solving its navigation problem, but results in a learning controller that is equally applicable, unaltered, in robots with a wide variety of kinematic structures and sensing capabilities. We show the effectiveness of this LCS-based controller through both simulation and experimental trials with a small robot. We then propose a new architecture, the Distributed Learning Classifier System (DLCS), which generalizes the message-passing behavior of the LCS from internal messages within a single agent to broadcast massages among multiple agents. This communications mode requires little bandwidth and is easily implemented with inexpensive, off-the-shelf hardware. The DLCS is shown to have potential application as a learning controller for multiple intelligent agents.

Cellular automata with object-oriented features for parallel molecular network modeling.

PubMed

Zhu, Hao; Wu, Yinghui; Huang, Sui; Sun, Yan; Dhar, Pawan

2005-06-01

Cellular automata are an important modeling paradigm for studying the dynamics of large, parallel systems composed of multiple, interacting components. However, to model biological systems, cellular automata need to be extended beyond the large-scale parallelism and intensive communication in order to capture two fundamental properties characteristic of complex biological systems: hierarchy and heterogeneity. This paper proposes extensions to a cellular automata language, Cellang, to meet this purpose. The extended language, with object-oriented features, can be used to describe the structure and activity of parallel molecular networks within cells. Capabilities of this new programming language include object structure to define molecular programs within a cell, floating-point data type and mathematical functions to perform quantitative computation, message passing capability to describe molecular interactions, as well as new operators, statements, and built-in functions. We discuss relevant programming issues of these features, including the object-oriented description of molecular interactions with molecule encapsulation, message passing, and the description of heterogeneity and anisotropy at the cell and molecule levels. By enabling the integration of modeling at the molecular level with system behavior at cell, tissue, organ, or even organism levels, the program will help improve our understanding of how complex and dynamic biological activities are generated and controlled by parallel functioning of molecular networks. Index Terms-Cellular automata, modeling, molecular network, object-oriented.

Combining Distributed and Shared Memory Models: Approach and Evolution of the Global Arrays Toolkit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nieplocha, Jarek; Harrison, Robert J.; Kumar, Mukul

2002-07-29

Both shared memory and distributed memory models have advantages and shortcomings. Shared memory model is much easier to use but it ignores data locality/placement. Given the hierarchical nature of the memory subsystems in the modern computers this characteristic might have a negative impact on performance and scalability. Various techniques, such as code restructuring to increase data reuse and introducing blocking in data accesses, can address the problem and yield performance competitive with message passing[Singh], however at the cost of compromising the ease of use feature. Distributed memory models such as message passing or one-sided communication offer performance and scalability butmore » they compromise the ease-of-use. In this context, the message-passing model is sometimes referred to as?assembly programming for the scientific computing?. The Global Arrays toolkit[GA1, GA2] attempts to offer the best features of both models. It implements a shared-memory programming model in which data locality is managed explicitly by the programmer. This management is achieved by explicit calls to functions that transfer data between a global address space (a distributed array) and local storage. In this respect, the GA model has similarities to the distributed shared-memory models that provide an explicit acquire/release protocol. However, the GA model acknowledges that remote data is slower to access than local data and allows data locality to be explicitly specified and hence managed. The GA model exposes to the programmer the hierarchical memory of modern high-performance computer systems, and by recognizing the communication overhead for remote data transfer, it promotes data reuse and locality of reference. This paper describes the characteristics of the Global Arrays programming model, capabilities of the toolkit, and discusses its evolution.« less

Performance Measurement, Visualization and Modeling of Parallel and Distributed Programs

NASA Technical Reports Server (NTRS)

Yan, Jerry C.; Sarukkai, Sekhar R.; Mehra, Pankaj; Lum, Henry, Jr. (Technical Monitor)

1994-01-01

This paper presents a methodology for debugging the performance of message-passing programs on both tightly coupled and loosely coupled distributed-memory machines. The AIMS (Automated Instrumentation and Monitoring System) toolkit, a suite of software tools for measurement and analysis of performance, is introduced and its application illustrated using several benchmark programs drawn from the field of computational fluid dynamics. AIMS includes (i) Xinstrument, a powerful source-code instrumentor, which supports both Fortran77 and C as well as a number of different message-passing libraries including Intel's NX Thinking Machines' CMMD, and PVM; (ii) Monitor, a library of timestamping and trace -collection routines that run on supercomputers (such as Intel's iPSC/860, Delta, and Paragon and Thinking Machines' CM5) as well as on networks of workstations (including Convex Cluster and SparcStations connected by a LAN); (iii) Visualization Kernel, a trace-animation facility that supports source-code clickback, simultaneous visualization of computation and communication patterns, as well as analysis of data movements; (iv) Statistics Kernel, an advanced profiling facility, that associates a variety of performance data with various syntactic components of a parallel program; (v) Index Kernel, a diagnostic tool that helps pinpoint performance bottlenecks through the use of abstract indices; (vi) Modeling Kernel, a facility for automated modeling of message-passing programs that supports both simulation -based and analytical approaches to performance prediction and scalability analysis; (vii) Intrusion Compensator, a utility for recovering true performance from observed performance by removing the overheads of monitoring and their effects on the communication pattern of the program; and (viii) Compatibility Tools, that convert AIMS-generated traces into formats used by other performance-visualization tools, such as ParaGraph, Pablo, and certain AVS/Explorer modules.

Applications Performance Under MPL and MPI on NAS IBM SP2

NASA Technical Reports Server (NTRS)

Saini, Subhash; Simon, Horst D.; Lasinski, T. A. (Technical Monitor)

1994-01-01

On July 5, 1994, an IBM Scalable POWER parallel System (IBM SP2) with 64 nodes, was installed at the Numerical Aerodynamic Simulation (NAS) Facility Each node of NAS IBM SP2 is a "wide node" consisting of a RISC 6000/590 workstation module with a clock of 66.5 MHz which can perform four floating point operations per clock with a peak performance of 266 Mflop/s. By the end of 1994, 64 nodes of IBM SP2 will be upgraded to 160 nodes with a peak performance of 42.5 Gflop/s. An overview of the IBM SP2 hardware is presented. The basic understanding of architectural details of RS 6000/590 will help application scientists the porting, optimizing, and tuning of codes from other machines such as the CRAY C90 and the Paragon to the NAS SP2. Optimization techniques such as quad-word loading, effective utilization of two floating point units, and data cache optimization of RS 6000/590 is illustrated, with examples giving performance gains at each optimization step. The conversion of codes using Intel's message passing library NX to codes using native Message Passing Library (MPL) and the Message Passing Interface (NMI) library available on the IBM SP2 is illustrated. In particular, we will present the performance of Fast Fourier Transform (FFT) kernel from NAS Parallel Benchmarks (NPB) under MPL and MPI. We have also optimized some of Fortran BLAS 2 and BLAS 3 routines, e.g., the optimized Fortran DAXPY runs at 175 Mflop/s and optimized Fortran DGEMM runs at 230 Mflop/s per node. The performance of the NPB (Class B) on the IBM SP2 is compared with the CRAY C90, Intel Paragon, TMC CM-5E, and the CRAY T3D.

Relations Among Central Auditory Abilities, Socio-Economic Factors, Speech Delay, Phonic Abilities and Reading Achievement: A Longitudinal Study.

ERIC Educational Resources Information Center

Flowers, Arthur; Crandell, Edwin W.

Three auditory perceptual processes (resistance to distortion, selective listening in the form of auditory dedifferentiation, and binaural synthesis) were evaluated by five assessment techniques: (1) low pass filtered speech, (2) accelerated speech, (3) competing messages, (4) accelerated plus competing messages, and (5) binaural synthesis.…

Strategies for Energy Efficient Resource Management of Hybrid Programming Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Dong; Supinski, Bronis de; Schulz, Martin

2013-01-01

Many scientific applications are programmed using hybrid programming models that use both message-passing and shared-memory, due to the increasing prevalence of large-scale systems with multicore, multisocket nodes. Previous work has shown that energy efficiency can be improved using software-controlled execution schemes that consider both the programming model and the power-aware execution capabilities of the system. However, such approaches have focused on identifying optimal resource utilization for one programming model, either shared-memory or message-passing, in isolation. The potential solution space, thus the challenge, increases substantially when optimizing hybrid models since the possible resource configurations increase exponentially. Nonetheless, with the accelerating adoptionmore » of hybrid programming models, we increasingly need improved energy efficiency in hybrid parallel applications on large-scale systems. In this work, we present new software-controlled execution schemes that consider the effects of dynamic concurrency throttling (DCT) and dynamic voltage and frequency scaling (DVFS) in the context of hybrid programming models. Specifically, we present predictive models and novel algorithms based on statistical analysis that anticipate application power and time requirements under different concurrency and frequency configurations. We apply our models and methods to the NPB MZ benchmarks and selected applications from the ASC Sequoia codes. Overall, we achieve substantial energy savings (8.74% on average and up to 13.8%) with some performance gain (up to 7.5%) or negligible performance loss.« less

Saguaro: A Distributed Operating System Based on Pools of Servers.

DTIC Science & Technology

1988-03-25

asynchronous message passing, multicast, and semaphores are supported. We have found this flexibility to be very useful for distributed programming. The...variety of communication primitives provided by SR has facilitated the research of Stella Atkins, who was a visiting professor at Arizona during Spring...data bits in a raw communication channel to help keep the source and destination synchronized , Psync explicitly embeds timing information drawn from the

Implementation of a Serial Delay Insertion Type Loop Communication for a Real Time Multitransputer System.

DTIC Science & Technology

1985-06-01

just pass the message WAIT NOW AFTER Rlock + timeo t -- if time is out write.screen( TIME IS OUT") MAIN PROGRAM* CHAN linki , link2, link3, link4...PAR D.I.Loop.Interface (link4, linkl,) D.I.Loop.Interface ( linki , link2, 2) D.I.Loop.Interface (link2, link3, 3) JD.I Loop.Interface (link3, link4, 4

Performance Analysis and Optimization of the Winnow Secret Key Reconciliation Protocol

DTIC Science & Technology

2011-06-01

use in a quantum key system can be defined in two ways :  The number of messages passed between Alice and Bob  The...classical and quantum environment. Post- quantum cryptography , which is generally used to describe classical quantum -resilient protocols, includes...composed of a one- way quantum channel and a two - way classical channel. Owing to the physics of the channel, the quantum channel is subject to

The equipment access software for a distributed UNIX-based accelerator control system

NASA Astrophysics Data System (ADS)

Trofimov, Nikolai; Zelepoukine, Serguei; Zharkov, Eugeny; Charrue, Pierre; Gareyte, Claire; Poirier, Hervé

1994-12-01

This paper presents a generic equipment access software package for a distributed control system using computers with UNIX or UNIX-like operating systems. The package consists of three main components, an application Equipment Access Library, Message Handler and Equipment Data Base. An application task, which may run in any computer in the network, sends requests to access equipment through Equipment Library calls. The basic request is in the form Equipment-Action-Data and is routed via a remote procedure call to the computer to which the given equipment is connected. In this computer the request is received by the Message Handler. According to the type of the equipment connection, the Message Handler either passes the request to the specific process software in the same computer or forwards it to a lower level network of equipment controllers using MIL1553B, GPIB, RS232 or BITBUS communication. The answer is then returned to the calling application. Descriptive information required for request routing and processing is stored in the real-time Equipment Data Base. The package has been written to be portable and is currently available on DEC Ultrix, LynxOS, HPUX, XENIX, OS-9 and Apollo domain.

Assessing clarity of message communication for mandated USEPA drinking water quality reports.

PubMed

Phetxumphou, Katherine; Roy, Siddhartha; Davy, Brenda M; Estabrooks, Paul A; You, Wen; Dietrich, Andrea M

2016-04-01

The United States Environmental Protection Agency mandates that community water systems (CWSs), or drinking water utilities, provide annual consumer confidence reports (CCRs) reporting on water quality, compliance with regulations, source water, and consumer education. While certain report formats are prescribed, there are no criteria ensuring that consumers understand messages in these reports. To assess clarity of message, trained raters evaluated a national sample of 30 CCRs using the Centers for Disease Control Clear Communication Index (Index) indices: (1) Main Message/Call to Action; (2) Language; (3) Information Design; (4) State of the Science; (5) Behavioral Recommendations; (6) Numbers; and (7) Risk. Communication materials are considered qualifying if they achieve a 90% Index score. Overall mean score across CCRs was 50 ± 14% and none scored 90% or higher. CCRs did not differ significantly by water system size. State of the Science (3 ± 15%) and Behavioral Recommendations (77 ± 36%) indices were the lowest and highest, respectively. Only 63% of CCRs explicitly stated if the water was safe to drink according to federal and state standards and regulations. None of the CCRs had passing Index scores, signaling that CWSs are not effectively communicating with their consumers; thus, the Index can serve as an evaluation tool for CCR effectiveness and a guide to improve water quality communications.

Information processing in the CNS: a supramolecular chemistry?

PubMed

Tozzi, Arturo

2015-10-01

How does central nervous system process information? Current theories are based on two tenets: (a) information is transmitted by action potentials, the language by which neurons communicate with each other-and (b) homogeneous neuronal assemblies of cortical circuits operate on these neuronal messages where the operations are characterized by the intrinsic connectivity among neuronal populations. In this view, the size and time course of any spike is stereotypic and the information is restricted to the temporal sequence of the spikes; namely, the "neural code". However, an increasing amount of novel data point towards an alternative hypothesis: (a) the role of neural code in information processing is overemphasized. Instead of simply passing messages, action potentials play a role in dynamic coordination at multiple spatial and temporal scales, establishing network interactions across several levels of a hierarchical modular architecture, modulating and regulating the propagation of neuronal messages. (b) Information is processed at all levels of neuronal infrastructure from macromolecules to population dynamics. For example, intra-neuronal (changes in protein conformation, concentration and synthesis) and extra-neuronal factors (extracellular proteolysis, substrate patterning, myelin plasticity, microbes, metabolic status) can have a profound effect on neuronal computations. This means molecular message passing may have cognitive connotations. This essay introduces the concept of "supramolecular chemistry", involving the storage of information at the molecular level and its retrieval, transfer and processing at the supramolecular level, through transitory non-covalent molecular processes that are self-organized, self-assembled and dynamic. Finally, we note that the cortex comprises extremely heterogeneous cells, with distinct regional variations, macromolecular assembly, receptor repertoire and intrinsic microcircuitry. This suggests that every neuron (or group of neurons) embodies different molecular information that hands an operational effect on neuronal computation.

''Towards a High-Performance and Robust Implementation of MPI-IO on Top of GPFS''

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prost, J.P.; Tremann, R.; Blackwore, R.

2000-01-11

MPI-IO/GPFS is a prototype implementation of the I/O chapter of the Message Passing Interface (MPI) 2 standard. It uses the IBM General Parallel File System (GPFS), with prototyped extensions, as the underlying file system. this paper describes the features of this prototype which support its high performance and robustness. The use of hints at the file system level and at the MPI-IO level allows tailoring the use of the file system to the application needs. Error handling in collective operations provides robust error reporting and deadlock prevention in case of returning errors.

Heartbeat-based error diagnosis framework for distributed embedded systems

NASA Astrophysics Data System (ADS)

Mishra, Swagat; Khilar, Pabitra Mohan

2012-01-01

Distributed Embedded Systems have significant applications in automobile industry as steer-by-wire, fly-by-wire and brake-by-wire systems. In this paper, we provide a general framework for fault detection in a distributed embedded real time system. We use heartbeat monitoring, check pointing and model based redundancy to design a scalable framework that takes care of task scheduling, temperature control and diagnosis of faulty nodes in a distributed embedded system. This helps in diagnosis and shutting down of faulty actuators before the system becomes unsafe. The framework is designed and tested using a new simulation model consisting of virtual nodes working on a message passing system.

Heartbeat-based error diagnosis framework for distributed embedded systems

NASA Astrophysics Data System (ADS)

Mishra, Swagat; Khilar, Pabitra Mohan

2011-12-01

Distributed Embedded Systems have significant applications in automobile industry as steer-by-wire, fly-by-wire and brake-by-wire systems. In this paper, we provide a general framework for fault detection in a distributed embedded real time system. We use heartbeat monitoring, check pointing and model based redundancy to design a scalable framework that takes care of task scheduling, temperature control and diagnosis of faulty nodes in a distributed embedded system. This helps in diagnosis and shutting down of faulty actuators before the system becomes unsafe. The framework is designed and tested using a new simulation model consisting of virtual nodes working on a message passing system.

Performance Evaluation of Remote Memory Access (RMA) Programming on Shared Memory Parallel Computers

NASA Technical Reports Server (NTRS)

Jin, Hao-Qiang; Jost, Gabriele; Biegel, Bryan A. (Technical Monitor)

2002-01-01

The purpose of this study is to evaluate the feasibility of remote memory access (RMA) programming on shared memory parallel computers. We discuss different RMA based implementations of selected CFD application benchmark kernels and compare them to corresponding message passing based codes. For the message-passing implementation we use MPI point-to-point and global communication routines. For the RMA based approach we consider two different libraries supporting this programming model. One is a shared memory parallelization library (SMPlib) developed at NASA Ames, the other is the MPI-2 extensions to the MPI Standard. We give timing comparisons for the different implementation strategies and discuss the performance.

Comparing the OpenMP, MPI, and Hybrid Programming Paradigm on an SMP Cluster

NASA Technical Reports Server (NTRS)

Jost, Gabriele; Jin, Hao-Qiang; anMey, Dieter; Hatay, Ferhat F.

2003-01-01

Clusters of SMP (Symmetric Multi-Processors) nodes provide support for a wide range of parallel programming paradigms. The shared address space within each node is suitable for OpenMP parallelization. Message passing can be employed within and across the nodes of a cluster. Multiple levels of parallelism can be achieved by combining message passing and OpenMP parallelization. Which programming paradigm is the best will depend on the nature of the given problem, the hardware components of the cluster, the network, and the available software. In this study we compare the performance of different implementations of the same CFD benchmark application, using the same numerical algorithm but employing different programming paradigms.

ADAPTIVE TETRAHEDRAL GRID REFINEMENT AND COARSENING IN MESSAGE-PASSING ENVIRONMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hallberg, J.; Stagg, A.

2000-10-01

A grid refinement and coarsening scheme has been developed for tetrahedral and triangular grid-based calculations in message-passing environments. The element adaption scheme is based on an edge bisection of elements marked for refinement by an appropriate error indicator. Hash-table/linked-list data structures are used to store nodal and element formation. The grid along inter-processor boundaries is refined and coarsened consistently with the update of these data structures via MPI calls. The parallel adaption scheme has been applied to the solution of a transient, three-dimensional, nonlinear, groundwater flow problem. Timings indicate efficiency of the grid refinement process relative to the flow solvermore » calculations.« less

A Survey of Rollback-Recovery Protocols in Message-Passing Systems

DTIC Science & Technology

1999-06-01

and M.A. Castillo. "Checkpointing through garbage collection." Technical report. Departamento de Ciencia de la Computation, Escuela de Ingenieria ...between consecutive checkpoints. It can be implemented by using the dirty-bit of the memory protection hardware or by emulating a dirty-bit in software [4...compare the program’s state with the previous checkpoint in software , and writing the difference in a new checkpoint [46]. The required storage and

A software bus for thread objects

NASA Technical Reports Server (NTRS)

Callahan, John R.; Li, Dehuai

1995-01-01

The authors have implemented a software bus for lightweight threads in an object-oriented programming environment that allows for rapid reconfiguration and reuse of thread objects in discrete-event simulation experiments. While previous research in object-oriented, parallel programming environments has focused on direct communication between threads, our lightweight software bus, called the MiniBus, provides a means to isolate threads from their contexts of execution by restricting communications between threads to message-passing via their local ports only. The software bus maintains a topology of connections between these ports. It routes, queues, and delivers messages according to this topology. This approach allows for rapid reconfiguration and reuse of thread objects in other systems without making changes to the specifications or source code. A layered approach that provides the needed transparency to developers is presented. Examples of using the MiniBus are given, and the value of bus architectures in building and conducting simulations of discrete-event systems is discussed.

Non-invasive lightweight integration engine for building EHR from autonomous distributed systems.

PubMed

Angulo, Carlos; Crespo, Pere; Maldonado, José A; Moner, David; Pérez, Daniel; Abad, Irene; Mandingorra, Jesús; Robles, Montserrat

2007-12-01

In this paper we describe Pangea-LE, a message-oriented lightweight data integration engine that allows homogeneous and concurrent access to clinical information from disperse and heterogeneous data sources. The engine extracts the information and passes it to the requesting client applications in a flexible XML format. The XML response message can be formatted on demand by appropriate Extensible Stylesheet Language (XSL) transformations in order to meet the needs of client applications. We also present a real deployment in a hospital where Pangea-LE collects and generates an XML view of all the available patient clinical information. The information is presented to healthcare professionals in an Electronic Health Record (EHR) viewer Web application with patient search and EHR browsing capabilities. Implantation in a real setting has been a success due to the non-invasive nature of Pangea-LE which respects the existing information systems.

Statistical mechanics of unsupervised feature learning in a restricted Boltzmann machine with binary synapses

NASA Astrophysics Data System (ADS)

Huang, Haiping

2017-05-01

Revealing hidden features in unlabeled data is called unsupervised feature learning, which plays an important role in pretraining a deep neural network. Here we provide a statistical mechanics analysis of the unsupervised learning in a restricted Boltzmann machine with binary synapses. A message passing equation to infer the hidden feature is derived, and furthermore, variants of this equation are analyzed. A statistical analysis by replica theory describes the thermodynamic properties of the model. Our analysis confirms an entropy crisis preceding the non-convergence of the message passing equation, suggesting a discontinuous phase transition as a key characteristic of the restricted Boltzmann machine. Continuous phase transition is also confirmed depending on the embedded feature strength in the data. The mean-field result under the replica symmetric assumption agrees with that obtained by running message passing algorithms on single instances of finite sizes. Interestingly, in an approximate Hopfield model, the entropy crisis is absent, and a continuous phase transition is observed instead. We also develop an iterative equation to infer the hyper-parameter (temperature) hidden in the data, which in physics corresponds to iteratively imposing Nishimori condition. Our study provides insights towards understanding the thermodynamic properties of the restricted Boltzmann machine learning, and moreover important theoretical basis to build simplified deep networks.

Computer-aided programming for message-passing system; Problems and a solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, M.Y.; Gajski, D.D.

1989-12-01

As the number of processors and the complexity of problems to be solved increase, programming multiprocessing systems becomes more difficult and error-prone. Program development tools are necessary since programmers are not able to develop complex parallel programs efficiently. Parallel models of computation, parallelization problems, and tools for computer-aided programming (CAP) are discussed. As an example, a CAP tool that performs scheduling and inserts communication primitives automatically is described. It also generates the performance estimates and other program quality measures to help programmers in improving their algorithms and programs.

Parallel community climate model: Description and user`s guide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drake, J.B.; Flanery, R.E.; Semeraro, B.D.

This report gives an overview of a parallel version of the NCAR Community Climate Model, CCM2, implemented for MIMD massively parallel computers using a message-passing programming paradigm. The parallel implementation was developed on an Intel iPSC/860 with 128 processors and on the Intel Delta with 512 processors, and the initial target platform for the production version of the code is the Intel Paragon with 2048 processors. Because the implementation uses a standard, portable message-passing libraries, the code has been easily ported to other multiprocessors supporting a message-passing programming paradigm. The parallelization strategy used is to decompose the problem domain intomore » geographical patches and assign each processor the computation associated with a distinct subset of the patches. With this decomposition, the physics calculations involve only grid points and data local to a processor and are performed in parallel. Using parallel algorithms developed for the semi-Lagrangian transport, the fast Fourier transform and the Legendre transform, both physics and dynamics are computed in parallel with minimal data movement and modest change to the original CCM2 source code. Sequential or parallel history tapes are written and input files (in history tape format) are read sequentially by the parallel code to promote compatibility with production use of the model on other computer systems. A validation exercise has been performed with the parallel code and is detailed along with some performance numbers on the Intel Paragon and the IBM SP2. A discussion of reproducibility of results is included. A user`s guide for the PCCM2 version 2.1 on the various parallel machines completes the report. Procedures for compilation, setup and execution are given. A discussion of code internals is included for those who may wish to modify and use the program in their own research.« less

Plasma Physics Calculations on a Parallel Macintosh Cluster

NASA Astrophysics Data System (ADS)

Decyk, Viktor; Dauger, Dean; Kokelaar, Pieter

2000-03-01

We have constructed a parallel cluster consisting of 16 Apple Macintosh G3 computers running the MacOS, and achieved very good performance on numerically intensive, parallel plasma particle-in-cell simulations. A subset of the MPI message-passing library was implemented in Fortran77 and C. This library enabled us to port code, without modification, from other parallel processors to the Macintosh cluster. For large problems where message packets are large and relatively few in number, performance of 50-150 MFlops/node is possible, depending on the problem. This is fast enough that 3D calculations can be routinely done. Unlike Unix-based clusters, no special expertise in operating systems is required to build and run the cluster. Full details are available on our web site: http://exodus.physics.ucla.edu/appleseed/.

Plasma Physics Calculations on a Parallel Macintosh Cluster

NASA Astrophysics Data System (ADS)

Decyk, Viktor K.; Dauger, Dean E.; Kokelaar, Pieter R.

We have constructed a parallel cluster consisting of 16 Apple Macintosh G3 computers running the MacOS, and achieved very good performance on numerically intensive, parallel plasma particle-in-cell simulations. A subset of the MPI message-passing library was implemented in Fortran77 and C. This library enabled us to port code, without modification, from other parallel processors to the Macintosh cluster. For large problems where message packets are large and relatively few in number, performance of 50-150 Mflops/node is possible, depending on the problem. This is fast enough that 3D calculations can be routinely done. Unlike Unix-based clusters, no special expertise in operating systems is required to build and run the cluster. Full details are available on our web site: http://exodus.physics.ucla.edu/appleseed/.

Applications of Multi-Channel Safety Authentication Protocols in Wireless Networks.

PubMed

Chen, Young-Long; Liau, Ren-Hau; Chang, Liang-Yu

2016-01-01

People can use their web browser or mobile devices to access web services and applications which are built into these servers. Users have to input their identity and password to login the server. The identity and password may be appropriated by hackers when the network environment is not safe. The multiple secure authentication protocol can improve the security of the network environment. Mobile devices can be used to pass the authentication messages through Wi-Fi or 3G networks to serve as a second communication channel. The content of the message number is not considered in a multiple secure authentication protocol. The more excessive transmission of messages would be easier to collect and decode by hackers. In this paper, we propose two schemes which allow the server to validate the user and reduce the number of messages using the XOR operation. Our schemes can improve the security of the authentication protocol. The experimental results show that our proposed authentication protocols are more secure and effective. In regard to applications of second authentication communication channels for a smart access control system, identity identification and E-wallet, our proposed authentication protocols can ensure the safety of person and property, and achieve more effective security management mechanisms.

Experiences using OpenMP based on Computer Directed Software DSM on a PC Cluster

NASA Technical Reports Server (NTRS)

Hess, Matthias; Jost, Gabriele; Mueller, Matthias; Ruehle, Roland

2003-01-01

In this work we report on our experiences running OpenMP programs on a commodity cluster of PCs running a software distributed shared memory (DSM) system. We describe our test environment and report on the performance of a subset of the NAS Parallel Benchmarks that have been automaticaly parallelized for OpenMP. We compare the performance of the OpenMP implementations with that of their message passing counterparts and discuss performance differences.

Earth Observation

NASA Image and Video Library

2013-08-20

Earth observation taken during day pass by an Expedition 36 crew member on board the International Space Station (ISS). Per Twitter message: Looking southwest over northern Africa. Libya, Algeria, Niger.

Application of a distributed network in computational fluid dynamic simulations

NASA Technical Reports Server (NTRS)

Deshpande, Manish; Feng, Jinzhang; Merkle, Charles L.; Deshpande, Ashish

1994-01-01

A general-purpose 3-D, incompressible Navier-Stokes algorithm is implemented on a network of concurrently operating workstations using parallel virtual machine (PVM) and compared with its performance on a CRAY Y-MP and on an Intel iPSC/860. The problem is relatively computationally intensive, and has a communication structure based primarily on nearest-neighbor communication, making it ideally suited to message passing. Such problems are frequently encountered in computational fluid dynamics (CDF), and their solution is increasingly in demand. The communication structure is explicitly coded in the implementation to fully exploit the regularity in message passing in order to produce a near-optimal solution. Results are presented for various grid sizes using up to eight processors.

Approximate message passing with restricted Boltzmann machine priors

NASA Astrophysics Data System (ADS)

Tramel, Eric W.; Drémeau, Angélique; Krzakala, Florent

2016-07-01

Approximate message passing (AMP) has been shown to be an excellent statistical approach to signal inference and compressed sensing problems. The AMP framework provides modularity in the choice of signal prior; here we propose a hierarchical form of the Gauss-Bernoulli prior which utilizes a restricted Boltzmann machine (RBM) trained on the signal support to push reconstruction performance beyond that of simple i.i.d. priors for signals whose support can be well represented by a trained binary RBM. We present and analyze two methods of RBM factorization and demonstrate how these affect signal reconstruction performance within our proposed algorithm. Finally, using the MNIST handwritten digit dataset, we show experimentally that using an RBM allows AMP to approach oracle-support performance.

New NAS Parallel Benchmarks Results

NASA Technical Reports Server (NTRS)

Yarrow, Maurice; Saphir, William; VanderWijngaart, Rob; Woo, Alex; Kutler, Paul (Technical Monitor)

1997-01-01

NPB2 (NAS (NASA Advanced Supercomputing) Parallel Benchmarks 2) is an implementation, based on Fortran and the MPI (message passing interface) message passing standard, of the original NAS Parallel Benchmark specifications. NPB2 programs are run with little or no tuning, in contrast to NPB vendor implementations, which are highly optimized for specific architectures. NPB2 results complement, rather than replace, NPB results. Because they have not been optimized by vendors, NPB2 implementations approximate the performance a typical user can expect for a portable parallel program on distributed memory parallel computers. Together these results provide an insightful comparison of the real-world performance of high-performance computers. New NPB2 features: New implementation (CG), new workstation class problem sizes, new serial sample versions, more performance statistics.

Passing messages between biological networks to refine predicted interactions.

PubMed

Glass, Kimberly; Huttenhower, Curtis; Quackenbush, John; Yuan, Guo-Cheng

2013-01-01

Regulatory network reconstruction is a fundamental problem in computational biology. There are significant limitations to such reconstruction using individual datasets, and increasingly people attempt to construct networks using multiple, independent datasets obtained from complementary sources, but methods for this integration are lacking. We developed PANDA (Passing Attributes between Networks for Data Assimilation), a message-passing model using multiple sources of information to predict regulatory relationships, and used it to integrate protein-protein interaction, gene expression, and sequence motif data to reconstruct genome-wide, condition-specific regulatory networks in yeast as a model. The resulting networks were not only more accurate than those produced using individual data sets and other existing methods, but they also captured information regarding specific biological mechanisms and pathways that were missed using other methodologies. PANDA is scalable to higher eukaryotes, applicable to specific tissue or cell type data and conceptually generalizable to include a variety of regulatory, interaction, expression, and other genome-scale data. An implementation of the PANDA algorithm is available at www.sourceforge.net/projects/panda-net.

A bidirectional ACR-NEMA interface between the VA's DHCP Integrated Imaging System and the Siemens-Loral PACS.

PubMed Central

Kuzmak, P. M.; Dayhoff, R. E.

1992-01-01

There is a wide range of requirements for digital hospital imaging systems. Radiology needs very high resolution black and white images. Other diagnostic disciplines need high resolution color imaging capabilities. Images need to be displayed in many locations throughout the hospital. Different imaging systems within a hospital need to cooperate in order to show the whole picture. At the Baltimore VA Medical Center, the DHCP Integrated Imaging System and a commercial Picture Archiving and Communication System (PACS) work in concert to provide a wide-range of departmental and hospital-wide imaging capabilities. An interface between the DHCP and the Siemens-Loral PACS systems enables patient text and image data to be passed between the two systems. The interface uses ACR-NEMA 2.0 Standard messages extended with shadow groups based on draft ACR-NEMA 3.0 prototypes. A Novell file server, accessible to both systems via Ethernet, is used to communicate all the messages. Patient identification information, orders, ADT, procedure status, changes, patient reports, and images are sent between the two systems across the interface. The systems together provide an extensive set of imaging capabilities for both the specialist and the general practitioner. PMID:1482906

A bidirectional ACR-NEMA interface between the VA's DHCP Integrated Imaging System and the Siemens-Loral PACS.

PubMed

Kuzmak, P M; Dayhoff, R E

1992-01-01

There is a wide range of requirements for digital hospital imaging systems. Radiology needs very high resolution black and white images. Other diagnostic disciplines need high resolution color imaging capabilities. Images need to be displayed in many locations throughout the hospital. Different imaging systems within a hospital need to cooperate in order to show the whole picture. At the Baltimore VA Medical Center, the DHCP Integrated Imaging System and a commercial Picture Archiving and Communication System (PACS) work in concert to provide a wide-range of departmental and hospital-wide imaging capabilities. An interface between the DHCP and the Siemens-Loral PACS systems enables patient text and image data to be passed between the two systems. The interface uses ACR-NEMA 2.0 Standard messages extended with shadow groups based on draft ACR-NEMA 3.0 prototypes. A Novell file server, accessible to both systems via Ethernet, is used to communicate all the messages. Patient identification information, orders, ADT, procedure status, changes, patient reports, and images are sent between the two systems across the interface. The systems together provide an extensive set of imaging capabilities for both the specialist and the general practitioner.

Earth observation taken by the Expedition 46 crew

NASA Image and Video Library

2016-01-23

ISS046e021993 (01/23/2016) --- Earth observation of the coast of Oman taken during a night pass by the Expedition 46 crew aboard the International Space Station. NASA astronaut Tim Kopra tweeted this image out with this message: "Passing over the Gulf of #Oman at night -- city lights of #Muscat #Dubai #AbuDhabi and #Doha in the distance".

Satellite telemetry: performance of animal-tracking systems

USGS Publications Warehouse

Keating, Kim A.; Brewster, Wayne G.; Key, Carl H.

1991-01-01

t: We used 10 Telonics ST-3 platform transmitter terminals (PTT's) configured for wolves and ungulates to examine the performance of the Argos satellite telemetry system. Under near-optimal conditions, 68 percentile errors for location qualities (NQ) 1, 2, and 3 were 1,188, 903, and 361 m, respectively. Errors (rE) exceeded expected values for NQ = 2 and 3, varied greatly among PTT's, increased as the difference (HE) between the estimated and actual PTT elevations increased, and were correlated nonlinearly with maximum satellite pass height (P,). We present a model of the relationships among rE, HE, and PH. Errors were bimodally distributed along the east-west axis and tended to occur away from the satellite when HE was positive. A southeasterly bias increased with HE, probably due to the particular distribution of satellite passes and effects of HE on rE. Under near-optimal conditions, 21 sensor message was received for up to 64% of available (PH, 50) satellite passes, and a location (NQ 2 1) was calculated for up to 63% of such passes. Sampling frequencies of sensor and location data declined 13 and 70%, respectively, for PTT's in a valley bottom and 65 and 86%, respectively, for PTT's on animals that were in valley bottoms. Sampling frequencies were greater for ungulate than for wolf collars.

Mean-field message-passing equations in the Hopfield model and its generalizations

NASA Astrophysics Data System (ADS)

Mézard, Marc

2017-02-01

Motivated by recent progress in using restricted Boltzmann machines as preprocessing algorithms for deep neural network, we revisit the mean-field equations [belief-propagation and Thouless-Anderson Palmer (TAP) equations] in the best understood of such machines, namely the Hopfield model of neural networks, and we explicit how they can be used as iterative message-passing algorithms, providing a fast method to compute the local polarizations of neurons. In the "retrieval phase", where neurons polarize in the direction of one memorized pattern, we point out a major difference between the belief propagation and TAP equations: The set of belief propagation equations depends on the pattern which is retrieved, while one can use a unique set of TAP equations. This makes the latter method much better suited for applications in the learning process of restricted Boltzmann machines. In the case where the patterns memorized in the Hopfield model are not independent, but are correlated through a combinatorial structure, we show that the TAP equations have to be modified. This modification can be seen either as an alteration of the reaction term in TAP equations or, more interestingly, as the consequence of message passing on a graphical model with several hidden layers, where the number of hidden layers depends on the depth of the correlations in the memorized patterns. This layered structure is actually necessary when one deals with more general restricted Boltzmann machines.

Earth Observation

NASA Image and Video Library

2013-08-03

Earth observation taken during day pass by an Expedition 36 crew member on board the International Space Station (ISS). Per Twitter message: Perhaps a dandelion losing its seeds in the wind? Love clouds!

Paralysis

MedlinePlus

Paralysis is the loss of muscle function in part of your body. It happens when something goes ... way messages pass between your brain and muscles. Paralysis can be complete or partial. It can occur ...

Data transfer using complete bipartite graph

NASA Astrophysics Data System (ADS)

Chandrasekaran, V. M.; Praba, B.; Manimaran, A.; Kailash, G.

2017-11-01

Information exchange extent is an estimation of the amount of information sent between two focuses on a framework in a given time period. It is an extremely significant perception in present world. There are many ways of message passing in the present situations. Some of them are through encryption, decryption, by using complete bipartite graph. In this paper, we recommend a method for communication using messages through encryption of a complete bipartite graph.

Teaching Controversial Topics to Skeptical High School Students

NASA Astrophysics Data System (ADS)

Ford, K. S.

2012-12-01

Tennessee passes the "Monkey Bill" (HB 0368, SB 0893), North Carolina's state government passes a law to criminalize reference in state documents to scientific models that predict sea level rise to reach at least one meter by the next century, and public concern still lags far behind the scientific community's concern on climate change. The American public and even science teachers across the country seem to have lost faith in the ability of the scientific community to unify a strong message about several important scientific lessons, including global warming in particular. This lack of a unified message has weakened the ability of science teachers to effectively teach the lesson of global warming. For science teachers in strongly conservative areas of the country, it is much easier to omit difficult topics and avoid angering parents and school board members. Teachers who do feel strongly about scientifically proven, yet publically controversial topics CAN teach these topics in conservative areas by confirming students' belief systems by being honest and open about motivations surrounding both sides of controversial topics, and by using vocabulary that avoids triggering negative perceptions about these controversial topics. For true learning and change of preconceived opinion to take place, it is important for students to come to the understanding in their own minds in an open and safe learning environment instead of having the message "preached" to them, which only serves to make them feel unintelligent and defensive if they disagree. This presentation will include lessons learned from a practicing science teacher who works in a community that overwhelmingly disputes the validity of human impacts on climate change.

Behavior of Flotsam in the California Current System Utilizing Surface Drift of RAFOS Floats

DTIC Science & Technology

2012-09-01

drifter is most widely used (Lumpkin and Pazos 2006). The evolution and construction of the SVP drifter is described by Lumpkin and Pazos (2006). SVP...weight them down so that they were almost submerged in order to reduce the effect of the wind force on drifting objects (Lumpkin and Pazos 2007...by Argos (2011) and Lumpkin and Pazos (2007). As the satellite passes over the drifter, it begins receiving messages. To calculate the drifter’s

NAS Parallel Benchmarks. 2.4

NASA Technical Reports Server (NTRS)

VanderWijngaart, Rob; Biegel, Bryan A. (Technical Monitor)

2002-01-01

We describe a new problem size, called Class D, for the NAS Parallel Benchmarks (NPB), whose MPI source code implementation is being released as NPB 2.4. A brief rationale is given for how the new class is derived. We also describe the modifications made to the MPI (Message Passing Interface) implementation to allow the new class to be run on systems with 32-bit integers, and with moderate amounts of memory. Finally, we give the verification values for the new problem size.

IMPETUS - Interactive MultiPhysics Environment for Unified Simulations.

PubMed

Ha, Vi Q; Lykotrafitis, George

2016-12-08

We introduce IMPETUS - Interactive MultiPhysics Environment for Unified Simulations, an object oriented, easy-to-use, high performance, C++ program for three-dimensional simulations of complex physical systems that can benefit a large variety of research areas, especially in cell mechanics. The program implements cross-communication between locally interacting particles and continuum models residing in the same physical space while a network facilitates long-range particle interactions. Message Passing Interface is used for inter-processor communication for all simulations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Trellis Tone Modulation Multiple-Access for Peer Discovery in D2D Networks

PubMed Central

Lim, Chiwoo; Kim, Sang-Hyo

2018-01-01

In this paper, a new non-orthogonal multiple-access scheme, trellis tone modulation multiple-access (TTMMA), is proposed for peer discovery of distributed device-to-device (D2D) communication. The range and capacity of discovery are important performance metrics in peer discovery. The proposed trellis tone modulation uses single-tone transmission and achieves a long discovery range due to its low Peak-to-Average Power Ratio (PAPR). The TTMMA also exploits non-orthogonal resource assignment to increase the discovery capacity. For the multi-user detection of superposed multiple-access signals, a message-passing algorithm with supplementary schemes are proposed. With TTMMA and its message-passing demodulation, approximately 1.5 times the number of devices are discovered compared to the conventional frequency division multiple-access (FDMA)-based discovery. PMID:29673167

Statistical physics of hard combinatorial optimization: Vertex cover problem

NASA Astrophysics Data System (ADS)

Zhao, Jin-Hua; Zhou, Hai-Jun

2014-07-01

Typical-case computation complexity is a research topic at the boundary of computer science, applied mathematics, and statistical physics. In the last twenty years, the replica-symmetry-breaking mean field theory of spin glasses and the associated message-passing algorithms have greatly deepened our understanding of typical-case computation complexity. In this paper, we use the vertex cover problem, a basic nondeterministic-polynomial (NP)-complete combinatorial optimization problem of wide application, as an example to introduce the statistical physical methods and algorithms. We do not go into the technical details but emphasize mainly the intuitive physical meanings of the message-passing equations. A nonfamiliar reader shall be able to understand to a large extent the physics behind the mean field approaches and to adjust the mean field methods in solving other optimization problems.

Trellis Tone Modulation Multiple-Access for Peer Discovery in D2D Networks.

PubMed

Lim, Chiwoo; Jang, Min; Kim, Sang-Hyo

2018-04-17

In this paper, a new non-orthogonal multiple-access scheme, trellis tone modulation multiple-access (TTMMA), is proposed for peer discovery of distributed device-to-device (D2D) communication. The range and capacity of discovery are important performance metrics in peer discovery. The proposed trellis tone modulation uses single-tone transmission and achieves a long discovery range due to its low Peak-to-Average Power Ratio (PAPR). The TTMMA also exploits non-orthogonal resource assignment to increase the discovery capacity. For the multi-user detection of superposed multiple-access signals, a message-passing algorithm with supplementary schemes are proposed. With TTMMA and its message-passing demodulation, approximately 1.5 times the number of devices are discovered compared to the conventional frequency division multiple-access (FDMA)-based discovery.

A Message Passing Approach to Side Chain Positioning with Applications in Protein Docking Refinement *

PubMed Central

Moghadasi, Mohammad; Kozakov, Dima; Mamonov, Artem B.; Vakili, Pirooz; Vajda, Sandor; Paschalidis, Ioannis Ch.

2013-01-01

We introduce a message-passing algorithm to solve the Side Chain Positioning (SCP) problem. SCP is a crucial component of protein docking refinement, which is a key step of an important class of problems in computational structural biology called protein docking. We model SCP as a combinatorial optimization problem and formulate it as a Maximum Weighted Independent Set (MWIS) problem. We then employ a modified and convergent belief-propagation algorithm to solve a relaxation of MWIS and develop randomized estimation heuristics that use the relaxed solution to obtain an effective MWIS feasible solution. Using a benchmark set of protein complexes we demonstrate that our approach leads to more accurate docking predictions compared to a baseline algorithm that does not solve the SCP. PMID:23515575

Multi-partitioning for ADI-schemes on message passing architectures

NASA Technical Reports Server (NTRS)

Vanderwijngaart, Rob F.

1994-01-01

A kind of discrete-operator splitting called Alternating Direction Implicit (ADI) has been found to be useful in simulating fluid flow problems. In particular, it is being used to study the effects of hot exhaust jets from high performance aircraft on landing surfaces. Decomposition techniques that minimize load imbalance and message-passing frequency are described. Three strategies that are investigated for implementing the NAS Scalar Penta-diagonal Parallel Benchmark (SP) are transposition, pipelined Gaussian elimination, and multipartitioning. The multipartitioning strategy, which was used on Ethernet, was found to be the most efficient, although it was considered only a moderate success because of Ethernet's limited communication properties. The efficiency derived largely from the coarse granularity of the strategy, which reduced latencies and allowed overlap of communication and computation.

Incremental Parallelization of Non-Data-Parallel Programs Using the Charon Message-Passing Library

NASA Technical Reports Server (NTRS)

VanderWijngaart, Rob F.

2000-01-01

Message passing is among the most popular techniques for parallelizing scientific programs on distributed-memory architectures. The reasons for its success are wide availability (MPI), efficiency, and full tuning control provided to the programmer. A major drawback, however, is that incremental parallelization, as offered by compiler directives, is not generally possible, because all data structures have to be changed throughout the program simultaneously. Charon remedies this situation through mappings between distributed and non-distributed data. It allows breaking up the parallelization into small steps, guaranteeing correctness at every stage. Several tools are available to help convert legacy codes into high-performance message-passing programs. They usually target data-parallel applications, whose loops carrying most of the work can be distributed among all processors without much dependency analysis. Others do a full dependency analysis and then convert the code virtually automatically. Even more toolkits are available that aid construction from scratch of message passing programs. None, however, allows piecemeal translation of codes with complex data dependencies (i.e. non-data-parallel programs) into message passing codes. The Charon library (available in both C and Fortran) provides incremental parallelization capabilities by linking legacy code arrays with distributed arrays. During the conversion process, non-distributed and distributed arrays exist side by side, and simple mapping functions allow the programmer to switch between the two in any location in the program. Charon also provides wrapper functions that leave the structure of the legacy code intact, but that allow execution on truly distributed data. Finally, the library provides a rich set of communication functions that support virtually all patterns of remote data demands in realistic structured grid scientific programs, including transposition, nearest-neighbor communication, pipelining, gather/scatter, and redistribution. At the end of the conversion process most intermediate Charon function calls will have been removed, the non-distributed arrays will have been deleted, and virtually the only remaining Charon functions calls are the high-level, highly optimized communications. Distribution of the data is under complete control of the programmer, although a wide range of useful distributions is easily available through predefined functions. A crucial aspect of the library is that it does not allocate space for distributed arrays, but accepts programmer-specified memory. This has two major consequences. First, codes parallelized using Charon do not suffer from encapsulation; user data is always directly accessible. This provides high efficiency, and also retains the possibility of using message passing directly for highly irregular communications. Second, non-distributed arrays can be interpreted as (trivial) distributions in the Charon sense, which allows them to be mapped to truly distributed arrays, and vice versa. This is the mechanism that enables incremental parallelization. In this paper we provide a brief introduction of the library and then focus on the actual steps in the parallelization process, using some representative examples from, among others, the NAS Parallel Benchmarks. We show how a complicated two-dimensional pipeline-the prototypical non-data-parallel algorithm- can be constructed with ease. To demonstrate the flexibility of the library, we give examples of the stepwise, efficient parallel implementation of nonlocal boundary conditions common in aircraft simulations, as well as the construction of the sequence of grids required for multigrid.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moryakov, A. V., E-mail: sailor@orc.ru

2016-12-15

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

An MPA-IO interface to HPSS

NASA Technical Reports Server (NTRS)

Jones, Terry; Mark, Richard; Martin, Jeanne; May, John; Pierce, Elsie; Stanberry, Linda

1996-01-01

This paper describes an implementation of the proposed MPI-IO (Message Passing Interface - Input/Output) standard for parallel I/O. Our system uses third-party transfer to move data over an external network between the processors where it is used and the I/O devices where it resides. Data travels directly from source to destination, without the need for shuffling it among processors or funneling it through a central node. Our distributed server model lets multiple compute nodes share the burden of coordinating data transfers. The system is built on the High Performance Storage System (HPSS), and a prototype version runs on a Meiko CS-2 parallel computer.

Development of a distributed control system for TOTEM experiment using ASIO Boost C++ libraries

NASA Astrophysics Data System (ADS)

Cafagna, F.; Mercadante, A.; Minafra, N.; Quinto, M.; Radicioni, E.

2014-06-01

The main goals of the TOTEM Experiment at the LHC are the measurements of the elastic and total p-p cross sections and the studies of the diffractive dissociation processes. Those scientific objectives are achieved by using three tracking detectors symmetrically arranged around the interaction point called IP5. The control system is based on a C++ software that allows the user, by means of a graphical interface, direct access to hardware and handling of devices configuration. A first release of the software was designed as a monolithic block, with all functionalities being merged together. Such approach showed soon its limits, mainly poor reusability and maintainability of the source code, evident not only in phase of bug-fixing, but also when one wants to extend functionalities or apply some other modifications. This led to the decision of a radical redesign of the software, now based on the dialogue (message-passing) among separate building blocks. Thanks to the acquired extensibility, the software gained new features and now is a complete tool by which it is possible not only to configure different devices interfacing with a large subset of buses like I2C and VME, but also to do data acquisition both for calibration and physics runs. Furthermore, the software lets the user set up a series of operations to be executed sequentially to handle complex operations. To achieve maximum flexibility, the program units may be run either as a single process or as separate processes on different PCs which exchange messages over the network, thus allowing remote control of the system. Portability is ensured by the adoption of the ASIO (Asynchronous Input Output) library of Boost, a cross-platform suite of libraries which is candidate to become part of the C++ 11 standard. We present the state of the art of this project and outline the future perspectives. In particular, we describe the system architecture and the message-passing scheme. We also report on the results obtained in a first complete test of the software both as a single process and on two PCs.

Evaluation of the implementation of new traceability and food safety requirements in the pig industry in eastern Australia.

PubMed

Hernández-Jover, M; Schembri, N; Toribio, J-A; Holyoake, P K

2009-10-01

To evaluate the implementation and barriers to adoption, among pig producers, of a newly introduced traceability and food safety system in Australia. Implementation of the PigPass national vendor declaration (NVD) linked to an on-farm quality assurance (QA) program was evaluated in May and December 2007 at saleyards and abattoirs in New South Wales, Victoria and Queensland. Four focus group discussions with saleyard producers were held between April and July 2007. Implementation of the PigPass system in terms of accurate completion of the form and QA accreditation was higher at the export abattoir than at the regional saleyard at the first audit (P < 0.01). Implementation increased at the second audit at the abattoirs, but little change with time was observed at saleyards. Approximately half of the producers at saleyards used photocopied PigPass forms, made at least one error (>64%), and many vendors did not appear to be QA-accredited. During focus groups, producers expressed the view that PigPass implementation improved animal and product traceability. They identified the associated costs and a perceived lack of support by information providers as obstacles for adoption. Improvement in the implementation of PigPass among producers marketing pigs at export abattoirs was observed during the 8-month period of the study. There is a need for a more uniform message to producers from government agencies on the importance of the PigPass NVD and QA and extension and education targeted toward producers supplying pigs to saleyards and domestic abattoirs to ensure compliance with the traceability requirements.

Statistical mechanics of complex neural systems and high dimensional data

NASA Astrophysics Data System (ADS)

Advani, Madhu; Lahiri, Subhaneil; Ganguli, Surya

2013-03-01

Recent experimental advances in neuroscience have opened new vistas into the immense complexity of neuronal networks. This proliferation of data challenges us on two parallel fronts. First, how can we form adequate theoretical frameworks for understanding how dynamical network processes cooperate across widely disparate spatiotemporal scales to solve important computational problems? Second, how can we extract meaningful models of neuronal systems from high dimensional datasets? To aid in these challenges, we give a pedagogical review of a collection of ideas and theoretical methods arising at the intersection of statistical physics, computer science and neurobiology. We introduce the interrelated replica and cavity methods, which originated in statistical physics as powerful ways to quantitatively analyze large highly heterogeneous systems of many interacting degrees of freedom. We also introduce the closely related notion of message passing in graphical models, which originated in computer science as a distributed algorithm capable of solving large inference and optimization problems involving many coupled variables. We then show how both the statistical physics and computer science perspectives can be applied in a wide diversity of contexts to problems arising in theoretical neuroscience and data analysis. Along the way we discuss spin glasses, learning theory, illusions of structure in noise, random matrices, dimensionality reduction and compressed sensing, all within the unified formalism of the replica method. Moreover, we review recent conceptual connections between message passing in graphical models, and neural computation and learning. Overall, these ideas illustrate how statistical physics and computer science might provide a lens through which we can uncover emergent computational functions buried deep within the dynamical complexities of neuronal networks.

Performance and Application of Parallel OVERFLOW Codes on Distributed and Shared Memory Platforms

NASA Technical Reports Server (NTRS)

Djomehri, M. Jahed; Rizk, Yehia M.

1999-01-01

The presentation discusses recent studies on the performance of the two parallel versions of the aerodynamics CFD code, OVERFLOW_MPI and _MLP. Developed at NASA Ames, the serial version, OVERFLOW, is a multidimensional Navier-Stokes flow solver based on overset (Chimera) grid technology. The code has recently been parallelized in two ways. One is based on the explicit message-passing interface (MPI) across processors and uses the _MPI communication package. This approach is primarily suited for distributed memory systems and workstation clusters. The second, termed the multi-level parallel (MLP) method, is simple and uses shared memory for all communications. The _MLP code is suitable on distributed-shared memory systems. For both methods, the message passing takes place across the processors or processes at the advancement of each time step. This procedure is, in effect, the Chimera boundary conditions update, which is done in an explicit "Jacobi" style. In contrast, the update in the serial code is done in more of the "Gauss-Sidel" fashion. The programming efforts for the _MPI code is more complicated than for the _MLP code; the former requires modification of the outer and some inner shells of the serial code, whereas the latter focuses only on the outer shell of the code. The _MPI version offers a great deal of flexibility in distributing grid zones across a specified number of processors in order to achieve load balancing. The approach is capable of partitioning zones across multiple processors or sending each zone and/or cluster of several zones into a single processor. The message passing across the processors consists of Chimera boundary and/or an overlap of "halo" boundary points for each partitioned zone. The MLP version is a new coarse-grain parallel concept at the zonal and intra-zonal levels. A grouping strategy is used to distribute zones into several groups forming sub-processes which will run in parallel. The total volume of grid points in each group are approximately balanced. A proper number of threads are initially allocated to each group, and in subsequent iterations during the run-time, the number of threads are adjusted to achieve load balancing across the processes. Each process exploits the multitasking directives already established in Overflow.

Passing Messages between Biological Networks to Refine Predicted Interactions

PubMed Central

Glass, Kimberly; Huttenhower, Curtis; Quackenbush, John; Yuan, Guo-Cheng

2013-01-01

Regulatory network reconstruction is a fundamental problem in computational biology. There are significant limitations to such reconstruction using individual datasets, and increasingly people attempt to construct networks using multiple, independent datasets obtained from complementary sources, but methods for this integration are lacking. We developed PANDA (Passing Attributes between Networks for Data Assimilation), a message-passing model using multiple sources of information to predict regulatory relationships, and used it to integrate protein-protein interaction, gene expression, and sequence motif data to reconstruct genome-wide, condition-specific regulatory networks in yeast as a model. The resulting networks were not only more accurate than those produced using individual data sets and other existing methods, but they also captured information regarding specific biological mechanisms and pathways that were missed using other methodologies. PANDA is scalable to higher eukaryotes, applicable to specific tissue or cell type data and conceptually generalizable to include a variety of regulatory, interaction, expression, and other genome-scale data. An implementation of the PANDA algorithm is available at www.sourceforge.net/projects/panda-net. PMID:23741402

Applications of Probabilistic Combiners on Linear Feedback Shift Register Sequences

DTIC Science & Technology

2016-12-01

on the resulting output strings show a drastic increase in complexity, while simultaneously passing the stringent randomness tests required by the...a three-variable function. Our tests on the resulting output strings show a drastic increase in complex- ity, while simultaneously passing the...10001101 01000010 11101001 Decryption of a message that has been encrypted using bitwise XOR is quite simple. Since each bit is its own additive inverse

ADHydro: A Parallel Implementation of a Large-scale High-Resolution Multi-Physics Distributed Water Resources Model Using the Charm++ Run Time System

NASA Astrophysics Data System (ADS)

Steinke, R. C.; Ogden, F. L.; Lai, W.; Moreno, H. A.; Pureza, L. G.

2014-12-01

Physics-based watershed models are useful tools for hydrologic studies, water resources management and economic analyses in the contexts of climate, land-use, and water-use changes. This poster presents a parallel implementation of a quasi 3-dimensional, physics-based, high-resolution, distributed water resources model suitable for simulating large watersheds in a massively parallel computing environment. Developing this model is one of the objectives of the NSF EPSCoR RII Track II CI-WATER project, which is joint between Wyoming and Utah EPSCoR jurisdictions. The model, which we call ADHydro, is aimed at simulating important processes in the Rocky Mountain west, including: rainfall and infiltration, snowfall and snowmelt in complex terrain, vegetation and evapotranspiration, soil heat flux and freezing, overland flow, channel flow, groundwater flow, water management and irrigation. Model forcing is provided by the Weather Research and Forecasting (WRF) model, and ADHydro is coupled with the NOAH-MP land-surface scheme for calculating fluxes between the land and atmosphere. The ADHydro implementation uses the Charm++ parallel run time system. Charm++ is based on location transparent message passing between migrateable C++ objects. Each object represents an entity in the model such as a mesh element. These objects can be migrated between processors or serialized to disk allowing the Charm++ system to automatically provide capabilities such as load balancing and checkpointing. Objects interact with each other by passing messages that the Charm++ system routes to the correct destination object regardless of its current location. This poster discusses the algorithms, communication patterns, and caching strategies used to implement ADHydro with Charm++. The ADHydro model code will be released to the hydrologic community in late 2014.

Earth Observation

NASA Image and Video Library

2013-07-26

Earth observation taken during day pass by an Expedition 36 crew member on board the International Space Station (ISS). Per Twitter message: Never tire of finding shapes in the clouds! These look very botanical to me. Simply perfect.

PREEMIE Reauthorization Act

THOMAS, 112th Congress

Sen. Alexander, Lamar [R-TN

2011-07-28

Senate - 12/19/2012 Message on House action received in Senate and at desk: House amendments to Senate bill. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

Electronic Cigarettes on Twitter – Spreading the Appeal of Flavors

PubMed Central

Chu, Kar-Hai; Unger, Jennifer B.; Cruz, Tess Boley; Soto, Daniel W.

2016-01-01

Objectives Social media platforms are used by tobacco companies to promote products. This study examines message content on Twitter from e-cigarette brands and determines if messages about flavors are more likely than non-flavor messages to be passed along to other viewers. Methods We examined Twitter data from 2 e-cigarette brands and identified messages that contained terms related to e-cigarette flavors. Results Flavor-related posts were retweeted at a significantly higher rate by e-cigarette brands (p = .04) and other Twitter users (p < .01) than non-flavor posts. Conclusions E-cigarette brands and other Twitter users pay attention to flavor-related posts and retweet them often. These findings suggest flavors continue to be an attractive characteristic and their marketing should be monitored closely. PMID:27853734

Parallelization of the TRIGRS model for rainfall-induced landslides using the message passing interface

USGS Publications Warehouse

Alvioli, M.; Baum, R.L.

2016-01-01

We describe a parallel implementation of TRIGRS, the Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability Model for the timing and distribution of rainfall-induced shallow landslides. We have parallelized the four time-demanding execution modes of TRIGRS, namely both the saturated and unsaturated model with finite and infinite soil depth options, within the Message Passing Interface framework. In addition to new features of the code, we outline details of the parallel implementation and show the performance gain with respect to the serial code. Results are obtained both on commercial hardware and on a high-performance multi-node machine, showing the different limits of applicability of the new code. We also discuss the implications for the application of the model on large-scale areas and as a tool for real-time landslide hazard monitoring.

The Physical Therapy and Society Summit (PASS) Meeting: observations and opportunities.

PubMed

Kigin, Colleen M; Rodgers, Mary M; Wolf, Steven L

2010-11-01

The construct of delivering high-quality and cost-effective health care is in flux, and the profession must strategically plan how to meet the needs of society. In 2006, the House of Delegates of the American Physical Therapy Association passed a motion to convene a summit on "how physical therapists can meet current, evolving, and future societal health care needs." The Physical Therapy and Society Summit (PASS) meeting on February 27-28, 2009, in Leesburg, Virginia, sent a clear message that for physical therapists to be effective and thrive in the health care environment of the future, a paradigm shift is required. During the PASS meeting, participants reframed our traditional focus on the physical therapist and the patient/client (consumer) to one in which physical therapists are an integral part of a collaborative, multidisciplinary health care team with the health care consumer as its focus. The PASS Steering Committee recognized that some of the opportunities that surfaced during the PASS meeting may be disruptive or may not be within the profession's present strategic or tactical plans. Thus, adopting a framework that helps to establish the need for change that is provocative and potentially disruptive to our present care delivery, yet prioritizes opportunities, is a critical and essential step. Each of us in the physical therapy profession must take on post-PASS roles and responsibilities to accomplish the systemic change that is so intimately intertwined with our destiny. This article offers a perspective of the dynamic dialogue and suggestions that emerged from the PASS event, providing further opportunities for discussion and action within our profession.

NAS Parallel Benchmark. Results 11-96: Performance Comparison of HPF and MPI Based NAS Parallel Benchmarks. 1.0

NASA Technical Reports Server (NTRS)

Saini, Subash; Bailey, David; Chancellor, Marisa K. (Technical Monitor)

1997-01-01

High Performance Fortran (HPF), the high-level language for parallel Fortran programming, is based on Fortran 90. HALF was defined by an informal standards committee known as the High Performance Fortran Forum (HPFF) in 1993, and modeled on TMC's CM Fortran language. Several HPF features have since been incorporated into the draft ANSI/ISO Fortran 95, the next formal revision of the Fortran standard. HPF allows users to write a single parallel program that can execute on a serial machine, a shared-memory parallel machine, or a distributed-memory parallel machine. HPF eliminates the complex, error-prone task of explicitly specifying how, where, and when to pass messages between processors on distributed-memory machines, or when to synchronize processors on shared-memory machines. HPF is designed in a way that allows the programmer to code an application at a high level, and then selectively optimize portions of the code by dropping into message-passing or calling tuned library routines as 'extrinsics'. Compilers supporting High Performance Fortran features first appeared in late 1994 and early 1995 from Applied Parallel Research (APR) Digital Equipment Corporation, and The Portland Group (PGI). IBM introduced an HPF compiler for the IBM RS/6000 SP/2 in April of 1996. Over the past two years, these implementations have shown steady improvement in terms of both features and performance. The performance of various hardware/ programming model (HPF and MPI (message passing interface)) combinations will be compared, based on latest NAS (NASA Advanced Supercomputing) Parallel Benchmark (NPB) results, thus providing a cross-machine and cross-model comparison. Specifically, HPF based NPB results will be compared with MPI based NPB results to provide perspective on performance currently obtainable using HPF versus MPI or versus hand-tuned implementations such as those supplied by the hardware vendors. In addition we would also present NPB (Version 1.0) performance results for the following systems: DEC Alpha Server 8400 5/440, Fujitsu VPP Series (VX, VPP300, and VPP700), HP/Convex Exemplar SPP2000, IBM RS/6000 SP P2SC node (120 MHz) NEC SX-4/32, SGI/CRAY T3E, SGI Origin2000.

Earth Observation

NASA Image and Video Library

2013-08-03

Earth observation taken during day pass by an Expedition 36 crew member on board the International Space Station (ISS). Per Twitter message: From southernmost point of orbit over the South Pacific- all clouds seemed to be leading to the South Pole.

Earth Observation

NASA Image and Video Library

2013-07-21

Earth observation taken during night pass by an Expedition 36 crew member on board the International Space Station (ISS). Per Twitter message this is labeled as : Tehran, Iran. Lights along the coast of the Caspian Sea visible through clouds. July 21.

Whistleblower Protection Enhancement Act of 2010

THOMAS, 111th Congress

Sen. Akaka, Daniel K. [D-HI

2009-02-03

Senate - 12/22/2010 Message on House action received in Senate and at desk: House amendments to Senate bill. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

Earth Observation

NASA Image and Video Library

2014-05-31

Earth Observation taken during a day pass by the Expedition 40 crew aboard the International Space Station (ISS). Folder lists this as: CEO - Arena de Sao Paolo. View used for Twitter message: Cloudy skies over São Paulo Brazil

Development of mpi_EPIC model for global agroecosystem modeling

DOE PAGES

Kang, Shujiang; Wang, Dali; Jeff A. Nichols; ...

2014-12-31

Models that address policy-maker concerns about multi-scale effects of food and bioenergy production systems are computationally demanding. We integrated the message passing interface algorithm into the process-based EPIC model to accelerate computation of ecosystem effects. Simulation performance was further enhanced by applying the Vampir framework. When this enhanced mpi_EPIC model was tested, total execution time for a global 30-year simulation of a switchgrass cropping system was shortened to less than 0.5 hours on a supercomputer. The results illustrate that mpi_EPIC using parallel design can balance simulation workloads and facilitate large-scale, high-resolution analysis of agricultural production systems, management alternatives and environmentalmore » effects.« less

A multiarchitecture parallel-processing development environment

NASA Technical Reports Server (NTRS)

Townsend, Scott; Blech, Richard; Cole, Gary

1993-01-01

A description is given of the hardware and software of a multiprocessor test bed - the second generation Hypercluster system. The Hypercluster architecture consists of a standard hypercube distributed-memory topology, with multiprocessor shared-memory nodes. By using standard, off-the-shelf hardware, the system can be upgraded to use rapidly improving computer technology. The Hypercluster's multiarchitecture nature makes it suitable for researching parallel algorithms in computational field simulation applications (e.g., computational fluid dynamics). The dedicated test-bed environment of the Hypercluster and its custom-built software allows experiments with various parallel-processing concepts such as message passing algorithms, debugging tools, and computational 'steering'. Such research would be difficult, if not impossible, to achieve on shared, commercial systems.

Porting LAMMPS to GPUs.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, William Michael; Plimpton, Steven James; Wang, Peng

2010-03-01

LAMMPS is a classical molecular dynamics code, and an acronym for Large-scale Atomic/Molecular Massively Parallel Simulator. LAMMPS has potentials for soft materials (biomolecules, polymers) and solid-state materials (metals, semiconductors) and coarse-grained or mesoscopic systems. It can be used to model atoms or, more generically, as a parallel particle simulator at the atomic, meso, or continuum scale. LAMMPS runs on single processors or in parallel using message-passing techniques and a spatial-decomposition of the simulation domain. The code is designed to be easy to modify or extend with new functionality.

Aspen: A microsimulation model of the economy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basu, N.; Pryor, R.J.; Quint, T.

1996-10-01

This report presents, Aspen. Sandia National Laboratories is developing this new agent-based microeconomic simulation model of the U.S. economy. The model is notable because it allows a large number of individual economic agents to be modeled at a high level of detail and with a great degree of freedom. Some features of Aspen are (a) a sophisticated message-passing system that allows individual pairs of agents to communicate, (b) the use of genetic algorithms to simulate the learning of certain agents, and (c) a detailed financial sector that includes a banking system and a bond market. Results from runs of themore » model are also presented.« less

Decaf: Decoupled Dataflows for In Situ High-Performance Workflows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dreher, M.; Peterka, T.

Decaf is a dataflow system for the parallel communication of coupled tasks in an HPC workflow. The dataflow can perform arbitrary data transformations ranging from simply forwarding data to complex data redistribution. Decaf does this by allowing the user to allocate resources and execute custom code in the dataflow. All communication through the dataflow is efficient parallel message passing over MPI. The runtime for calling tasks is entirely message-driven; Decaf executes a task when all messages for the task have been received. Such a messagedriven runtime allows cyclic task dependencies in the workflow graph, for example, to enact computational steeringmore » based on the result of downstream tasks. Decaf includes a simple Python API for describing the workflow graph. This allows Decaf to stand alone as a complete workflow system, but Decaf can also be used as the dataflow layer by one or more other workflow systems to form a heterogeneous task-based computing environment. In one experiment, we couple a molecular dynamics code with a visualization tool using the FlowVR and Damaris workflow systems and Decaf for the dataflow. In another experiment, we test the coupling of a cosmology code with Voronoi tessellation and density estimation codes using MPI for the simulation, the DIY programming model for the two analysis codes, and Decaf for the dataflow. Such workflows consisting of heterogeneous software infrastructures exist because components are developed separately with different programming models and runtimes, and this is the first time that such heterogeneous coupling of diverse components was demonstrated in situ on HPC systems.« less

Terrorism Risk Insurance Program Reauthorization Act of 2014

THOMAS, 113th Congress

Sen. Schumer, Charles E. [D-NY

2014-04-10

Senate - 12/11/2014 Message on House action received in Senate and at desk: House amendment to Senate bill. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

Electronic Message Preservation Act

THOMAS, 111th Congress

Rep. Hodes, Paul W. [D-NH-2

2009-03-09

Senate - 03/18/2010 Received in the Senate and Read twice and referred to the Committee on Homeland Security and Governmental Affairs. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

Federal Financial Assistance Management Improvement Act of 2009

THOMAS, 111th Congress

Sen. Voinovich, George V. [R-OH

2009-01-22

Senate - 12/15/2009 Message on House action received in Senate and at desk: House amendment to Senate bill. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

Messaging to Increase Public Support for Naloxone Distribution Policies in the United States: Results from a Randomized Survey Experiment.

PubMed

Bachhuber, Marcus A; McGinty, Emma E; Kennedy-Hendricks, Alene; Niederdeppe, Jeff; Barry, Colleen L

2015-01-01

Barriers to public support for naloxone distribution include lack of knowledge, concerns about potential unintended consequences, and lack of sympathy for people at risk of overdose. A randomized survey experiment was conducted with a nationally-representative web-based survey research panel (GfK KnowledgePanel). Participants were randomly assigned to read different messages alone or in combination: 1) factual information about naloxone; 2) pre-emptive refutation of potential concerns about naloxone distribution; and 3) a sympathetic narrative about a mother whose daughter died of an opioid overdose. Participants were then asked if they support or oppose policies related to naloxone distribution. For each policy item, logistic regression models were used to test the effect of each message exposure compared with the no-exposure control group. The final sample consisted of 1,598 participants (completion rate: 72.6%). Factual information and the sympathetic narrative alone each led to higher support for training first responders to use naloxone, providing naloxone to friends and family members of people using opioids, and passing laws to protect people who administer naloxone. Participants receiving the combination of the sympathetic narrative and factual information, compared to factual information alone, were more likely to support all policies: providing naloxone to friends and family members (OR: 2.0 [95% CI: 1.4 to 2.9]), training first responders to use naloxone (OR: 2.0 [95% CI: 1.2 to 3.4]), passing laws to protect people if they administer naloxone (OR: 1.5 [95% CI: 1.04 to 2.2]), and passing laws to protect people if they call for medical help for an overdose (OR: 1.7 [95% CI: 1.2 to 2.5]). All messages increased public support, but combining factual information and the sympathetic narrative was most effective. Public support for naloxone distribution can be improved through education and sympathetic portrayals of the population who stands to benefit from these policies.

Message-passing-interface-based parallel FDTD investigation on the EM scattering from a 1-D rough sea surface using uniaxial perfectly matched layer absorbing boundary.

PubMed

Li, J; Guo, L-X; Zeng, H; Han, X-B

2009-06-01

A message-passing-interface (MPI)-based parallel finite-difference time-domain (FDTD) algorithm for the electromagnetic scattering from a 1-D randomly rough sea surface is presented. The uniaxial perfectly matched layer (UPML) medium is adopted for truncation of FDTD lattices, in which the finite-difference equations can be used for the total computation domain by properly choosing the uniaxial parameters. This makes the parallel FDTD algorithm easier to implement. The parallel performance with different processors is illustrated for one sea surface realization, and the computation time of the parallel FDTD algorithm is dramatically reduced compared to a single-process implementation. Finally, some numerical results are shown, including the backscattering characteristics of sea surface for different polarization and the bistatic scattering from a sea surface with large incident angle and large wind speed.

Performance Analysis of Distributed Object-Oriented Applications

NASA Technical Reports Server (NTRS)

Schoeffler, James D.

1998-01-01

The purpose of this research was to evaluate the efficiency of a distributed simulation architecture which creates individual modules which are made self-scheduling through the use of a message-based communication system used for requesting input data from another module which is the source of that data. To make the architecture as general as possible, the message-based communication architecture was implemented using standard remote object architectures (Common Object Request Broker Architecture (CORBA) and/or Distributed Component Object Model (DCOM)). A series of experiments were run in which different systems are distributed in a variety of ways across multiple computers and the performance evaluated. The experiments were duplicated in each case so that the overhead due to message communication and data transmission can be separated from the time required to actually perform the computational update of a module each iteration. The software used to distribute the modules across multiple computers was developed in the first year of the current grant and was modified considerably to add a message-based communication scheme supported by the DCOM distributed object architecture. The resulting performance was analyzed using a model created during the first year of this grant which predicts the overhead due to CORBA and DCOM remote procedure calls and includes the effects of data passed to and from the remote objects. A report covering the distributed simulation software and the results of the performance experiments has been submitted separately. The above report also discusses possible future work to apply the methodology to dynamically distribute the simulation modules so as to minimize overall computation time.

Message passing with queues and channels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dozsa, Gabor J; Heidelberger, Philip; Kumar, Sameer

In an embodiment, a send thread receives an identifier that identifies a destination node and a pointer to data. The send thread creates a first send request in response to the receipt of the identifier and the data pointer. The send thread selects a selected channel from among a plurality of channels. The selected channel comprises a selected hand-off queue and an identification of a selected message unit. Each of the channels identifies a different message unit. The selected hand-off queue is randomly accessible. If the selected hand-off queue contains an available entry, the send thread adds the first sendmore » request to the selected hand-off queue. If the selected hand-off queue does not contain an available entry, the send thread removes a second send request from the selected hand-off queue and sends the second send request to the selected message unit.« less

Cluster Computing For Real Time Seismic Array Analysis.

NASA Astrophysics Data System (ADS)

Martini, M.; Giudicepietro, F.

A seismic array is an instrument composed by a dense distribution of seismic sen- sors that allow to measure the directional properties of the wavefield (slowness or wavenumber vector) radiated by a seismic source. Over the last years arrays have been widely used in different fields of seismological researches. In particular they are applied in the investigation of seismic sources on volcanoes where they can be suc- cessfully used for studying the volcanic microtremor and long period events which are critical for getting information on the volcanic systems evolution. For this reason arrays could be usefully employed for the volcanoes monitoring, however the huge amount of data produced by this type of instruments and the processing techniques which are quite time consuming limited their potentiality for this application. In order to favor a direct application of arrays techniques to continuous volcano monitoring we designed and built a small PC cluster able to near real time computing the kinematics properties of the wavefield (slowness or wavenumber vector) produced by local seis- mic source. The cluster is composed of 8 Intel Pentium-III bi-processors PC working at 550 MHz, and has 4 Gigabytes of RAM memory. It runs under Linux operating system. The developed analysis software package is based on the Multiple SIgnal Classification (MUSIC) algorithm and is written in Fortran. The message-passing part is based upon the LAM programming environment package, an open-source imple- mentation of the Message Passing Interface (MPI). The developed software system includes modules devote to receiving date by internet and graphical applications for the continuous displaying of the processing results. The system has been tested with a data set collected during a seismic experiment conducted on Etna in 1999 when two dense seismic arrays have been deployed on the northeast and the southeast flanks of this volcano. A real time continuous acquisition system has been simulated by a pro- gram which reads data from disk files and send them to a remote host by using the Internet protocols.

SBML-PET-MPI: a parallel parameter estimation tool for Systems Biology Markup Language based models.

PubMed

Zi, Zhike

2011-04-01

Parameter estimation is crucial for the modeling and dynamic analysis of biological systems. However, implementing parameter estimation is time consuming and computationally demanding. Here, we introduced a parallel parameter estimation tool for Systems Biology Markup Language (SBML)-based models (SBML-PET-MPI). SBML-PET-MPI allows the user to perform parameter estimation and parameter uncertainty analysis by collectively fitting multiple experimental datasets. The tool is developed and parallelized using the message passing interface (MPI) protocol, which provides good scalability with the number of processors. SBML-PET-MPI is freely available for non-commercial use at http://www.bioss.uni-freiburg.de/cms/sbml-pet-mpi.html or http://sites.google.com/site/sbmlpetmpi/.

Domestic Minor Sex Trafficking Deterrence and Victims Support Act of 2010

THOMAS, 111th Congress

Sen. Wyden, Ron [D-OR

2009-12-22

Senate - 12/21/2010 Message on House action received in Senate and at desk: House amendment to Senate bill. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

Supporting shared data structures on distributed memory architectures

NASA Technical Reports Server (NTRS)

Koelbel, Charles; Mehrotra, Piyush; Vanrosendale, John

1990-01-01

Programming nonshared memory systems is more difficult than programming shared memory systems, since there is no support for shared data structures. Current programming languages for distributed memory architectures force the user to decompose all data structures into separate pieces, with each piece owned by one of the processors in the machine, and with all communication explicitly specified by low-level message-passing primitives. A new programming environment is presented for distributed memory architectures, providing a global name space and allowing direct access to remote parts of data values. The analysis and program transformations required to implement this environment are described, and the efficiency of the resulting code on the NCUBE/7 and IPSC/2 hypercubes are described.

Multi-petascale highly efficient parallel supercomputer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asaad, Sameh; Bellofatto, Ralph E.; Blocksome, Michael A.

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

Vascular system modeling in parallel environment - distributed and shared memory approaches

PubMed Central

Jurczuk, Krzysztof; Kretowski, Marek; Bezy-Wendling, Johanne

2011-01-01

The paper presents two approaches in parallel modeling of vascular system development in internal organs. In the first approach, new parts of tissue are distributed among processors and each processor is responsible for perfusing its assigned parts of tissue to all vascular trees. Communication between processors is accomplished by passing messages and therefore this algorithm is perfectly suited for distributed memory architectures. The second approach is designed for shared memory machines. It parallelizes the perfusion process during which individual processing units perform calculations concerning different vascular trees. The experimental results, performed on a computing cluster and multi-core machines, show that both algorithms provide a significant speedup. PMID:21550891

Software Mechanisms for Multiprocessor TLB Consistency

DTIC Science & Technology

1989-12-01

thanks. Raj V aswani implemented the DASH message-passing system. Ramesh Govindan implemented part of the DASH virtual memory system. G . Scott...1 Latency (ma) 5𔃺 ---·-r··-·r···r··-T·-·-r··-·r····r····-r··-·r··- . g ~~~R=r 18 -----1·--·-r··-T·----1·--··r·---1·----1·--··r·---T·----1 16...model development. Synchronizing TLBs is similar to updating replicated data in a distributed environment. Lee and Garcia-Molina both used an M/ G /1

HyperForest: A high performance multi-processor architecture for real-time intelligent systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia, P. Jr.; Rebeil, J.P.; Pollard, H.

1997-04-01

Intelligent Systems are characterized by the intensive use of computer power. The computer revolution of the last few years is what has made possible the development of the first generation of Intelligent Systems. Software for second generation Intelligent Systems will be more complex and will require more powerful computing engines in order to meet real-time constraints imposed by new robots, sensors, and applications. A multiprocessor architecture was developed that merges the advantages of message-passing and shared-memory structures: expendability and real-time compliance. The HyperForest architecture will provide an expandable real-time computing platform for computationally intensive Intelligent Systems and open the doorsmore » for the application of these systems to more complex tasks in environmental restoration and cleanup projects, flexible manufacturing systems, and DOE`s own production and disassembly activities.« less

Automation Framework for Flight Dynamics Products Generation

NASA Technical Reports Server (NTRS)

Wiegand, Robert E.; Esposito, Timothy C.; Watson, John S.; Jun, Linda; Shoan, Wendy; Matusow, Carla

2010-01-01

XFDS provides an easily adaptable automation platform. To date it has been used to support flight dynamics operations. It coordinates the execution of other applications such as Satellite TookKit, FreeFlyer, MATLAB, and Perl code. It provides a mechanism for passing messages among a collection of XFDS processes, and allows sending and receiving of GMSEC messages. A unified and consistent graphical user interface (GUI) is used for the various tools. Its automation configuration is stored in text files, and can be edited either directly or using the GUI.

Scalability and Portability of Two Parallel Implementations of ADI

NASA Technical Reports Server (NTRS)

Phung, Thanh; VanderWijngaart, Rob F.

1994-01-01

Two domain decompositions for the implementation of the NAS Scalar Penta-diagonal Parallel Benchmark on MIMD systems are investigated, namely transposition and multi-partitioning. Hardware platforms considered are the Intel iPSC/860 and Paragon XP/S-15, and clusters of SGI workstations on ethernet, communicating through PVM. It is found that the multi-partitioning strategy offers the kind of coarse granularity that allows scaling up to hundreds of processors on a massively parallel machine. Moreover, efficiency is retained when the code is ported verbatim (save message passing syntax) to a PVM environment on a modest size cluster of workstations.

Disaster Relief Appropriations Act, 2013

THOMAS, 112th Congress

Rep. Rogers, Harold [R-KY-5

2011-02-11

Senate - 12/30/2012 Message on Senate action sent to the House. (All Actions) Notes: This bill was for a time the Senate legislative vehicle for Hurricane Sandy supplemental appropriations. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

Parallelization of a hydrological model using the message passing interface

USGS Publications Warehouse

Wu, Yiping; Li, Tiejian; Sun, Liqun; Chen, Ji

2013-01-01

With the increasing knowledge about the natural processes, hydrological models such as the Soil and Water Assessment Tool (SWAT) are becoming larger and more complex with increasing computation time. Additionally, other procedures such as model calibration, which may require thousands of model iterations, can increase running time and thus further reduce rapid modeling and analysis. Using the widely-applied SWAT as an example, this study demonstrates how to parallelize a serial hydrological model in a Windows® environment using a parallel programing technology—Message Passing Interface (MPI). With a case study, we derived the optimal values for the two parameters (the number of processes and the corresponding percentage of work to be distributed to the master process) of the parallel SWAT (P-SWAT) on an ordinary personal computer and a work station. Our study indicates that model execution time can be reduced by 42%–70% (or a speedup of 1.74–3.36) using multiple processes (two to five) with a proper task-distribution scheme (between the master and slave processes). Although the computation time cost becomes lower with an increasing number of processes (from two to five), this enhancement becomes less due to the accompanied increase in demand for message passing procedures between the master and all slave processes. Our case study demonstrates that the P-SWAT with a five-process run may reach the maximum speedup, and the performance can be quite stable (fairly independent of a project size). Overall, the P-SWAT can help reduce the computation time substantially for an individual model run, manual and automatic calibration procedures, and optimization of best management practices. In particular, the parallelization method we used and the scheme for deriving the optimal parameters in this study can be valuable and easily applied to other hydrological or environmental models.

Enabling Energy Saving Innovations Act

THOMAS, 112th Congress

Rep. Aderholt, Robert B. [R-AL-4

2012-04-26

Senate - 09/24/2012 Message on Senate action sent to the House. (All Actions) Notes: For further action, see H.R.6582, which became Public Law 112-210 on 12/18/2012. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

A Model for Speedup of Parallel Programs

DTIC Science & Technology

1997-01-01

Sanjeev. K Setia . The interaction between mem- ory allocation and adaptive partitioning in message- passing multicomputers. In IPPS 󈨣 Workshop on Job...Scheduling Strategies for Parallel Processing, pages 89{99, 1995. [15] Sanjeev K. Setia and Satish K. Tripathi. A compar- ative analysis of static

Interstate Recognition of Notarizations Act of 2010

THOMAS, 111th Congress

Rep. Aderholt, Robert B. [R-AL-4

2009-10-14

House - 11/17/2010 On motion to refer the bill and the accompanying veto message to the Committee on the Judiciary. Agreed to without objection. (All Actions) Tracker: This bill has the status Failed to pass over vetoHere are the steps for Status of Legislation:

Communication Studies of DMP and SMP Machines

NASA Technical Reports Server (NTRS)

Sohn, Andrew; Biswas, Rupak; Chancellor, Marisa K. (Technical Monitor)

1997-01-01

Understanding the interplay between machines and problems is key to obtaining high performance on parallel machines. This paper investigates the interplay between programming paradigms and communication capabilities of parallel machines. In particular, we explicate the communication capabilities of the IBM SP-2 distributed-memory multiprocessor and the SGI PowerCHALLENGEarray symmetric multiprocessor. Two benchmark problems of bitonic sorting and Fast Fourier Transform are selected for experiments. Communication-efficient algorithms are developed to exploit the overlapping capabilities of the machines. Programs are written in Message-Passing Interface for portability and identical codes are used for both machines. Various data sizes and message sizes are used to test the machines' communication capabilities. Experimental results indicate that the communication performance of the multiprocessors are consistent with the size of messages. The SP-2 is sensitive to message size but yields a much higher communication overlapping because of the communication co-processor. The PowerCHALLENGEarray is not highly sensitive to message size and yields a low communication overlapping. Bitonic sorting yields lower performance compared to FFT due to a smaller computation-to-communication ratio.

Message passing for integrating and assessing renewable generation in a redundant power grid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zdeborova, Lenka; Backhaus, Scott; Chertkov, Michael

2009-01-01

A simplified model of a redundant power grid is used to study integration of fluctuating renewable generation. The grid consists of large number of generator and consumer nodes. The net power consumption is determined by the difference between the gross consumption and the level of renewable generation. The gross consumption is drawn from a narrow distribution representing the predictability of aggregated loads, and we consider two different distributions representing wind and solar resources. Each generator is connected to D consumers, and redundancy is built in by connecting R {le} D of these consumers to other generators. The lines are switchablemore » so that at any instance each consumer is connected to a single generator. We explore the capacity of the renewable generation by determining the level of 'firm' generation capacity that can be displaced for different levels of redundancy R. We also develop message-passing control algorithm for finding switch sellings where no generator is overloaded.« less

Mapping a battlefield simulation onto message-passing parallel architectures

NASA Technical Reports Server (NTRS)

Nicol, David M.

1987-01-01

Perhaps the most critical problem in distributed simulation is that of mapping: without an effective mapping of workload to processors the speedup potential of parallel processing cannot be realized. Mapping a simulation onto a message-passing architecture is especially difficult when the computational workload dynamically changes as a function of time and space; this is exactly the situation faced by battlefield simulations. This paper studies an approach where the simulated battlefield domain is first partitioned into many regions of equal size; typically there are more regions than processors. The regions are then assigned to processors; a processor is responsible for performing all simulation activity associated with the regions. The assignment algorithm is quite simple and attempts to balance load by exploiting locality of workload intensity. The performance of this technique is studied on a simple battlefield simulation implemented on the Flex/32 multiprocessor. Measurements show that the proposed method achieves reasonable processor efficiencies. Furthermore, the method shows promise for use in dynamic remapping of the simulation.

High speed bus technology development

NASA Astrophysics Data System (ADS)

Modrow, Marlan B.; Hatfield, Donald W.

1989-09-01

The development and demonstration of the High Speed Data Bus system, a 50 Million bits per second (Mbps) local data network intended for avionics applications in advanced military aircraft is described. The Advanced System Avionics (ASA)/PAVE PILLAR program provided the avionics architecture concept and basic requirements. Designs for wire and fiber optic media were produced and hardware demonstrations were performed. An efficient, robust token-passing protocol was developed and partially demonstrated. The requirements specifications, the trade-offs made, and the resulting designs for both a coaxial wire media system and a fiber optics design are examined. Also, the development of a message-oriented media access protocol is described, from requirements definition through analysis, simulation and experimentation. Finally, the testing and demonstrations conducted on the breadboard and brassboard hardware is presented.

Kingman and Heritage Islands Act of 2009

THOMAS, 111th Congress

Rep. Norton, Eleanor Holmes [D-DC-At Large

2009-04-23

Senate - 09/28/2010 Message on Senate action sent to the House. (All Actions) Notes: For further action, see H.R.6278, which became Public Law 111-328 on 12/22/2010. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

Distance Learning and Public School Finance.

ERIC Educational Resources Information Center

Monahan, Brian; Wimber, Charles

This discussion of the application of computers and telecommunications technology to distance learning begins by describing a workstation equipped to produce "lessonware" in such formats as audiocassettes, videocassettes, diskettes, and voice messages. Such workstations would be located in classrooms equipped with two-way reverse passes to a cable…

Reducing Flight Delays Act of 2013

THOMAS, 113th Congress

Sen. Collins, Susan M. [R-ME

2013-04-25

Senate - 04/30/2013 Message on Senate action sent to the House. (All Actions) Notes: For further action, see H.R.1765, which became Public Law 113-9 on 5/1/2013. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

Temporary Bankruptcy Judgeships Extension Act of 2011

THOMAS, 112th Congress

Rep. Smith, Lamar [R-TX-21

2011-03-10

Senate - 04/23/2012 Message on Senate action sent to the House. (All Actions) Notes: For further action, see H.R.4967, which became Public Law 112-121 on 5/25/2012. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

Operational effectiveness of a Multiple Aquila Control System (MACS)

NASA Technical Reports Server (NTRS)

Brown, R. W.; Flynn, J. D.; Frey, M. R.

1983-01-01

The operational effectiveness of a multiple aquila control system (MACS) was examined under a variety of remotely piloted vehicle (RPV) mission configurations. The set of assumptions and inputs used to form the rules under which a computerized simulation of MACS was run is given. The characteristics that are to govern MACS operations include: the battlefield environment that generates the requests for RPV missions, operating time-lines of the RPV-peculiar equipment, maintenance requirements, and vulnerability to enemy fire. The number of RPV missions and the number of operation days are discussed. Command, control, and communication data rates are estimated by determining how many messages are passed and what information is necessary in them to support ground coordination between MACS sections.

Optimization of the design of Gas Cherenkov Detectors for ICF diagnosis

NASA Astrophysics Data System (ADS)

Liu, Bin; Hu, Huasi; Han, Hetong; Lv, Huanwen; Li, Lan

2018-07-01

A design method, which combines a genetic algorithm (GA) with Monte-Carlo simulation, is established and applied to two different types of Cherenkov detectors, namely, Gas Cherenkov Detector (GCD) and Gamma Reaction History (GRH). For accelerating the optimization program, open Message Passing Interface (MPI) is used in the Geant4 simulation. Compared with the traditional optical ray-tracing method, the performances of these detectors have been improved with the optimization method. The efficiency for GCD system, with a threshold of 6.3 MeV, is enhanced by ∼20% and time response improved by ∼7.2%. For the GRH system, with threshold of 10 MeV, the efficiency is enhanced by ∼76% in comparison with previously published results.

Networking and AI systems: Requirements and benefits

NASA Technical Reports Server (NTRS)

1988-01-01

The price performance benefits of network systems is well documented. The ability to share expensive resources sold timesharing for mainframes, department clusters of minicomputers, and now local area networks of workstations and servers. In the process, other fundamental system requirements emerged. These have now been generalized with open system requirements for hardware, software, applications and tools. The ability to interconnect a variety of vendor products has led to a specification of interfaces that allow new techniques to extend existing systems for new and exciting applications. As an example of the message passing system, local area networks provide a testbed for many of the issues addressed by future concurrent architectures: synchronization, load balancing, fault tolerance and scalability. Gold Hill has been working with a number of vendors on distributed architectures that range from a network of workstations to a hypercube of microprocessors with distributed memory. Results from early applications are promising both for performance and scalability.

A multiprocessing architecture for real-time monitoring

NASA Technical Reports Server (NTRS)

Schmidt, James L.; Kao, Simon M.; Read, Jackson Y.; Weitzenkamp, Scott M.; Laffey, Thomas J.

1988-01-01

A multitasking architecture for performing real-time monitoring and analysis using knowledge-based problem solving techniques is described. To handle asynchronous inputs and perform in real time, the system consists of three or more distributed processes which run concurrently and communicate via a message passing scheme. The Data Management Process acquires, compresses, and routes the incoming sensor data to other processes. The Inference Process consists of a high performance inference engine that performs a real-time analysis on the state and health of the physical system. The I/O Process receives sensor data from the Data Management Process and status messages and recommendations from the Inference Process, updates its graphical displays in real time, and acts as the interface to the console operator. The distributed architecture has been interfaced to an actual spacecraft (NASA's Hubble Space Telescope) and is able to process the incoming telemetry in real-time (i.e., several hundred data changes per second). The system is being used in two locations for different purposes: (1) in Sunnyville, California at the Space Telescope Test Control Center it is used in the preflight testing of the vehicle; and (2) in Greenbelt, Maryland at NASA/Goddard it is being used on an experimental basis in flight operations for health and safety monitoring.

Hyperswitch Communication Network Computer

NASA Technical Reports Server (NTRS)

Peterson, John C.; Chow, Edward T.; Priel, Moshe; Upchurch, Edwin T.

1993-01-01

Hyperswitch Communications Network (HCN) computer is prototype multiple-processor computer being developed. Incorporates improved version of hyperswitch communication network described in "Hyperswitch Network For Hypercube Computer" (NPO-16905). Designed to support high-level software and expansion of itself. HCN computer is message-passing, multiple-instruction/multiple-data computer offering significant advantages over older single-processor and bus-based multiple-processor computers, with respect to price/performance ratio, reliability, availability, and manufacturing. Design of HCN operating-system software provides flexible computing environment accommodating both parallel and distributed processing. Also achieves balance among following competing factors; performance in processing and communications, ease of use, and tolerance of (and recovery from) faults.

How to Build an AppleSeed: A Parallel Macintosh Cluster for Numerically Intensive Computing

NASA Astrophysics Data System (ADS)

Decyk, V. K.; Dauger, D. E.

We have constructed a parallel cluster consisting of a mixture of Apple Macintosh G3 and G4 computers running the Mac OS, and have achieved very good performance on numerically intensive, parallel plasma particle-incell simulations. A subset of the MPI message-passing library was implemented in Fortran77 and C. This library enabled us to port code, without modification, from other parallel processors to the Macintosh cluster. Unlike Unix-based clusters, no special expertise in operating systems is required to build and run the cluster. This enables us to move parallel computing from the realm of experts to the main stream of computing.

Scalable Replay with Partial-Order Dependencies for Message-Logging Fault Tolerance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lifflander, Jonathan; Meneses, Esteban; Menon, Harshita

2014-09-22

Deterministic replay of a parallel application is commonly used for discovering bugs or to recover from a hard fault with message-logging fault tolerance. For message passing programs, a major source of overhead during forward execution is recording the order in which messages are sent and received. During replay, this ordering must be used to deterministically reproduce the execution. Previous work in replay algorithms often makes minimal assumptions about the programming model and application in order to maintain generality. However, in many cases, only a partial order must be recorded due to determinism intrinsic in the code, ordering constraints imposed bymore » the execution model, and events that are commutative (their relative execution order during replay does not need to be reproduced exactly). In this paper, we present a novel algebraic framework for reasoning about the minimum dependencies required to represent the partial order for different concurrent orderings and interleavings. By exploiting this theory, we improve on an existing scalable message-logging fault tolerance scheme. The improved scheme scales to 131,072 cores on an IBM BlueGene/P with up to 2x lower overhead than one that records a total order.« less

A Modern Operating System for Near-real-time Environmental Observatories

NASA Astrophysics Data System (ADS)

Orcutt, John; Vernon, Frank

2014-05-01

The NSF Ocean Observatory Initiative (OOI) provided an opportunity for expanding the capabilities for managing open, near-real-time (latencies of seconds) data from ocean observatories. The sensors deployed in this system largely return data from seafloor, cabled fiber optic cables as well as satellite telemetry. Bandwidth demands range from high-definition movies to the transmission of data via Iridium satellite. The extended Internet also provides an opportunity to not only return data, but to also control the sensors and platforms that comprise the observatory. The data themselves are openly available to any users. In order to provide heightened network security and overall reliability, the connections to and from the sensors/platforms are managed without Layer 3 of the Internet, but instead rely upon message passing using an open protocol termed Advanced Queuing Messaging Protocol (AMQP). The highest bandwidths in the system are in the Regional Scale Network (RSN) off Oregon and Washington and on the continent with highly reliable network connections between observatory components at 10 Gbps. The maintenance of metadata and life cycle histories of sensors and platforms is critical for providing data provenance over the years. The integrated cyberinfrastructure is best thought of as an operating system for the observatory - like the data, the software is also open and can be readily applied to new observatories, for example, in the rapidly evolving Arctic.

Hyperswitch communication network

NASA Technical Reports Server (NTRS)

Peterson, J.; Pniel, M.; Upchurch, E.

1991-01-01

The Hyperswitch Communication Network (HCN) is a large scale parallel computer prototype being developed at JPL. Commercial versions of the HCN computer are planned. The HCN computer being designed is a message passing multiple instruction multiple data (MIMD) computer, and offers many advantages in price-performance ratio, reliability and availability, and manufacturing over traditional uniprocessors and bus based multiprocessors. The design of the HCN operating system is a uniquely flexible environment that combines both parallel processing and distributed processing. This programming paradigm can achieve a balance among the following competing factors: performance in processing and communications, user friendliness, and fault tolerance. The prototype is being designed to accommodate a maximum of 64 state of the art microprocessors. The HCN is classified as a distributed supercomputer. The HCN system is described, and the performance/cost analysis and other competing factors within the system design are reviewed.

A no-key-exchange secure image sharing scheme based on Shamir's three-pass cryptography protocol and the multiple-parameter fractional Fourier transform.

PubMed

Lang, Jun

2012-01-30

In this paper, we propose a novel secure image sharing scheme based on Shamir's three-pass protocol and the multiple-parameter fractional Fourier transform (MPFRFT), which can safely exchange information with no advance distribution of either secret keys or public keys between users. The image is encrypted directly by the MPFRFT spectrum without the use of phase keys, and information can be shared by transmitting the encrypted image (or message) three times between users. Numerical simulation results are given to verify the performance of the proposed algorithm.

E-mail, decisional styles, and rest breaks.

PubMed

Baker, James R; Phillips, James G

2007-10-01

E-mail is a common but problematic work application. A scale was created to measure tendencies to use e-mail to take breaks (e-breaking); and self-esteem and decisional style (vigilance, procrastination, buck-passing, hypervigilance) were used to predict the self-reported and actual e-mail behaviors of 133 participants (students and marketing employees). Individuals who were low in defensive avoidance (buck-passing) engaged in more e-mailing per week, both in time spent on e-mail and message volume. E-breakers were more likely to engage in behavioral procrastination and spent more time on personal e-mail.

PyPanda: a Python package for gene regulatory network reconstruction

PubMed Central

van IJzendoorn, David G.P.; Glass, Kimberly; Quackenbush, John; Kuijjer, Marieke L.

2016-01-01

Summary: PANDA (Passing Attributes between Networks for Data Assimilation) is a gene regulatory network inference method that uses message-passing to integrate multiple sources of ‘omics data. PANDA was originally coded in C ++. In this application note we describe PyPanda, the Python version of PANDA. PyPanda runs considerably faster than the C ++ version and includes additional features for network analysis. Availability and implementation: The open source PyPanda Python package is freely available at http://github.com/davidvi/pypanda. Contact: mkuijjer@jimmy.harvard.edu or d.g.p.van_ijzendoorn@lumc.nl PMID:27402905

PyPanda: a Python package for gene regulatory network reconstruction.

PubMed

van IJzendoorn, David G P; Glass, Kimberly; Quackenbush, John; Kuijjer, Marieke L

2016-11-01

PANDA (Passing Attributes between Networks for Data Assimilation) is a gene regulatory network inference method that uses message-passing to integrate multiple sources of 'omics data. PANDA was originally coded in C ++. In this application note we describe PyPanda, the Python version of PANDA. PyPanda runs considerably faster than the C ++ version and includes additional features for network analysis. The open source PyPanda Python package is freely available at http://github.com/davidvi/pypanda CONTACT: mkuijjer@jimmy.harvard.edu or d.g.p.van_ijzendoorn@lumc.nl. © The Author 2016. Published by Oxford University Press.

To amend the DNA Analysis Backlog Elimination Act of 2000 to provide for Debbie Smith grants for auditing sexual assault evidence backlogs, and for other purposes.

THOMAS, 112th Congress

Sen. Cornyn, John [R-TX

2012-05-24

Senate - 01/02/2013 Message on House action received in Senate and at desk: House amendments to Senate bill. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

Support for Debugging Automatically Parallelized Programs

NASA Technical Reports Server (NTRS)

Hood, Robert; Jost, Gabriele

2001-01-01

This viewgraph presentation provides information on support sources available for the automatic parallelization of computer program. CAPTools, a support tool developed at the University of Greenwich, transforms, with user guidance, existing sequential Fortran code into parallel message passing code. Comparison routines are then run for debugging purposes, in essence, ensuring that the code transformation was accurate.

Earth observation taken by the Expedition 43 crew.

NASA Image and Video Library

2015-03-13

Earth observation taken during a day pass by the Expedition 43 crew aboard the International Space Station (ISS). Sent as part of Twitter message: #HappyStPatrickDay with best wishes from the #E43 crew! From space you can see the “Emerald Isle” is very green!

New Frontier Congressional Gold Medal Act

THOMAS, 111th Congress

Sen. Nelson, Bill [D-FL

2009-05-01

Senate - 09/23/2010 Message received in the Senate: Returned to the Senate pursuant to the provisions of H.Res. 1653. (All Actions) Notes: For further action, see H.R.2245, which became Public Law 111-44 on 8/7/2009. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

Travel Promotion Act of 2009

THOMAS, 111th Congress

Sen. Dorgan, Byron L. [D-ND

2009-05-12

Senate - 09/23/2010 Message received in the Senate: Returned to the Senate pursuant to the provisions of H.Res. 1653. (All Actions) Notes: For further action, see H.R.1299, which became Public Law 111-145 on 3/4/2010. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

Union Agitators

ERIC Educational Resources Information Center

Honawar, Vaishali

2006-01-01

A decade has passed since a few union leaders formed the network known as Teacher Union Reform Network (TURN) to search for innovative ways to enhance education. Selling their message has not always been easy. Created in 1995, TURN was the brain child of Adam Urbanski, the president of the Rochester (N.Y.) Teachers Association for the past 25…

Monitoring Data-Structure Evolution in Distributed Message-Passing Programs

NASA Technical Reports Server (NTRS)

Sarukkai, Sekhar R.; Beers, Andrew; Woodrow, Thomas S. (Technical Monitor)

1996-01-01

Monitoring the evolution of data structures in parallel and distributed programs, is critical for debugging its semantics and performance. However, the current state-of-art in tracking and presenting data-structure information on parallel and distributed environments is cumbersome and does not scale. In this paper we present a methodology that automatically tracks memory bindings (not the actual contents) of static and dynamic data-structures of message-passing C programs, using PVM. With the help of a number of examples we show that in addition to determining the impact of memory allocation overheads on program performance, graphical views can help in debugging the semantics of program execution. Scalable animations of virtual address bindings of source-level data-structures are used for debugging the semantics of parallel programs across all processors. In conjunction with light-weight core-files, this technique can be used to complement traditional debuggers on single processors. Detailed information (such as data-structure contents), on specific nodes, can be determined using traditional debuggers after the data structure evolution leading to the semantic error is observed graphically.

PVM Wrapper

NASA Technical Reports Server (NTRS)

Katz, Daniel

2004-01-01

PVM Wrapper is a software library that makes it possible for code that utilizes the Parallel Virtual Machine (PVM) software library to run using the message-passing interface (MPI) software library, without needing to rewrite the entire code. PVM and MPI are the two most common software libraries used for applications that involve passing of messages among parallel computers. Since about 1996, MPI has been the de facto standard. Codes written when PVM was popular often feature patterns of {"initsend," "pack," "send"} and {"receive," "unpack"} calls. In many cases, these calls are not contiguous and one set of calls may even exist over multiple subroutines. These characteristics make it difficult to obtain equivalent functionality via a single MPI "send" call. Because PVM Wrapper is written to run with MPI- 1.2, some PVM functions are not permitted and must be replaced - a task that requires some programming expertise. The "pvm_spawn" and "pvm_parent" function calls are not replaced, but a programmer can use "mpirun" and knowledge of the ranks of parent and child tasks with supplied macroinstructions to enable execution of codes that use "pvm_spawn" and "pvm_parent."

Message Passing and Shared Address Space Parallelism on an SMP Cluster

NASA Technical Reports Server (NTRS)

Shan, Hongzhang; Singh, Jaswinder P.; Oliker, Leonid; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

2002-01-01

Currently, message passing (MP) and shared address space (SAS) are the two leading parallel programming paradigms. MP has been standardized with MPI, and is the more common and mature approach; however, code development can be extremely difficult, especially for irregularly structured computations. SAS offers substantial ease of programming, but may suffer from performance limitations due to poor spatial locality and high protocol overhead. In this paper, we compare the performance of and the programming effort required for six applications under both programming models on a 32-processor PC-SMP cluster, a platform that is becoming increasingly attractive for high-end scientific computing. Our application suite consists of codes that typically do not exhibit scalable performance under shared-memory programming due to their high communication-to-computation ratios and/or complex communication patterns. Results indicate that SAS can achieve about half the parallel efficiency of MPI for most of our applications, while being competitive for the others. A hybrid MPI+SAS strategy shows only a small performance advantage over pure MPI in some cases. Finally, improved implementations of two MPI collective operations on PC-SMP clusters are presented.

Impact of the infectious period on epidemics

NASA Astrophysics Data System (ADS)

Wilkinson, Robert R.; Sharkey, Kieran J.

2018-05-01

The duration of the infectious period is a crucial determinant of the ability of an infectious disease to spread. We consider an epidemic model that is network based and non-Markovian, containing classic Kermack-McKendrick, pairwise, message passing, and spatial models as special cases. For this model, we prove a monotonic relationship between the variability of the infectious period (with fixed mean) and the probability that the infection will reach any given subset of the population by any given time. For certain families of distributions, this result implies that epidemic severity is decreasing with respect to the variance of the infectious period. The striking importance of this relationship is demonstrated numerically. We then prove, with a fixed basic reproductive ratio (R0), a monotonic relationship between the variability of the posterior transmission probability (which is a function of the infectious period) and the probability that the infection will reach any given subset of the population by any given time. Thus again, even when R0 is fixed, variability of the infectious period tends to dampen the epidemic. Numerical results illustrate this but indicate the relationship is weaker. We then show how our results apply to message passing, pairwise, and Kermack-McKendrick epidemic models, even when they are not exactly consistent with the stochastic dynamics. For Poissonian contact processes, and arbitrarily distributed infectious periods, we demonstrate how systems of delay differential equations and ordinary differential equations can provide upper and lower bounds, respectively, for the probability that any given individual has been infected by any given time.

Design considerations for parallel graphics libraries

NASA Technical Reports Server (NTRS)

Crockett, Thomas W.

1994-01-01

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

Privacy Sensitive Surveillance for Assisted Living - A Smart Camera Approach

NASA Astrophysics Data System (ADS)

Fleck, Sven; Straßer, Wolfgang

An elderly woman wanders about aimlessly in a home for assisted living. Suddenly, she collapses on the floor of a lonesome hallway. Usually it can take over two hours until a night nurse passes this spot on her next inspection round. But in this case she is already on site after two minutes, ready to help. She has received an alert message on her beeper: "Inhabitant fallen in hallway 2b". The source: the SmartSurv distributed network of smart cameras for automated and privacy respecting video analysis.Welcome to the future of smart surveillance Although this scenario is not yet daily practice, it shall make clear how such systems will impact the safety of the elderly without the privacy intrusion of traditional video surveillance systems.

Message passing with queues and channels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dozsa, Gabor J; Heidelberger, Philip; Kumar, Sameer

In an embodiment, a reception thread receives a source node identifier, a type, and a data pointer from an application and, in response, creates a receive request. If the source node identifier specifies a source node, the reception thread adds the receive request to a fast-post queue. If a message received from a network does not match a receive request on a posted queue, a polling thread adds a receive request that represents the message to an unexpected queue. If the fast-post queue contains the receive request, the polling thread removes the receive request from the fast-post queue. If themore » receive request that was removed from the fast-post queue does not match the receive request on the unexpected queue, the polling thread adds the receive request that was removed from the fast-post queue to the posted queue. The reception thread and the polling thread execute asynchronously from each other.« less

Secure Web-Site Access with Tickets and Message-Dependent Digests

USGS Publications Warehouse

Donato, David I.

2008-01-01

Although there are various methods for restricting access to documents stored on a World Wide Web (WWW) site (a Web site), none of the widely used methods is completely suitable for restricting access to Web applications hosted on an otherwise publicly accessible Web site. A new technique, however, provides a mix of features well suited for restricting Web-site or Web-application access to authorized users, including the following: secure user authentication, tamper-resistant sessions, simple access to user state variables by server-side applications, and clean session terminations. This technique, called message-dependent digests with tickets, or MDDT, maintains secure user sessions by passing single-use nonces (tickets) and message-dependent digests of user credentials back and forth between client and server. Appendix 2 provides a working implementation of MDDT with PHP server-side code and JavaScript client-side code.

Real time explosive hazard information sensing, processing, and communication for autonomous operation

DOEpatents

Versteeg, Roelof J; Few, Douglas A; Kinoshita, Robert A; Johnson, Doug; Linda, Ondrej

2015-02-24

Methods, computer readable media, and apparatuses provide robotic explosive hazard detection. A robot intelligence kernel (RIK) includes a dynamic autonomy structure with two or more autonomy levels between operator intervention and robot initiative A mine sensor and processing module (ESPM) operating separately from the RIK perceives environmental variables indicative of a mine using subsurface perceptors. The ESPM processes mine information to determine a likelihood of a presence of a mine. A robot can autonomously modify behavior responsive to an indication of a detected mine. The behavior is modified between detection of mines, detailed scanning and characterization of the mine, developing mine indication parameters, and resuming detection. Real time messages are passed between the RIK and the ESPM. A combination of ESPM bound messages and RIK bound messages cause the robot platform to switch between modes including a calibration mode, the mine detection mode, and the mine characterization mode.

Real time explosive hazard information sensing, processing, and communication for autonomous operation

DOEpatents

Versteeg, Roelof J.; Few, Douglas A.; Kinoshita, Robert A.; Johnson, Douglas; Linda, Ondrej

2015-12-15

Methods, computer readable media, and apparatuses provide robotic explosive hazard detection. A robot intelligence kernel (RIK) includes a dynamic autonomy structure with two or more autonomy levels between operator intervention and robot initiative A mine sensor and processing module (ESPM) operating separately from the RIK perceives environmental variables indicative of a mine using subsurface perceptors. The ESPM processes mine information to determine a likelihood of a presence of a mine. A robot can autonomously modify behavior responsive to an indication of a detected mine. The behavior is modified between detection of mines, detailed scanning and characterization of the mine, developing mine indication parameters, and resuming detection. Real time messages are passed between the RIK and the ESPM. A combination of ESPM bound messages and RIK bound messages cause the robot platform to switch between modes including a calibration mode, the mine detection mode, and the mine characterization mode.

Machine-checked proofs of the design and implementation of a fault-tolerant circuit

NASA Technical Reports Server (NTRS)

Bevier, William R.; Young, William D.

1990-01-01

A formally verified implementation of the 'oral messages' algorithm of Pease, Shostak, and Lamport is described. An abstract implementation of the algorithm is verified to achieve interactive consistency in the presence of faults. This abstract characterization is then mapped down to a hardware level implementation which inherits the fault-tolerant characteristics of the abstract version. All steps in the proof were checked with the Boyer-Moore theorem prover. A significant results is the demonstration of a fault-tolerant device that is formally specified and whose implementation is proved correct with respect to this specification. A significant simplifying assumption is that the redundant processors behave synchronously. A mechanically checked proof that the oral messages algorithm is 'optimal' in the sense that no algorithm which achieves agreement via similar message passing can tolerate a larger proportion of faulty processor is also described.

Using Publish-Subscribe Messaging for System Status and Automation

NASA Technical Reports Server (NTRS)

Smith, Danford S.

2015-01-01

The NASA Goddard Mission Services Evolution Center (GMSEC) system is a message-based plug-and-play open system architecture used in many of NASA mission operations centers. This presentation will focus on the use of GMSEC standard messages to report and analyze the status of a system and enable the automation of the system's components. In GMSEC systems, each component reports its status using a keep-alive message and also publishes status and activities as log messages. In addition, the components can accept functional directive messages from the GMSEC message bus. Over the past several years, development teams have found ways to utilize these messages to create innovative display pages and increasingly sophisticated approaches to automation. This presentation will show the flexibility and value of the message-based approach to system awareness and automation.

Bringing the sense back into healthy eating advice.

PubMed

Drummond, Sandra

2006-01-01

Conflicting messages about diet in the media, including publicity for "fad" diets, tend to distort the public's understanding of healthy eating. Several myths also persist, such as "skipping meals is a good way to lose weight," "all fats are bad" or "carbohydrates should be limited when trying to lose weight" Food labels, including the "traffic light" system, may also be confusing for some people. Food preferences vary between individuals, but health professionals can help guide individuals and towards a varied, balanced diet. This will include foods the individual and family enjoy, but based on appropriate proportions of all the five food groups, cooked in healthy ways. Some simple healthy eating tips are given to pass on to clients.

Parallel, Distributed Scripting with Python

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, P J

2002-05-24

Parallel computers used to be, for the most part, one-of-a-kind systems which were extremely difficult to program portably. With SMP architectures, the advent of the POSIX thread API and OpenMP gave developers ways to portably exploit on-the-box shared memory parallelism. Since these architectures didn't scale cost-effectively, distributed memory clusters were developed. The associated MPI message passing libraries gave these systems a portable paradigm too. Having programmers effectively use this paradigm is a somewhat different question. Distributed data has to be explicitly transported via the messaging system in order for it to be useful. In high level languages, the MPI librarymore » gives access to data distribution routines in C, C++, and FORTRAN. But we need more than that. Many reasonable and common tasks are best done in (or as extensions to) scripting languages. Consider sysadm tools such as password crackers, file purgers, etc ... These are simple to write in a scripting language such as Python (an open source, portable, and freely available interpreter). But these tasks beg to be done in parallel. Consider the a password checker that checks an encrypted password against a 25,000 word dictionary. This can take around 10 seconds in Python (6 seconds in C). It is trivial to parallelize if you can distribute the information and co-ordinate the work.« less

Approving the renewal of import restrictions contained in the Burmese Freedom and Democracy Act of 2003.

THOMAS, 112th Congress

Rep. Crowley, Joseph [D-NY-7

2011-05-26

Senate - 09/15/2011 Message on Senate action sent to the House. (All Actions) Notes: For further action, see H.R.2017, which became Public Law 112-33 on 9/30/2011. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

Final report: Compiled MPI. Cost-Effective Exascale Application Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gropp, William Douglas

2015-12-21

This is the final report on Compiled MPI: Cost-Effective Exascale Application Development, and summarizes the results under this project. The project investigated runtime enviroments that improve the performance of MPI (Message-Passing Interface) programs; work at Illinois in the last period of this project looked at optimizing data access optimizations expressed with MPI datatypes.

Emergency Border Security Supplemental Appropriations Act, 2010

THOMAS, 111th Congress

Rep. Price, David E. [D-NC-4

2010-07-27

Senate - 09/23/2010 Message received in the Senate: Returned to the Senate pursuant to the provisions of H.Res. 1653. (All Actions) Notes: For further action, see H.R.6080, which became Public Law 111-230 on 8/13/2010. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

LDPC Codes--Structural Analysis and Decoding Techniques

ERIC Educational Resources Information Center

Zhang, Xiaojie

2012-01-01

Low-density parity-check (LDPC) codes have been the focus of much research over the past decade thanks to their near Shannon limit performance and to their efficient message-passing (MP) decoding algorithms. However, the error floor phenomenon observed in MP decoding, which manifests itself as an abrupt change in the slope of the error-rate curve,…

Comprehensive Iran Sanctions, Accountability, and Divestment Act of 2009

THOMAS, 111th Congress

Sen. Dodd, Christopher J. [D-CT

2009-11-19

Senate - 09/23/2010 Message received in the Senate: Returned to the Senate pursuant to the provisions of H.Res. 1653. (All Actions) Notes: For further action, see H.R.2194, which became Public Law 111-195 on 7/1/2010. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

Federal Aviation Administration Extension Act of 2010

THOMAS, 111th Congress

Sen. Rockefeller, John D., IV [D-WV

2010-03-25

Senate - 09/23/2010 Message received in the Senate: Returned to the Senate pursuant to the provisions of H.Res. 1653. (All Actions) Notes: For further action, see H.R.5147, which became Public Law 111-161 on 4/30/2010. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

Minority Journalists Push Media to Maintain Diversity Commitment

ERIC Educational Resources Information Center

Anderson, Michelle D.

2008-01-01

In a media advisory released earlier this month, the National Association of Black Journalists (NABJ) had an urgent message for the newspaper industry: Diversity should not be treated like a passing fad and it should continue to be a top priority. The advocacy organization, where a majority of its 4,000 members are Black print journalists, warned…

The BaBar Data Reconstruction Control System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ceseracciu, A

2005-04-20

The BaBar experiment is characterized by extremely high luminosity and very large volume of data produced and stored, with increasing computing requirements each year. To fulfill these requirements a Control System has been designed and developed for the offline distributed data reconstruction system. The control system described in this paper provides the performance and flexibility needed to manage a large number of small computing farms, and takes full benefit of OO design. The infrastructure is well isolated from the processing layer, it is generic and flexible, based on a light framework providing message passing and cooperative multitasking. The system ismore » distributed in a hierarchical way: the top-level system is organized in farms, farms in services, and services in subservices or code modules. It provides a powerful Finite State Machine framework to describe custom processing models in a simple regular language. This paper describes the design and evolution of this control system, currently in use at SLAC and Padova on {approx}450 CPUs organized in 9 farms.« less

The BaBar Data Reconstruction Control System

NASA Astrophysics Data System (ADS)

Ceseracciu, A.; Piemontese, M.; Tehrani, F. S.; Pulliam, T. M.; Galeazzi, F.

2005-08-01

The BaBar experiment is characterized by extremely high luminosity and very large volume of data produced and stored, with increasing computing requirements each year. To fulfill these requirements a control system has been designed and developed for the offline distributed data reconstruction system. The control system described in this paper provides the performance and flexibility needed to manage a large number of small computing farms, and takes full benefit of object oriented (OO) design. The infrastructure is well isolated from the processing layer, it is generic and flexible, based on a light framework providing message passing and cooperative multitasking. The system is distributed in a hierarchical way: the top-level system is organized in farms, farms in services, and services in subservices or code modules. It provides a powerful finite state machine framework to describe custom processing models in a simple regular language. This paper describes the design and evolution of this control system, currently in use at SLAC and Padova on /spl sim/450 CPUs organized in nine farms.

From Our Practices to Yours: Key Messages for the Journey to Integrated Behavioral Health.

PubMed

Gold, Stephanie B; Green, Larry A; Peek, C J

The historic, cultural separation of primary care and behavioral health has caused the spread of integrated care to lag behind other practice transformation efforts. The Advancing Care Together study was a 3-year evaluation of how practices implemented integrated care in their local contexts; at its culmination, practice leaders ("innovators") identified lessons learned to pass on to others. Individual feedback from innovators, key messages created by workgroups of innovators and the study team, and a synthesis of key messages from a facilitated discussion were analyzed for themes via immersion/crystallization. Five key themes were captured: (1) frame integrated care as a necessary paradigm shift to patient-centered, whole-person health care; (2) initialize: define relationships and protocols up-front, understanding they will evolve; (3) build inclusive, empowered teams to provide the foundation for integration; (4) develop a change management strategy of continuous evaluation and course-correction; and (5) use targeted data collection pertinent to integrated care to drive improvement and impart accountability. Innovators integrating primary care and behavioral health discerned key messages from their practical experience that they felt were worth sharing with others. Their messages present insight into the challenges unique to integrating care beyond other practice transformation efforts. © Copyright 2017 by the American Board of Family Medicine.

Facilitating Co-Design for Extreme-Scale Systems Through Lightweight Simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engelmann, Christian; Lauer, Frank

This work focuses on tools for investigating algorithm performance at extreme scale with millions of concurrent threads and for evaluating the impact of future architecture choices to facilitate the co-design of high-performance computing (HPC) architectures and applications. The approach focuses on lightweight simulation of extreme-scale HPC systems with the needed amount of accuracy. The prototype presented in this paper is able to provide this capability using a parallel discrete event simulation (PDES), such that a Message Passing Interface (MPI) application can be executed at extreme scale, and its performance properties can be evaluated. The results of an initial prototype aremore » encouraging as a simple 'hello world' MPI program could be scaled up to 1,048,576 virtual MPI processes on a four-node cluster, and the performance properties of two MPI programs could be evaluated at up to 16,384 virtual MPI processes on the same system.« less

Reliable broadcast protocols

NASA Technical Reports Server (NTRS)

Joseph, T. A.; Birman, Kenneth P.

1989-01-01

A number of broadcast protocols that are reliable subject to a variety of ordering and delivery guarantees are considered. Developing applications that are distributed over a number of sites and/or must tolerate the failures of some of them becomes a considerably simpler task when such protocols are available for communication. Without such protocols the kinds of distributed applications that can reasonably be built will have a very limited scope. As the trend towards distribution and decentralization continues, it will not be surprising if reliable broadcast protocols have the same role in distributed operating systems of the future that message passing mechanisms have in the operating systems of today. On the other hand, the problems of engineering such a system remain large. For example, deciding which protocol is the most appropriate to use in a certain situation or how to balance the latency-communication-storage costs is not an easy question.

Parallel file system with metadata distributed across partitioned key-value store c

DOEpatents

Bent, John M.; Faibish, Sorin; Grider, Gary; Torres, Aaron

2017-09-19

Improved techniques are provided for storing metadata associated with a plurality of sub-files associated with a single shared file in a parallel file system. The shared file is generated by a plurality of applications executing on a plurality of compute nodes. A compute node implements a Parallel Log Structured File System (PLFS) library to store at least one portion of the shared file generated by an application executing on the compute node and metadata for the at least one portion of the shared file on one or more object storage servers. The compute node is also configured to implement a partitioned data store for storing a partition of the metadata for the shared file, wherein the partitioned data store communicates with partitioned data stores on other compute nodes using a message passing interface. The partitioned data store can be implemented, for example, using Multidimensional Data Hashing Indexing Middleware (MDHIM).

Performance issues for domain-oriented time-driven distributed simulations

NASA Technical Reports Server (NTRS)

Nicol, David M.

1987-01-01

It has long been recognized that simulations form an interesting and important class of computations that may benefit from distributed or parallel processing. Since the point of parallel processing is improved performance, the recent proliferation of multiprocessors requires that we consider the performance issues that naturally arise when attempting to implement a distributed simulation. Three such issues are: (1) the problem of mapping the simulation onto the architecture, (2) the possibilities for performing redundant computation in order to reduce communication, and (3) the avoidance of deadlock due to distributed contention for message-buffer space. These issues are discussed in the context of a battlefield simulation implemented on a medium-scale multiprocessor message-passing architecture.

Parallel integer sorting with medium and fine-scale parallelism

NASA Technical Reports Server (NTRS)

Dagum, Leonardo

1993-01-01

Two new parallel integer sorting algorithms, queue-sort and barrel-sort, are presented and analyzed in detail. These algorithms do not have optimal parallel complexity, yet they show very good performance in practice. Queue-sort designed for fine-scale parallel architectures which allow the queueing of multiple messages to the same destination. Barrel-sort is designed for medium-scale parallel architectures with a high message passing overhead. The performance results from the implementation of queue-sort on a Connection Machine CM-2 and barrel-sort on a 128 processor iPSC/860 are given. The two implementations are found to be comparable in performance but not as good as a fully vectorized bucket sort on the Cray YMP.

[Old age in primary school readers: a journey through the end of the 19th century to the start of the 21st century in Argentina].

PubMed

Oddone, María Julieta

2013-04-01

This article presents the content (discourse) analysis of messages transmitted by primary school readers in the period between 1880 to 2012. This study allowed us to explore the image of old age and aging that society has and passes on to new generations as well as the role assigned to this generational group. The historical periods that provide the context for the data were defined according to the continuity of or the turning points in the social values transmitted in the reading materials. The role assigned to elderly people and the image of old age that the Argentine society passed on and continues to pass on to younger generations demonstrate that each period described has its own model of aging.

The New BaBar Data Reconstruction Control System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ceseracciu, Antonio

2003-06-02

The BaBar experiment is characterized by extremely high luminosity, a complex detector, and a huge data volume, with increasing requirements each year. To fulfill these requirements a new control system has been designed and developed for the offline data reconstruction system. The new control system described in this paper provides the performance and flexibility needed to manage a large number of small computing farms, and takes full benefit of OO design. The infrastructure is well isolated from the processing layer, it is generic and flexible, based on a light framework providing message passing and cooperative multitasking. The system is activelymore » distributed, enforces the separation between different processing tiers by using different naming domains, and glues them together by dedicated brokers. It provides a powerful Finite State Machine framework to describe custom processing models in a simple regular language. This paper describes this new control system, currently in use at SLAC and Padova on {approx}450 CPUs organized in 12 farms.« less

Telemedicine: Development of a distance care system for pre-dialysis chronic kidney disease patients.

PubMed

Fernandes, Natália Maria da Silva; Bastos, Marcus Gomes; Oliveira, Nivalda A C de; Costa, Alex do Vale; Bernardino, Heder Soares

2015-01-01

The focus in the treatment of CKD is to prevent its progression through optimal medical control. The large number of patients with CKD has pressed nephrologists to assess more patients into ever-smaller periods of consultation. The use of light technologies as a promising form of health care. The internet offers the opportunity to manipulate the doctor in his professional contact with the user. To develop a web system to attend the patients with CKD not on dialysis and clinically stable stages at distance. Developed a system using the Java language, MySQL database and PrimeFaces framework; available on a Glassfish application server. The initial access is performed by the nephrologist, which registers the patients with their personal information and access data. After being registered, the patient (or family doctor) can enter the data of your query and these will be following, passed on to the nephrologist for evaluation. The form with the data of interest is pre-determined, but there is possibility to add free-form information. The system enables, in addition, there is exchange of messages between doctors and patients. In addition, users receive messages via e-mail alerting them of their duties. Confidentiality is guaranteed by individual passwords for doctors and patients. This tool will enable to increase the coverage area of nephrologists, reduce costs and bring the patient to the primary care physician, using the Family Health Program as an interface between the patient and the nephrology secondary care.

Comparative Implementation of High Performance Computing for Power System Dynamic Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Shuangshuang; Huang, Zhenyu; Diao, Ruisheng

Dynamic simulation for transient stability assessment is one of the most important, but intensive, computations for power system planning and operation. Present commercial software is mainly designed for sequential computation to run a single simulation, which is very time consuming with a single processer. The application of High Performance Computing (HPC) to dynamic simulations is very promising in accelerating the computing process by parallelizing its kernel algorithms while maintaining the same level of computation accuracy. This paper describes the comparative implementation of four parallel dynamic simulation schemes in two state-of-the-art HPC environments: Message Passing Interface (MPI) and Open Multi-Processing (OpenMP).more » These implementations serve to match the application with dedicated multi-processor computing hardware and maximize the utilization and benefits of HPC during the development process.« less

Spot: A Programming Language for Verified Flight Software

NASA Technical Reports Server (NTRS)

Bocchino, Robert L., Jr.; Gamble, Edward; Gostelow, Kim P.; Some, Raphael R.

2014-01-01

The C programming language is widely used for programming space flight software and other safety-critical real time systems. C, however, is far from ideal for this purpose: as is well known, it is both low-level and unsafe. This paper describes Spot, a language derived from C for programming space flight systems. Spot aims to maintain compatibility with existing C code while improving the language and supporting verification with the SPIN model checker. The major features of Spot include actor-based concurrency, distributed state with message passing and transactional updates, and annotations for testing and verification. Spot also supports domain-specific annotations for managing spacecraft state, e.g., communicating telemetry information to the ground. We describe the motivation and design rationale for Spot, give an overview of the design, provide examples of Spot's capabilities, and discuss the current status of the implementation.

NASIS data base management system - IBM 360/370 OS MVT implementation. 6: NASIS message file

NASA Technical Reports Server (NTRS)

1973-01-01

The message file for the NASA Aerospace Safety Information System (NASIS) is discussed. The message file contains all the message and term explanations for the system. The data contained in the file can be broken down into three separate sections: (1) global terms, (2) local terms, and (3) system messages. The various terms are defined and their use within the system is explained.

NASIS data base management system: IBM 360 TSS implementation. Volume 6: NASIS message file

NASA Technical Reports Server (NTRS)

1973-01-01

The message file for the NASA Aerospace Safety Information System (NASIS) is discussed. The message file contains all the message and term explanations for the system. The data contained in the file can be broken down into three separate sections: (1) global terms, (2) local terms, and (3) system messages. The various terms are defined and their use within the system is explained.

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

PubMed

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

2017-02-01

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

Sharing Content and Experiences in Smart Environments

NASA Astrophysics Data System (ADS)

Plomp, Johan; Heinilä, Juhani; Ikonen, Veikko; Kaasinen, Eija; Välkkynen, Pasi

Once upon a time… Stories used to be the only way to pass a message. The story teller would take his audience through the events by mere oration. Here and there he would hesitate, whisper, or gesticulate to emphasise his story or induce the right emotions in his audience. No doubt troubadourswere loved, they both brought news of the world as well as entertainment.

PyPele Rewritten To Use MPI

NASA Technical Reports Server (NTRS)

Hockney, George; Lee, Seungwon

2008-01-01

A computer program known as PyPele, originally written as a Pythonlanguage extension module of a C++ language program, has been rewritten in pure Python language. The original version of PyPele dispatches and coordinates parallel-processing tasks on cluster computers and provides a conceptual framework for spacecraft-mission- design and -analysis software tools to run in an embarrassingly parallel mode. The original version of PyPele uses SSH (Secure Shell a set of standards and an associated network protocol for establishing a secure channel between a local and a remote computer) to coordinate parallel processing. Instead of SSH, the present Python version of PyPele uses Message Passing Interface (MPI) [an unofficial de-facto standard language-independent application programming interface for message- passing on a parallel computer] while keeping the same user interface. The use of MPI instead of SSH and the preservation of the original PyPele user interface make it possible for parallel application programs written previously for the original version of PyPele to run on MPI-based cluster computers. As a result, engineers using the previously written application programs can take advantage of embarrassing parallelism without need to rewrite those programs.

Detecting and Preventing Sybil Attacks in Wireless Sensor Networks Using Message Authentication and Passing Method.

PubMed

Dhamodharan, Udaya Suriya Raj Kumar; Vayanaperumal, Rajamani

2015-01-01

Wireless sensor networks are highly indispensable for securing network protection. Highly critical attacks of various kinds have been documented in wireless sensor network till now by many researchers. The Sybil attack is a massive destructive attack against the sensor network where numerous genuine identities with forged identities are used for getting an illegal entry into a network. Discerning the Sybil attack, sinkhole, and wormhole attack while multicasting is a tremendous job in wireless sensor network. Basically a Sybil attack means a node which pretends its identity to other nodes. Communication to an illegal node results in data loss and becomes dangerous in the network. The existing method Random Password Comparison has only a scheme which just verifies the node identities by analyzing the neighbors. A survey was done on a Sybil attack with the objective of resolving this problem. The survey has proposed a combined CAM-PVM (compare and match-position verification method) with MAP (message authentication and passing) for detecting, eliminating, and eventually preventing the entry of Sybil nodes in the network. We propose a scheme of assuring security for wireless sensor network, to deal with attacks of these kinds in unicasting and multicasting.

Detecting and Preventing Sybil Attacks in Wireless Sensor Networks Using Message Authentication and Passing Method

PubMed Central

Dhamodharan, Udaya Suriya Raj Kumar; Vayanaperumal, Rajamani

2015-01-01

Wireless sensor networks are highly indispensable for securing network protection. Highly critical attacks of various kinds have been documented in wireless sensor network till now by many researchers. The Sybil attack is a massive destructive attack against the sensor network where numerous genuine identities with forged identities are used for getting an illegal entry into a network. Discerning the Sybil attack, sinkhole, and wormhole attack while multicasting is a tremendous job in wireless sensor network. Basically a Sybil attack means a node which pretends its identity to other nodes. Communication to an illegal node results in data loss and becomes dangerous in the network. The existing method Random Password Comparison has only a scheme which just verifies the node identities by analyzing the neighbors. A survey was done on a Sybil attack with the objective of resolving this problem. The survey has proposed a combined CAM-PVM (compare and match-position verification method) with MAP (message authentication and passing) for detecting, eliminating, and eventually preventing the entry of Sybil nodes in the network. We propose a scheme of assuring security for wireless sensor network, to deal with attacks of these kinds in unicasting and multicasting. PMID:26236773

Streaming data analytics via message passing with application to graph algorithms

DOE PAGES

Plimpton, Steven J.; Shead, Tim

2014-05-06

The need to process streaming data, which arrives continuously at high-volume in real-time, arises in a variety of contexts including data produced by experiments, collections of environmental or network sensors, and running simulations. Streaming data can also be formulated as queries or transactions which operate on a large dynamic data store, e.g. a distributed database. We describe a lightweight, portable framework named PHISH which enables a set of independent processes to compute on a stream of data in a distributed-memory parallel manner. Datums are routed between processes in patterns defined by the application. PHISH can run on top of eithermore » message-passing via MPI or sockets via ZMQ. The former means streaming computations can be run on any parallel machine which supports MPI; the latter allows them to run on a heterogeneous, geographically dispersed network of machines. We illustrate how PHISH can support streaming MapReduce operations, and describe streaming versions of three algorithms for large, sparse graph analytics: triangle enumeration, subgraph isomorphism matching, and connected component finding. Lastly, we also provide benchmark timings for MPI versus socket performance of several kernel operations useful in streaming algorithms.« less

A concurrent distributed system for aircraft tactical decision generation

NASA Technical Reports Server (NTRS)

Mcmanus, John W.

1990-01-01

A research program investigating the use of AI techniques to aid in the development of a tactical decision generator (TDG) for within visual range (WVR) air combat engagements is discussed. The application of AI programming and problem-solving methods in the development and implementation of a concurrent version of the computerized logic for air-to-air warfare simulations (CLAWS) program, a second-generation TDG, is presented. Concurrent computing environments and programming approaches are discussed, and the design and performance of prototype concurrent TDG system (Cube CLAWS) are presented. It is concluded that the Cube CLAWS has provided a useful testbed to evaluate the development of a distributed blackboard system. The project has shown that the complexity of developing specialized software on a distributed, message-passing architecture such as the Hypercube is not overwhelming, and that reasonable speedups and processor efficiency can be achieved by a distributed blackboard system. The project has also highlighted some of the costs of using a distributed approach to designing a blackboard system.

Bad News Has Wings: Dread Risk Mediates Social Amplification in Risk Communication.

PubMed

Jagiello, Robert D; Hills, Thomas T

2018-05-29

Social diffusion of information amplifies risk through processes of birth, death, and distortion of message content. Dread risk-involving uncontrollable, fatal, involuntary, and catastrophic outcomes (e.g., terrorist attacks and nuclear accidents)-may be particularly susceptible to amplification because of the psychological biases inherent in dread risk avoidance. To test this, initially balanced information about high or low dread topics was given to a set of individuals who then communicated this information through diffusion chains, each person passing a message to the next. A subset of these chains were also reexposed to the original information. We measured prior knowledge, perceived risk before and after transmission, and, at each link, number of positive and negative statements. Results showed that the more a message was transmitted the more negative statements it contained. This was highest for the high dread topic. Increased perceived risk and production of negative messages was closely related to the amount of negative information that was received, with domain knowledge mitigating this effect. Reexposue to the initial information was ineffectual in reducing bias, demonstrating the enhanced danger of socially transmitted information. © 2018 Society for Risk Analysis.

GenASiS Basics: Object-oriented utilitarian functionality for large-scale physics simulations

DOE PAGES

Cardall, Christian Y.; Budiardja, Reuben D.

2015-06-11

Aside from numerical algorithms and problem setup, large-scale physics simulations on distributed-memory supercomputers require more basic utilitarian functionality, such as physical units and constants; display to the screen or standard output device; message passing; I/O to disk; and runtime parameter management and usage statistics. Here we describe and make available Fortran 2003 classes furnishing extensible object-oriented implementations of this sort of rudimentary functionality, along with individual `unit test' programs and larger example problems demonstrating their use. Lastly, these classes compose the Basics division of our developing astrophysics simulation code GenASiS (General Astrophysical Simulation System), but their fundamental nature makes themmore » useful for physics simulations in many fields.« less

Matching pursuit parallel decomposition of seismic data

NASA Astrophysics Data System (ADS)

Li, Chuanhui; Zhang, Fanchang

2017-07-01

In order to improve the computation speed of matching pursuit decomposition of seismic data, a matching pursuit parallel algorithm is designed in this paper. We pick a fixed number of envelope peaks from the current signal in every iteration according to the number of compute nodes and assign them to the compute nodes on average to search the optimal Morlet wavelets in parallel. With the help of parallel computer systems and Message Passing Interface, the parallel algorithm gives full play to the advantages of parallel computing to significantly improve the computation speed of the matching pursuit decomposition and also has good expandability. Besides, searching only one optimal Morlet wavelet by every compute node in every iteration is the most efficient implementation.

Portable programming on parallel/networked computers using the Application Portable Parallel Library (APPL)

NASA Technical Reports Server (NTRS)

Quealy, Angela; Cole, Gary L.; Blech, Richard A.

1993-01-01

The Application Portable Parallel Library (APPL) is a subroutine-based library of communication primitives that is callable from applications written in FORTRAN or C. APPL provides a consistent programmer interface to a variety of distributed and shared-memory multiprocessor MIMD machines. The objective of APPL is to minimize the effort required to move parallel applications from one machine to another, or to a network of homogeneous machines. APPL encompasses many of the message-passing primitives that are currently available on commercial multiprocessor systems. This paper describes APPL (version 2.3.1) and its usage, reports the status of the APPL project, and indicates possible directions for the future. Several applications using APPL are discussed, as well as performance and overhead results.

PCTDSE: A parallel Cartesian-grid-based TDSE solver for modeling laser-atom interactions

NASA Astrophysics Data System (ADS)

Fu, Yongsheng; Zeng, Jiaolong; Yuan, Jianmin

2017-01-01

We present a parallel Cartesian-grid-based time-dependent Schrödinger equation (TDSE) solver for modeling laser-atom interactions. It can simulate the single-electron dynamics of atoms in arbitrary time-dependent vector potentials. We use a split-operator method combined with fast Fourier transforms (FFT), on a three-dimensional (3D) Cartesian grid. Parallelization is realized using a 2D decomposition strategy based on the Message Passing Interface (MPI) library, which results in a good parallel scaling on modern supercomputers. We give simple applications for the hydrogen atom using the benchmark problems coming from the references and obtain repeatable results. The extensions to other laser-atom systems are straightforward with minimal modifications of the source code.

Managing coherence via put/get windows

DOEpatents

Blumrich, Matthias A [Ridgefield, CT; Chen, Dong [Croton on Hudson, NY; Coteus, Paul W [Yorktown Heights, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Hoenicke, Dirk [Ossining, NY; Ohmacht, Martin [Yorktown Heights, NY

2011-01-11

A method and apparatus for managing coherence between two processors of a two processor node of a multi-processor computer system. Generally the present invention relates to a software algorithm that simplifies and significantly speeds the management of cache coherence in a message passing parallel computer, and to hardware apparatus that assists this cache coherence algorithm. The software algorithm uses the opening and closing of put/get windows to coordinate the activated required to achieve cache coherence. The hardware apparatus may be an extension to the hardware address decode, that creates, in the physical memory address space of the node, an area of virtual memory that (a) does not actually exist, and (b) is therefore able to respond instantly to read and write requests from the processing elements.

Managing coherence via put/get windows

DOEpatents

Blumrich, Matthias A [Ridgefield, CT; Chen, Dong [Croton on Hudson, NY; Coteus, Paul W [Yorktown Heights, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Hoenicke, Dirk [Ossining, NY; Ohmacht, Martin [Yorktown Heights, NY

2012-02-21

A method and apparatus for managing coherence between two processors of a two processor node of a multi-processor computer system. Generally the present invention relates to a software algorithm that simplifies and significantly speeds the management of cache coherence in a message passing parallel computer, and to hardware apparatus that assists this cache coherence algorithm. The software algorithm uses the opening and closing of put/get windows to coordinate the activated required to achieve cache coherence. The hardware apparatus may be an extension to the hardware address decode, that creates, in the physical memory address space of the node, an area of virtual memory that (a) does not actually exist, and (b) is therefore able to respond instantly to read and write requests from the processing elements.

Flood predictions using the parallel version of distributed numerical physical rainfall-runoff model TOPKAPI

NASA Astrophysics Data System (ADS)

Boyko, Oleksiy; Zheleznyak, Mark

2015-04-01

The original numerical code TOPKAPI-IMMS of the distributed rainfall-runoff model TOPKAPI ( Todini et al, 1996-2014) is developed and implemented in Ukraine. The parallel version of the code has been developed recently to be used on multiprocessors systems - multicore/processors PC and clusters. Algorithm is based on binary-tree decomposition of the watershed for the balancing of the amount of computation for all processors/cores. Message passing interface (MPI) protocol is used as a parallel computing framework. The numerical efficiency of the parallelization algorithms is demonstrated for the case studies for the flood predictions of the mountain watersheds of the Ukrainian Carpathian regions. The modeling results is compared with the predictions based on the lumped parameters models.

Parallel Three-Dimensional Computation of Fluid Dynamics and Fluid-Structure Interactions of Ram-Air Parachutes

NASA Technical Reports Server (NTRS)

Tezduyar, Tayfun E.

1998-01-01

This is a final report as far as our work at University of Minnesota is concerned. The report describes our research progress and accomplishments in development of high performance computing methods and tools for 3D finite element computation of aerodynamic characteristics and fluid-structure interactions (FSI) arising in airdrop systems, namely ram-air parachutes and round parachutes. This class of simulations involves complex geometries, flexible structural components, deforming fluid domains, and unsteady flow patterns. The key components of our simulation toolkit are a stabilized finite element flow solver, a nonlinear structural dynamics solver, an automatic mesh moving scheme, and an interface between the fluid and structural solvers; all of these have been developed within a parallel message-passing paradigm.

National Combustion Code Parallel Performance Enhancements

NASA Technical Reports Server (NTRS)

Quealy, Angela; Benyo, Theresa (Technical Monitor)

2002-01-01

The National Combustion Code (NCC) is being developed by an industry-government team for the design and analysis of combustion systems. The unstructured grid, reacting flow code uses a distributed memory, message passing model for its parallel implementation. The focus of the present effort has been to improve the performance of the NCC code to meet combustor designer requirements for model accuracy and analysis turnaround time. Improving the performance of this code contributes significantly to the overall reduction in time and cost of the combustor design cycle. This report describes recent parallel processing modifications to NCC that have improved the parallel scalability of the code, enabling a two hour turnaround for a 1.3 million element fully reacting combustion simulation on an SGI Origin 2000.

A Multiple Sphere T-Matrix Fortran Code for Use on Parallel Computer Clusters

NASA Technical Reports Server (NTRS)

Mackowski, D. W.; Mishchenko, M. I.

2011-01-01

A general-purpose Fortran-90 code for calculation of the electromagnetic scattering and absorption properties of multiple sphere clusters is described. The code can calculate the efficiency factors and scattering matrix elements of the cluster for either fixed or random orientation with respect to the incident beam and for plane wave or localized- approximation Gaussian incident fields. In addition, the code can calculate maps of the electric field both interior and exterior to the spheres.The code is written with message passing interface instructions to enable the use on distributed memory compute clusters, and for such platforms the code can make feasible the calculation of absorption, scattering, and general EM characteristics of systems containing several thousand spheres.

ms2: A molecular simulation tool for thermodynamic properties

NASA Astrophysics Data System (ADS)

Deublein, Stephan; Eckl, Bernhard; Stoll, Jürgen; Lishchuk, Sergey V.; Guevara-Carrion, Gabriela; Glass, Colin W.; Merker, Thorsten; Bernreuther, Martin; Hasse, Hans; Vrabec, Jadran

2011-11-01

This work presents the molecular simulation program ms2 that is designed for the calculation of thermodynamic properties of bulk fluids in equilibrium consisting of small electro-neutral molecules. ms2 features the two main molecular simulation techniques, molecular dynamics (MD) and Monte-Carlo. It supports the calculation of vapor-liquid equilibria of pure fluids and multi-component mixtures described by rigid molecular models on the basis of the grand equilibrium method. Furthermore, it is capable of sampling various classical ensembles and yields numerous thermodynamic properties. To evaluate the chemical potential, Widom's test molecule method and gradual insertion are implemented. Transport properties are determined by equilibrium MD simulations following the Green-Kubo formalism. ms2 is designed to meet the requirements of academia and industry, particularly achieving short response times and straightforward handling. It is written in Fortran90 and optimized for a fast execution on a broad range of computer architectures, spanning from single processor PCs over PC-clusters and vector computers to high-end parallel machines. The standard Message Passing Interface (MPI) is used for parallelization and ms2 is therefore easily portable to different computing platforms. Feature tools facilitate the interaction with the code and the interpretation of input and output files. The accuracy and reliability of ms2 has been shown for a large variety of fluids in preceding work. Program summaryProgram title:ms2 Catalogue identifier: AEJF_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJF_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Special Licence supplied by the authors No. of lines in distributed program, including test data, etc.: 82 794 No. of bytes in distributed program, including test data, etc.: 793 705 Distribution format: tar.gz Programming language: Fortran90 Computer: The simulation tool ms2 is usable on a wide variety of platforms, from single processor machines over PC-clusters and vector computers to vector-parallel architectures. (Tested with Fortran compilers: gfortran, Intel, PathScale, Portland Group and Sun Studio.) Operating system: Unix/Linux, Windows Has the code been vectorized or parallelized?: Yes. Message Passing Interface (MPI) protocol Scalability. Excellent scalability up to 16 processors for molecular dynamics and >512 processors for Monte-Carlo simulations. RAM:ms2 runs on single processors with 512 MB RAM. The memory demand rises with increasing number of processors used per node and increasing number of molecules. Classification: 7.7, 7.9, 12 External routines: Message Passing Interface (MPI) Nature of problem: Calculation of application oriented thermodynamic properties for rigid electro-neutral molecules: vapor-liquid equilibria, thermal and caloric data as well as transport properties of pure fluids and multi-component mixtures. Solution method: Molecular dynamics, Monte-Carlo, various classical ensembles, grand equilibrium method, Green-Kubo formalism. Restrictions: No. The system size is user-defined. Typical problems addressed by ms2 can be solved by simulating systems containing typically 2000 molecules or less. Unusual features: Feature tools are available for creating input files, analyzing simulation results and visualizing molecular trajectories. Additional comments: Sample makefiles for multiple operation platforms are provided. Documentation is provided with the installation package and is available at http://www.ms-2.de. Running time: The running time of ms2 depends on the problem set, the system size and the number of processes used in the simulation. Running four processes on a "Nehalem" processor, simulations calculating VLE data take between two and twelve hours, calculating transport properties between six and 24 hours.

Information and the Origin of Qualia

PubMed Central

Orpwood, Roger

2017-01-01

This article argues that qualia are a likely outcome of the processing of information in local cortical networks. It uses an information-based approach and makes a distinction between information structures (the physical embodiment of information in the brain, primarily patterns of action potentials), and information messages (the meaning of those structures to the brain, and the basis of qualia). It develops formal relationships between these two kinds of information, showing how information structures can represent messages, and how information messages can be identified from structures. The article applies this perspective to basic processing in cortical networks or ensembles, showing how networks can transform between the two kinds of information. The article argues that an input pattern of firing is identified by a network as an information message, and that the output pattern of firing generated is a representation of that message. If a network is encouraged to develop an attractor state through attention or other re-entrant processes, then the message identified each time physical information is cycled through the network becomes “representation of the previous message”. Using an example of olfactory perception, it is shown how this piggy-backing of messages on top of previous messages could lead to olfactory qualia. The message identified on each pass of information could evolve from inner identity, to inner form, to inner likeness or image. The outcome is an olfactory quale. It is shown that the same outcome could result from information cycled through a hierarchy of networks in a resonant state. The argument for qualia generation is applied to other sensory modalities, showing how, through a process of brain-wide constraint satisfaction, a particular state of consciousness could develop at any given moment. Evidence for some of the key predictions of the theory is presented, using ECoG data and studies of gamma oscillations and attractors, together with an outline of what further evidence is needed to provide support for the theory. PMID:28484376

Software architecture for time-constrained machine vision applications

NASA Astrophysics Data System (ADS)

Usamentiaga, Rubén; Molleda, Julio; García, Daniel F.; Bulnes, Francisco G.

2013-01-01

Real-time image and video processing applications require skilled architects, and recent trends in the hardware platform make the design and implementation of these applications increasingly complex. Many frameworks and libraries have been proposed or commercialized to simplify the design and tuning of real-time image processing applications. However, they tend to lack flexibility, because they are normally oriented toward particular types of applications, or they impose specific data processing models such as the pipeline. Other issues include large memory footprints, difficulty for reuse, and inefficient execution on multicore processors. We present a novel software architecture for time-constrained machine vision applications that addresses these issues. The architecture is divided into three layers. The platform abstraction layer provides a high-level application programming interface for the rest of the architecture. The messaging layer provides a message-passing interface based on a dynamic publish/subscribe pattern. A topic-based filtering in which messages are published to topics is used to route the messages from the publishers to the subscribers interested in a particular type of message. The application layer provides a repository for reusable application modules designed for machine vision applications. These modules, which include acquisition, visualization, communication, user interface, and data processing, take advantage of the power of well-known libraries such as OpenCV, Intel IPP, or CUDA. Finally, the proposed architecture is applied to a real machine vision application: a jam detector for steel pickling lines.

User's guide to the Reliability Estimation System Testbed (REST)

NASA Technical Reports Server (NTRS)

Nicol, David M.; Palumbo, Daniel L.; Rifkin, Adam

1992-01-01

The Reliability Estimation System Testbed is an X-window based reliability modeling tool that was created to explore the use of the Reliability Modeling Language (RML). RML was defined to support several reliability analysis techniques including modularization, graphical representation, Failure Mode Effects Simulation (FMES), and parallel processing. These techniques are most useful in modeling large systems. Using modularization, an analyst can create reliability models for individual system components. The modules can be tested separately and then combined to compute the total system reliability. Because a one-to-one relationship can be established between system components and the reliability modules, a graphical user interface may be used to describe the system model. RML was designed to permit message passing between modules. This feature enables reliability modeling based on a run time simulation of the system wide effects of a component's failure modes. The use of failure modes effects simulation enhances the analyst's ability to correctly express system behavior when using the modularization approach to reliability modeling. To alleviate the computation bottleneck often found in large reliability models, REST was designed to take advantage of parallel processing on hypercube processors.

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.

A smart room for hospitalised elderly people: essay of modelling and first steps of an experiment.

PubMed

Rialle, V; Lauvernay, N; Franco, A; Piquard, J F; Couturier, P

1999-01-01

We present a study of modelling and the first steps of an experiment of a smart room for hospitalised elderly people. The system aims at detecting falls and sicknesses, and implements four main functions: perception of patient and environment through sensors, reasoning from perceived events and patient clinical findings, action by way of alarm triggering and message passing to medical staff, and adaptation to various patient profiles, sensor layouts, house fixtures and architecture. It includes a physical multisensory device located in the patient's room, and a multi-agent system for fall detection and alarm triggering. This system encompasses a perception agent, and a reasoning agent. The latter has two complementary capacities implemented by sub-agents: deduction of type of alarm from incoming events, and knowledge induction from recorded events. The system has been tested with a few patients in real clinical situation, and the first experiment provides encouraging results which are described in a precise manner.

Compiled MPI: Cost-Effective Exascale Applications Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bronevetsky, G; Quinlan, D; Lumsdaine, A

2012-04-10

The complexity of petascale and exascale machines makes it increasingly difficult to develop applications that can take advantage of them. Future systems are expected to feature billion-way parallelism, complex heterogeneous compute nodes and poor availability of memory (Peter Kogge, 2008). This new challenge for application development is motivating a significant amount of research and development on new programming models and runtime systems designed to simplify large-scale application development. Unfortunately, DoE has significant multi-decadal investment in a large family of mission-critical scientific applications. Scaling these applications to exascale machines will require a significant investment that will dwarf the costs of hardwaremore » procurement. A key reason for the difficulty in transitioning today's applications to exascale hardware is their reliance on explicit programming techniques, such as the Message Passing Interface (MPI) programming model to enable parallelism. MPI provides a portable and high performance message-passing system that enables scalable performance on a wide variety of platforms. However, it also forces developers to lock the details of parallelization together with application logic, making it very difficult to adapt the application to significant changes in the underlying system. Further, MPI's explicit interface makes it difficult to separate the application's synchronization and communication structure, reducing the amount of support that can be provided by compiler and run-time tools. This is in contrast to the recent research on more implicit parallel programming models such as Chapel, OpenMP and OpenCL, which promise to provide significantly more flexibility at the cost of reimplementing significant portions of the application. We are developing CoMPI, a novel compiler-driven approach to enable existing MPI applications to scale to exascale systems with minimal modifications that can be made incrementally over the application's lifetime. It includes: (1) New set of source code annotations, inserted either manually or automatically, that will clarify the application's use of MPI to the compiler infrastructure, enabling greater accuracy where needed; (2) A compiler transformation framework that leverages these annotations to transform the original MPI source code to improve its performance and scalability; (3) Novel MPI runtime implementation techniques that will provide a rich set of functionality extensions to be used by applications that have been transformed by our compiler; and (4) A novel compiler analysis that leverages simple user annotations to automatically extract the application's communication structure and synthesize most complex code annotations.« less

Distributed parallel messaging for multiprocessor systems

DOEpatents

Chen, Dong; Heidelberger, Philip; Salapura, Valentina; Senger, Robert M; Steinmacher-Burrow, Burhard; Sugawara, Yutaka

2013-06-04

A method and apparatus for distributed parallel messaging in a parallel computing system. The apparatus includes, at each node of a multiprocessor network, multiple injection messaging engine units and reception messaging engine units, each implementing a DMA engine and each supporting both multiple packet injection into and multiple reception from a network, in parallel. The reception side of the messaging unit (MU) includes a switch interface enabling writing of data of a packet received from the network to the memory system. The transmission side of the messaging unit, includes switch interface for reading from the memory system when injecting packets into the network.

Clandestine Message Passing in Virtual Environments

DTIC Science & Technology

2008-09-01

accessed April 4, 2008). Weir, Laila. “Boring Game? Outsorce It.” (August 24, 2004). http://www.wired.com/ entertainment / music /news/2004/08/ 64638...Multiplayer Online MOVES - Modeling Virtual Environments and Simulation MTV – Music Television NPS - Naval Postgraduate School PAN – Personal Area...Network PSP - PlayStation Portable RPG – Role-playing Game SL - Second Life SVN - Subversion VE – Virtual Environments vMTV – Virtual Music

An Ode to Stuart Hall's "The Supply of Demand": The Case of Post-Secondary Education in Ontario Fifty Years Later

ERIC Educational Resources Information Center

FitzGerald Murphy, Maggie

2016-01-01

Despite the fact that over fifty years have passed since its publication, Stuart Hall's article "The Supply of Demand" (1960), is remarkably relevant today. The central message that society must not be blinded by "prosperity" such that it no longer envisions and demands a better world is especially pertinent in light of the…

The Guardian. Volume 9, Number 3, Winter 2007

DTIC Science & Technology

2007-01-01

message correctly. Muslims will ultimately determine whether the ideology of al Qaeda, its affiliates, franchisees , and fellow travelers represents...opined that the effort would not work or would not pass the cost– benefit comparison. Others wanted to develop comprehensive NATO doctrine to guide...full BAT capability, the access-control benefits of BAT/HIIDE are a significant improvement to overall ISAF force protection, even in stand-alone mode

PETSc Users Manual Revision 3.7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balay, Satish; Abhyankar, S.; Adams, M.

This manual describes the use of PETSc for the numerical solution of partial differential equations and related problems on high-performance computers. The Portable, Extensible Toolkit for Scientific Computation (PETSc) is a suite of data structures and routines that provide the building blocks for the implementation of large-scale application codes on parallel (and serial) computers. PETSc uses the MPI standard for all message-passing communication.

PETSc Users Manual Revision 3.8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balay, S.; Abhyankar, S.; Adams, M.

This manual describes the use of PETSc for the numerical solution of partial differential equations and related problems on high-performance computers. The Portable, Extensible Toolkit for Scientific Computation (PETSc) is a suite of data structures and routines that provide the building blocks for the implementation of large-scale application codes on parallel (and serial) computers. PETSc uses the MPI standard for all message-passing communication.

Statistical Inference in Graphical Models

DTIC Science & Technology

2008-06-17

fuse probability theory and graph theory in such a way as to permit efficient rep- resentation and computation with probability distributions. They...message passing. 59 viii 1. INTRODUCTION In approaching real-world problems, we often need to deal with uncertainty. Probability and statis- tics provide a...dynamic programming methods. However, for many sensors of interest, the signal-to-noise ratio does not allow such a treatment. Another source of

Driver performance while text messaging using handheld and in-vehicle systems.

PubMed

Owens, Justin M; McLaughlin, Shane B; Sudweeks, Jeremy

2011-05-01

This study presents an evaluation of driver performance while text messaging via handheld mobile phones and an in-vehicle texting system. Participants sent and received text messages while driving with an experimenter on a closed-road course, using their personal mobile phones and the vehicle's system. The test vehicle was an instrumented 2010 Mercury Mariner equipped with an OEM in-vehicle system that supports text messaging and voice control of mobile devices via Bluetooth, which was modified to allow text message sending during driving. Twenty participants were tested, 11 younger (19-34) and 9 older (39-51). All participants were regular users of the in-vehicle system, although none had experience with the texting functions. Results indicated that handheld text message sending and receiving resulted in higher mental demand, more frequent and longer glances away from the roadway, and degraded steering measures compared to baseline. Using the in-vehicle system to send messages showed less performance degradation, but still had more task-related interior glance time and higher mental demand than baseline; using the system's text-to-speech functionality for incoming messages showed no differences from baseline. These findings suggest that using handheld phones to send and receive text messages may interfere with drivers' visual and steering behaviors; the in-vehicle system showed improvement, but performance was not at baseline levels during message sending. Copyright © 2010 Elsevier Ltd. All rights reserved.

Testing New Programming Paradigms with NAS Parallel Benchmarks

NASA Technical Reports Server (NTRS)

Jin, H.; Frumkin, M.; Schultz, M.; Yan, J.

2000-01-01

Over the past decade, high performance computing has evolved rapidly, not only in hardware architectures but also with increasing complexity of real applications. Technologies have been developing to aim at scaling up to thousands of processors on both distributed and shared memory systems. Development of parallel programs on these computers is always a challenging task. Today, writing parallel programs with message passing (e.g. MPI) is the most popular way of achieving scalability and high performance. However, writing message passing programs is difficult and error prone. Recent years new effort has been made in defining new parallel programming paradigms. The best examples are: HPF (based on data parallelism) and OpenMP (based on shared memory parallelism). Both provide simple and clear extensions to sequential programs, thus greatly simplify the tedious tasks encountered in writing message passing programs. HPF is independent of memory hierarchy, however, due to the immaturity of compiler technology its performance is still questionable. Although use of parallel compiler directives is not new, OpenMP offers a portable solution in the shared-memory domain. Another important development involves the tremendous progress in the internet and its associated technology. Although still in its infancy, Java promisses portability in a heterogeneous environment and offers possibility to "compile once and run anywhere." In light of testing these new technologies, we implemented new parallel versions of the NAS Parallel Benchmarks (NPBs) with HPF and OpenMP directives, and extended the work with Java and Java-threads. The purpose of this study is to examine the effectiveness of alternative programming paradigms. NPBs consist of five kernels and three simulated applications that mimic the computation and data movement of large scale computational fluid dynamics (CFD) applications. We started with the serial version included in NPB2.3. Optimization of memory and cache usage was applied to several benchmarks, noticeably BT and SP, resulting in better sequential performance. In order to overcome the lack of an HPF performance model and guide the development of the HPF codes, we employed an empirical performance model for several primitives found in the benchmarks. We encountered a few limitations of HPF, such as lack of supporting the "REDISTRIBUTION" directive and no easy way to handle irregular computation. The parallelization with OpenMP directives was done at the outer-most loop level to achieve the largest granularity. The performance of six HPF and OpenMP benchmarks is compared with their MPI counterparts for the Class-A problem size in the figure in next page. These results were obtained on an SGI Origin2000 (195MHz) with MIPSpro-f77 compiler 7.2.1 for OpenMP and MPI codes and PGI pghpf-2.4.3 compiler with MPI interface for HPF programs.

Engineered cell-cell communication via DNA messaging

PubMed Central

2012-01-01

Background Evolution has selected for organisms that benefit from genetically encoded cell-cell communication. Engineers have begun to repurpose elements of natural communication systems to realize programmed pattern formation and coordinate other population-level behaviors. However, existing engineered systems rely on system-specific small molecules to send molecular messages among cells. Thus, the information transmission capacity of current engineered biological communication systems is physically limited by specific biomolecules that are capable of sending only a single message, typically “regulate transcription.” Results We have engineered a cell-cell communication platform using bacteriophage M13 gene products to autonomously package and deliver heterologous DNA messages of varying lengths and encoded functions. We demonstrate the decoupling of messages from a common communication channel via the autonomous transmission of various arbitrary genetic messages. Further, we increase the range of engineered DNA messaging across semisolid media by linking message transmission or receipt to active cellular chemotaxis. Conclusions We demonstrate decoupling of a communication channel from message transmission within engineered biological systems via the autonomous targeted transduction of user-specified heterologous DNA messages. We also demonstrate that bacteriophage M13 particle production and message transduction occurs among chemotactic bacteria. We use chemotaxis to improve the range of DNA messaging, increasing both transmission distance and communication bit rates relative to existing small molecule-based communication systems. We postulate that integration of different engineered cell-cell communication platforms will allow for more complex spatial programming of dynamic cellular consortia. PMID:22958599

An interactive parallel programming environment applied in atmospheric science

NASA Technical Reports Server (NTRS)

vonLaszewski, G.

1996-01-01

This article introduces an interactive parallel programming environment (IPPE) that simplifies the generation and execution of parallel programs. One of the tasks of the environment is to generate message-passing parallel programs for homogeneous and heterogeneous computing platforms. The parallel programs are represented by using visual objects. This is accomplished with the help of a graphical programming editor that is implemented in Java and enables portability to a wide variety of computer platforms. In contrast to other graphical programming systems, reusable parts of the programs can be stored in a program library to support rapid prototyping. In addition, runtime performance data on different computing platforms is collected in a database. A selection process determines dynamically the software and the hardware platform to be used to solve the problem in minimal wall-clock time. The environment is currently being tested on a Grand Challenge problem, the NASA four-dimensional data assimilation system.

Using PVM to host CLIPS in distributed environments

NASA Technical Reports Server (NTRS)

Myers, Leonard; Pohl, Kym

1994-01-01

It is relatively easy to enhance CLIPS (C Language Integrated Production System) to support multiple expert systems running in a distributed environment with heterogeneous machines. The task is minimized by using the PVM (Parallel Virtual Machine) code from Oak Ridge Labs to provide the distributed utility. PVM is a library of C and FORTRAN subprograms that supports distributive computing on many different UNIX platforms. A PVM deamon is easily installed on each CPU that enters the virtual machine environment. Any user with rsh or rexec access to a machine can use the one PVM deamon to obtain a generous set of distributed facilities. The ready availability of both CLIPS and PVM makes the combination of software particularly attractive for budget conscious experimentation of heterogeneous distributive computing with multiple CLIPS executables. This paper presents a design that is sufficient to provide essential message passing functions in CLIPS and enable the full range of PVM facilities.

CAST: a new program package for the accurate characterization of large and flexible molecular systems.

PubMed

Grebner, Christoph; Becker, Johannes; Weber, Daniel; Bellinger, Daniel; Tafipolski, Maxim; Brückner, Charlotte; Engels, Bernd

2014-09-15

The presented program package, Conformational Analysis and Search Tool (CAST) allows the accurate treatment of large and flexible (macro) molecular systems. For the determination of thermally accessible minima CAST offers the newly developed TabuSearch algorithm, but algorithms such as Monte Carlo (MC), MC with minimization, and molecular dynamics are implemented as well. For the determination of reaction paths, CAST provides the PathOpt, the Nudge Elastic band, and the umbrella sampling approach. Access to free energies is possible through the free energy perturbation approach. Along with a number of standard force fields, a newly developed symmetry-adapted perturbation theory-based force field is included. Semiempirical computations are possible through DFTB+ and MOPAC interfaces. For calculations based on density functional theory, a Message Passing Interface (MPI) interface to the Graphics Processing Unit (GPU)-accelerated TeraChem program is available. The program is available on request. Copyright © 2014 Wiley Periodicals, Inc.

Launch Control System Master Console Event Message Reduction

NASA Technical Reports Server (NTRS)

Nguyen, Uyen

2014-01-01

System monitoring and control (SMC) message browsers receive so many messages daily that operators do not need to see. Important messages are often mixed up among the less important ones. My job is to reduce the messages displayed in the message browser so that warning and emergency messages can be seen easily and therefore, responded promptly. There are multiple methods to achieve this. Firstly, duplicate messages should not appear many times in the message browser. Instead, the message should appear only once but with a number that counts the times that it appears. This method is called duplicate message suppression. Secondly, messages that update the most recent state (e.g. up/down) of a component should replace the old-state messages. This method is called state based message correlation. Thirdly, messages that display "normal" alarm level should be suppressed unless it's a response to an operator action. In addition to message reduction, I also work on correcting the severity level and text formats on messages.

MPI-IO: A Parallel File I/O Interface for MPI Version 0.3

NASA Technical Reports Server (NTRS)

Corbett, Peter; Feitelson, Dror; Hsu, Yarsun; Prost, Jean-Pierre; Snir, Marc; Fineberg, Sam; Nitzberg, Bill; Traversat, Bernard; Wong, Parkson

1995-01-01

Thanks to MPI [9], writing portable message passing parallel programs is almost a reality. One of the remaining problems is file I/0. Although parallel file systems support similar interfaces, the lack of a standard makes developing a truly portable program impossible. Further, the closest thing to a standard, the UNIX file interface, is ill-suited to parallel computing. Working together, IBM Research and NASA Ames have drafted MPI-I0, a proposal to address the portable parallel I/0 problem. In a nutshell, this proposal is based on the idea that I/0 can be modeled as message passing: writing to a file is like sending a message, and reading from a file is like receiving a message. MPI-IO intends to leverage the relatively wide acceptance of the MPI interface in order to create a similar I/0 interface. The above approach can be materialized in different ways. The current proposal represents the result of extensive discussions (and arguments), but is by no means finished. Many changes can be expected as additional participants join the effort to define an interface for portable I/0. This document is organized as follows. The remainder of this section includes a discussion of some issues that have shaped the style of the interface. Section 2 presents an overview of MPI-IO as it is currently defined. It specifies what the interface currently supports and states what would need to be added to the current proposal to make the interface more complete and robust. The next seven sections contain the interface definition itself. Section 3 presents definitions and conventions. Section 4 contains functions for file control, most notably open. Section 5 includes functions for independent I/O, both blocking and nonblocking. Section 6 includes functions for collective I/O, both blocking and nonblocking. Section 7 presents functions to support system-maintained file pointers, and shared file pointers. Section 8 presents constructors that can be used to define useful filetypes (the role of filetypes is explained in Section 2 below). Section 9 presents how the error handling mechanism of MPI is supported by the MPI-IO interface. All this is followed by a set of appendices, which contain information about issues that have not been totally resolved yet, and about design considerations. The reader can find there the motivation behind some of our design choices. More information on this would definitely be welcome and will be included in a further release of this document. The first appendix contains a description of MPI-I0's 'hints' structure which is used when opening a file. Appendix B is a discussion of various issues in the support for file pointers. Appendix C explains what we mean in talking about atomic access. Appendix D provides detailed examples of filetype constructors, and Appendix E contains a collection of arguments for and against various design decisions.

System and Method for Providing a Real Time Audible Message to a Pilot

NASA Technical Reports Server (NTRS)

Johnson, Walter W. (Inventor); Lachter, Joel B. (Inventor); Koteskey, Robert W. (Inventor); Battiste, Vernol (Inventor)

2016-01-01

A system and method for providing information to a crew of the aircraft while in-flight. The system includes a module having: a receiver for receiving a message while in-flight; a filter having a set of screening parameters and operative to filter the message based on the set of screening parameters; and a converter for converting the message into an audible message. The message includes a pilot report having at least one of weather information, separation information, congestion information, flight deviation information and destination information. The message is sent to the aircraft by another aircraft or an air traffic controller.

A flexible software architecture for scalable real-time image and video processing applications

NASA Astrophysics Data System (ADS)

Usamentiaga, Rubén; Molleda, Julio; García, Daniel F.; Bulnes, Francisco G.

2012-06-01

Real-time image and video processing applications require skilled architects, and recent trends in the hardware platform make the design and implementation of these applications increasingly complex. Many frameworks and libraries have been proposed or commercialized to simplify the design and tuning of real-time image processing applications. However, they tend to lack flexibility because they are normally oriented towards particular types of applications, or they impose specific data processing models such as the pipeline. Other issues include large memory footprints, difficulty for reuse and inefficient execution on multicore processors. This paper presents a novel software architecture for real-time image and video processing applications which addresses these issues. The architecture is divided into three layers: the platform abstraction layer, the messaging layer, and the application layer. The platform abstraction layer provides a high level application programming interface for the rest of the architecture. The messaging layer provides a message passing interface based on a dynamic publish/subscribe pattern. A topic-based filtering in which messages are published to topics is used to route the messages from the publishers to the subscribers interested in a particular type of messages. The application layer provides a repository for reusable application modules designed for real-time image and video processing applications. These modules, which include acquisition, visualization, communication, user interface and data processing modules, take advantage of the power of other well-known libraries such as OpenCV, Intel IPP, or CUDA. Finally, we present different prototypes and applications to show the possibilities of the proposed architecture.

Proteus: a reconfigurable computational network for computer vision

NASA Astrophysics Data System (ADS)

Haralick, Robert M.; Somani, Arun K.; Wittenbrink, Craig M.; Johnson, Robert; Cooper, Kenneth; Shapiro, Linda G.; Phillips, Ihsin T.; Hwang, Jenq N.; Cheung, William; Yao, Yung H.; Chen, Chung-Ho; Yang, Larry; Daugherty, Brian; Lorbeski, Bob; Loving, Kent; Miller, Tom; Parkins, Larye; Soos, Steven L.

1992-04-01

The Proteus architecture is a highly parallel MIMD, multiple instruction, multiple-data machine, optimized for large granularity tasks such as machine vision and image processing The system can achieve 20 Giga-flops (80 Giga-flops peak). It accepts data via multiple serial links at a rate of up to 640 megabytes/second. The system employs a hierarchical reconfigurable interconnection network with the highest level being a circuit switched Enhanced Hypercube serial interconnection network for internal data transfers. The system is designed to use 256 to 1,024 RISC processors. The processors use one megabyte external Read/Write Allocating Caches for reduced multiprocessor contention. The system detects, locates, and replaces faulty subsystems using redundant hardware to facilitate fault tolerance. The parallelism is directly controllable through an advanced software system for partitioning, scheduling, and development. System software includes a translator for the INSIGHT language, a parallel debugger, low and high level simulators, and a message passing system for all control needs. Image processing application software includes a variety of point operators neighborhood, operators, convolution, and the mathematical morphology operations of binary and gray scale dilation, erosion, opening, and closing.

Power flow prediction in vibrating systems via model reduction

NASA Astrophysics Data System (ADS)

Li, Xianhui

This dissertation focuses on power flow prediction in vibrating systems. Reduced order models (ROMs) are built based on rational Krylov model reduction which preserve power flow information in the original systems over a specified frequency band. Stiffness and mass matrices of the ROMs are obtained by projecting the original system matrices onto the subspaces spanned by forced responses. A matrix-free algorithm is designed to construct ROMs directly from the power quantities at selected interpolation frequencies. Strategies for parallel implementation of the algorithm via message passing interface are proposed. The quality of ROMs is iteratively refined according to the error estimate based on residual norms. Band capacity is proposed to provide a priori estimate of the sizes of good quality ROMs. Frequency averaging is recast as ensemble averaging and Cauchy distribution is used to simplify the computation. Besides model reduction for deterministic systems, details of constructing ROMs for parametric and nonparametric random systems are also presented. Case studies have been conducted on testbeds from Harwell-Boeing collections. Input and coupling power flow are computed for the original systems and the ROMs. Good agreement is observed in all cases.

PANDA: A distributed multiprocessor operating system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chubb, P.

1989-01-01

PANDA is a design for a distributed multiprocessor and an operating system. PANDA is designed to allow easy expansion of both hardware and software. As such, the PANDA kernel provides only message passing and memory and process management. The other features needed for the system (device drivers, secondary storage management, etc.) are provided as replaceable user tasks. The thesis presents PANDA's design and implementation, both hardware and software. PANDA uses multiple 68010 processors sharing memory on a VME bus, each such node potentially connected to others via a high speed network. The machine is completely homogeneous: there are no differencesmore » between processors that are detectable by programs running on the machine. A single two-processor node has been constructed. Each processor contains memory management circuits designed to allow processors to share page tables safely. PANDA presents a programmers' model similar to the hardware model: a job is divided into multiple tasks, each having its own address space. Within each task, multiple processes share code and data. Tasks can send messages to each other, and set up virtual circuits between themselves. Peripheral devices such as disc drives are represented within PANDA by tasks. PANDA divides secondary storage into volumes, each volume being accessed by a volume access task, or VAT. All knowledge about the way that data is stored on a disc is kept in its volume's VAT. The design is such that PANDA should provide a useful testbed for file systems and device drivers, as these can be installed without recompiling PANDA itself, and without rebooting the machine.« less

The Solar-Sail Launched Interstellar Probe: Pre-Perihelion Trajectories and Application of Holography

NASA Technical Reports Server (NTRS)

Matloff, Gregory L.

2002-01-01

Design of missions beyond our solar system presents many challenges. Here, we consider certain aspects of the solar-sail launched interstellar probe (ISP), a spacecraft slated for launch in the 2010 time period that is planned to reach the heliopause, at 200 Astronomical Units (AU) from the Sun after a flight of about 20-years duration. The baseline mission under consideration by NASA / JPL has a sail radius of 200 m, a science payload of 25 kg, a spacecraft areal mass thickness of about two grams per square meter and is accelerated out of the solar system at about 14 AU per year after performing a perihelion pass of about 0.25 AU. In current plans, the sail is to be dropped near Jupiter's orbit (5.2 AU from the Sun) on the outbound trajectory leg. One aspect of this study is application of a realistic model of sail thermo-optics to sail kinematics that includes diffuse / specular reflectance and sail roughness. The effects of solar-wind degradation of sail material, based on recent measurements at the NASA MSFC (Marshall Space Flight Center) Space Environment Facility were incorporated in the kinematical model. After setting initial and final conditions for the spacecraft, trajectory was optimized using the provision of variable sail aspect angle. The second phase of the study included consideration of rainbow holography as a medium for a message plaque that would be carried aboard the ISP in the spirit of the message plaques aboard Pioneer 10 /11 and Voyager 1 /2. A prototype holographic message plaque was designed and created by artist C. Bangs with the assistance of Ana Maria Nicholson and Dan Schweitzer of the Center for Holographic Arts in Long Island City, NY. The piece was framed by Simon Liu Inc. of Brooklyn, NY. Concurrent to the creation of the prototype message plaque, we explored the potential of this medium to transmit large amounts of visual information to any extraterrestrial civilization that might detect and intercept ISP. It was also necessary to investigate possible degradation of holograms by the space environment. We developed a new way of characterizing the optical quality of holograms.

Secure UNIX socket-based controlling system for high-throughput protein crystallography experiments.

PubMed

Gaponov, Yurii; Igarashi, Noriyuki; Hiraki, Masahiko; Sasajima, Kumiko; Matsugaki, Naohiro; Suzuki, Mamoru; Kosuge, Takashi; Wakatsuki, Soichi

2004-01-01

A control system for high-throughput protein crystallography experiments has been developed based on a multilevel secure (SSL v2/v3) UNIX socket under the Linux operating system. Main features of protein crystallography experiments (purification, crystallization, loop preparation, data collecting, data processing) are dealt with by the software. All information necessary to perform protein crystallography experiments is stored (except raw X-ray data, that are stored in Network File Server) in a relational database (MySQL). The system consists of several servers and clients. TCP/IP secure UNIX sockets with four predefined behaviors [(a) listening to a request followed by a reply, (b) sending a request and waiting for a reply, (c) listening to a broadcast message, and (d) sending a broadcast message] support communications between all servers and clients allowing one to control experiments, view data, edit experimental conditions and perform data processing remotely. The usage of the interface software is well suited for developing well organized control software with a hierarchical structure of different software units (Gaponov et al., 1998), which will pass and receive different types of information. All communication is divided into two parts: low and top levels. Large and complicated control tasks are split into several smaller ones, which can be processed by control clients independently. For communicating with experimental equipment (beamline optical elements, robots, and specialized experimental equipment etc.), the STARS server, developed at the Photon Factory, is used (Kosuge et al., 2002). The STARS server allows any application with an open socket to be connected with any other clients that control experimental equipment. Majority of the source code is written in C/C++. GUI modules of the system were built mainly using Glade user interface builder for GTK+ and Gnome under Red Hat Linux 7.1 operating system.

LCS Master Console Event Message Reduction

NASA Technical Reports Server (NTRS)

Nguyen, Uyen

2014-01-01

System monitoring and control (SMC) message browsers receive so many messages daily that operators are unable to keep track all of them. Important messages are often mixed up among the less important ones. My job is to reduce the messages so that warning and emergency messages can be seen easily and therefore, responded promptly. There are multiple methods to achieve this. Firstly, messages that look the same should not appear many times in the message browser. Instead, the message should appear only once but with a number that counts the times that it appears. This method is called duplicate message suppression. Messages that display "normal" or "advisory" alarm level should be suppressed. Secondly, messages that update the most recent status of a system should replace the old-status messages. This method is called state based message correlation. Thirdly, some unnecessary messages should be sent straight to history after being displayed or not displayed at all. For an example, normal messages that are not a response to an operator's action should not be displayed. I also work on fixing messages that are not color-coded and formatted properly.

High-performance computing — an overview

NASA Astrophysics Data System (ADS)

Marksteiner, Peter

1996-08-01

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

A bill to clarify the health care provided by the Secretary of Veterans Affairs that constitutes minimum essential coverage.

THOMAS, 111th Congress

Sen. Akaka, Daniel K. [D-HI

2010-03-24

Senate - 09/23/2010 Message received in the Senate: Returned to the Senate pursuant to the provisions of H.Res. 1653. (All Actions) Notes: For further action, see H.R.5014, which became Public Law 111-173 on 5/27/2010. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:

FPGA implementation of low complexity LDPC iterative decoder

NASA Astrophysics Data System (ADS)

Verma, Shivani; Sharma, Sanjay

2016-07-01

Low-density parity-check (LDPC) codes, proposed by Gallager, emerged as a class of codes which can yield very good performance on the additive white Gaussian noise channel as well as on the binary symmetric channel. LDPC codes have gained lots of importance due to their capacity achieving property and excellent performance in the noisy channel. Belief propagation (BP) algorithm and its approximations, most notably min-sum, are popular iterative decoding algorithms used for LDPC and turbo codes. The trade-off between the hardware complexity and the decoding throughput is a critical factor in the implementation of the practical decoder. This article presents introduction to LDPC codes and its various decoding algorithms followed by realisation of LDPC decoder by using simplified message passing algorithm and partially parallel decoder architecture. Simplified message passing algorithm has been proposed for trade-off between low decoding complexity and decoder performance. It greatly reduces the routing and check node complexity of the decoder. Partially parallel decoder architecture possesses high speed and reduced complexity. The improved design of the decoder possesses a maximum symbol throughput of 92.95 Mbps and a maximum of 18 decoding iterations. The article presents implementation of 9216 bits, rate-1/2, (3, 6) LDPC decoder on Xilinx XC3D3400A device from Spartan-3A DSP family.

"Some convincing arguments to pass back to nervous customers": the role of the tobacco retailer in the Australian tobacco industry's smoker reassurance campaign 1950-1978.

PubMed

Tofler, A; Chapman, S

2003-12-01

Epidemiological studies and reports on smoking and health published in the 1950s and 1960s threatened the tobacco industry worldwide, which acted to reassure smokers and counteract mounting evidence that smoking posed a serious risk to smokers' health. To document the use of tobacco retailers (1) as a conduit to pass messages of reassurance onto smokers, and (2) to recruit youth and women into smoking. Review of an extensive collection of Australian tobacco retail trade journals (1950-1978) for articles consistent with the industry's efforts to counter messages about smoking and health, and how to attract non-smokers, particularly youth and women. The main arguments advanced in the journals included the notion that air pollution and other substances cause cancer, that "statistics" did not constitute proof in the tobacco health scare, and that the industry was committed to research into the causes of cancer and into developing a "safer" cigarette. Numerous articles designed to be reiterated to customers were published, arguing against the link between tobacco and ill health. Tobacco retailers, salesmen and retail trade organisations played a significant role in dissembling the tobacco health nexus. Tobacco retail journals may be an important component in tobacco industry misinformation strategies.

A Bayesian Model for Highly Accelerated Phase-Contrast MRI

PubMed Central

Rich, Adam; Potter, Lee C.; Jin, Ning; Ash, Joshua; Simonetti, Orlando P.; Ahmad, Rizwan

2015-01-01

Purpose Phase-contrast magnetic resonance imaging (PC-MRI) is a noninvasive tool to assess cardiovascular disease by quantifying blood flow; however, low data acquisition efficiency limits the spatial and temporal resolutions, real-time application, and extensions to 4D flow imaging in clinical settings. We propose a new data processing approach called Reconstructing Velocity Encoded MRI with Approximate message passing aLgorithms (ReVEAL) that accelerates the acquisition by exploiting data structure unique to PC-MRI. Theory and Methods ReVEAL models physical correlations across space, time, and velocity encodings. The proposed Bayesian approach exploits the relationships in both magnitude and phase among velocity encodings. A fast iterative recovery algorithm is introduced based on message passing. For validation, prospectively undersampled data are processed from a pulsatile flow phantom and five healthy volunteers. Results ReVEAL is in good agreement, quantified by peak velocity and stroke volume (SV), with reference data for acceleration rates R ≤ 10. For SV, Pearson r ≥ 0.996 for phantom imaging (n = 24) and r ≥ 0.956 for prospectively accelerated in vivo imaging (n = 10) for R ≤ 10. Conclusion ReVEAL enables accurate quantification of blood flow from highly undersampled data. The technique is extensible to 4D flow imaging, where higher acceleration may be possible due to additional redundancy. PMID:26444911

A practical approach to portability and performance problems on massively parallel supercomputers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beazley, D.M.; Lomdahl, P.S.

1994-12-08

We present an overview of the tactics we have used to achieve a high-level of performance while improving portability for a large-scale molecular dynamics code SPaSM. SPaSM was originally implemented in ANSI C with message passing for the Connection Machine 5 (CM-5). In 1993, SPaSM was selected as one of the winners in the IEEE Gordon Bell Prize competition for sustaining 50 Gflops on the 1024 node CM-5 at Los Alamos National Laboratory. Achieving this performance on the CM-5 required rewriting critical sections of code in CDPEAC assembler language. In addition, the code made extensive use of CM-5 parallel I/Omore » and the CMMD message passing library. Given this highly specialized implementation, we describe how we have ported the code to the Cray T3D and high performance workstations. In addition we will describe how it has been possible to do this using a single version of source code that runs on all three platforms without sacrificing any performance. Sound too good to be true? We hope to demonstrate that one can realize both code performance and portability without relying on the latest and greatest prepackaged tool or parallelizing compiler.« less

Toward Abstracting the Communication Intent in Applications to Improve Portability and Productivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mintz, Tiffany M; Hernandez, Oscar R; Kartsaklis, Christos

Programming with communication libraries such as the Message Passing Interface (MPI) obscures the high-level intent of the communication in an application and makes static communication analysis difficult to do. Compilers are unaware of communication libraries specifics, leading to the exclusion of communication patterns from any automated analysis and optimizations. To overcome this, communication patterns can be expressed at higher-levels of abstraction and incrementally added to existing MPI applications. In this paper, we propose the use of directives to clearly express the communication intent of an application in a way that is not specific to a given communication library. Our communicationmore » directives allow programmers to express communication among processes in a portable way, giving hints to the compiler on regions of computations that can be overlapped with communication and relaxing communication constraints on the ordering, completion and synchronization of the communication imposed by specific libraries such as MPI. The directives can then be translated by the compiler into message passing calls that efficiently implement the intended pattern and be targeted to multiple communication libraries. Thus far, we have used the directives to express point-to-point communication patterns in C, C++ and Fortran applications, and have translated them to MPI and SHMEM.« less

Organizational aspects of e-referrals.

PubMed

Wootton, R; Harno, K; Reponen, J

2003-01-01

Three different, well established systems for e-referral were examined. They ranged from a system in a single country handling a large number of cases (60,000 per year) to a global system covering many countries which handled fewer cases (150 per year). Nonetheless, there appeared to be a number of common features. Whether the purpose is e-transfer or e-consultation, the underlying model of the e-referral process is: the referrer initiates an e-request; the organization managing the process receives it; the organization allocates it for reply; the responder replies to the initiator. Various things can go wrong and the organization managing the e-referral process needs to be able to track requests through the system; this requires various performance metrics. E-referral can be conducted using email, or as messages passed either directly between computer systems or via a Web-link to a server. The experience of the three systems studied shows that significant changes in work practice are needed to launch an e-referral service successfully. The use of e-referral between primary and secondary care improves access to services and can be shown to be cost-effective.

Compiling global name-space programs for distributed execution

NASA Technical Reports Server (NTRS)

Koelbel, Charles; Mehrotra, Piyush

1990-01-01

Distributed memory machines do not provide hardware support for a global address space. Thus programmers are forced to partition the data across the memories of the architecture and use explicit message passing to communicate data between processors. The compiler support required to allow programmers to express their algorithms using a global name-space is examined. A general method is presented for analysis of a high level source program and along with its translation to a set of independently executing tasks communicating via messages. If the compiler has enough information, this translation can be carried out at compile-time. Otherwise run-time code is generated to implement the required data movement. The analysis required in both situations is described and the performance of the generated code on the Intel iPSC/2 is presented.

High Performance Fortran for Aerospace Applications

NASA Technical Reports Server (NTRS)

Mehrotra, Piyush; Zima, Hans; Bushnell, Dennis M. (Technical Monitor)

2000-01-01

This paper focuses on the use of High Performance Fortran (HPF) for important classes of algorithms employed in aerospace applications. HPF is a set of Fortran extensions designed to provide users with a high-level interface for programming data parallel scientific applications, while delegating to the compiler/runtime system the task of generating explicitly parallel message-passing programs. We begin by providing a short overview of the HPF language. This is followed by a detailed discussion of the efficient use of HPF for applications involving multiple structured grids such as multiblock and adaptive mesh refinement (AMR) codes as well as unstructured grid codes. We focus on the data structures and computational structures used in these codes and on the high-level strategies that can be expressed in HPF to optimally exploit the parallelism in these algorithms.

CFD Analysis and Design Optimization Using Parallel Computers

NASA Technical Reports Server (NTRS)

Martinelli, Luigi; Alonso, Juan Jose; Jameson, Antony; Reuther, James

1997-01-01

A versatile and efficient multi-block method is presented for the simulation of both steady and unsteady flow, as well as aerodynamic design optimization of complete aircraft configurations. The compressible Euler and Reynolds Averaged Navier-Stokes (RANS) equations are discretized using a high resolution scheme on body-fitted structured meshes. An efficient multigrid implicit scheme is implemented for time-accurate flow calculations. Optimum aerodynamic shape design is achieved at very low cost using an adjoint formulation. The method is implemented on parallel computing systems using the MPI message passing interface standard to ensure portability. The results demonstrate that, by combining highly efficient algorithms with parallel computing, it is possible to perform detailed steady and unsteady analysis as well as automatic design for complex configurations using the present generation of parallel computers.

Simplifying and speeding the management of intra-node cache coherence

DOEpatents

Blumrich, Matthias A [Ridgefield, CT; Chen, Dong [Croton on Hudson, NY; Coteus, Paul W [Yorktown Heights, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Phillip [Cortlandt Manor, NY; Hoenicke, Dirk [Ossining, NY; Ohmacht, Martin [Yorktown Heights, NY

2012-04-17

A method and apparatus for managing coherence between two processors of a two processor node of a multi-processor computer system. Generally the present invention relates to a software algorithm that simplifies and significantly speeds the management of cache coherence in a message passing parallel computer, and to hardware apparatus that assists this cache coherence algorithm. The software algorithm uses the opening and closing of put/get windows to coordinate the activated required to achieve cache coherence. The hardware apparatus may be an extension to the hardware address decode, that creates, in the physical memory address space of the node, an area of virtual memory that (a) does not actually exist, and (b) is therefore able to respond instantly to read and write requests from the processing elements.

A practical guide to replica-exchange Wang—Landau simulations

NASA Astrophysics Data System (ADS)

Vogel, Thomas; Li, Ying Wai; Landau, David P.

2018-04-01

This paper is based on a series of tutorial lectures about the replica-exchange Wang-Landau (REWL) method given at the IX Brazilian Meeting on Simulational Physics (BMSP 2017). It provides a practical guide for the implementation of the method. A complete example code for a model system is available online. In this paper, we discuss the main parallel features of this code after a brief introduction to the REWL algorithm. The tutorial section is mainly directed at users who have written a single-walker Wang–Landau program already but might have just taken their first steps in parallel programming using the Message Passing Interface (MPI). In the last section, we answer “frequently asked questions” from users about the implementation of REWL for different scientific problems.

Managing coherence via put/get windows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blumrich, Matthias A; Chen, Dong; Coteus, Paul W

A method and apparatus for managing coherence between two processors of a two processor node of a multi-processor computer system. Generally the present invention relates to a software algorithm that simplifies and significantly speeds the management of cache coherence in a message passing parallel computer, and to hardware apparatus that assists this cache coherence algorithm. The software algorithm uses the opening and closing of put/get windows to coordinate the activated required to achieve cache coherence. The hardware apparatus may be an extension to the hardware address decode, that creates, in the physical memory address space of the node, an areamore » of virtual memory that (a) does not actually exist, and (b) is therefore able to respond instantly to read and write requests from the processing elements.« less

Extending the length and time scales of Gram-Schmidt Lyapunov vector computations

NASA Astrophysics Data System (ADS)

Costa, Anthony B.; Green, Jason R.

2013-08-01

Lyapunov vectors have found growing interest recently due to their ability to characterize systems out of thermodynamic equilibrium. The computation of orthogonal Gram-Schmidt vectors requires multiplication and QR decomposition of large matrices, which grow as N2 (with the particle count). This expense has limited such calculations to relatively small systems and short time scales. Here, we detail two implementations of an algorithm for computing Gram-Schmidt vectors. The first is a distributed-memory message-passing method using Scalapack. The second uses the newly-released MAGMA library for GPUs. We compare the performance of both codes for Lennard-Jones fluids from N=100 to 1300 between Intel Nahalem/Infiniband DDR and NVIDIA C2050 architectures. To our best knowledge, these are the largest systems for which the Gram-Schmidt Lyapunov vectors have been computed, and the first time their calculation has been GPU-accelerated. We conclude that Lyapunov vector calculations can be significantly extended in length and time by leveraging the power of GPU-accelerated linear algebra.

Accelerating three-dimensional FDTD calculations on GPU clusters for electromagnetic field simulation.

PubMed

Nagaoka, Tomoaki; Watanabe, Soichi

2012-01-01

Electromagnetic simulation with anatomically realistic computational human model using the finite-difference time domain (FDTD) method has recently been performed in a number of fields in biomedical engineering. To improve the method's calculation speed and realize large-scale computing with the computational human model, we adapt three-dimensional FDTD code to a multi-GPU cluster environment with Compute Unified Device Architecture and Message Passing Interface. Our multi-GPU cluster system consists of three nodes. The seven GPU boards (NVIDIA Tesla C2070) are mounted on each node. We examined the performance of the FDTD calculation on multi-GPU cluster environment. We confirmed that the FDTD calculation on the multi-GPU clusters is faster than that on a multi-GPU (a single workstation), and we also found that the GPU cluster system calculate faster than a vector supercomputer. In addition, our GPU cluster system allowed us to perform the large-scale FDTD calculation because were able to use GPU memory of over 100 GB.

Porting the AVS/Express scientific visualization software to Cray XT4.

PubMed

Leaver, George W; Turner, Martin J; Perrin, James S; Mummery, Paul M; Withers, Philip J

2011-08-28

Remote scientific visualization, where rendering services are provided by larger scale systems than are available on the desktop, is becoming increasingly important as dataset sizes increase beyond the capabilities of desktop workstations. Uptake of such services relies on access to suitable visualization applications and the ability to view the resulting visualization in a convenient form. We consider five rules from the e-Science community to meet these goals with the porting of a commercial visualization package to a large-scale system. The application uses message-passing interface (MPI) to distribute data among data processing and rendering processes. The use of MPI in such an interactive application is not compatible with restrictions imposed by the Cray system being considered. We present details, and performance analysis, of a new MPI proxy method that allows the application to run within the Cray environment yet still support MPI communication required by the application. Example use cases from materials science are considered.

The AI Bus architecture for distributed knowledge-based systems

NASA Technical Reports Server (NTRS)

Schultz, Roger D.; Stobie, Iain

1991-01-01

The AI Bus architecture is layered, distributed object oriented framework developed to support the requirements of advanced technology programs for an order of magnitude improvement in software costs. The consequent need for highly autonomous computer systems, adaptable to new technology advances over a long lifespan, led to the design of an open architecture and toolbox for building large scale, robust, production quality systems. The AI Bus accommodates a mix of knowledge based and conventional components, running on heterogeneous, distributed real world and testbed environment. The concepts and design is described of the AI Bus architecture and its current implementation status as a Unix C++ library or reusable objects. Each high level semiautonomous agent process consists of a number of knowledge sources together with interagent communication mechanisms based on shared blackboards and message passing acquaintances. Standard interfaces and protocols are followed for combining and validating subsystems. Dynamic probes or demons provide an event driven means for providing active objects with shared access to resources, and each other, while not violating their security.

Supporting Beacon and Event-Driven Messages in Vehicular Platoons through Token-Based Strategies

PubMed Central

Uhlemann, Elisabeth

2018-01-01

Timely and reliable inter-vehicle communications is a critical requirement to support traffic safety applications, such as vehicle platooning. Furthermore, low-delay communications allow the platoon to react quickly to unexpected events. In this scope, having a predictable and highly effective medium access control (MAC) method is of utmost importance. However, the currently available IEEE 802.11p technology is unable to adequately address these challenges. In this paper, we propose a MAC method especially adapted to platoons, able to transmit beacons within the required time constraints, but with a higher reliability level than IEEE 802.11p, while concurrently enabling efficient dissemination of event-driven messages. The protocol circulates the token within the platoon not in a round-robin fashion, but based on beacon data age, i.e., the time that has passed since the previous collection of status information, thereby automatically offering repeated beacon transmission opportunities for increased reliability. In addition, we propose three different methods for supporting event-driven messages co-existing with beacons. Analysis and simulation results in single and multi-hop scenarios showed that, by providing non-competitive channel access and frequent retransmission opportunities, our protocol can offer beacon delivery within one beacon generation interval while fulfilling the requirements on low-delay dissemination of event-driven messages for traffic safety applications. PMID:29570676

Supporting Beacon and Event-Driven Messages in Vehicular Platoons through Token-Based Strategies.

PubMed

Balador, Ali; Uhlemann, Elisabeth; Calafate, Carlos T; Cano, Juan-Carlos

2018-03-23

Timely and reliable inter-vehicle communications is a critical requirement to support traffic safety applications, such as vehicle platooning. Furthermore, low-delay communications allow the platoon to react quickly to unexpected events. In this scope, having a predictable and highly effective medium access control (MAC) method is of utmost importance. However, the currently available IEEE 802.11p technology is unable to adequately address these challenges. In this paper, we propose a MAC method especially adapted to platoons, able to transmit beacons within the required time constraints, but with a higher reliability level than IEEE 802.11p, while concurrently enabling efficient dissemination of event-driven messages. The protocol circulates the token within the platoon not in a round-robin fashion, but based on beacon data age, i.e., the time that has passed since the previous collection of status information, thereby automatically offering repeated beacon transmission opportunities for increased reliability. In addition, we propose three different methods for supporting event-driven messages co-existing with beacons. Analysis and simulation results in single and multi-hop scenarios showed that, by providing non-competitive channel access and frequent retransmission opportunities, our protocol can offer beacon delivery within one beacon generation interval while fulfilling the requirements on low-delay dissemination of event-driven messages for traffic safety applications.

Autoplan: A self-processing network model for an extended blocks world planning environment

NASA Technical Reports Server (NTRS)

Dautrechy, C. Lynne; Reggia, James A.; Mcfadden, Frank

1990-01-01

Self-processing network models (neural/connectionist models, marker passing/message passing networks, etc.) are currently undergoing intense investigation for a variety of information processing applications. These models are potentially very powerful in that they support a large amount of explicit parallel processing, and they cleanly integrate high level and low level information processing. However they are currently limited by a lack of understanding of how to apply them effectively in many application areas. The formulation of self-processing network methods for dynamic, reactive planning is studied. The long-term goal is to formulate robust, computationally effective information processing methods for the distributed control of semiautonomous exploration systems, e.g., the Mars Rover. The current research effort is focusing on hierarchical plan generation, execution and revision through local operations in an extended blocks world environment. This scenario involves many challenging features that would be encountered in a real planning and control environment: multiple simultaneous goals, parallel as well as sequential action execution, action sequencing determined not only by goals and their interactions but also by limited resources (e.g., three tasks, two acting agents), need to interpret unanticipated events and react appropriately through replanning, etc.

Hierarchy of conversational rule violations involving utterance-based augmentative and alternative communication systems.

PubMed

Hoag, Linda A; Bedrosian, Jan L; McCoy, Kathleen F; Johnson, Dallas E

2008-01-01

This study examined the effects of using messages with conversational rule violations on attitudes toward people who used utterance-based augmentative and alternative communication (AAC) systems in transactional interactions. Specifically, the ratings were compared across messages with relevance, informativeness, and brevity violations, when latency remained constant (i.e., short). The 96 participating sales clerks viewed scripted, videotaped bookstore conversations and completed an attitude questionnaire. Results indicated that the prestored message with repeated words/phrases was rated the highest, followed by the message with excessive information; next was the message with inadequate information, followed by the message with partly relevant information. The findings may be useful to those using utterance-based systems when making message choices during interactions with service providers. Technological implications point to the development of schema/script-based systems and intelligent editing.

Decentralized Formation Flying Control in a Multiple-Team Hierarchy

NASA Technical Reports Server (NTRS)

Mueller, Joseph .; Thomas, Stephanie J.

2005-01-01

This paper presents the prototype of a system that addresses these objectives-a decentralized guidance and control system that is distributed across spacecraft using a multiple-team framework. The objective is to divide large clusters into teams of manageable size, so that the communication and computational demands driven by N decentralized units are related to the number of satellites in a team rather than the entire cluster. The system is designed to provide a high-level of autonomy, to support clusters with large numbers of satellites, to enable the number of spacecraft in the cluster to change post-launch, and to provide for on-orbit software modification. The distributed guidance and control system will be implemented in an object-oriented style using MANTA (Messaging Architecture for Networking and Threaded Applications). In this architecture, tasks may be remotely added, removed or replaced post-launch to increase mission flexibility and robustness. This built-in adaptability will allow software modifications to be made on-orbit in a robust manner. The prototype system, which is implemented in MATLAB, emulates the object-oriented and message-passing features of the MANTA software. In this paper, the multiple-team organization of the cluster is described, and the modular software architecture is presented. The relative dynamics in eccentric reference orbits is reviewed, and families of periodic, relative trajectories are identified, expressed as sets of static geometric parameters. The guidance law design is presented, and an example reconfiguration scenario is used to illustrate the distributed process of assigning geometric goals to the cluster. Next, a decentralized maneuver planning approach is presented that utilizes linear-programming methods to enact reconfiguration and coarse formation keeping maneuvers. Finally, a method for performing online collision avoidance is discussed, and an example is provided to gauge its performance.

LEGION: Lightweight Expandable Group of Independently Operating Nodes

NASA Technical Reports Server (NTRS)

Burl, Michael C.

2012-01-01

LEGION is a lightweight C-language software library that enables distributed asynchronous data processing with a loosely coupled set of compute nodes. Loosely coupled means that a node can offer itself in service to a larger task at any time and can withdraw itself from service at any time, provided it is not actively engaged in an assignment. The main program, i.e., the one attempting to solve the larger task, does not need to know up front which nodes will be available, how many nodes will be available, or at what times the nodes will be available, which is normally the case in a "volunteer computing" framework. The LEGION software accomplishes its goals by providing message-based, inter-process communication similar to MPI (message passing interface), but without the tight coupling requirements. The software is lightweight and easy to install as it is written in standard C with no exotic library dependencies. LEGION has been demonstrated in a challenging planetary science application in which a machine learning system is used in closed-loop fashion to efficiently explore the input parameter space of a complex numerical simulation. The machine learning system decides which jobs to run through the simulator; then, through LEGION calls, the system farms those jobs out to a collection of compute nodes, retrieves the job results as they become available, and updates a predictive model of how the simulator maps inputs to outputs. The machine learning system decides which new set of jobs would be most informative to run given the results so far; this basic loop is repeated until sufficient insight into the physical system modeled by the simulator is obtained.

Design of Instant Messaging System of Multi-language E-commerce Platform

NASA Astrophysics Data System (ADS)

Yang, Heng; Chen, Xinyi; Li, Jiajia; Cao, Yaru

2017-09-01

This paper aims at researching the message system in the instant messaging system based on the multi-language e-commerce platform in order to design the instant messaging system in multi-language environment and exhibit the national characteristics based information as well as applying national languages to e-commerce. In order to develop beautiful and friendly system interface for the front end of the message system and reduce the development cost, the mature jQuery framework is adopted in this paper. The high-performance server Tomcat is adopted at the back end to process user requests, and MySQL database is adopted for data storage to persistently store user data, and meanwhile Oracle database is adopted as the message buffer for system optimization. Moreover, AJAX technology is adopted for the client to actively pull the newest data from the server at the specified time. In practical application, the system has strong reliability, good expansibility, short response time, high system throughput capacity and high user concurrency.

Extended write combining using a write continuation hint flag

DOEpatents

Chen, Dong; Gara, Alan; Heidelberger, Philip; Ohmacht, Martin; Vranas, Pavlos

2013-06-04

A computing apparatus for reducing the amount of processing in a network computing system which includes a network system device of a receiving node for receiving electronic messages comprising data. The electronic messages are transmitted from a sending node. The network system device determines when more data of a specific electronic message is being transmitted. A memory device stores the electronic message data and communicating with the network system device. A memory subsystem communicates with the memory device. The memory subsystem stores a portion of the electronic message when more data of the specific message will be received, and the buffer combines the portion with later received data and moves the data to the memory device for accessible storage.

Hypertext: Improved Capability for Shipboard Naval Messages

DTIC Science & Technology

1989-09-01

message handling system; a complete working model of the system has not been developed . 3 D. ORGANIZATION OF STUDY 1. The "Paperless" Ship Initiative...work in tandem to improve afloat message handling procedures. The objective of the PCMT project is to develop a system that could be installed on...working group has identified a list of requirements to guide the DoD’s progress towards improving its message communication system. These

Porting Gravitational Wave Signal Extraction to Parallel Virtual Machine (PVM)

NASA Technical Reports Server (NTRS)

Thirumalainambi, Rajkumar; Thompson, David E.; Redmon, Jeffery

2009-01-01

Laser Interferometer Space Antenna (LISA) is a planned NASA-ESA mission to be launched around 2012. The Gravitational Wave detection is fundamentally the determination of frequency, source parameters, and waveform amplitude derived in a specific order from the interferometric time-series of the rotating LISA spacecrafts. The LISA Science Team has developed a Mock LISA Data Challenge intended to promote the testing of complicated nested search algorithms to detect the 100-1 millihertz frequency signals at amplitudes of 10E-21. However, it has become clear that, sequential search of the parameters is very time consuming and ultra-sensitive; hence, a new strategy has been developed. Parallelization of existing sequential search algorithms of Gravitational Wave signal identification consists of decomposing sequential search loops, beginning with outermost loops and working inward. In this process, the main challenge is to detect interdependencies among loops and partitioning the loops so as to preserve concurrency. Existing parallel programs are based upon either shared memory or distributed memory paradigms. In PVM, master and node programs are used to execute parallelization and process spawning. The PVM can handle process management and process addressing schemes using a virtual machine configuration. The task scheduling and the messaging and signaling can be implemented efficiently for the LISA Gravitational Wave search process using a master and 6 nodes. This approach is accomplished using a server that is available at NASA Ames Research Center, and has been dedicated to the LISA Data Challenge Competition. Historically, gravitational wave and source identification parameters have taken around 7 days in this dedicated single thread Linux based server. Using PVM approach, the parameter extraction problem can be reduced to within a day. The low frequency computation and a proxy signal-to-noise ratio are calculated in separate nodes that are controlled by the master using message and vector of data passing. The message passing among nodes follows a pattern of synchronous and asynchronous send-and-receive protocols. The communication model and the message buffers are allocated dynamically to address rapid search of gravitational wave source information in the Mock LISA data sets.

Monitoring tools of COMPASS experiment at CERN

NASA Astrophysics Data System (ADS)

Bodlak, M.; Frolov, V.; Huber, S.; Jary, V.; Konorov, I.; Levit, D.; Novy, J.; Salac, R.; Tomsa, J.; Virius, M.

2015-12-01

This paper briefly introduces the data acquisition system of the COMPASS experiment and is mainly focused on the part that is responsible for the monitoring of the nodes in the whole newly developed data acquisition system of this experiment. The COMPASS is a high energy particle experiment with a fixed target located at the SPS of the CERN laboratory in Geneva, Switzerland. The hardware of the data acquisition system has been upgraded to use FPGA cards that are responsible for data multiplexing and event building. The software counterpart of the system includes several processes deployed in heterogenous network environment. There are two processes, namely Message Logger and Message Browser, taking care of monitoring. These tools handle messages generated by nodes in the system. While Message Logger collects and saves messages to the database, the Message Browser serves as a graphical interface over the database containing these messages. For better performance, certain database optimizations have been used. Lastly, results of performance tests are presented.

WE-G-BRA-02: SafetyNet: Automating Radiotherapy QA with An Event Driven Framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hadley, S; Kessler, M; Litzenberg, D

2015-06-15

Purpose: Quality assurance is an essential task in radiotherapy that often requires many manual tasks. We investigate the use of an event driven framework in conjunction with software agents to automate QA and eliminate wait times. Methods: An in house developed subscription-publication service, EventNet, was added to the Aria OIS to be a message broker for critical events occurring in the OIS and software agents. Software agents operate without user intervention and perform critical QA steps. The results of the QA are documented and the resulting event is generated and passed back to EventNet. Users can subscribe to those eventsmore » and receive messages based on custom filters designed to send passing or failing results to physicists or dosimetrists. Agents were developed to expedite the following QA tasks: Plan Revision, Plan 2nd Check, SRS Winston-Lutz isocenter, Treatment History Audit, Treatment Machine Configuration. Results: Plan approval in the Aria OIS was used as the event trigger for plan revision QA and Plan 2nd check agents. The agents pulled the plan data, executed the prescribed QA, stored the results and updated EventNet for publication. The Winston Lutz agent reduced QA time from 20 minutes to 4 minutes and provided a more accurate quantitative estimate of radiation isocenter. The Treatment Machine Configuration agent automatically reports any changes to the Treatment machine or HDR unit configuration. The agents are reliable, act immediately, and execute each task identically every time. Conclusion: An event driven framework has inverted the data chase in our radiotherapy QA process. Rather than have dosimetrists and physicists push data to QA software and pull results back into the OIS, the software agents perform these steps immediately upon receiving the sentinel events from EventNet. Mr Keranen is an employee of Varian Medical Systems. Dr. Moran’s institution receives research support for her effort for a linear accelerator QA project from Varian Medical Systems. Other quality projects involving her effort are funded by Blue Cross Blue Shield of Michigan, Breast Cancer Research Foundation, and the NIH.« less

A Parallel Workload Model and its Implications for Processor Allocation

DTIC Science & Technology

1996-11-01

with SEV or AVG, both of which can tolerate c = 0.4 { 0.6 before their performance deteriorates signi cantly. On the other hand, Setia [10] has...Sanjeev. K Setia . The interaction between memory allocation and adaptive partitioning in message-passing multicomputers. In IPPS 󈨣 Workshop on Job...Scheduling Strategies for Parallel Processing, pages 89{99, 1995. [11] Sanjeev K. Setia and Satish K. Tripathi. An analysis of several processor

Parallel deterministic neutronics with AMR in 3D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clouse, C.; Ferguson, J.; Hendrickson, C.

1997-12-31

AMTRAN, a three dimensional Sn neutronics code with adaptive mesh refinement (AMR) has been parallelized over spatial domains and energy groups and runs on the Meiko CS-2 with MPI message passing. Block refined AMR is used with linear finite element representations for the fluxes, which allows for a straight forward interpretation of fluxes at block interfaces with zoning differences. The load balancing algorithm assumes 8 spatial domains, which minimizes idle time among processors.

GENASIS Basics: Object-oriented utilitarian functionality for large-scale physics simulations (Version 2)

NASA Astrophysics Data System (ADS)

Cardall, Christian Y.; Budiardja, Reuben D.

2017-05-01

GenASiS Basics provides Fortran 2003 classes furnishing extensible object-oriented utilitarian functionality for large-scale physics simulations on distributed memory supercomputers. This functionality includes physical units and constants; display to the screen or standard output device; message passing; I/O to disk; and runtime parameter management and usage statistics. This revision -Version 2 of Basics - makes mostly minor additions to functionality and includes some simplifying name changes.

An HLA-Based Approach to Quantify Achievable Performance for Tactical Edge Applications

DTIC Science & Technology

2011-05-01

in: Proceedings of the 2002 Fall Simulation Interoperability Workshop, 02F- SIW -068, Nov 2002. [16] P. Knight, et al. ―WBT RTI Independent...Benchmark Tests: Design, Implementation, and Updated Results‖, in: Proceedings of the 2002 Spring Simulation Interoperability Workshop, 02S- SIW -081, March...Interoperability Workshop, 98F- SIW -085, Nov 1998. [18] S. Ferenci and R. Fujimoto. ―RTI Performance on Shared Memory and Message Passing Architectures‖, in

AMS -- The Unix ADAM Message System

NASA Astrophysics Data System (ADS)

Kelly, B. D.; Chipperfield, A. J.

The ADAM Message System (AMS) library, which implements the ADAM inter-task communications protocol under Unix, is described, along with its Fortran-callable interface (FAMS). The description of AMS is distinguished from the current implementation which uses the Message System Primitives (MSP).

Patients’ Engagement With “Sweet Talk” – A Text Messaging Support System for Young People With Diabetes

PubMed Central

Franklin, Victoria Louise; Greene, Alexandra; Waller, Annalu; Greene, Stephen Alan

2008-01-01

Background Guidelines for optimizing type 1 diabetes in young people advocate intensive insulin therapy coupled with personal support from the health care team. “Sweet Talk” is a novel intervention designed to support patients between clinic visits using text messages sent to a mobile phone. Scheduled messages are tailored to patient profiles and diabetes self-management goals, and generic messages include topical “newsletters” and anonymized tips from other participants. The system also allows patients to submit data and questions to the diabetes care team. Objectives The aim was to explore how patients with type 1 diabetes interact with the Sweet Talk system in order to understand its utility to this user group. Methods Subjects were 64 young people with diabetes who were participating in the intervention arms of a randomized controlled trial. All text messages submitted to Sweet Talk during a 12-month period were recorded. Messaging patterns and content were analyzed using mixed quantitative and qualitative methods. Results Patients submitted 1180 messages during the observation period (mean 18.4, median 6). Messaging frequency ranged widely between participants (0-240) with a subset of 5 high users contributing 52% of the total. Patients’ clinical and sociodemographic characteristics were not associated with total messaging frequency, although girls sent significantly more messages unrelated to diabetes than did boys (P = .002). The content of patients’ messages fell into 8 main categories: blood glucose readings, diabetes questions, diabetes information, personal health administration, social messages, technical messages, message errors, and message responses. Unprompted submission of blood glucose values was the most frequent incoming message type (35% of total). Responses to requests for personal experiences and tips generated 40% of all the incoming messages, while topical news items also generated good responses. Patients also used the service to ask questions, submit information about their self-management, and order supplies. No patients nominated supporters to receive text messages about their self-management goals. Another option that was not used was the birthday reminder service. Conclusions Automated, scheduled text messaging successfully engaged young people with diabetes. While the system was primarily designed to provide “push” support to patients, submission of clinical data and queries illustrates that it was seen as a trusted medium for communicating with care providers. Responses to the newsletters and submission of personal experiences and tips for circulation to other participants also illustrate the potential value of such interventions for establishing a sense of community. Although participants submitted relatively few messages, positive responses to the system suggest that most derived passive support from reading the messages. The Sweet Talk system could be readily adapted to suit other chronic disease models and age groups, and the results of this study may help to inform the design of future text message support interventions. PMID:18653444

The clinical usefulness of a web-based messaging system between patients with Crohn disease and their physicians.

PubMed

Jeong, Da Eun; Kim, Kyeong Ok; Jang, Byung Ik; Kim, Eun Young; Jung, Jin Tae; Jeon, Seong Woo; Lee, Hyun Seok; Kim, Eun Soo; Park, Kyung Sik; Cho, Kwang Bum

2016-06-01

To avoid missing events associated with clinical activity, the authors previously developed a novel, web-based, self-reporting Crohn disease (CD) symptom diary. However, although this diary provided a means of self-checking based on responses to set questions based on Harvey-Bradshaw index scores, it was limited in terms of describing other specific symptoms. Thus, the authors added a space to the questionnaire, which allows patients to send clinicians questions or a description of unpredictable events. The aim of the present study was to assess the clinical usefulness of this messaging system by analyzing patients' messages.The messaging system between patients and their doctors was included in a webpage created for recording patients' symptom diaries (www.cdsd.or.kr). Using this system, patients can send messages easily at any time and doctors can read and respond to these messages immediately using a smart phone or computer. In the present study, the authors retrospectively reviewed 686 messages sent by 152 patients from July 2012 to July 2014 and patient medical records.Mean patient age was 29.0 ± 11.6 years and the male-to-female ratio was 99:53. Most messages regarded symptoms (381 messages, 55.5%), which was followed by self-reports about general condition (195 messages, 28.4%) and questions about treatment (71 messages, 10.3%). With respect to symptoms, abdominal pain was most common (145 cases, 21.1%) followed by hematochezia (36 cases, 5.2%). Problems about medication were the most frequently associated with treatment (65, 91.5%). Patients above 40 years showed a greater tendency to focus on symptoms and treatment (P = 0.025). The doctor answer rate was 56.3% (n = 386), and based on these responses, an early visit was needed in 28 cases (7.3%).Using this web-based messaging system, patients were able to obtain proper advice from their physicians without visiting clinics or searching the Internet, and in addition, 7.3% of messages prompted an early visit. Although longer follow-up is required, this study shows that the devised messaging system provides a clinically relevant communication tool for patients and physicians.

Development of a text messaging system to improve receipt of survivorship care in adolescent and young adult survivors of childhood cancer.

PubMed

Casillas, Jacqueline; Goyal, Anju; Bryman, Jason; Alquaddoomi, Faisal; Ganz, Patricia A; Lidington, Emma; Macadangdang, Joshua; Estrin, Deborah

2017-08-01

This study aimed to develop and examine the acceptability, feasibility, and usability of a text messaging, or Short Message Service (SMS), system for improving the receipt of survivorship care for adolescent and young adult (AYA) survivors of childhood cancer. Researchers developed and refined the text messaging system based on qualitative data from AYA survivors in an iterative three-stage process. In stage 1, a focus group (n = 4) addressed acceptability; in stage 2, key informant interviews (n = 10) following a 6-week trial addressed feasibility; and in stage 3, key informant interviews (n = 23) following a 6-week trial addressed usability. Qualitative data were analyzed using a constant comparative analytic approach exploring in-depth themes. The final system includes programmed reminders to schedule and attend late effect screening appointments, tailored suggestions for community resources for cancer survivors, and messages prompting participant feedback regarding the appointments and resources. Participants found the text messaging system an acceptable form of communication, the screening reminders and feedback prompts feasible for improving the receipt of survivorship care, and the tailored suggestions for community resources usable for connecting survivors to relevant services. Participants suggested supplementing survivorship care visits and forming AYA survivor social networks as future implementations for the text messaging system. The text messaging system may assist AYA survivors by coordinating late effect screening appointments, facilitating a partnership with the survivorship care team, and connecting survivors with relevant community resources. The text messaging system has the potential to improve the receipt of survivorship care.

Implementation of Pass Through PPTP Relay System with Authentication at Each Gateway and Its Performance Evaluations

NASA Astrophysics Data System (ADS)

Saito, Shoichi; Uehara, Tetsutaro; Izumi, Yutaka; Kunieda, Yoshitoshi

The VPN (Virtual Private Network) technique becomes more and more popular to protect contents of messages and to achieve secure communication from incidents, such as tapping. However, it grow in usage that a VPN server is used on a sub-network in part of an office-wide network. But, a PPTP system included in Windows operating systems cannot establish nested VPN links. Moreover encrypted communication by VPN hides a user of the VPN connection. Consequently, any administrators of network systems can’t find out the users of the VPN connection via firewall, moreover can’t decide whether if the user is legal or not. In order to solve this problem, we developed a multi step PPTP relay system on a firewall. This system solves all the problems of our previously developed PPTP relay system(1). The new relay system improves security by encrypting through the whole end-to-end communication and abolishing of prior registration of passwords for the next step. Furthermore, transport speed is accelerated, and the restriction of the number of steps on relay is also abolished. By these features the multi step PPTP relay system expands usability.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorentla Venkata, Manjunath; Graham, Richard L; Ladd, Joshua S

This paper describes the design and implementation of InfiniBand (IB) CORE-Direct based blocking and nonblocking broadcast operations within the Cheetah collective operation framework. It describes a novel approach that fully ofFLoads collective operations and employs only user-supplied buffers. For a 64 rank communicator, the latency of CORE-Direct based hierarchical algorithm is better than production-grade Message Passing Interface (MPI) implementations, 150% better than the default Open MPI algorithm and 115% better than the shared memory optimized MVAPICH implementation for a one kilobyte (KB) message, and for eight mega-bytes (MB) it is 48% and 64% better, respectively. Flat-topology broadcast achieves 99.9% overlapmore » in a polling based communication-computation test, and 95.1% overlap for a wait based test, compared with 92.4% and 17.0%, respectively, for a similar Central Processing Unit (CPU) based implementation.« less

An Introduction to Message-Bus Architectures for Space Systems

NASA Technical Reports Server (NTRS)

Smith, Danford; Gregory, Brian

2005-01-01

This course presents technical and programmatic information on the development of message-based architectures for space mission ground and flight software systems. Message-based architecture approaches provide many significant advantages over the more traditional socket-based one-of-a-kind integrated system development approaches. The course provides an overview of publish/subscribe concepts, the use of common isolation layer API's, approaches to message standardization, and other technical topics. Several examples of currently operational systems are discussed and possible changes to the system discussed and time for questions and answers will be provided.

Automated Instrumentation, Monitoring and Visualization of PVM Programs Using AIMS

NASA Technical Reports Server (NTRS)

Mehra, Pankaj; VanVoorst, Brian; Yan, Jerry; Lum, Henry, Jr. (Technical Monitor)

1994-01-01

We present views and analysis of the execution of several PVM (Parallel Virtual Machine) codes for Computational Fluid Dynamics on a networks of Sparcstations, including: (1) NAS Parallel Benchmarks CG and MG; (2) a multi-partitioning algorithm for NAS Parallel Benchmark SP; and (3) an overset grid flowsolver. These views and analysis were obtained using our Automated Instrumentation and Monitoring System (AIMS) version 3.0, a toolkit for debugging the performance of PVM programs. We will describe the architecture, operation and application of AIMS. The AIMS toolkit contains: (1) Xinstrument, which can automatically instrument various computational and communication constructs in message-passing parallel programs; (2) Monitor, a library of runtime trace-collection routines; (3) VK (Visual Kernel), an execution-animation tool with source-code clickback; and (4) Tally, a tool for statistical analysis of execution profiles. Currently, Xinstrument can handle C and Fortran 77 programs using PVM 3.2.x; Monitor has been implemented and tested on Sun 4 systems running SunOS 4.1.2; and VK uses XIIR5 and Motif 1.2. Data and views obtained using AIMS clearly illustrate several characteristic features of executing parallel programs on networked workstations: (1) the impact of long message latencies; (2) the impact of multiprogramming overheads and associated load imbalance; (3) cache and virtual-memory effects; and (4) significant skews between workstation clocks. Interestingly, AIMS can compensate for constant skew (zero drift) by calibrating the skew between a parent and its spawned children. In addition, AIMS' skew-compensation algorithm can adjust timestamps in a way that eliminates physically impossible communications (e.g., messages going backwards in time). Our current efforts are directed toward creating new views to explain the observed performance of PVM programs. Some of the features planned for the near future include: (1) ConfigView, showing the physical topology of the virtual machine, inferred using specially formatted IP (Internet Protocol) packets: and (2) LoadView, synchronous animation of PVM-program execution and resource-utilization patterns.

SMSaúde: Design, Development, and Implementation of a Remote/Mobile Patient Management System to Improve Retention in Care for HIV/AIDS and Tuberculosis Patients.

PubMed

Nhavoto, José António; Grönlund, Åke; Chaquilla, Walter Ponce

2015-03-09

The widespread and low cost of mobile phones and the convenience of short message service (SMS) text messaging suggest potential suitability for use with alternative strategies for supporting retention in care and adherence to the treatment of various chronic diseases, such as HIV and tuberculosis (TB). Despite the growing body of literature reporting positive outcomes of SMS text message-based communication with patients, there is yet very little research about the integration of communication technologies and electronic medical records or electronic patient tracking systems. To design, develop, and implement an integrated mobile phone text messaging system used to follow up with patients with HIV and TB in treatment in Mozambique. Following the design science research methodology, we developed a Web-based system that provides support to patients. A case study involving three health care sites in Mozambique was a basis for discussing design issues for this kind of system. We used brainstorming techniques to solicit usability requirements, focus group meetings to discuss and define system architecture, and prototyping to test in real environments and to improve the system. We found six sets of system requirements that need to be addressed for success: data collection, telecommunication costs, privacy and data security, text message content, connectivity, and system scalability. A text messaging system was designed and implemented in three health facilities. These sites feed data into a central data repository, which can be used for analysis of operations and decision support. Based on the treatment schedule, the system automatically sent SMS text message appointment reminders, medication reminders, as well as motivational and educational messages to patients enrolled in antiretroviral therapy and TB treatment programs. We successfully defined the requirements for, designed, and implemented a mobile phone text messaging system to support HIV and TB treatments. Implementation of this system could improve patients' self-management skills and strengthen communication between patients and health care providers.

A Pub/Sub Message Distribution Architecture for Disruption Tolerant Networks

NASA Astrophysics Data System (ADS)

Carrilho, Sergio; Esaki, Hiroshi

Access to information is taken for granted in urban areas covered by a robust communication infrastructure. Nevertheless most of the areas in the world, are not covered by such infrastructures. We propose a DTN publish and subscribe system called Hikari, which uses nodes' mobility in order to distribute messages without using a robust infrastructure. The area of Disruption/Delay Tolerant Networks (DTN) focuses on providing connectivity to locations separated by networks with disruptions and delays. The Hikari system does not use node identifiers for message forwarding thus eliminating the complexity of routing associated with many forwarding schemes in DTN. Hikari uses nodes paths' information, advertised by special nodes in the system or predicted by the system itself, for optimizing the message dissemination process. We have used the Paris subway system, due to it's complexity, to validate Hikari and to analyze it's performance. We have shown that Hikari achieves a superior deliver rate while keeping redundant messages in the system low, which is ideal when using devices with limited resources for message dissemination.

Towards collaborative filtering recommender systems for tailored health communications.

PubMed

Marlin, Benjamin M; Adams, Roy J; Sadasivam, Rajani; Houston, Thomas K

2013-01-01

The goal of computer tailored health communications (CTHC) is to promote healthy behaviors by sending messages tailored to individual patients. Current CTHC systems collect baseline patient "profiles" and then use expert-written, rule-based systems to target messages to subsets of patients. Our main interest in this work is the study of collaborative filtering-based CTHC systems that can learn to tailor future message selections to individual patients based explicit feedback about past message selections. This paper reports the results of a study designed to collect explicit feedback (ratings) regarding four aspects of messages from 100 subjects in the smoking cessation support domain. Our results show that most users have positive opinions of most messages and that the ratings for all four aspects of the messages are highly correlated with each other. Finally, we conduct a range of rating prediction experiments comparing several different model variations. Our results show that predicting future ratings based on each user's past ratings contributes the most to predictive accuracy.

Towards Collaborative Filtering Recommender Systems for Tailored Health Communications

PubMed Central

Marlin, Benjamin M.; Adams, Roy J.; Sadasivam, Rajani; Houston, Thomas K.

2013-01-01

The goal of computer tailored health communications (CTHC) is to promote healthy behaviors by sending messages tailored to individual patients. Current CTHC systems collect baseline patient “profiles” and then use expert-written, rule-based systems to target messages to subsets of patients. Our main interest in this work is the study of collaborative filtering-based CTHC systems that can learn to tailor future message selections to individual patients based explicit feedback about past message selections. This paper reports the results of a study designed to collect explicit feedback (ratings) regarding four aspects of messages from 100 subjects in the smoking cessation support domain. Our results show that most users have positive opinions of most messages and that the ratings for all four aspects of the messages are highly correlated with each other. Finally, we conduct a range of rating prediction experiments comparing several different model variations. Our results show that predicting future ratings based on each user’s past ratings contributes the most to predictive accuracy. PMID:24551430

Generic Ada code in the NASA space station command, control and communications environment

NASA Technical Reports Server (NTRS)

Mcdougall, D. P.; Vollman, T. E.

1986-01-01

The results of efforts to apply powerful Ada constructs to the formatted message handling process are described. The goal of these efforts was to extend the state-of-technology in message handling while at the same time producing production-quality, reusable code. The first effort was initiated in September, 1984 and delivered in April, 1985. That product, the Generic Message Handling Facility, met initial goals, was reused, and is available in the Ada Repository on ARPANET. However, it became apparent during its development that the initial approach to building a message handler template was not optimal. As a result of this initial effort, several alternate approaches were identified, and research is now on-going to identify an improved product. The ultimate goal is to be able to instantly build a message handling system for any message format given a specification of that message format. The problem lies in how to specify the message format, and one that is done, how to use that information to build the message handler. Message handling systems and message types are described. The initial efforts, its results and its shortcomings are detailed. The approach now being taken to build a system which will be significantly easier to implement, and once implemented, easier to use, is described. Finally, conclusions are offered.

SMC Message Browser Projects

NASA Technical Reports Server (NTRS)

Wichmann, Benjamin C.

2013-01-01

I work directly with the System Monitoring and Control (SMC) software engineers who develop, test and release custom and commercial software in support of the Kennedy Space Center Spaceport Command and Control System. (SCCS). SMC uses Commercial Off-The-Shelf (COTS) Enterprise Management Systems (EMS) software which provides a centralized subsystem for configuring, monitoring, and controlling SCCS hardware and software used in the Control Rooms. There are multiple projects being worked on using the COTS EMS software. I am currently working with the HP Operations Manager for UNIX (OMU) software which allows Master Console Operators (MCO) to access, view and interpret messages regarding the status of the SCCS hardware and software. The OMU message browser gets cluttered with messages which can make it difficult for the MCO to manage. My main project involves determining ways to reduce the number of messages being displayed in the OMU message browser. I plan to accomplish this task in two different ways: (1) by correlating multiple messages into one single message being displayed and (2) to create policies that will determine the significance of each message and whether or not it needs to be displayed to the MCO. The core idea is to lessen the number of messages being sent to the OMU message browser so the MCO can more effectively use it.

SKIRT: Hybrid parallelization of radiative transfer simulations

NASA Astrophysics Data System (ADS)

Verstocken, S.; Van De Putte, D.; Camps, P.; Baes, M.

2017-07-01

We describe the design, implementation and performance of the new hybrid parallelization scheme in our Monte Carlo radiative transfer code SKIRT, which has been used extensively for modelling the continuum radiation of dusty astrophysical systems including late-type galaxies and dusty tori. The hybrid scheme combines distributed memory parallelization, using the standard Message Passing Interface (MPI) to communicate between processes, and shared memory parallelization, providing multiple execution threads within each process to avoid duplication of data structures. The synchronization between multiple threads is accomplished through atomic operations without high-level locking (also called lock-free programming). This improves the scaling behaviour of the code and substantially simplifies the implementation of the hybrid scheme. The result is an extremely flexible solution that adjusts to the number of available nodes, processors and memory, and consequently performs well on a wide variety of computing architectures.

Parallel Conjugate Gradient: Effects of Ordering Strategies, Programming Paradigms, and Architectural Platforms

NASA Technical Reports Server (NTRS)

Oliker, Leonid; Heber, Gerd; Biswas, Rupak

2000-01-01

The Conjugate Gradient (CG) algorithm is perhaps the best-known iterative technique to solve sparse linear systems that are symmetric and positive definite. A sparse matrix-vector multiply (SPMV) usually accounts for most of the floating-point operations within a CG iteration. In this paper, we investigate the effects of various ordering and partitioning strategies on the performance of parallel CG and SPMV using different programming paradigms and architectures. Results show that for this class of applications, ordering significantly improves overall performance, that cache reuse may be more important than reducing communication, and that it is possible to achieve message passing performance using shared memory constructs through careful data ordering and distribution. However, a multi-threaded implementation of CG on the Tera MTA does not require special ordering or partitioning to obtain high efficiency and scalability.

Performance Analysis of GYRO: A Tool Evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Worley, P.; Roth, P.; Candy, J.

2005-06-26

The performance of the Eulerian gyrokinetic-Maxwell solver code GYRO is analyzed on five high performance computing systems. First, a manual approach is taken, using custom scripts to analyze the output of embedded wall clock timers, floating point operation counts collected using hardware performance counters, and traces of user and communication events collected using the profiling interface to Message Passing Interface (MPI) libraries. Parts of the analysis are then repeated or extended using a number of sophisticated performance analysis tools: IPM, KOJAK, SvPablo, TAU, and the PMaC modeling tool suite. The paper briefly discusses what has been discovered via this manualmore » analysis process, what performance analyses are inconvenient or infeasible to attempt manually, and to what extent the tools show promise in accelerating or significantly extending the manual performance analyses.« less

Performance Analysis and Portability of the PLUM Load Balancing System

NASA Technical Reports Server (NTRS)

Oliker, Leonid; Biswas, Rupak; Gabow, Harold N.

1998-01-01

The ability to dynamically adapt an unstructured mesh is a powerful tool for solving computational problems with evolving physical features; however, an efficient parallel implementation is rather difficult. To address this problem, we have developed PLUM, an automatic portable framework for performing adaptive numerical computations in a message-passing environment. PLUM requires that all data be globally redistributed after each mesh adaption to achieve load balance. We present an algorithm for minimizing this remapping overhead by guaranteeing an optimal processor reassignment. We also show that the data redistribution cost can be significantly reduced by applying our heuristic processor reassignment algorithm to the default mapping of the parallel partitioner. Portability is examined by comparing performance on a SP2, an Origin2000, and a T3E. Results show that PLUM can be successfully ported to different platforms without any code modifications.

Secure message authentication system for node to node network

NASA Astrophysics Data System (ADS)

Sindhu, R.; Vanitha, M. M.; Norman, J.

2017-10-01

The Message verification remains some of the best actual methods for prevent the illegal and dis honored communication after presence progressed to WSNs (Wireless Sensor Networks). Intend for this purpose, several message verification systems must stand established, created on both symmetric key cryptography otherwise public key cryptosystems. Best of them will have some limits for great computational then statement above in count of deficiency of climb ability then flexibility in node settlement occurrence. In a polynomial based system was newly presented for these problems. Though, this system then situations delay will must the dimness of integral limitation firm in the point of polynomial: once the amount of message transferred remains the greater than the limitation then the opponent will completely improve the polynomial approaches. This paper suggests using ECC (Elliptic Curve Cryptography). Though using the node verification the technique in this paper permits some nodes to transfer a limitless amount of messages lacking misery in the limit problem. This system will have the message cause secrecy. Equally theoretic study then model effects show our planned system will be effective than the polynomial based method in positions of calculation then statement above in privacy points though message basis privacy.

The amplification of risk in experimental diffusion chains.

PubMed

Moussaïd, Mehdi; Brighton, Henry; Gaissmaier, Wolfgang

2015-05-05

Understanding how people form and revise their perception of risk is central to designing efficient risk communication methods, eliciting risk awareness, and avoiding unnecessary anxiety among the public. However, public responses to hazardous events such as climate change, contagious outbreaks, and terrorist threats are complex and difficult-to-anticipate phenomena. Although many psychological factors influencing risk perception have been identified in the past, it remains unclear how perceptions of risk change when propagated from one person to another and what impact the repeated social transmission of perceived risk has at the population scale. Here, we study the social dynamics of risk perception by analyzing how messages detailing the benefits and harms of a controversial antibacterial agent undergo change when passed from one person to the next in 10-subject experimental diffusion chains. Our analyses show that when messages are propagated through the diffusion chains, they tend to become shorter, gradually inaccurate, and increasingly dissimilar between chains. In contrast, the perception of risk is propagated with higher fidelity due to participants manipulating messages to fit their preconceptions, thereby influencing the judgments of subsequent participants. Computer simulations implementing this simple influence mechanism show that small judgment biases tend to become more extreme, even when the injected message contradicts preconceived risk judgments. Our results provide quantitative insights into the social amplification of risk perception, and can help policy makers better anticipate and manage the public response to emerging threats.

The amplification of risk in experimental diffusion chains

PubMed Central

Moussaïd, Mehdi; Brighton, Henry; Gaissmaier, Wolfgang

2015-01-01

Understanding how people form and revise their perception of risk is central to designing efficient risk communication methods, eliciting risk awareness, and avoiding unnecessary anxiety among the public. However, public responses to hazardous events such as climate change, contagious outbreaks, and terrorist threats are complex and difficult-to-anticipate phenomena. Although many psychological factors influencing risk perception have been identified in the past, it remains unclear how perceptions of risk change when propagated from one person to another and what impact the repeated social transmission of perceived risk has at the population scale. Here, we study the social dynamics of risk perception by analyzing how messages detailing the benefits and harms of a controversial antibacterial agent undergo change when passed from one person to the next in 10-subject experimental diffusion chains. Our analyses show that when messages are propagated through the diffusion chains, they tend to become shorter, gradually inaccurate, and increasingly dissimilar between chains. In contrast, the perception of risk is propagated with higher fidelity due to participants manipulating messages to fit their preconceptions, thereby influencing the judgments of subsequent participants. Computer simulations implementing this simple influence mechanism show that small judgment biases tend to become more extreme, even when the injected message contradicts preconceived risk judgments. Our results provide quantitative insights into the social amplification of risk perception, and can help policy makers better anticipate and manage the public response to emerging threats. PMID:25902519

Advances in Parallel Computing and Databases for Digital Pathology in Cancer Research

DTIC Science & Technology

2016-11-13

these technologies and how we have used them in the past. We are interested in learning more about the needs of clinical pathologists as we continue to...such as image processing and correlation. Further, High Performance Computing (HPC) paradigms such as the Message Passing Interface (MPI) have been...Defense for Research and Engineering. such as pMatlab [4], or bcMPI [5] can significantly reduce the need for deep knowledge of parallel computing. In

Discrete Event Simulation Modeling and Analysis of Key Leader Engagements

DTIC Science & Technology

2012-06-01

to offer. GreenPlayer agents require four parameters, pC, pKLK, pTK, and pRK , which give probabilities for being corrupt, having key leader...HandleMessageRequest component. The same parameter constraints apply to these four parameters. The parameter pRK is the same parameter from the CreatePlayers component...whether the local Green player has resource critical knowledge by using the parameter pRK . It schedules an EndResourceKnowledgeRequest event, passing

Time-Dependent Simulations of Incompressible Flow in a Turbopump Using Overset Grid Approach

NASA Technical Reports Server (NTRS)

Kiris, Cetin; Kwak, Dochan

2001-01-01

This viewgraph presentation provides information on mathematical modelling of the SSME (space shuttle main engine). The unsteady SSME-rig1 start-up procedure from the pump at rest has been initiated by using 34.3 million grid points. The computational model for the SSME-rig1 has been completed. Moving boundary capability is obtained by using DCF module in OVERFLOW-D. MPI (Message Passing Interface)/OpenMP hybrid parallel code has been benchmarked.

Murmer, a message generator and reporter for Unix, VMS, and VxWorks

NASA Astrophysics Data System (ADS)

Oleynik, G.; Appleton, B.; Moore, C.; Sergey, G.; Udumula, L.

1994-02-01

Murmer is a Unix based message generation, reporting, display, and logging system that we have developed for use in data acquisition systems at Fermilab. Murmer is a tool for the production and management of message reporting. Its usefulness ranges from software product development and maintenance to system level shakedown and diagnostics. Murmer provides a VMS MESSAGE-like function code generation utility, a client routine package for sending these codes over the network to a central server, and a server which translates the codes into meaningful visual information, writes the information to a logfile, and display it on B&W or color X windows. Because Murmer stores message information in keyed access files, it can provide advanced features such as popping up help when a displayed message is clicked on by the mouse and executing 'action' shell scripts when selected messages are received by the server.

"Some convincing arguments to pass back to nervous customers": the role of the tobacco retailer in the Australian tobacco industry's smoker reassurance campaign 1950–1978

PubMed Central

Tofler, A; Chapman, S

2003-01-01

Background: Epidemiological studies and reports on smoking and health published in the 1950s and 1960s threatened the tobacco industry worldwide, which acted to reassure smokers and counteract mounting evidence that smoking posed a serious risk to smokers' health. Objective: To document the use of tobacco retailers (1) as a conduit to pass messages of reassurance onto smokers, and (2) to recruit youth and women into smoking. Methods: Review of an extensive collection of Australian tobacco retail trade journals (1950–1978) for articles consistent with the industry's efforts to counter messages about smoking and health, and how to attract non-smokers, particularly youth and women. Results: The main arguments advanced in the journals included the notion that air pollution and other substances cause cancer, that "statistics" did not constitute proof in the tobacco health scare, and that the industry was committed to research into the causes of cancer and into developing a "safer" cigarette. Conclusions: Numerous articles designed to be reiterated to customers were published, arguing against the link between tobacco and ill health. Tobacco retailers, salesmen and retail trade organisations played a significant role in dissembling the tobacco health nexus. Tobacco retail journals may be an important component in tobacco industry misinformation strategies. PMID:14645943

Weighted community detection and data clustering using message passing

NASA Astrophysics Data System (ADS)

Shi, Cheng; Liu, Yanchen; Zhang, Pan

2018-03-01

Grouping objects into clusters based on the similarities or weights between them is one of the most important problems in science and engineering. In this work, by extending message-passing algorithms and spectral algorithms proposed for an unweighted community detection problem, we develop a non-parametric method based on statistical physics, by mapping the problem to the Potts model at the critical temperature of spin-glass transition and applying belief propagation to solve the marginals corresponding to the Boltzmann distribution. Our algorithm is robust to over-fitting and gives a principled way to determine whether there are significant clusters in the data and how many clusters there are. We apply our method to different clustering tasks. In the community detection problem in weighted and directed networks, we show that our algorithm significantly outperforms existing algorithms. In the clustering problem, where the data were generated by mixture models in the sparse regime, we show that our method works all the way down to the theoretical limit of detectability and gives accuracy very close to that of the optimal Bayesian inference. In the semi-supervised clustering problem, our method only needs several labels to work perfectly in classic datasets. Finally, we further develop Thouless-Anderson-Palmer equations which heavily reduce the computation complexity in dense networks but give almost the same performance as belief propagation.

A Bayesian model for highly accelerated phase-contrast MRI.

PubMed

Rich, Adam; Potter, Lee C; Jin, Ning; Ash, Joshua; Simonetti, Orlando P; Ahmad, Rizwan

2016-08-01

Phase-contrast magnetic resonance imaging is a noninvasive tool to assess cardiovascular disease by quantifying blood flow; however, low data acquisition efficiency limits the spatial and temporal resolutions, real-time application, and extensions to four-dimensional flow imaging in clinical settings. We propose a new data processing approach called Reconstructing Velocity Encoded MRI with Approximate message passing aLgorithms (ReVEAL) that accelerates the acquisition by exploiting data structure unique to phase-contrast magnetic resonance imaging. The proposed approach models physical correlations across space, time, and velocity encodings. The proposed Bayesian approach exploits the relationships in both magnitude and phase among velocity encodings. A fast iterative recovery algorithm is introduced based on message passing. For validation, prospectively undersampled data are processed from a pulsatile flow phantom and five healthy volunteers. The proposed approach is in good agreement, quantified by peak velocity and stroke volume (SV), with reference data for acceleration rates R≤10. For SV, Pearson r≥0.99 for phantom imaging (n = 24) and r≥0.96 for prospectively accelerated in vivo imaging (n = 10) for R≤10. The proposed approach enables accurate quantification of blood flow from highly undersampled data. The technique is extensible to four-dimensional flow imaging, where higher acceleration may be possible due to additional redundancy. Magn Reson Med 76:689-701, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Evaluating user experiences of the secure messaging tool on the Veterans Affairs' patient portal system.

PubMed

Haun, Jolie N; Lind, Jason D; Shimada, Stephanie L; Martin, Tracey L; Gosline, Robert M; Antinori, Nicole; Stewart, Max; Simon, Steven R

2014-03-06

The United States Department of Veterans Affairs has implemented an electronic asynchronous "Secure Messaging" tool within a Web-based patient portal (ie, My HealtheVet) to support patient-provider communication. This electronic resource promotes continuous and coordinated patient-centered care, but to date little research has evaluated patients' experiences and preferences for using Secure Messaging. The objectives of this mixed-methods study were to (1) characterize veterans' experiences using Secure Messaging in the My HealtheVet portal over a 3-month period, including system usability, (2) identify barriers to and facilitators of use, and (3) describe strategies to support veterans' use of Secure Messaging. We recruited 33 veterans who had access to and had previously used the portal's Secure Messaging tool. We used a combination of in-depth interviews, face-to-face user-testing, review of transmitted secure messages between veterans and staff, and telephone interviews three months following initial contact. We assessed participants' computer and health literacy during initial and follow-up interviews. We used a content-analysis approach to identify dominant themes in the qualitative data. We compared inferences from each of the data sources (interviews, user-testing, and message review) to identify convergent and divergent data trends. The majority of veterans (27/33, 82%) reported being satisfied with Secure Messaging at initial interview; satisfaction ratings increased to 97% (31/32, 1 missing) during follow-up interviews. Veterans noted Secure Messaging to be useful for communicating with their primary care team to manage health care needs (eg, health-related questions, test requests and results, medication refills and questions, managing appointments). Four domains emerged from interviews: (1) perceived benefits of using Secure Messaging, (2) barriers to using Secure Messaging, (3) facilitators for using Secure Messaging, and (4) suggestions for improving Secure Messaging. Veterans identified and demonstrated impediments to successful system usage that can be addressed with education, skill building, and system modifications. Analysis of secure message content data provided insights to reasons for use that were not disclosed by participants during interviews, specifically sensitive health topics such as erectile dysfunction and sexually transmitted disease inquiries. Veterans perceive Secure Messaging in the My HealtheVet patient portal as a useful tool for communicating with health care teams. However, to maximize sustained utilization of Secure Messaging, marketing, education, skill building, and system modifications are needed. Data from this study can inform a large-scale quantitative assessment of Secure Messaging users' experiences in a representative sample to validate qualitative findings.

47 CFR 10.420 - Message elements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Message elements. 10.420 Section 10.420 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL MOBILE ALERT SYSTEM Alert Message Requirements § 10.420 Message elements. A CMAS Alert Message processed by a Participating CMS Provider shall...

Introduction to Message-Bus Architectures for Space Systems

NASA Technical Reports Server (NTRS)

Smith, Dan; Gregory, Brian

2005-01-01

This course presents technical and programmatic information on the development of message-based architectures for space mission ground and flight software systems. Message-based architecture approaches provide many significant advantages over the more traditional socket-based one-of-a-kind integrated system development approaches. The course provides an overview of publish/subscribe concepts, the use of common isolation layer API's, approaches to message standardization, and other technical topics. Several examples of currently operational systems are discussed and possible changes to the system development process are presented. Benefits and lessons learned will be discussed and time for questions and answers will be provided.

I-39 dynamic message sign project summary

DOT National Transportation Integrated Search

2005-01-01

The Illinois Department of Transportation (IDOT) sought to deploy a message sign system consisting of permanently-mounted dynamic message signs around the Rockford metropolitan area. The project goal was to begin building a system of remotely-activat...

Two Women with Multiple Disabilities Communicate with Distant Partners via a Special Text Messaging System

ERIC Educational Resources Information Center

Lancioni, Giulio E.; O'Reilly, Mark F.; Singh, Nirbhay N.; Sigafoos, Jeff; Green, Vanessa A.; Oliva, Doretta; Alberti, Gloria; Carrella, Luigina

2013-01-01

This study extended the research on a special text messaging system, which allows persons with multiple disabilities to (a) write and send messages to distant partners and (b) have messages from those partners read out to them. The study involved two women with multiple disabilities (including blindness or minimal residual vision). The system…

Implementing the PM Programming Language using MPI and OpenMP - a New Tool for Programming Geophysical Models on Parallel Systems

NASA Astrophysics Data System (ADS)

Bellerby, Tim

2015-04-01

PM (Parallel Models) is a new parallel programming language specifically designed for writing environmental and geophysical models. The language is intended to enable implementers to concentrate on the science behind the model rather than the details of running on parallel hardware. At the same time PM leaves the programmer in control - all parallelisation is explicit and the parallel structure of any given program may be deduced directly from the code. This paper describes a PM implementation based on the Message Passing Interface (MPI) and Open Multi-Processing (OpenMP) standards, looking at issues involved with translating the PM parallelisation model to MPI/OpenMP protocols and considering performance in terms of the competing factors of finer-grained parallelisation and increased communication overhead. In order to maximise portability, the implementation stays within the MPI 1.3 standard as much as possible, with MPI-2 MPI-IO file handling the only significant exception. Moreover, it does not assume a thread-safe implementation of MPI. PM adopts a two-tier abstract representation of parallel hardware. A PM processor is a conceptual unit capable of efficiently executing a set of language tasks, with a complete parallel system consisting of an abstract N-dimensional array of such processors. PM processors may map to single cores executing tasks using cooperative multi-tasking, to multiple cores or even to separate processing nodes, efficiently sharing tasks using algorithms such as work stealing. While tasks may move between hardware elements within a PM processor, they may not move between processors without specific programmer intervention. Tasks are assigned to processors using a nested parallelism approach, building on ideas from Reyes et al. (2009). The main program owns all available processors. When the program enters a parallel statement then either processors are divided out among the newly generated tasks (number of new tasks < number of processors) or tasks are divided out among the available processors (number of tasks > number of processors). Nested parallel statements may further subdivide the processor set owned by a given task. Tasks or processors are distributed evenly by default, but uneven distributions are possible under programmer control. It is also possible to explicitly enable child tasks to migrate within the processor set owned by their parent task, reducing load unbalancing at the potential cost of increased inter-processor message traffic. PM incorporates some programming structures from the earlier MIST language presented at a previous EGU General Assembly, while adopting a significantly different underlying parallelisation model and type system. PM code is available at www.pm-lang.org under an unrestrictive MIT license. Reference Ruymán Reyes, Antonio J. Dorta, Francisco Almeida, Francisco de Sande, 2009. Automatic Hybrid MPI+OpenMP Code Generation with llc, Recent Advances in Parallel Virtual Machine and Message Passing Interface, Lecture Notes in Computer Science Volume 5759, 185-195

Evaluation of a new parallel numerical parameter optimization algorithm for a dynamical system

NASA Astrophysics Data System (ADS)

Duran, Ahmet; Tuncel, Mehmet

2016-10-01

It is important to have a scalable parallel numerical parameter optimization algorithm for a dynamical system used in financial applications where time limitation is crucial. We use Message Passing Interface parallel programming and present such a new parallel algorithm for parameter estimation. For example, we apply the algorithm to the asset flow differential equations that have been developed and analyzed since 1989 (see [3-6] and references contained therein). We achieved speed-up for some time series to run up to 512 cores (see [10]). Unlike [10], we consider more extensive financial market situations, for example, in presence of low volatility, high volatility and stock market price at a discount/premium to its net asset value with varying magnitude, in this work. Moreover, we evaluated the convergence of the model parameter vector, the nonlinear least squares error and maximum improvement factor to quantify the success of the optimization process depending on the number of initial parameter vectors.

Parallelization of NAS Benchmarks for Shared Memory Multiprocessors

NASA Technical Reports Server (NTRS)

Waheed, Abdul; Yan, Jerry C.; Saini, Subhash (Technical Monitor)

1998-01-01

This paper presents our experiences of parallelizing the sequential implementation of NAS benchmarks using compiler directives on SGI Origin2000 distributed shared memory (DSM) system. Porting existing applications to new high performance parallel and distributed computing platforms is a challenging task. Ideally, a user develops a sequential version of the application, leaving the task of porting to new generations of high performance computing systems to parallelization tools and compilers. Due to the simplicity of programming shared-memory multiprocessors, compiler developers have provided various facilities to allow the users to exploit parallelism. Native compilers on SGI Origin2000 support multiprocessing directives to allow users to exploit loop-level parallelism in their programs. Additionally, supporting tools can accomplish this process automatically and present the results of parallelization to the users. We experimented with these compiler directives and supporting tools by parallelizing sequential implementation of NAS benchmarks. Results reported in this paper indicate that with minimal effort, the performance gain is comparable with the hand-parallelized, carefully optimized, message-passing implementations of the same benchmarks.

Performance of a parallel code for the Euler equations on hypercube computers

NASA Technical Reports Server (NTRS)

Barszcz, Eric; Chan, Tony F.; Jesperson, Dennis C.; Tuminaro, Raymond S.

1990-01-01

The performance of hypercubes were evaluated on a computational fluid dynamics problem and the parallel environment issues were considered that must be addressed, such as algorithm changes, implementation choices, programming effort, and programming environment. The evaluation focuses on a widely used fluid dynamics code, FLO52, which solves the two dimensional steady Euler equations describing flow around the airfoil. The code development experience is described, including interacting with the operating system, utilizing the message-passing communication system, and code modifications necessary to increase parallel efficiency. Results from two hypercube parallel computers (a 16-node iPSC/2, and a 512-node NCUBE/ten) are discussed and compared. In addition, a mathematical model of the execution time was developed as a function of several machine and algorithm parameters. This model accurately predicts the actual run times obtained and is used to explore the performance of the code in interesting but yet physically realizable regions of the parameter space. Based on this model, predictions about future hypercubes are made.

Constructing a working taxonomy of functional Ada software components for real-time embedded system applications

NASA Technical Reports Server (NTRS)

Wallace, Robert

1986-01-01

A major impediment to a systematic attack on Ada software reusability is the lack of an effective taxonomy for software component functions. The scope of all possible applications of Ada software is considered too great to allow the practical development of a working taxonomy. Instead, for the purposes herein, the scope of Ada software application is limited to device and subsystem control in real-time embedded systems. A functional approach is taken in constructing the taxonomy tree for identified Ada domain. The use of modular software functions as a starting point fits well with the object oriented programming philosophy of Ada. Examples of the types of functions represented within the working taxonomy are real time kernels, interrupt service routines, synchronization and message passing, data conversion, digital filtering and signal conditioning, and device control. The constructed taxonomy is proposed as a framework from which a need analysis can be performed to reveal voids in current Ada real-time embedded programming efforts for Space Station.

A Loader for Executing Multi-Binary Applications on the Thinking Machines CM-5: It's Not Just for SPMD Anymore

NASA Technical Reports Server (NTRS)

Becker, Jeffrey C.

1995-01-01

The Thinking Machines CM-5 platform was designed to run single program, multiple data (SPMD) applications, i.e., to run a single binary across all nodes of a partition, with each node possibly operating on different data. Certain classes of applications, such as multi-disciplinary computational fluid dynamics codes, are facilitated by the ability to have subsets of the partition nodes running different binaries. In order to extend the CM-5 system software to permit such applications, a multi-program loader was developed. This system is based on the dld loader which was originally developed for workstations. This paper provides a high level description of dld, and describes how it was ported to the CM-5 to provide support for multi-binary applications. Finally, it elaborates how the loader has been used to implement the CM-5 version of MPIRUN, a portable facility for running multi-disciplinary/multi-zonal MPI (Message-Passing Interface Standard) codes.

A hybrid neurogenetic approach for stock forecasting.

PubMed

Kwon, Yung-Keun; Moon, Byung-Ro

2007-05-01

In this paper, we propose a hybrid neurogenetic system for stock trading. A recurrent neural network (NN) having one hidden layer is used for the prediction model. The input features are generated from a number of technical indicators being used by financial experts. The genetic algorithm (GA) optimizes the NN's weights under a 2-D encoding and crossover. We devised a context-based ensemble method of NNs which dynamically changes on the basis of the test day's context. To reduce the time in processing mass data, we parallelized the GA on a Linux cluster system using message passing interface. We tested the proposed method with 36 companies in NYSE and NASDAQ for 13 years from 1992 to 2004. The neurogenetic hybrid showed notable improvement on the average over the buy-and-hold strategy and the context-based ensemble further improved the results. We also observed that some companies were more predictable than others, which implies that the proposed neurogenetic hybrid can be used for financial portfolio construction.

Driver memory retention of in-vehicle information system messages

DOT National Transportation Integrated Search

1997-01-01

Memory retention of drivers was tested for traffic- and traveler-related messages displayed on an in-vehicle information system (IVIS). Three research questions were asked: (a) How does in-vehicle visual message format affect comprehension? (b) How d...

Evaluating User Experiences of the Secure Messaging Tool on the Veterans Affairs’ Patient Portal System

PubMed Central

Lind, Jason D; Shimada, Stephanie L; Martin, Tracey L; Gosline, Robert M; Antinori, Nicole; Stewart, Max; Simon, Steven R

2014-01-01

Background The United States Department of Veterans Affairs has implemented an electronic asynchronous “Secure Messaging” tool within a Web-based patient portal (ie, My HealtheVet) to support patient-provider communication. This electronic resource promotes continuous and coordinated patient-centered care, but to date little research has evaluated patients’ experiences and preferences for using Secure Messaging. Objective The objectives of this mixed-methods study were to (1) characterize veterans’ experiences using Secure Messaging in the My HealtheVet portal over a 3-month period, including system usability, (2) identify barriers to and facilitators of use, and (3) describe strategies to support veterans’ use of Secure Messaging. Methods We recruited 33 veterans who had access to and had previously used the portal’s Secure Messaging tool. We used a combination of in-depth interviews, face-to-face user-testing, review of transmitted secure messages between veterans and staff, and telephone interviews three months following initial contact. We assessed participants’ computer and health literacy during initial and follow-up interviews. We used a content-analysis approach to identify dominant themes in the qualitative data. We compared inferences from each of the data sources (interviews, user-testing, and message review) to identify convergent and divergent data trends. Results The majority of veterans (27/33, 82%) reported being satisfied with Secure Messaging at initial interview; satisfaction ratings increased to 97% (31/32, 1 missing) during follow-up interviews. Veterans noted Secure Messaging to be useful for communicating with their primary care team to manage health care needs (eg, health-related questions, test requests and results, medication refills and questions, managing appointments). Four domains emerged from interviews: (1) perceived benefits of using Secure Messaging, (2) barriers to using Secure Messaging, (3) facilitators for using Secure Messaging, and (4) suggestions for improving Secure Messaging. Veterans identified and demonstrated impediments to successful system usage that can be addressed with education, skill building, and system modifications. Analysis of secure message content data provided insights to reasons for use that were not disclosed by participants during interviews, specifically sensitive health topics such as erectile dysfunction and sexually transmitted disease inquiries. Conclusions Veterans perceive Secure Messaging in the My HealtheVet patient portal as a useful tool for communicating with health care teams. However, to maximize sustained utilization of Secure Messaging, marketing, education, skill building, and system modifications are needed. Data from this study can inform a large-scale quantitative assessment of Secure Messaging users’ experiences in a representative sample to validate qualitative findings. PMID:24610454

Predictors for assessing electronic messaging between nurses and general practitioners as a useful tool for communication in home health care services: a cross-sectional study.

PubMed

Lyngstad, Merete; Hofoss, Dag; Grimsmo, Anders; Hellesø, Ragnhild

2015-02-17

Nurses providing home health care services are dependent on access to patient information and communicating with general practitioners (GPs) to deliver safe and effective health care to patients. Information and communication technology (ICT) systems are viewed as powerful tools for this purpose. In Norway, a standardized electronic messaging (e-messaging) system is currently being established in health care. The aim of this study was to explore home health care nurses' assessments of the utility of the e-messaging system for communicating with GPs and identify elements that influence the assessment of e-messaging as a useful communication tool. The data were collected using a self-developed questionnaire based on variables identified by focus group interviews with home health care nurses (n=425) who used e-messaging and existing research. Data were analyzed using logistic regression analyses. Over two-thirds (425/632, 67.2%) of the home health care nurses returned the questionnaire. A high proportion (388/399, 97.2%) of the home health care nurses who returned the questionnaire found the e-messaging system to be a useful tool for communication with GPs. The odds of reporting that e-messaging was a useful tool were over five times higher (OR 5.1, CI 2.489-10.631, P<.001) if the nurses agreed or strongly agreed that e-messaging was easy to use. The odds of finding e-messaging easy to use were nearly seven times higher (OR 6.9, CI 1.713-27.899, P=.007) if the nurses did not consider the system functionality poor. If the nurses had received training in the use of e-messaging, the odds were over six times higher (OR 6.6, CI 2.515-17.437, P<.001) that they would consider e-messaging easy to use. The odds that a home health care nurse would experience e-messaging as easy to use increased as the full-time equivalent percentage of the nurses increased (OR 1.032, CI 1.001-1.064, P=.045). This study has shown that technical (ease of use and system functionality), organizational (training), and individual (full-time equivalent percentage) elements had an impact on home health care nurses' assessments of using e-messaging to communicate with GPs. By identifying these elements, it is easier to determine which interventions are the most important for the development and implementation of ICT systems in home health care services.

Predictors for Assessing Electronic Messaging Between Nurses and General Practitioners as a Useful Tool for Communication in Home Health Care Services: A Cross-Sectional Study

PubMed Central

Hofoss, Dag; Grimsmo, Anders; Hellesø, Ragnhild

2015-01-01

Background Nurses providing home health care services are dependent on access to patient information and communicating with general practitioners (GPs) to deliver safe and effective health care to patients. Information and communication technology (ICT) systems are viewed as powerful tools for this purpose. In Norway, a standardized electronic messaging (e-messaging) system is currently being established in health care. Objective The aim of this study was to explore home health care nurses’ assessments of the utility of the e-messaging system for communicating with GPs and identify elements that influence the assessment of e-messaging as a useful communication tool. Methods The data were collected using a self-developed questionnaire based on variables identified by focus group interviews with home health care nurses (n=425) who used e-messaging and existing research. Data were analyzed using logistic regression analyses. Results Over two-thirds (425/632, 67.2%) of the home health care nurses returned the questionnaire. A high proportion (388/399, 97.2%) of the home health care nurses who returned the questionnaire found the e-messaging system to be a useful tool for communication with GPs. The odds of reporting that e-messaging was a useful tool were over five times higher (OR 5.1, CI 2.489-10.631, P<.001) if the nurses agreed or strongly agreed that e-messaging was easy to use. The odds of finding e-messaging easy to use were nearly seven times higher (OR 6.9, CI 1.713-27.899, P=.007) if the nurses did not consider the system functionality poor. If the nurses had received training in the use of e-messaging, the odds were over six times higher (OR 6.6, CI 2.515-17.437, P<.001) that they would consider e-messaging easy to use. The odds that a home health care nurse would experience e-messaging as easy to use increased as the full-time equivalent percentage of the nurses increased (OR 1.032, CI 1.001-1.064, P=.045). Conclusions This study has shown that technical (ease of use and system functionality), organizational (training), and individual (full-time equivalent percentage) elements had an impact on home health care nurses’ assessments of using e-messaging to communicate with GPs. By identifying these elements, it is easier to determine which interventions are the most important for the development and implementation of ICT systems in home health care services. PMID:25691234

Description of a MIL-STD-1553B Data Bus Ada Driver for the LeRC EPS Testbed

NASA Technical Reports Server (NTRS)

Mackin, Michael A.

1995-01-01

This document describes the software designed to provide communication between control computers in the NASA Lewis Research Center Electrical Power System Testbed using MIL-STD-1553B. The software drivers are coded in the Ada programming language and were developed on a MSDOS-based computer workstation. The Electrical Power System (EPS) Testbed is a reduced-scale prototype space station electrical power system. The power system manages and distributes electrical power from the sources (batteries or photovoltaic arrays) to the end-user loads. The electrical system primary operates at 120 volts DC, and the secondary system operates at 28 volts DC. The devices which direct the flow of electrical power are controlled by a network of six control computers. Data and control messages are passed between the computers using the MIL-STD-1553B network. One of the computers, the Power Management Controller (PMC), controls the primary power distribution and another, the Load Management Controller (LMC), controls the secondary power distribution. Each of these computers communicates with two other computers which act as subsidiary controllers. These subsidiary controllers are, in turn, connected to the devices which directly control the flow of electrical power.

Towards ontology personalization to enrich social conversations on AAC systems

NASA Astrophysics Data System (ADS)

Mancilla V., Daniela; Sastoque H., Sebastian; Iregui G., Marcela

2015-01-01

Communication is one of the essential needs of human beings. Augmentative and Alternative Communication Systems (AAC) seek to help in the generation of oral and written language to people with physical disorders that limit their natural communication. These systems present significant challenges such as: the composition of consistent messages according to syntactic and semantic rules, the improvement of message production times, the application to social contexts and, consequently, the incorporation of user-specific information. This work presents an original ontology personalization approach for an AAC instant messaging system incorporating personalized information to improve the efficacy and efficiency of the message production. This proposal is based on a projection of a general ontology into a more specific one, avoiding storage redundancy and data coupling, representing a big opportunity to enrich communication capabilities of current AAC systems. The evaluation was performed for a study case based on an AAC system for assistance in composing messages. The results show that adding user-specific information allows generation of enriched phrases, so improving the accuracy of the message, facilitating the communication process.

Time Triggered Ethernet System Testing Means and Method

NASA Technical Reports Server (NTRS)

Smithgall, William Todd (Inventor); Hall, Brendan (Inventor); Varadarajan, Srivatsan (Inventor)

2014-01-01

Methods and apparatus are provided for evaluating the performance of a Time Triggered Ethernet (TTE) system employing Time Triggered (TT) communication. A real TTE system under test (SUT) having real input elements communicating using TT messages with output elements via one or more first TTE switches during a first time interval schedule established for the SUT. A simulation system is also provided having input simulators that communicate using TT messages via one or more second TTE switches with the same output elements during a second time interval schedule established for the simulation system. The first and second time interval schedules are off-set slightly so that messages from the input simulators, when present, arrive at the output elements prior to messages from the analogous real inputs, thereby having priority over messages from the real inputs and causing the system to operate based on the simulated inputs when present.

GEOS Atmospheric Model: Challenges at Exascale

NASA Technical Reports Server (NTRS)

Putman, William M.; Suarez, Max J.

2017-01-01

The Goddard Earth Observing System (GEOS) model at NASA's Global Modeling and Assimilation Office (GMAO) is used to simulate the multi-scale variability of the Earth's weather and climate, and is used primarily to assimilate conventional and satellite-based observations for weather forecasting and reanalysis. In addition, assimilations coupled to an ocean model are used for longer-term forecasting (e.g., El Nino) on seasonal to interannual times-scales. The GMAO's research activities, including system development, focus on numerous time and space scales, as detailed on the GMAO website, where they are tabbed under five major themes: Weather Analysis and Prediction; Seasonal-Decadal Analysis and Prediction; Reanalysis; Global Mesoscale Modeling, and Observing System Science. A brief description of the GEOS systems can also be found at the GMAO website. GEOS executes as a collection of earth system components connected through the Earth System Modeling Framework (ESMF). The ESMF layer is supplemented with the MAPL (Modeling, Analysis, and Prediction Layer) software toolkit developed at the GMAO, which facilitates the organization of the computational components into a hierarchical architecture. GEOS systems run in parallel using a horizontal decomposition of the Earth's sphere into processing elements (PEs). Communication between PEs is primarily through a message passing framework, using the message passing interface (MPI), and through explicit use of node-level shared memory access via the SHMEM (Symmetric Hierarchical Memory access) protocol. Production GEOS weather prediction systems currently run at 12.5-kilometer horizontal resolution with 72 vertical levels decomposed into PEs associated with 5,400 MPI processes. Research GEOS systems run at resolutions as fine as 1.5 kilometers globally using as many as 30,000 MPI processes. Looking forward, these systems can be expected to see a 2 times increase in horizontal resolution every two to three years, as well as less frequent increases in vertical resolution. Coupling these resolution changes with increases in complexity, the computational demands on the GEOS production and research systems should easily increase 100-fold over the next five years. Currently, our 12.5 kilometer weather prediction system narrowly meets the time-to-solution demands of a near-real-time production system. Work is now in progress to take advantage of a hybrid MPI-OpenMP parallelism strategy, in an attempt to achieve a modest two-fold speed-up to accommodate an immediate demand due to increased scientific complexity and an increase in vertical resolution. Pursuing demands that require a 10- to 100-fold increases or more, however, would require a detailed exploration of the computational profile of GEOS, as well as targeted solutions using more advanced high-performance computing technologies. Increased computing demands of 100-fold will be required within five years based on anticipated changes in the GEOS production systems, increases of 1000-fold can be anticipated over the next ten years.

Unified messaging solution for biosurveillance and disease surveillance.

PubMed

Abellera, John P; Srinivasan, Arunkumar; Danos, C Scott; McNabb, Scott; Rhodes, Barry

2007-10-11

Biosurveillance and disease surveillance systems serve different purposes. However, the richness and quality of an existing data stream and infrastructure used in biosurveillance may prove beneficial for any state-based electronic disease surveillance system, especially if an electronic laboratory data feed does not exist between a hospital and state-based system. The use of an Enterprise Application Integration(EAI) engine, such as the BioSense Integrator,will be necessary to map heterogeneous messages into standard representations, then validate and route them [1] to a disparate system. This poster illustrates the use of an existing BioSense Integrator in order to create a unified message to support the exchange of electronic lab messages necessary for reportable disease notification. An evaluation of the infrastructure for data messaging will be examined and presented, along with a cost and benefit analysis between hospital and state-based system.

An implementation and evaluation of the MPI 3.0 one-sided communication interface

DOE PAGES

Dinan, James S.; Balaji, Pavan; Buntinas, Darius T.; ...

2016-01-09

The Q1 Message Passing Interface (MPI) 3.0 standard includes a significant revision to MPI’s remote memory access (RMA) interface, which provides support for one-sided communication. MPI-3 RMA is expected to greatly enhance the usability and performance ofMPI RMA.We present the first complete implementation of MPI-3 RMA and document implementation techniques and performance optimization opportunities enabled by the new interface. Our implementation targets messaging-based networks and is publicly available in the latest release of the MPICH MPI implementation. Here using this implementation, we explore the performance impact of new MPI-3 functionality and semantics. Results indicate that the MPI-3 RMA interface providesmore » significant advantages over the MPI-2 interface by enabling increased communication concurrency through relaxed semantics in the interface and additional routines that provide new window types, synchronization modes, and atomic operations.« less

An implementation and evaluation of the MPI 3.0 one-sided communication interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dinan, James S.; Balaji, Pavan; Buntinas, Darius T.

The Q1 Message Passing Interface (MPI) 3.0 standard includes a significant revision to MPI’s remote memory access (RMA) interface, which provides support for one-sided communication. MPI-3 RMA is expected to greatly enhance the usability and performance ofMPI RMA.We present the first complete implementation of MPI-3 RMA and document implementation techniques and performance optimization opportunities enabled by the new interface. Our implementation targets messaging-based networks and is publicly available in the latest release of the MPICH MPI implementation. Here using this implementation, we explore the performance impact of new MPI-3 functionality and semantics. Results indicate that the MPI-3 RMA interface providesmore » significant advantages over the MPI-2 interface by enabling increased communication concurrency through relaxed semantics in the interface and additional routines that provide new window types, synchronization modes, and atomic operations.« less

Assisted entry mitigates text messaging-based driving detriment.

PubMed

Sawyer, Benjamin D; Hancock, Peter A

2012-01-01

Previous research using cell phones indicates that manual manipulation is not a principal component of text messaging relating driving detriment. This paper suggests that manipulation of a phone in conjunction with the cognitive need to compose the message itself co-act to contribute to driving degradation. This being so, drivers sending text messages might experience reduced interference to the driving task if the text messaging itself were assisted through the predictive T9 system. We evaluated undergraduate drivers in a simulator who drove and texted using either Assisted Text entry, via Nokia's T9 system, or unassisted entry via the multitap interface. Results supported the superiority of the T9 system over the multitap system implying that specific assistive technologies can modulate the degradation of capacity which texting tragically induces.

Proof of Concept for the Rewrite Rule Machine: Interensemble Studies

DTIC Science & Technology

1994-02-23

34 -,,, S2 •fbo fibo 0 1 Figure 1: Concurrent Rewriting of Fibonacci Expressions exploit a problem’s parallelism at several levels. We call this...property multigrain concurrency; it makes the RRM very well suited for solving not only homogeneous problems, but also complex, locally homogeneous but...interprocessor message passing over a network-is not well suited to data parallelism. A key goal of the RRM is to combine the best of these two approaches in a

Alexander George Karczmar (1917-2017).

PubMed

Soreq, Hermona; Silman, Israel

2017-12-01

The neurochemistry community at large and the Advisory Board of The International Symposia on Cholinergic Mechanisms mourn the loss of Alexander George Karczmar, the elected Honorary President of these international symposia, who passed away peacefully in his Chicago home at the age of 100 on August 17, 2017. For many of us Alex was the essence of cholinergic signaling, and personified its versatile power to send messages between the brain and the peripheral tissues and organs, and to connect between body and soul. © 2017 International Society for Neurochemistry.

Strategic and Tactical Decision-Making Under Uncertainty

DTIC Science & Technology

2006-01-03

message passing algorithms. In recent work we applied this method to the problem of joint decoding of a low-density parity-check ( LDPC ) code and a partial...Joint Decoding of LDPC Codes and Partial-Response Channels." IEEE Transactions on Communications. Vol. 54, No. 7, 1149-1153, 2006. P. Pakzad and V...Michael I. Jordan PAGES U U U SAPR 20 19b. TELEPHONE NUMBER (Include area code ) 510/642-3806 Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18

Specification of Fenix MPI Fault Tolerance library version 1.0.1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gamble, Marc; Van Der Wijngaart, Rob; Teranishi, Keita

This document provides a specification of Fenix, a software library compatible with the Message Passing Interface (MPI) to support fault recovery without application shutdown. The library consists of two modules. The first, termed process recovery , restores an application to a consistent state after it has suffered a loss of one or more MPI processes (ranks). The second specifies functions the user can invoke to store application data in Fenix managed redundant storage, and to retrieve it from that storage after process recovery.

Relay Forward-Link File Management Services (MaROS Phase 2)

NASA Technical Reports Server (NTRS)

Allard, Daniel A.; Wallick, Michael N.; Hy, Franklin H.; Gladden, Roy E.

2013-01-01

This software provides the service-level functionality to manage the delivery of files from a lander mission repository to an orbiter mission repository for eventual spacelink relay by the orbiter asset on a specific communications pass. It provides further functions to deliver and track a set of mission-defined messages detailing lander authorization instructions and orbiter data delivery state. All of the information concerning these transactions is persisted in a database providing a high level of accountability of the forward-link relay process.

8755 Emulator Design

DTIC Science & Technology

1988-12-01

Break Control....................51 8755 I/O Control..................54 Z-100 Control Software................. 55 Pass User Memory...the emulator SRAM and the other is 55 for the target SRAM. If either signal is replaced by the NACK signal the host computer displays an error message...Block Diagram 69 AUU M/M 8 in Fiur[:. cemti Daga 70m F’M I-- ’I ANLAD AMam U52 COMM ow U2 i M.2 " -n ax- U 6_- Figure 2b. Schematic Diagram 71 )-M -A -I

Some Aspects of Parallel Implementation of the Finite Element Method on Message Passing Architectures

DTIC Science & Technology

1988-05-01

for Advanced Computer Studies and Department of Computer Science University of Maryland College Park, MD 20742 4, ABSTRACT We discuss some aspects of...Computer Studies and Technology & Dept. of Compute. Scienc II. CONTROLLING OFFICE NAME AND ADDRESS Viyriyf~ 12. REPORT DATE Department of the Navy uo...number)-1/ 2.) We study the performance of CG and PCG by examining its performance for u E (0,1), for solving the two model problems with an accuracy

Effects of Ordering Strategies and Programming Paradigms on Sparse Matrix Computations

NASA Technical Reports Server (NTRS)

Oliker, Leonid; Li, Xiaoye; Husbands, Parry; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

2002-01-01

The Conjugate Gradient (CG) algorithm is perhaps the best-known iterative technique to solve sparse linear systems that are symmetric and positive definite. For systems that are ill-conditioned, it is often necessary to use a preconditioning technique. In this paper, we investigate the effects of various ordering and partitioning strategies on the performance of parallel CG and ILU(O) preconditioned CG (PCG) using different programming paradigms and architectures. Results show that for this class of applications: ordering significantly improves overall performance on both distributed and distributed shared-memory systems, that cache reuse may be more important than reducing communication, that it is possible to achieve message-passing performance using shared-memory constructs through careful data ordering and distribution, and that a hybrid MPI+OpenMP paradigm increases programming complexity with little performance gains. A implementation of CG on the Cray MTA does not require special ordering or partitioning to obtain high efficiency and scalability, giving it a distinct advantage for adaptive applications; however, it shows limited scalability for PCG due to a lack of thread level parallelism.

Parallel computation and the Basis system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, G.R.

1992-12-16

A software package has been written that can facilitate efforts to develop powerful, flexible, and easy-to-use programs that can run in single-processor, massively parallel, and distributed computing environments. Particular attention has been given to the difficulties posed by a program consisting of many science packages that represent subsystems of a complicated, coupled system. Methods have been found to maintain independence of the packages by hiding data structures without increasing the communication costs in a parallel computing environment. Concepts developed in this work are demonstrated by a prototype program that uses library routines from two existing software systems, Basis and Parallelmore » Virtual Machine (PVM). Most of the details of these libraries have been encapsulated in routines and macros that could be rewritten for alternative libraries that possess certain minimum capabilities. The prototype software uses a flexible master-and-slaves paradigm for parallel computation and supports domain decomposition with message passing for partitioning work among slaves. Facilities are provided for accessing variables that are distributed among the memories of slaves assigned to subdomains. The software is named PROTOPAR.« less

Parallel computation and the basis system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, G.R.

1993-05-01

A software package has been written that can facilitate efforts to develop powerful, flexible, and easy-to use programs that can run in single-processor, massively parallel, and distributed computing environments. Particular attention has been given to the difficulties posed by a program consisting of many science packages that represent subsystems of a complicated, coupled system. Methods have been found to maintain independence of the packages by hiding data structures without increasing the communications costs in a parallel computing environment. Concepts developed in this work are demonstrated by a prototype program that uses library routines from two existing software systems, Basis andmore » Parallel Virtual Machine (PVM). Most of the details of these libraries have been encapsulated in routines and macros that could be rewritten for alternative libraries that possess certain minimum capabilities. The prototype software uses a flexible master-and-slaves paradigm for parallel computation and supports domain decomposition with message passing for partitioning work among slaves. Facilities are provided for accessing variables that are distributed among the memories of slaves assigned to subdomains. The software is named PROTOPAR.« less

CDC WONDER: a cooperative processing architecture for public health.

PubMed Central

Friede, A; Rosen, D H; Reid, J A

1994-01-01

CDC WONDER is an information management architecture designed for public health. It provides access to information and communications without the user's needing to know the location of data or communication pathways and mechanisms. CDC WONDER users have access to extractions from some 40 databases; electronic mail (e-mail); and surveillance data processing. System components include the Remote Client, the Communications Server, the Queue Managers, and Data Servers and Process Servers. The Remote Client software resides in the user's machine; other components are at the Centers for Disease Control and Prevention (CDC). The Remote Client, the Communications Server, and the Applications Server provide access to the information and functions in the Data Servers and Process Servers. The system architecture is based on cooperative processing, and components are coupled via pure message passing, using several protocols. This architecture allows flexibility in the choice of hardware and software. One system limitation is that final results from some subsystems are obtained slowly. Although designed for public health, CDC WONDER could be useful for other disciplines that need flexible, integrated information exchange. PMID:7719813

Analysis of a parallelized nonlinear elliptic boundary value problem solver with application to reacting flows

NASA Technical Reports Server (NTRS)

Keyes, David E.; Smooke, Mitchell D.

1987-01-01

A parallelized finite difference code based on the Newton method for systems of nonlinear elliptic boundary value problems in two dimensions is analyzed in terms of computational complexity and parallel efficiency. An approximate cost function depending on 15 dimensionless parameters is derived for algorithms based on stripwise and boxwise decompositions of the domain and a one-to-one assignment of the strip or box subdomains to processors. The sensitivity of the cost functions to the parameters is explored in regions of parameter space corresponding to model small-order systems with inexpensive function evaluations and also a coupled system of nineteen equations with very expensive function evaluations. The algorithm was implemented on the Intel Hypercube, and some experimental results for the model problems with stripwise decompositions are presented and compared with the theory. In the context of computational combustion problems, multiprocessors of either message-passing or shared-memory type may be employed with stripwise decompositions to realize speedup of O(n), where n is mesh resolution in one direction, for reasonable n.

Extending the length and time scales of Gram–Schmidt Lyapunov vector computations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Costa, Anthony B., E-mail: acosta@northwestern.edu; Green, Jason R., E-mail: jason.green@umb.edu; Department of Chemistry, University of Massachusetts Boston, Boston, MA 02125

Lyapunov vectors have found growing interest recently due to their ability to characterize systems out of thermodynamic equilibrium. The computation of orthogonal Gram–Schmidt vectors requires multiplication and QR decomposition of large matrices, which grow as N{sup 2} (with the particle count). This expense has limited such calculations to relatively small systems and short time scales. Here, we detail two implementations of an algorithm for computing Gram–Schmidt vectors. The first is a distributed-memory message-passing method using Scalapack. The second uses the newly-released MAGMA library for GPUs. We compare the performance of both codes for Lennard–Jones fluids from N=100 to 1300 betweenmore » Intel Nahalem/Infiniband DDR and NVIDIA C2050 architectures. To our best knowledge, these are the largest systems for which the Gram–Schmidt Lyapunov vectors have been computed, and the first time their calculation has been GPU-accelerated. We conclude that Lyapunov vector calculations can be significantly extended in length and time by leveraging the power of GPU-accelerated linear algebra.« less

MLP: A Parallel Programming Alternative to MPI for New Shared Memory Parallel Systems

NASA Technical Reports Server (NTRS)

Taft, James R.

1999-01-01

Recent developments at the NASA AMES Research Center's NAS Division have demonstrated that the new generation of NUMA based Symmetric Multi-Processing systems (SMPs), such as the Silicon Graphics Origin 2000, can successfully execute legacy vector oriented CFD production codes at sustained rates far exceeding processing rates possible on dedicated 16 CPU Cray C90 systems. This high level of performance is achieved via shared memory based Multi-Level Parallelism (MLP). This programming approach, developed at NAS and outlined below, is distinct from the message passing paradigm of MPI. It offers parallelism at both the fine and coarse grained level, with communication latencies that are approximately 50-100 times lower than typical MPI implementations on the same platform. Such latency reductions offer the promise of performance scaling to very large CPU counts. The method draws on, but is also distinct from, the newly defined OpenMP specification, which uses compiler directives to support a limited subset of multi-level parallel operations. The NAS MLP method is general, and applicable to a large class of NASA CFD codes.

Optimizing NEURON Simulation Environment Using Remote Memory Access with Recursive Doubling on Distributed Memory Systems.

PubMed

Shehzad, Danish; Bozkuş, Zeki

2016-01-01

Increase in complexity of neuronal network models escalated the efforts to make NEURON simulation environment efficient. The computational neuroscientists divided the equations into subnets amongst multiple processors for achieving better hardware performance. On parallel machines for neuronal networks, interprocessor spikes exchange consumes large section of overall simulation time. In NEURON for communication between processors Message Passing Interface (MPI) is used. MPI_Allgather collective is exercised for spikes exchange after each interval across distributed memory systems. The increase in number of processors though results in achieving concurrency and better performance but it inversely affects MPI_Allgather which increases communication time between processors. This necessitates improving communication methodology to decrease the spikes exchange time over distributed memory systems. This work has improved MPI_Allgather method using Remote Memory Access (RMA) by moving two-sided communication to one-sided communication, and use of recursive doubling mechanism facilitates achieving efficient communication between the processors in precise steps. This approach enhanced communication concurrency and has improved overall runtime making NEURON more efficient for simulation of large neuronal network models.

Optimizing NEURON Simulation Environment Using Remote Memory Access with Recursive Doubling on Distributed Memory Systems

PubMed Central

Bozkuş, Zeki

2016-01-01

Increase in complexity of neuronal network models escalated the efforts to make NEURON simulation environment efficient. The computational neuroscientists divided the equations into subnets amongst multiple processors for achieving better hardware performance. On parallel machines for neuronal networks, interprocessor spikes exchange consumes large section of overall simulation time. In NEURON for communication between processors Message Passing Interface (MPI) is used. MPI_Allgather collective is exercised for spikes exchange after each interval across distributed memory systems. The increase in number of processors though results in achieving concurrency and better performance but it inversely affects MPI_Allgather which increases communication time between processors. This necessitates improving communication methodology to decrease the spikes exchange time over distributed memory systems. This work has improved MPI_Allgather method using Remote Memory Access (RMA) by moving two-sided communication to one-sided communication, and use of recursive doubling mechanism facilitates achieving efficient communication between the processors in precise steps. This approach enhanced communication concurrency and has improved overall runtime making NEURON more efficient for simulation of large neuronal network models. PMID:27413363

The implementation of an aeronautical CFD flow code onto distributed memory parallel systems

NASA Astrophysics Data System (ADS)

Ierotheou, C. S.; Forsey, C. R.; Leatham, M.

2000-04-01

The parallelization of an industrially important in-house computational fluid dynamics (CFD) code for calculating the airflow over complex aircraft configurations using the Euler or Navier-Stokes equations is presented. The code discussed is the flow solver module of the SAUNA CFD suite. This suite uses a novel grid system that may include block-structured hexahedral or pyramidal grids, unstructured tetrahedral grids or a hybrid combination of both. To assist in the rapid convergence to a solution, a number of convergence acceleration techniques are employed including implicit residual smoothing and a multigrid full approximation storage scheme (FAS). Key features of the parallelization approach are the use of domain decomposition and encapsulated message passing to enable the execution in parallel using a single programme multiple data (SPMD) paradigm. In the case where a hybrid grid is used, a unified grid partitioning scheme is employed to define the decomposition of the mesh. The parallel code has been tested using both structured and hybrid grids on a number of different distributed memory parallel systems and is now routinely used to perform industrial scale aeronautical simulations. Copyright

A pilot test of a tailored mobile and web-based diabetes messaging system for adolescents.

PubMed

Mulvaney, Shelagh A; Anders, Shilo; Smith, Annie K; Pittel, Eric J; Johnson, Kevin B

2012-03-01

We conducted a pilot trial of a new mobile and web-based intervention to improve diabetes adherence. The text messaging system was designed to motivate and remind adolescents about diabetes self-care tasks. Text messages were tailored according to individually-reported barriers to diabetes self-care. A total of 23 adolescents with type 1 diabetes used the system for a period of three months. On average, they received 10 text messages per week (range 8-12). A matched historical control group from the same clinic was used for comparison. After three months, system users rated the content, usability and experiences with the system, which were very favourable. Comparison of the intervention and control groups indicated a significant interaction between group and time. Both groups had similar HbA(1c) levels at baseline. After three months, the mean HbA(1c) level in the intervention group was unchanged (8.8%), but the mean level in the control group was significantly higher (9.9%), P = 0.006. The results demonstrate the feasibility of the messaging system, user acceptance and a promising effect on glycaemic control. Integrating this type of messaging system with online educational programming could prove to be beneficial.

Development of a Grid-Independent Geos-Chem Chemical Transport Model (v9-02) as an Atmospheric Chemistry Module for Earth System Models

NASA Technical Reports Server (NTRS)

Long, M. S.; Yantosca, R.; Nielsen, J. E; Keller, C. A.; Da Silva, A.; Sulprizio, M. P.; Pawson, S.; Jacob, D. J.

2015-01-01

The GEOS-Chem global chemical transport model (CTM), used by a large atmospheric chemistry research community, has been re-engineered to also serve as an atmospheric chemistry module for Earth system models (ESMs). This was done using an Earth System Modeling Framework (ESMF) interface that operates independently of the GEOSChem scientific code, permitting the exact same GEOSChem code to be used as an ESM module or as a standalone CTM. In this manner, the continual stream of updates contributed by the CTM user community is automatically passed on to the ESM module, which remains state of science and referenced to the latest version of the standard GEOS-Chem CTM. A major step in this re-engineering was to make GEOS-Chem grid independent, i.e., capable of using any geophysical grid specified at run time. GEOS-Chem data sockets were also created for communication between modules and with external ESM code. The grid-independent, ESMF-compatible GEOS-Chem is now the standard version of the GEOS-Chem CTM. It has been implemented as an atmospheric chemistry module into the NASA GEOS- 5 ESM. The coupled GEOS-5-GEOS-Chem system was tested for scalability and performance with a tropospheric oxidant-aerosol simulation (120 coupled species, 66 transported tracers) using 48-240 cores and message-passing interface (MPI) distributed-memory parallelization. Numerical experiments demonstrate that the GEOS-Chem chemistry module scales efficiently for the number of cores tested, with no degradation as the number of cores increases. Although inclusion of atmospheric chemistry in ESMs is computationally expensive, the excellent scalability of the chemistry module means that the relative cost goes down with increasing number of cores in a massively parallel environment.

Mission Services Evolution Center Message Bus

NASA Technical Reports Server (NTRS)

Mayorga, Arturo; Bristow, John O.; Butschky, Mike

2011-01-01

The Goddard Mission Services Evolution Center (GMSEC) Message Bus is a robust, lightweight, fault-tolerant middleware implementation that supports all messaging capabilities of the GMSEC API. This architecture is a distributed software system that routes messages based on message subject names and knowledge of the locations in the network of the interested software components.

Optimizing Blocking and Nonblocking Reduction Operations for Multicore Systems: Hierarchical Design and Implementation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorentla Venkata, Manjunath; Shamis, Pavel; Graham, Richard L

2013-01-01

Many scientific simulations, using the Message Passing Interface (MPI) programming model, are sensitive to the performance and scalability of reduction collective operations such as MPI Allreduce and MPI Reduce. These operations are the most widely used abstractions to perform mathematical operations over all processes that are part of the simulation. In this work, we propose a hierarchical design to implement the reduction operations on multicore systems. This design aims to improve the efficiency of reductions by 1) tailoring the algorithms and customizing the implementations for various communication mechanisms in the system 2) providing the ability to configure the depth ofmore » hierarchy to match the system architecture, and 3) providing the ability to independently progress each of this hierarchy. Using this design, we implement MPI Allreduce and MPI Reduce operations (and its nonblocking variants MPI Iallreduce and MPI Ireduce) for all message sizes, and evaluate on multiple architectures including InfiniBand and Cray XT5. We leverage and enhance our existing infrastructure, Cheetah, which is a framework for implementing hierarchical collective operations to implement these reductions. The experimental results show that the Cheetah reduction operations outperform the production-grade MPI implementations such as Open MPI default, Cray MPI, and MVAPICH2, demonstrating its efficiency, flexibility and portability. On Infini- Band systems, with a microbenchmark, a 512-process Cheetah nonblocking Allreduce and Reduce achieves a speedup of 23x and 10x, respectively, compared to the default Open MPI reductions. The blocking variants of the reduction operations also show similar performance benefits. A 512-process nonblocking Cheetah Allreduce achieves a speedup of 3x, compared to the default MVAPICH2 Allreduce implementation. On a Cray XT5 system, a 6144-process Cheetah Allreduce outperforms the Cray MPI by 145%. The evaluation with an application kernel, Conjugate Gradient solver, shows that the Cheetah reductions speeds up total time to solution by 195%, demonstrating the potential benefits for scientific simulations.« less

DIRECT secure messaging as a common transport layer for reporting structured and unstructured lab results to outpatient providers.

PubMed

Sujansky, Walter; Wilson, Tom

2015-04-01

This report describes a grant-funded project to explore the use of DIRECT secure messaging for the electronic delivery of laboratory test results to outpatient physicians and electronic health record systems. The project seeks to leverage the inherent attributes of DIRECT secure messaging and electronic provider directories to overcome certain barriers to the delivery of lab test results in the outpatient setting. The described system enables laboratories that generate test results as HL7 messages to deliver these results as structured or unstructured documents attached to DIRECT secure messages. The system automatically analyzes generated HL7 messages and consults an electronic provider directory to determine the appropriate DIRECT address and delivery format for each indicated recipient. The system also enables lab results delivered to providers as structured attachments to be consumed by HL7 interface engines and incorporated into electronic health record systems. Lab results delivered as unstructured attachments may be printed or incorporated into patient records as PDF files. The system receives and logs acknowledgement messages to document the status of each transmitted lab result, and a graphical interface allows searching and review of this logged information. The described system is a fully implemented prototype that has been tested in a laboratory setting. Although this approach is promising, further work is required to pilot test the system in production settings with clinical laboratories and outpatient provider organizations. Copyright © 2015 Elsevier Inc. All rights reserved.

Tailored motivational message generation: A model and practical framework for real-time physical activity coaching.

PubMed

Op den Akker, Harm; Cabrita, Miriam; Op den Akker, Rieks; Jones, Valerie M; Hermens, Hermie J

2015-06-01

This paper presents a comprehensive and practical framework for automatic generation of real-time tailored messages in behavior change applications. Basic aspects of motivational messages are time, intention, content and presentation. Tailoring of messages to the individual user may involve all aspects of communication. A linear modular system is presented for generating such messages. It is explained how properties of user and context are taken into account in each of the modules of the system and how they affect the linguistic presentation of the generated messages. The model of motivational messages presented is based on an analysis of existing literature as well as the analysis of a corpus of motivational messages used in previous studies. The model extends existing 'ontology-based' approaches to message generation for real-time coaching systems found in the literature. Practical examples are given on how simple tailoring rules can be implemented throughout the various stages of the framework. Such examples can guide further research by clarifying what it means to use e.g. user targeting to tailor a message. As primary example we look at the issue of promoting daily physical activity. Future work is pointed out in applying the present model and framework, defining efficient ways of evaluating individual tailoring components, and improving effectiveness through the creation of accurate and complete user- and context models. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of a high visibility enforcement project focused on passenger vehicles interacting with commercial vehicles.

PubMed

Thomas, F Dennis; Blomberg, Richard D; Peck, Raymond C; Cosgrove, Linda A; Salzberg, Philip M

2008-01-01

In 2004, Washington State applied NHTSA's High Visibility Enforcement model used in the Click It or Ticket seat belt campaign in an attempt to reduce unsafe driving behaviors around commercial motor vehicles (CMVs). The program was called Ticketing Aggressive Cars and Trucks (TACT). This paper details the methods used to evaluate the program's effectiveness and the results of the evaluation. Four high-crash interstate highway corridors, each approximately 25 miles in length, were selected. Two of these corridors received TACT media messages and increased enforcement over an 18-month period while two comparison corridors did not receive any increased media or enforcement. A total of 4,737 contacts were made with drivers during the two enforcement waves, and 72% of these contacts led to a citation. Drivers at the intervention sites who said they saw or heard any of the TACT messages increased from 17.7% in the pre period to a high of 67.3% in the post periods. Drivers at the intervention sites also reported increased exposure to the core message of leaving more space when passing trucks (14% pre to 40% post period). The percentage of drivers who said they leave more room when passing trucks than when passing cars rose from 16% in the pre period to 24% in the post period at the intervention sites, while comparison sites showed no change. Over 150 hours of video recorded by law enforcement officers in unmarked vehicles were utilized to examine violation rates and severity of violations before and after the intervention campaigns. Statistical analyses showed that violation rates were reduced significantly at the intervention sites (between 23% and 46%), while remaining constant at the comparison sites. Analyses of the video data also showed that the seriousness of the residual violations at the intervention sites decreased. Overall, the evaluation results provide a consistent picture of the effectiveness of the TACT pilot project. Success was demonstrated at every step - messages were received and understood, knowledge was changed in the intended direction, self reported driving behavior around large trucks improved, and observed driving behaviors confirmed the self reports. After this initial success in Washington State, the TACT model will continue to be implemented and evaluated by FMCSA in an attempt to validate the program. Based on the results of this study and the consistent positive results found for other sTEP projects, it is likely that TACT will show continued success in a variety of settings and will help reduce the number and severity of crashes involving CMVs. Future research should attempt to use many of the methods described here to further validate the methods for not only evaluations of TACT programs, but also for any other highway safety programs that require measurements of the program's effectiveness.

Instant messaging at the hospital: supporting articulation work?

PubMed

Iversen, Tobias Buschmann; Melby, Line; Toussaint, Pieter

2013-09-01

Clinical work is increasingly fragmented and requires extensive articulation and coordination. Computer systems may support such work. In this study, we investigate how instant messaging functions as a tool for supporting articulation work at the hospital. This paper aims to describe the characteristics of instant messaging communication in terms of number and length of messages, distribution over time, and the number of participants included in conversations. We also aim to determine what kind of articulation work is supported by analysing message content. Analysis of one month's worth of instant messages sent through the perioperative coordination and communication system at a Danish hospital. Instant messaging was found to be used extensively for articulation work, mostly through short, simple conversational exchanges. It is used particularly often for communication concerning the patient, specifically, the coordination and logistics of patient care. Instant messaging is used by all actors involved in the perioperative domain. Articulation work and clinical work are hard to separate in a real clinical setting. Predefined messages and strict workflow design do not suffice when supporting communication in the context of collaborative clinical work. Flexibility is of vital importance, and this needs to be reflected in the design of supportive communication systems. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Defining the ATC Controller Interface for Data Link Clearances

NASA Technical Reports Server (NTRS)

Rankin, James

1998-01-01

The Controller Interface (CI) is the primary method for Air Traffic Controllers to communicate with aircraft via Controller-Pilot Data Link Communications (CPDLC). The controller, wearing a microphone/headset, aurally gives instructions to aircraft as he/she would with today's voice radio systems. The CI's voice recognition system converts the instructions to digitized messages that are formatted according to the RTCA DO-219 Operational Performance Standards for ATC Two-Way Data Link Communications. The DO-219 messages are transferred via RS-232 to the ATIDS system for uplink using a Mode-S datalink. Pilot acknowledgments of controller messages are downlinked to the ATIDS system and transferred to the Cl. A computer monitor is used to convey information to the controller. Aircraft data from the ARTS database are displayed on flight strips. The flight strips are electronic versions of the strips currently used in the ATC system. Outgoing controller messages cause the respective strip to change color to indicate an unacknowledged transmission. The message text is shown on the flight strips for reference. When the pilot acknowledges the message, the strip returns to its normal color. A map of the airport can also be displayed on the monitor. In addition to voice recognition, the controller can enter messages using the monitor's touch screen or by mouse/keyboard.

GMSEC Interface Specification Document 2016 March

NASA Technical Reports Server (NTRS)

Handy, Matthew

2016-01-01

The GMSEC Interface Specification Document contains the standard set of defined messages. Each GMSEC standard message contains a GMSEC Information Bus Header section and a Message Contents section. Each message section identifies required fields, optional fields, data type and recommended use of the fields. Additionally, this document includes the message subjects associated with the standard messages. The system design of the operations center should ensure the components that are selected use both the API and the defined standard messages in order to achieve full interoperability from component to component.

C2 Core and UCore Message Design Capstone: Interoperable Message Structure

DTIC Science & Technology

2009-09-01

there are sufficient resources to carry out a mission. The Team used the Theatre Battle Management Command System ( TBMCS ) to generate sample CMD...System ( TBMCS ) was used to generate CMD messages as inputs for both use cases. These were programmatically transformed into the three-layer message...used for the experiment was generated from the TBMCS in the form of a CMD XML document. The Capstone experiment included transforming that document to

Creating buzz: the neural correlates of effective message propagation.

PubMed

Falk, Emily B; Morelli, Sylvia A; Welborn, B Locke; Dambacher, Karl; Lieberman, Matthew D

2013-07-01

Social interaction promotes the spread of values, attitudes, and behaviors. Here, we report on neural responses to ideas that are destined to spread. We scanned message communicators using functional MRI during their initial exposure to the to-be-communicated ideas. These message communicators then had the opportunity to spread the messages and their corresponding subjective evaluations to message recipients outside the scanner. Successful ideas were associated with neural responses in the communicators' mentalizing systems and reward systems when they first heard the messages, prior to spreading them. Similarly, individuals more able to spread their own views to others produced greater mentalizing-system activity during initial encoding. Unlike prior social-influence studies that focused on the individuals being influenced, this investigation focused on the brains of influencers. Successful social influence is reliably associated with an influencer-to-be's state of mind when first encoding ideas.

Accelerating atomistic calculations of quantum energy eigenstates on graphic cards

NASA Astrophysics Data System (ADS)

Rodrigues, Walter; Pecchia, A.; Lopez, M.; Auf der Maur, M.; Di Carlo, A.

2014-10-01

Electronic properties of nanoscale materials require the calculation of eigenvalues and eigenvectors of large matrices. This bottleneck can be overcome by parallel computing techniques or the introduction of faster algorithms. In this paper we report a custom implementation of the Lanczos algorithm with simple restart, optimized for graphical processing units (GPUs). The whole algorithm has been developed using CUDA and runs entirely on the GPU, with a specialized implementation that spares memory and reduces at most machine-to-device data transfers. Furthermore parallel distribution over several GPUs has been attained using the standard message passing interface (MPI). Benchmark calculations performed on a GaN/AlGaN wurtzite quantum dot with up to 600,000 atoms are presented. The empirical tight-binding (ETB) model with an sp3d5s∗+spin-orbit parametrization has been used to build the system Hamiltonian (H).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shipman, Galen M.

These are the slides for a presentation on programming models in HPC, at the Los Alamos National Laboratory's Parallel Computing Summer School. The following topics are covered: Flynn's Taxonomy of computer architectures; single instruction single data; single instruction multiple data; multiple instruction multiple data; address space organization; definition of Trinity (Intel Xeon-Phi is a MIMD architecture); single program multiple data; multiple program multiple data; ExMatEx workflow overview; definition of a programming model, programming languages, runtime systems; programming model and environments; MPI (Message Passing Interface); OpenMP; Kokkos (Performance Portable Thread-Parallel Programming Model); Kokkos abstractions, patterns, policies, and spaces; RAJA, a systematicmore » approach to node-level portability and tuning; overview of the Legion Programming Model; mapping tasks and data to hardware resources; interoperability: supporting task-level models; Legion S3D execution and performance details; workflow, integration of external resources into the programming model.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sayan Ghosh, Jeff Hammond

OpenSHMEM is a community effort to unifyt and standardize the SHMEM programming model. MPI (Message Passing Interface) is a well-known community standard for parallel programming using distributed memory. The most recen t release of MPI, version 3.0, was designed in part to support programming models like SHMEM.OSHMPI is an implementation of the OpenSHMEM standard using MPI-3 for the Linux operating system. It is the first implementation of SHMEM over MPI one-sided communication and has the potential to be widely adopted due to the portability and widely availability of Linux and MPI-3. OSHMPI has been tested on a variety of systemsmore » and implementations of MPI-3, includingInfiniBand clusters using MVAPICH2 and SGI shared-memory supercomputers using MPICH. Current support is limited to Linux but may be extended to Apple OSX if there is sufficient interest. The code is opensource via https://github.com/jeffhammond/oshmpi« less

Symbolically Modeling Concurrent MCAPI Executions

NASA Technical Reports Server (NTRS)

Fischer, Topher; Mercer, Eric; Rungta, Neha

2011-01-01

Improper use of Inter-Process Communication (IPC) within concurrent systems often creates data races which can lead to bugs that are challenging to discover. Techniques that use Satisfiability Modulo Theories (SMT) problems to symbolically model possible executions of concurrent software have recently been proposed for use in the formal verification of software. In this work we describe a new technique for modeling executions of concurrent software that use a message passing API called MCAPI. Our technique uses an execution trace to create an SMT problem that symbolically models all possible concurrent executions and follows the same sequence of conditional branch outcomes as the provided execution trace. We check if there exists a satisfying assignment to the SMT problem with respect to specific safety properties. If such an assignment exists, it provides the conditions that lead to the violation of the property. We show how our method models behaviors of MCAPI applications that are ignored in previously published techniques.

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

Optimal deployment of resources for maximizing impact in spreading processes

PubMed Central

2017-01-01

The effective use of limited resources for controlling spreading processes on networks is of prime significance in diverse contexts, ranging from the identification of “influential spreaders” for maximizing information dissemination and targeted interventions in regulatory networks, to the development of mitigation policies for infectious diseases and financial contagion in economic systems. Solutions for these optimization tasks that are based purely on topological arguments are not fully satisfactory; in realistic settings, the problem is often characterized by heterogeneous interactions and requires interventions in a dynamic fashion over a finite time window via a restricted set of controllable nodes. The optimal distribution of available resources hence results from an interplay between network topology and spreading dynamics. We show how these problems can be addressed as particular instances of a universal analytical framework based on a scalable dynamic message-passing approach and demonstrate the efficacy of the method on a variety of real-world examples. PMID:28900013

Portable Parallel Programming for the Dynamic Load Balancing of Unstructured Grid Applications

NASA Technical Reports Server (NTRS)

Biswas, Rupak; Das, Sajal K.; Harvey, Daniel; Oliker, Leonid

1999-01-01

The ability to dynamically adapt an unstructured -rid (or mesh) is a powerful tool for solving computational problems with evolving physical features; however, an efficient parallel implementation is rather difficult, particularly from the view point of portability on various multiprocessor platforms We address this problem by developing PLUM, tin automatic anti architecture-independent framework for adaptive numerical computations in a message-passing environment. Portability is demonstrated by comparing performance on an SP2, an Origin2000, and a T3E, without any code modifications. We also present a general-purpose load balancer that utilizes symmetric broadcast networks (SBN) as the underlying communication pattern, with a goal to providing a global view of system loads across processors. Experiments on, an SP2 and an Origin2000 demonstrate the portability of our approach which achieves superb load balance at the cost of minimal extra overhead.

User-Defined Data Distributions in High-Level Programming Languages

NASA Technical Reports Server (NTRS)

Diaconescu, Roxana E.; Zima, Hans P.

2006-01-01

One of the characteristic features of today s high performance computing systems is a physically distributed memory. Efficient management of locality is essential for meeting key performance requirements for these architectures. The standard technique for dealing with this issue has involved the extension of traditional sequential programming languages with explicit message passing, in the context of a processor-centric view of parallel computation. This has resulted in complex and error-prone assembly-style codes in which algorithms and communication are inextricably interwoven. This paper presents a high-level approach to the design and implementation of data distributions. Our work is motivated by the need to improve the current parallel programming methodology by introducing a paradigm supporting the development of efficient and reusable parallel code. This approach is currently being implemented in the context of a new programming language called Chapel, which is designed in the HPCS project Cascade.

National Combustion Code: Parallel Implementation and Performance

NASA Technical Reports Server (NTRS)

Quealy, A.; Ryder, R.; Norris, A.; Liu, N.-S.

2000-01-01

The National Combustion Code (NCC) is being developed by an industry-government team for the design and analysis of combustion systems. CORSAIR-CCD is the current baseline reacting flow solver for NCC. This is a parallel, unstructured grid code which uses a distributed memory, message passing model for its parallel implementation. The focus of the present effort has been to improve the performance of the NCC flow solver to meet combustor designer requirements for model accuracy and analysis turnaround time. Improving the performance of this code contributes significantly to the overall reduction in time and cost of the combustor design cycle. This paper describes the parallel implementation of the NCC flow solver and summarizes its current parallel performance on an SGI Origin 2000. Earlier parallel performance results on an IBM SP-2 are also included. The performance improvements which have enabled a turnaround of less than 15 hours for a 1.3 million element fully reacting combustion simulation are described.

Translation of globin messenger RNA by the mouse ovum

PubMed Central

Brinster, R. L.; Chen, H. Y.; Trumbauer, M. E.; Avarbock, M. R.

2016-01-01

It has been demonstrated that the Xenopus oocyte can translate rabbit haemoglobin messenger RNA (mRNA) following microinjection of the message into the cell1. The Xenopus oocyte has since been shown to be capable of translating a variety of messenger RNAs from different species2–4. This system has proved useful in understanding the mechanism of message translation and has also provided information about the translation capability of the Xenopus oocyte5,6. Several other cell types, including HeLa cells and fibroblasts, can also translate exogenous message injected into the cell7,8. However, there have been no reports of injection of mRNA into oocytes or fertilised one-cell ova of mammalian species. Nevertheless, the latter system could be of considerable use in studying the processing of exogenous messages in a mammalian system undergoing development, as well as providing insight into the way the early embryo processes injected messages and the protein products of such messages. We report here the results of injecting message into the fertilised one-cell mouse ovum and show that both mouse and rabbit globin mRNA are translated in this system. PMID:7352032

A Messaging Infrastructure for WLCG

NASA Astrophysics Data System (ADS)

Casey, James; Cons, Lionel; Lapka, Wojciech; Paladin, Massimo; Skaburskas, Konstantin

2011-12-01

During the EGEE-III project operational tools such as SAM, Nagios, Gridview, the regional Dashboard and GGUS moved to a communication architecture based on ActiveMQ, an open-source enterprise messaging solution. LHC experiments, in particular ATLAS, developed prototypes of systems using the same messaging infrastructure, validating the system for their use-cases. In this paper we describe the WLCG messaging use cases and outline an improved messaging architecture based on the experience gained during the EGEE-III period. We show how this provides a solid basis for many applications, including the grid middleware, to improve their resilience and reliability.

A Novel Free Flap Monitoring System Using Tissue Oximetry with Text Message Alerts.

PubMed

Ricci, Joseph A; Vargas, Christina R; Lin, Samuel J; Tobias, Adam M; Taghinia, Amir H; Lee, Bernard T

2016-06-01

Background The time to detection of vascular compromise is a significant predictor of free flap salvage outcomes as early reexploration improves salvage rates. Continuous transcutaneous near-infrared tissue oximetry is an objective, quantitative method of detecting flap vascular compromise and has been shown to allow earlier reexploration and higher salvage rates than clinical assessment alone. We designed a novel text messaging system to improve communication using tissue oximetry monitoring. Methods A retrospective review was performed of a prospectively collected database of all microsurgical breast reconstructions from 2008 to 2015. A novel text messaging system was introduced in 2013 and programmed to send text messages alert when the tissue oximetry readings suggested potential flap compromise based on established thresholds. Patient demographics and complications, including rate of reexploration and flap loss were assessed. Results There were 900 autologous microsurgical breast free flaps during the study period: 614 were monitored with standard clinical monitoring and tissue oximetry compared with 286 flaps with the additional text messaging system. There were 27 unplanned returns to the operating room in the tissue oximetry group and 5 in the text messaging group with 1 complete flap loss in each group. Reexploration occurred sooner as a result of these text message alerts (17.5 vs. 26.6 hours postoperatively), however, it did not achieve statistical significance. Conclusions We were able to demonstrate the use of a novel text messaging system for tissue oximetry. This alert system shows promise in identifying impending flap loss with rapid notification of the surgical team. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

PASTE: patient-centered SMS text tagging in a medication management system.

PubMed

Stenner, Shane P; Johnson, Kevin B; Denny, Joshua C

2012-01-01

To evaluate the performance of a system that extracts medication information and administration-related actions from patient short message service (SMS) messages. Mobile technologies provide a platform for electronic patient-centered medication management. MyMediHealth (MMH) is a medication management system that includes a medication scheduler, a medication administration record, and a reminder engine that sends text messages to cell phones. The object of this work was to extend MMH to allow two-way interaction using mobile phone-based SMS technology. Unprompted text-message communication with patients using natural language could engage patients in their healthcare, but presents unique natural language processing challenges. The authors developed a new functional component of MMH, the Patient-centered Automated SMS Tagging Engine (PASTE). The PASTE web service uses natural language processing methods, custom lexicons, and existing knowledge sources to extract and tag medication information from patient text messages. A pilot evaluation of PASTE was completed using 130 medication messages anonymously submitted by 16 volunteers via a website. System output was compared with manually tagged messages. Verified medication names, medication terms, and action terms reached high F-measures of 91.3%, 94.7%, and 90.4%, respectively. The overall medication name F-measure was 79.8%, and the medication action term F-measure was 90%. Other studies have demonstrated systems that successfully extract medication information from clinical documents using semantic tagging, regular expression-based approaches, or a combination of both approaches. This evaluation demonstrates the feasibility of extracting medication information from patient-generated medication messages.

International Students, University Health Centers, and Memorable Messages about Health

ERIC Educational Resources Information Center

Carmack, Heather J.; Bedi, Shireen; Heiss, Sarah N.

2016-01-01

International students entering US universities often experience a variety of important socialization messages. One important message is learning about and using the US health system. International students often first encounter the US health system through their experiences with university health centers. The authors explore the memorable…

The data acquisition system for the Anglo-Australian Observatory 2-degree field project

NASA Technical Reports Server (NTRS)

Shortridge, K.; Farrell, T. J.; Bailey, J.

1992-01-01

The Anglo-Australian Observatory (AAO) is building a system that will provide a two-degree field of view at prime focus. A robot positioner will be used to locate up to 400 optical fibers at pre-determined positions in this field. While observations are being made using one set of 400 fibers, the robot will be positioning a second set of fibers in a background field that can be moved in to replace the first when the telescope is moved to a new position. The fibers feed two spectrographs each with a 1024 square CCD detector. The software system being produced to control this involves Vaxes for overall control and data recording, UNIX workstations for fiber configuration calculations and on-line data reduction, and VME systems running VxWorks for real-time control of critical parts such as the positioner robot. The system has to be able to interact with the observatory's present data acquisition systems, which use the ADAM system. As yet, the real-time parts of ADAM have not been ported to Unix, and so we are having to produce a smaller-scale system that is similar but inherently distributed (which ADAM is not). We are using this system as a testbed for ideas that we hope may eventually influence an ADAM II system. The system we are producing is based on a message system that is designed to be able to handle inter-process and inter-processor messages of any length, efficiently, and without ever requiring a task to block (i.e., be unresponsive to 'cancel' messages, enquiry messages), other than when deliberately waiting for external input - all of which will be through such messages. The essential requirement is that a message 'send' operation should never be able to block. The messages will be hierarchical, self-defining, machine-independent data structures. This allows us to provide very simple monitoring of messages for diagnostic purposes, and allows general purpose interface programs to be written without needing to share precise byte by byte message format definitions. Programs in this system have interfaces defined simply in terms of named actions and their parameters. Real-time control programs are required to be able to handle a number of such actions concurrently; data reduction programs will normally only need to handle one action at a time ('process an image', 'display a spectrum', etc).

Mobile Delivery of Treatment for Alcohol Use Disorders

PubMed Central

Quanbeck, Andrew; Chih, Ming-Yuan; Isham, Andrew; Johnson, Roberta; Gustafson, David

2014-01-01

Several systems for treating alcohol-use disorders (AUDs) exist that operate on mobile phones. These systems are categorized into four groups: text-messaging monitoring and reminder systems, text-messaging intervention systems, comprehensive recovery management systems, and game-based systems. Text-messaging monitoring and reminder systems deliver reminders and prompt reporting of alcohol consumption, enabling continuous monitoring of alcohol use. Text-messaging intervention systems additionally deliver text messages designed to promote abstinence and recovery. Comprehensive recovery management systems use the capabilities of smart-phones to provide a variety of tools and services that can be tailored to individuals, including in-the-moment assessments and access to peer discussion groups. Game-based systems engage the user using video games. Although many commercial applications for treatment of AUDs exist, few (if any) have empirical evidence of effectiveness. The available evidence suggests that although texting-based applications may have beneficial effects, they are probably insufficient as interventions for AUDs. Comprehensive recovery management systems have the strongest theoretical base and have yielded the strongest and longest-lasting effects, but challenges remain, including cost, understanding which features account for effects, and keeping up with technological advances. PMID:26259005

Task-parallel message passing interface implementation of Autodock4 for docking of very large databases of compounds using high-performance super-computers.

PubMed

Collignon, Barbara; Schulz, Roland; Smith, Jeremy C; Baudry, Jerome

2011-04-30

A message passing interface (MPI)-based implementation (Autodock4.lga.MPI) of the grid-based docking program Autodock4 has been developed to allow simultaneous and independent docking of multiple compounds on up to thousands of central processing units (CPUs) using the Lamarkian genetic algorithm. The MPI version reads a single binary file containing precalculated grids that represent the protein-ligand interactions, i.e., van der Waals, electrostatic, and desolvation potentials, and needs only two input parameter files for the entire docking run. In comparison, the serial version of Autodock4 reads ASCII grid files and requires one parameter file per compound. The modifications performed result in significantly reduced input/output activity compared with the serial version. Autodock4.lga.MPI scales up to 8192 CPUs with a maximal overhead of 16.3%, of which two thirds is due to input/output operations and one third originates from MPI operations. The optimal docking strategy, which minimizes docking CPU time without lowering the quality of the database enrichments, comprises the docking of ligands preordered from the most to the least flexible and the assignment of the number of energy evaluations as a function of the number of rotatable bounds. In 24 h, on 8192 high-performance computing CPUs, the present MPI version would allow docking to a rigid protein of about 300K small flexible compounds or 11 million rigid compounds.

Some Features of Maritime Telex Service Communication.

ERIC Educational Resources Information Center

Johnson, Barry

1995-01-01

This article analyzes four categories of English-language maritime telex service communication: (1) standard, system- generated messages; (2) standard procedures for transmitting messages; (3) nonstandard messages related to maritime mobile radio service (MMRS); and (4) nonstandard messages related to the organization, procedures, or equipment of…

Potential effects of the introduction of the discrete address beacon system data link on air/ground information transfer problems

NASA Technical Reports Server (NTRS)

Grayson, R. L.

1981-01-01

This study of Aviation Safety Reporting System reports suggests that benefits should accure from implementation of discrete address beacon system data link. The phase enhanced terminal information system service is expected to provide better terminal information than present systems by improving currency and accuracy. In the exchange of air traffic control messages, discrete address insures that only the intended recipient receives and acts on a specific message. Visual displays and printer copy of messages should mitigate many of the reported problems associated with voice communications. The problems that remain unaffected include error in addressing the intended recipient and messages whose content is wrong but are otherwise correct as to format and reasonableness.

An Application of the "Virtual Spacecraft" Concept in Evaluation of the Mars Pathfinder Lander Low Gain Antenna

NASA Technical Reports Server (NTRS)

Pogorzelski, R. J.; Beckon, R. J.

1997-01-01

The virtual spacecraft concept is embodied in a set of subsystems, either in the form of hardware or computational models, which together represent all, or a portion of, a spacecraft. For example, the telecommunications transponder may be a hardware prototype while the propulsion system may exist only as a simulation. As the various subsystems are realized in hardware, the spacecraft becomes progressively less virtual. This concept is enabled by JPL's Mission System Testbed which is a set of networked workstations running a message passing operating system called "TRAMEL" which stands for Task Remote Asynchronous Message Exchange Layer. Each simulation on the workstations, which may in fact be hardware controlled by the workstation, "publishes" its operating parameters on TRAMEL and other simulations requiring those parameters as input may "subscribe" to them. In this manner, the whole simulation operates as a single virtual system. This paper describes a simulation designed to evaluate a communications link between the earth and the Mars Pathfinder Lander module as it descends under a parachute through the Martian atmosphere toward the planet's surface. This link includes a transmitter and a low gain antenna on the spacecraft and a receiving antenna and receiver on the earth as well as a simulation of the dynamics of the spacecraft. The transmitter, the ground station antenna, the receiver and the dynamics are all simulated computationally while the spacecraft antenna is implemented in hardware on a very simple spacecraft mockup. The dynamics simulation is a record of one output of the ensemble of outputs of a Monte Carlo simulation of the descent. Additionally, the antenna/spacecraft mock-up system was simulated using APATCH, a shooting and bouncing ray code developed by Demaco, Inc. The antenna simulation, the antenna hardware, and the link simulation are all physically located in different facilities at JPL separated by several hundred meters and are linked via the local area network (LAN).

Usability Assessment of Secure Messaging for Clinical Document Sharing between Health Care Providers and Patients.

PubMed

Jahn, Michelle A; Porter, Brian W; Patel, Himalaya; Zillich, Alan J; Simon, Steven R; Russ, Alissa L

2018-04-01

 Web-based patient portals feature secure messaging systems that enable health care providers and patients to communicate information. However, little is known about the usability of these systems for clinical document sharing.  This article evaluates the usability of a secure messaging system for providers and patients in terms of its ability to support sharing of electronic clinical documents.  We conducted usability testing with providers and patients in a human-computer interaction laboratory at a Midwestern U.S. hospital. Providers sent a medication list document to a fictitious patient via secure messaging. Separately, patients retrieved the clinical document from a secure message and returned it to a fictitious provider. We collected use errors, task completion, task time, and satisfaction.  Twenty-nine individuals participated: 19 providers (6 physicians, 6 registered nurses, and 7 pharmacists) and 10 patients. Among providers, 11 (58%) attached and sent the clinical document via secure messaging without requiring assistance, in a median (range) of 4.5 (1.8-12.7) minutes. No patients completed tasks without moderator assistance. Patients accessed the secure messaging system within 3.6 (1.2-15.0) minutes; retrieved the clinical document within 0.8 (0.5-5.7) minutes; and sent the attached clinical document in 6.3 (1.5-18.1) minutes. Although median satisfaction ratings were high, with 5.8 for providers and 6.0 for patients (scale, 0-7), we identified 36 different use errors. Physicians and pharmacists requested additional features to support care coordination via health information technology, while nurses requested features to support efficiency for their tasks.  This study examined the usability of clinical document sharing, a key feature of many secure messaging systems. Our results highlight similarities and differences between provider and patient end-user groups, which can inform secure messaging design to improve learnability and efficiency. The observations suggest recommendations for improving the technical aspects of secure messaging for clinical document sharing. Schattauer GmbH Stuttgart.

System and method for transferring telemetry data between a ground station and a control center

NASA Technical Reports Server (NTRS)

Ray, Timothy J. (Inventor); Ly, Vuong T. (Inventor)

2012-01-01

Disclosed herein are systems, computer-implemented methods, and tangible computer-readable media for coordinating communications between a ground station, a control center, and a spacecraft. The method receives a call to a simple, unified application programmer interface implementing communications protocols related to outer space, when instruction relates to receiving a command at the control center for the ground station generate an abstract message by agreeing upon a format for each type of abstract message with the ground station and using a set of message definitions to configure the command in the agreed upon format, encode the abstract message to generate an encoded message, and transfer the encoded message to the ground station, and perform similar actions when the instruction relates to receiving a second command as a second encoded message at the ground station from the control center and when the determined instruction type relates to transmitting information to the control center.

Prevalence and Risk Profile Of Unread Messages To Patients In A Patient Web Portal.

PubMed

Crotty, B H; Mostaghimi, A; O'Brien, J; Bajracharya, A; Safran, C; Landon, B E

2015-01-01

Excitement around the adoption of electronic communication between physicians and patients is tempered by the possibility of increased clinical and legal risk. If patients do not read messages in a timely fashion, duplicative communication efforts may be required and patient safety may be jeopardized. We sought to assess the prevalence and risk profile of unread messages in a mature patient portal. We analyzed six years of messages (2005-2010) from physicians to patients to determine the prevalence and associated characteristics of unread messages in a patient portal. We focused on clinical messages, and excluded announcements. Because some physicians sent clinical messages to groups of patients, we labeled messages sent to more than 5 patients as "outreach" messages and excluded them from general analyses. We performed a chart review of 75 clinical messages to assess for harm. We found that 3% of clinical messages were unread after 21 days. Messages arriving outside of business hours were slightly more likely to go unread (RR 1.15 95% CI 1.11-1.19). Patients who were male (OR 1.14 CI 1.04-1.26) African American (OR 1.69 CI 1.29-2.22) or Hispanic (OR 1.74 CI 1.17-2.59), or in the lowest income group (OR 1.72 CI 1.19-2.49) were more likely to have unread messages. Chart review showed no evidence of harm, but 13% of sampled unread messages were associated with potential delays in care. Incidentally, we found 50% of the physician-initiated outreach messages were unread. Overall, secure messaging appears a safe form of communication, but systems to notify senders when messages are unread may have value. While most clinical messages were read, many outreach messages were not, providing caution for relying on such systems for information dissemination. Similar to other studies, differences by race and income were observed and require further study.

Human factors research problems in electronic voice warning system design

NASA Technical Reports Server (NTRS)

Simpson, C. A.; Williams, D. H.

1975-01-01

The speech messages issued by voice warning systems must be carefully designed in accordance with general principles of human decision making processes, human speech comprehension, and the conditions in which the warnings can occur. The operator's effectiveness must not be degraded by messages that are either inappropriate or difficult to comprehend. Important experimental variables include message content, linguistic redundancy, signal/noise ratio, interference with concurrent tasks, and listener expectations generated by the pragmatic or real world context in which the messages are presented.

MESA: Message-Based System Analysis Using Runtime Verification

NASA Technical Reports Server (NTRS)

Shafiei, Nastaran; Tkachuk, Oksana; Mehlitz, Peter

2017-01-01

In this paper, we present a novel approach and framework for run-time verication of large, safety critical messaging systems. This work was motivated by verifying the System Wide Information Management (SWIM) project of the Federal Aviation Administration (FAA). SWIM provides live air traffic, site and weather data streams for the whole National Airspace System (NAS), which can easily amount to several hundred messages per second. Such safety critical systems cannot be instrumented, therefore, verification and monitoring has to happen using a nonintrusive approach, by connecting to a variety of network interfaces. Due to a large number of potential properties to check, the verification framework needs to support efficient formulation of properties with a suitable Domain Specific Language (DSL). Our approach is to utilize a distributed system that is geared towards connectivity and scalability and interface it at the message queue level to a powerful verification engine. We implemented our approach in the tool called MESA: Message-Based System Analysis, which leverages the open source projects RACE (Runtime for Airspace Concept Evaluation) and TraceContract. RACE is a platform for instantiating and running highly concurrent and distributed systems and enables connectivity to SWIM and scalability. TraceContract is a runtime verication tool that allows for checking traces against properties specified in a powerful DSL. We applied our approach to verify a SWIM service against several requirements.We found errors such as duplicate and out-of-order messages.

Message development for surface markers at the Hanford Radwaste Disposal sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaplan, M.F.

1984-12-31

At the Hanford Reservation in Washington, there are sites which received liquid and solid transuranic wastes from the late 1940`s until 1970. Rockwell Hanford Operations (Rockwell) is investigating the feasibility of several options for the permanent disposal of these wastes. One option is to stabilize the wastes in their present locations and to add barriers to minimize water infiltration and root penetration into the wastes. This report forms part of the project to develop a marking system for transuranic wastes on the Hanford Reservation. The focus of this report is the development of the message system to appear on themore » surface markers. A logical framework is developed to deduce what is required by the message system. Alternatives for each message component are evaluated and justification is provided for the choice of each component. The components are then laid out on the surface marker to provide a legible, comprehensible message system. The surface markers are tall, standing monoliths which ring the perimeter of each disposal area. Based on the logical framework, it is recommended that three domains of representation -- symbols, pictures, and language -- be used in the message system. The warning symbol chosen for the message system is the radiation trefoil. Two other options were considered, including the warning symbol developed by the Human Interference Task Force for a high-level waste repository. The trefoil was preferred because of the widespread usage and international acceptance which is already enjoys.« less

PASTE: patient-centered SMS text tagging in a medication management system

PubMed Central

Johnson, Kevin B; Denny, Joshua C

2011-01-01

Objective To evaluate the performance of a system that extracts medication information and administration-related actions from patient short message service (SMS) messages. Design Mobile technologies provide a platform for electronic patient-centered medication management. MyMediHealth (MMH) is a medication management system that includes a medication scheduler, a medication administration record, and a reminder engine that sends text messages to cell phones. The object of this work was to extend MMH to allow two-way interaction using mobile phone-based SMS technology. Unprompted text-message communication with patients using natural language could engage patients in their healthcare, but presents unique natural language processing challenges. The authors developed a new functional component of MMH, the Patient-centered Automated SMS Tagging Engine (PASTE). The PASTE web service uses natural language processing methods, custom lexicons, and existing knowledge sources to extract and tag medication information from patient text messages. Measurements A pilot evaluation of PASTE was completed using 130 medication messages anonymously submitted by 16 volunteers via a website. System output was compared with manually tagged messages. Results Verified medication names, medication terms, and action terms reached high F-measures of 91.3%, 94.7%, and 90.4%, respectively. The overall medication name F-measure was 79.8%, and the medication action term F-measure was 90%. Conclusion Other studies have demonstrated systems that successfully extract medication information from clinical documents using semantic tagging, regular expression-based approaches, or a combination of both approaches. This evaluation demonstrates the feasibility of extracting medication information from patient-generated medication messages. PMID:21984605

Perceptions of the Feasibility and Practicalities of Text Messaging-Based Infectious Disease Surveillance: A Questionnaire Survey.

PubMed

Dang, Linh Thuy; Vu, Nguyen Cong; Vu, Thiem Dinh; James, Spencer L; Katona, Peter; Katona, Lindsay; Rosen, Joseph M; Nguyen, Cuong Kieu

2016-05-25

In Vietnam, infectious disease surveillance data are collected via a paper-based system through four government tiers leading to a large delay. Meanwhile, mobile phones are abundant and very popular in the country, and known to be a useful tool in health care worldwide. Therefore, there is a great potential for the development of a timely disease surveillance system through the use of mobile phone short message service (SMS) text messages. This study aims to explore insights about the feasibility and practicalities of the utilization of SMS text messaging-based interventions in disease-reporting systems by identifying potential challenges and barriers in the text messaging process and looking at lessons learned. An SMS text messaging-based disease tracking system was set up in Vietnam with patient reports texted by clinic staff. Two 6-month trials utilizing this disease tracking system were designed and implemented in two northern provinces of Vietnam to report two infectious diseases: diarrhea and influenza-like illness. A structured self-reported questionnaire was developed to measure the feasibility and practicalities of the system from the participants. On the completion of the second trial in 2013, participating health staff from 40 commune health centers in the two pilot provinces were asked to complete the survey (N=80). Most participants were female (61%, 49/80) and nearly half (44%, 35/80) were heads of a commune health center. Approximately two-thirds (63%, 50/80) of participants retained the basic structure of the SMS text message report and there was a strong influence (OR 28.2, 95% CI 5.3-151.2) of those people on the time they spent texting the information. The majority (88%, 70/80) felt the information conveyed in the SMS text message report was not difficult to understand. Most (86%, 69/80) believed that they could report all 28 infectious diseases asked for by the Ministry of Health by using SMS text messaging. From a health center staff perspective, a disease-reporting system utilizing text messaging technology is easy to use and has great potential to be implemented and expanded nationwide. The survey showed positive perceptions and feedback from the participants and contributed to a promising practical solution to improve the surveillance system of infectious disease in Vietnam.

Electronic health information quality challenges and interventions to improve public health surveillance data and practice.

PubMed

Dixon, Brian E; Siegel, Jason A; Oemig, Tanya V; Grannis, Shaun J

2013-01-01

We examined completeness, an attribute of data quality, in the context of electronic laboratory reporting (ELR) of notifiable disease information to public health agencies. We extracted more than seven million ELR messages from multiple clinical information systems in two states. We calculated and compared the completeness of various data fields within the messages that were identified to be important to public health reporting processes. We compared unaltered, original messages from source systems with similar messages from another state as well as messages enriched by a health information exchange (HIE). Our analysis focused on calculating completeness (i.e., the number of nonmissing values) for fields deemed important for inclusion in notifiable disease case reports. The completeness of data fields for laboratory transactions varied across clinical information systems and jurisdictions. Fields identifying the patient and test results were usually complete (97%-100%). Fields containing patient demographics, patient contact information, and provider contact information were suboptimal (6%-89%). Transactions enhanced by the HIE were found to be more complete (increases ranged from 2% to 25%) than the original messages. ELR data from clinical information systems can be of suboptimal quality. Public health monitoring of data sources and augmentation of ELR message content using HIE services can improve data quality.

Six-Message Electromechanical Display System

NASA Technical Reports Server (NTRS)

Howard, Richard T.

2007-01-01

A proposed electromechanical display system would be capable of presenting as many as six distinct messages. In the proposed system, each display element would include a cylinder having a regular hexagonal cross section.

Individual differences in drivers' cognitive processing of road safety messages.

PubMed

Kaye, Sherrie-Anne; White, Melanie J; Lewis, Ioni M

2013-01-01

Using Gray and McNaughton's (2000) revised reinforcement sensitivity theory (r-RST), we examined the influence of personality on processing of words presented in gain-framed and loss-framed anti-speeding messages and how the processing biases associated with personality influenced message acceptance. The r-RST predicts that the nervous system regulates personality and that behaviour is dependent upon the activation of the behavioural activation system (BAS), activated by reward cues and the fight-flight-freeze system (FFFS), activated by punishment cues. According to r-RST, individuals differ in the sensitivities of their BAS and FFFS (i.e., weak to strong), which in turn leads to stable patterns of behaviour in the presence of rewards and punishments, respectively. It was hypothesised that individual differences in personality (i.e., strength of the BAS and the FFFS) would influence the degree of both message processing (as measured by reaction time to previously viewed message words) and message acceptance (measured three ways by perceived message effectiveness, behavioural intentions, and attitudes). Specifically, it was anticipated that, individuals with a stronger BAS would process the words presented in the gain-frame messages faster than those with a weaker BAS and individuals with a stronger FFFS would process the words presented in the loss-frame messages faster than those with a weaker FFFS. Further, it was expected that greater processing (faster reaction times) would be associated with greater acceptance for that message. Driver licence holding students (N=108) were recruited to view one of four anti-speeding messages (i.e., social gain-frame, social loss-frame, physical gain-frame, and physical loss-frame). A computerised lexical decision task assessed participants' subsequent reaction times to message words, as an indicator of the extent of processing of the previously viewed message. Self-report measures assessed personality and the three message acceptance measures. As predicted, the degree of initial processing of the content of the social gain-framed message mediated the relationship between the reward sensitive trait and message effectiveness. Initial processing of the physical loss-framed message partially mediated the relationship between the punishment sensitive trait and both message effectiveness and behavioural intention ratings. These results show that reward sensitivity and punishment sensitivity traits influence cognitive processing of gain-framed and loss-framed message content, respectively, and subsequently, message effectiveness and behavioural intention ratings. Specifically, a range of road safety messages (i.e., gain-frame and loss-frame messages) could be designed which align with the processing biases associated with personality and which would target those individuals who are sensitive to rewards and those who are sensitive to punishments. Copyright © 2012 Elsevier Ltd. All rights reserved.

Broadcasting a message in a parallel computer

DOEpatents

Archer, Charles J; Faraj, Ahmad A

2013-04-16

Methods, systems, and products are disclosed for broadcasting a message in a parallel computer that includes: transmitting, by the logical root to all of the nodes directly connected to the logical root, a message; and for each node except the logical root: receiving the message; if that node is the physical root, then transmitting the message to all of the child nodes except the child node from which the message was received; if that node received the message from a parent node and if that node is not a leaf node, then transmitting the message to all of the child nodes; and if that node received the message from a child node and if that node is not the physical root, then transmitting the message to all of the child nodes except the child node from which the message was received and transmitting the message to the parent node.

Broadcasting a message in a parallel computer

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Methods, systems, and products are disclosed for broadcasting a message in a parallel computer that includes: transmitting, by the logical root to all of the nodes directly connected to the logical root, a message; and for each node except the logical root: receiving the message; if that node is the physical root, then transmitting the message to all of the child nodes except the child node from which the message was received; if that node received the message from a parent node and if that node is not a leaf node, then transmitting the message to all of the childmore » nodes; and if that node received the message from a child node and if that node is not the physical root, then transmitting the message to all of the child nodes except the child node from which the message was received and transmitting the message to the parent node.« less

Send-side matching of data communications messages

DOEpatents

Archer, Charles J.; Blocksome, Michael A.; Ratterman, Joseph D.; Smith, Brian E.

2014-06-17

Send-side matching of data communications messages in a distributed computing system comprising a plurality of compute nodes, including: issuing by a receiving node to source nodes a receive message that specifies receipt of a single message to be sent from any source node, the receive message including message matching information, a specification of a hardware-level mutual exclusion device, and an identification of a receive buffer; matching by two or more of the source nodes the receive message with pending send messages in the two or more source nodes; operating by one of the source nodes having a matching send message the mutual exclusion device, excluding messages from other source nodes with matching send messages and identifying to the receiving node the source node operating the mutual exclusion device; and sending to the receiving node from the source node operating the mutual exclusion device a matched pending message.

Alert!: In Emergencies, Schools Use Technology to Get the Message out Quickly

ERIC Educational Resources Information Center

Violino, Bob

2008-01-01

This article describes how a growing number of community colleges have begun deploying emergency alert systems that can be used to send information via e-mail and text messaging directly to students' cell phones and other portable devices. Such systems enable authorized campus administrators to send messages to thousands of people within minutes.…

A new deadlock resolution protocol and message matching algorithm for the extreme-scale simulator

DOE PAGES

Engelmann, Christian; Naughton, III, Thomas J.

2016-03-22

Investigating the performance of parallel applications at scale on future high-performance computing (HPC) architectures and the performance impact of different HPC architecture choices is an important component of HPC hardware/software co-design. The Extreme-scale Simulator (xSim) is a simulation toolkit for investigating the performance of parallel applications at scale. xSim scales to millions of simulated Message Passing Interface (MPI) processes. The overhead introduced by a simulation tool is an important performance and productivity aspect. This paper documents two improvements to xSim: (1)~a new deadlock resolution protocol to reduce the parallel discrete event simulation overhead and (2)~a new simulated MPI message matchingmore » algorithm to reduce the oversubscription management overhead. The results clearly show a significant performance improvement. The simulation overhead for running the NAS Parallel Benchmark suite was reduced from 102% to 0% for the embarrassingly parallel (EP) benchmark and from 1,020% to 238% for the conjugate gradient (CG) benchmark. xSim offers a highly accurate simulation mode for better tracking of injected MPI process failures. Furthermore, with highly accurate simulation, the overhead was reduced from 3,332% to 204% for EP and from 37,511% to 13,808% for CG.« less

MessageSpace: a messaging system for health research

NASA Astrophysics Data System (ADS)

Escobar, Rodrigo D.; Akopian, David; Parra-Medina, Deborah; Esparza, Laura

2013-03-01

Mobile Health (mHealth) has emerged as a promising direction for delivery of healthcare services via mobile communication devices such as cell phones. Examples include texting-based interventions for chronic disease monitoring, diabetes management, control of hypertension, smoking cessation, monitoring medication adherence, appointment keeping and medical test result delivery; as well as improving patient-provider communication, health information communication, data collection and access to health records. While existing messaging systems very well support bulk messaging and some polling applications, they are not designed for data collection and processing of health research oriented studies. For that reason known studies based on text-messaging campaigns have been constrained in participant numbers. In order to empower healthcare promotion and education research, this paper presents a system dedicated for healthcare research. It is designed for convenient communication with various study groups, feedback collection and automated processing.

Development of a staff recall system for mass casualty incidents using cell phone text messaging.

PubMed

Epstein, Richard H; Ekbatani, Ali; Kaplan, Javier; Shechter, Ronen; Grunwald, Zvi

2010-03-01

After a mass casualty incident (MCI), rapid mobilization of hospital personnel is required because of an expected surge of victims. Risk assessment of our department's manual phone tree recall system revealed multiple weaknesses that would limit an effective response. Because cell phone use is widespread within the department, we developed and tested a staff recall system, based in our anesthesia information management system (AIMS), using Short Message Service (SMS) text messaging. We sent test text messages to anesthesia staff members' cell phone numbers, determined the distance from their home to the hospital, and stored this information in our AIMS. Latency testing for the time from transmission of SMS test messages from the server to return of an e-mail reply was determined at 2 different times on 2 different dates, 1 of which was a busy holiday weekend, using volunteers within the department. Two unannounced simulated disaster recall drills were conducted, with text messages sent asking for the anticipated time to return to the hospital. A timeline of available staff on site was determined. Reasons for failure to respond to the disaster notification message were tabulated. Latency data were fit by a log-normal distribution with an average of 82 seconds from message transmission to e-mail reply. Replies to the simulated disaster alert were received from approximately 50% of staff, with 16 projecting that they would have been able to be back at the hospital within 30 minutes on both dates. There would have been 21 and 23 staff in-house at 30 minutes, and 32 and 37 staff in-house at 60 minutes on the first and second test date, respectively, including in-house staff. Of the nonresponders to the alert, 48% indicated that their cell phone was not with them or was turned off, whereas 22% missed the message. Our SMS staff recall system is likely to be able to rapidly mobilize sufficient numbers of anesthesia personnel in response to an MCI, but actual performance cannot be predicted with confidence. Using our AIMS as the source for contact information and from which to send messages was simple, inexpensive, and easy to implement. Updating contact information, periodic testing, and analysis of responses to simulated disaster alerts are essential for the effective functioning of such a system. However, maintenance of alternative methods of communication is recommended, because there may be more significant message transmission delays and failures during an actual MCI, and not all staff will receive the text message in a timely fashion.

Automated Instrumentation, Monitoring and Visualization of PVM Programs Using AIMS

NASA Technical Reports Server (NTRS)

Mehra, Pankaj; VanVoorst, Brian; Yan, Jerry; Tucker, Deanne (Technical Monitor)

1994-01-01

We present views and analysis of the execution of several PVM codes for Computational Fluid Dynamics on a network of Sparcstations, including (a) NAS Parallel benchmarks CG and MG (White, Alund and Sunderam 1993); (b) a multi-partitioning algorithm for NAS Parallel Benchmark SP (Wijngaart 1993); and (c) an overset grid flowsolver (Smith 1993). These views and analysis were obtained using our Automated Instrumentation and Monitoring System (AIMS) version 3.0, a toolkit for debugging the performance of PVM programs. We will describe the architecture, operation and application of AIMS. The AIMS toolkit contains (a) Xinstrument, which can automatically instrument various computational and communication constructs in message-passing parallel programs; (b) Monitor, a library of run-time trace-collection routines; (c) VK (Visual Kernel), an execution-animation tool with source-code clickback; and (d) Tally, a tool for statistical analysis of execution profiles. Currently, Xinstrument can handle C and Fortran77 programs using PVM 3.2.x; Monitor has been implemented and tested on Sun 4 systems running SunOS 4.1.2; and VK uses X11R5 and Motif 1.2. Data and views obtained using AIMS clearly illustrate several characteristic features of executing parallel programs on networked workstations: (a) the impact of long message latencies; (b) the impact of multiprogramming overheads and associated load imbalance; (c) cache and virtual-memory effects; and (4significant skews between workstation clocks. Interestingly, AIMS can compensate for constant skew (zero drift) by calibrating the skew between a parent and its spawned children. In addition, AIMS' skew-compensation algorithm can adjust timestamps in a way that eliminates physically impossible communications (e.g., messages going backwards in time). Our current efforts are directed toward creating new views to explain the observed performance of PVM programs. Some of the features planned for the near future include: (a) ConfigView, showing the physical topology of the virtual machine, inferred using specially formatted IP (Internet Protocol) packets; and (b) LoadView, synchronous animation of PVM-program execution and resource-utilization patterns.

New Secure E-mail System Based on Bio-Chaos Key Generation and Modified AES Algorithm

NASA Astrophysics Data System (ADS)

Hoomod, Haider K.; Radi, A. M.

2018-05-01

The E-mail messages exchanged between sender’s Mailbox and recipient’s Mailbox over the open systems and insecure Networks. These messages may be vulnerable to eavesdropping and itself poses a real threat to the privacy and data integrity from unauthorized persons. The E-mail Security includes the following properties (Confidentiality, Authentication, Message integrity). We need a safe encryption algorithm to encrypt Email messages such as the algorithm Advanced Encryption Standard (AES) or Data Encryption Standard DES, as well as biometric recognition and chaotic system. The proposed E-mail system security uses modified AES algorithm and uses secret key-bio-chaos that consist of biometric (Fingerprint) and chaotic system (Lu and Lorenz). This modification makes the proposed system more sensitive and random. The execution time for both encryption and decryption of the proposed system is much less from original AES, in addition to being compatible with all Mail Servers.

Application Portable Parallel Library

NASA Technical Reports Server (NTRS)

Cole, Gary L.; Blech, Richard A.; Quealy, Angela; Townsend, Scott

1995-01-01

Application Portable Parallel Library (APPL) computer program is subroutine-based message-passing software library intended to provide consistent interface to variety of multiprocessor computers on market today. Minimizes effort needed to move application program from one computer to another. User develops application program once and then easily moves application program from parallel computer on which created to another parallel computer. ("Parallel computer" also include heterogeneous collection of networked computers). Written in C language with one FORTRAN 77 subroutine for UNIX-based computers and callable from application programs written in C language or FORTRAN 77.

Design and evaluation of Nemesis, a scalable, low-latency, message-passing communication subsystem.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buntinas, D.; Mercier, G.; Gropp, W.

2005-12-02

This paper presents a new low-level communication subsystem called Nemesis. Nemesis has been designed and implemented to be scalable and efficient both in the intranode communication context using shared-memory and in the internode communication case using high-performance networks and is natively multimethod-enabled. Nemesis has been integrated in MPICH2 as a CH3 channel and delivers better performance than other dedicated communication channels in MPICH2. Furthermore, the resulting MPICH2 architecture outperforms other MPI implementations in point-to-point benchmarks.

Leading article: Use of smartphones to pass on information about patients - what are the current issues?

PubMed

Rokadiya, S; McCaul, J A; Mitchell, D A; Brennan, P A

2016-07-01

Many doctors now use mobile devices such as smartphones to communicate with one another about their patients, and sometimes this is without the knowledge and approval of their employer. We know of little information about the use of texting and other web-based messaging services by doctors in hospitals, so we reviewed relevant published studies to assess the safety and usefulness of current methods of digital communication. Copyright © 2016 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Implementation of a 3D mixing layer code on parallel computers

NASA Technical Reports Server (NTRS)

Roe, K.; Thakur, R.; Dang, T.; Bogucz, E.

1995-01-01

This paper summarizes our progress and experience in the development of a Computational-Fluid-Dynamics code on parallel computers to simulate three-dimensional spatially-developing mixing layers. In this initial study, the three-dimensional time-dependent Euler equations are solved using a finite-volume explicit time-marching algorithm. The code was first programmed in Fortran 77 for sequential computers. The code was then converted for use on parallel computers using the conventional message-passing technique, while we have not been able to compile the code with the present version of HPF compilers.

High-energy physics software parallelization using database techniques

NASA Astrophysics Data System (ADS)

Argante, E.; van der Stok, P. D. V.; Willers, I.

1997-02-01

A programming model for software parallelization, called CoCa, is introduced that copes with problems caused by typical features of high-energy physics software. By basing CoCa on the database transaction paradimg, the complexity induced by the parallelization is for a large part transparent to the programmer, resulting in a higher level of abstraction than the native message passing software. CoCa is implemented on a Meiko CS-2 and on a SUN SPARCcenter 2000 parallel computer. On the CS-2, the performance is comparable with the performance of native PVM and MPI.

Multiple-Ring Digital Communication Network

NASA Technical Reports Server (NTRS)

Kirkham, Harold

1992-01-01

Optical-fiber digital communication network to support data-acquisition and control functions of electric-power-distribution networks. Optical-fiber links of communication network follow power-distribution routes. Since fiber crosses open power switches, communication network includes multiple interconnected loops with occasional spurs. At each intersection node is needed. Nodes of communication network include power-distribution substations and power-controlling units. In addition to serving data acquisition and control functions, each node acts as repeater, passing on messages to next node(s). Multiple-ring communication network operates on new AbNET protocol and features fiber-optic communication.

Performance measurement and modeling of component applications in a high performance computing environment : a case study.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Armstrong, Robert C.; Ray, Jaideep; Malony, A.

2003-11-01

We present a case study of performance measurement and modeling of a CCA (Common Component Architecture) component-based application in a high performance computing environment. We explore issues peculiar to component-based HPC applications and propose a performance measurement infrastructure for HPC based loosely on recent work done for Grid environments. A prototypical implementation of the infrastructure is used to collect data for a three components in a scientific application and construct performance models for two of them. Both computational and message-passing performance are addressed.

{open_quotes}Media-On-Demand{close_quotes} multimedia electronic mail: A tool for collaboration on the web

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsoi, Kei Nam; Rahman, S.M.

1996-12-31

Undoubtedly, multimedia electronic mail has many advantages in exchanging information electronically in a collaborative work. The existing design of e-mail systems architecture is inefficient in exchanging multimedia message which has much larger volume, and requires more bandwidth and storage space than the text-only messages. This paper presents an innovative method for exchanging multimedia mail messages in a heterogeneous environment to support collaborative work over YAW on the Internet. We propose a {open_quotes}Parcel Collection{close_quotes} approach for exchanging multimedia electronic mail messages. This approach for exchanging multimedia electronic mail messages integrates the current WWW technologies with the existing electronic mail systems.

Controlled Bidirectional Quantum Secure Direct Communication

PubMed Central

Chou, Yao-Hsin; Lin, Yu-Ting; Zeng, Guo-Jyun; Lin, Fang-Jhu; Chen, Chi-Yuan

2014-01-01

We propose a novel protocol for controlled bidirectional quantum secure communication based on a nonlocal swap gate scheme. Our proposed protocol would be applied to a system in which a controller (supervisor/Charlie) controls the bidirectional communication with quantum information or secret messages between legitimate users (Alice and Bob). In this system, the legitimate users must obtain permission from the controller in order to exchange their respective quantum information or secret messages simultaneously; the controller is unable to obtain any quantum information or secret messages from the decoding process. Moreover, the presence of the controller also avoids the problem of one legitimate user receiving the quantum information or secret message before the other, and then refusing to help the other user decode the quantum information or secret message. Our proposed protocol is aimed at protecting against external and participant attacks on such a system, and the cost of transmitting quantum bits using our protocol is less than that achieved in other studies. Based on the nonlocal swap gate scheme, the legitimate users exchange their quantum information or secret messages without transmission in a public channel, thus protecting against eavesdroppers stealing the secret messages. PMID:25006596

Getting Your Message Across: Mobile Phone Text Messaging

ERIC Educational Resources Information Center

Beecher, Constance C.; Hayungs, Lori

2017-01-01

Want to send a message that 99% of your audience will read? Many Extension professionals are familiar with using social media tools to enhance Extension programming. Extension professionals may be less familiar with the use of mobile phone text-based marketing tools. The purpose of this article is to introduce SMS (short message system) marketing…

High occupancy vehicle (HOV) lane management system : amendment A.

DOT National Transportation Integrated Search

2011-12-01

This report describes a system designed to provide Single Occupancy Hybrid Vehicles (SOHVs) restriction : messages dynamically to drivers through variable message signs. This system will allow California to : comply with federal requirements (that Si...

Eliminating livelock by assigning the same priority state to each message that is input into a flushable routing system during N time intervals

DOEpatents

Faber, V.

1994-11-29

Livelock-free message routing is provided in a network of interconnected nodes that is flushable in time T. An input message processor generates sequences of at least N time intervals, each of duration T. An input register provides for receiving and holding each input message, where the message is assigned a priority state p during an nth one of the N time intervals. At each of the network nodes a message processor reads the assigned priority state and awards priority to messages with priority state (p-1) during an nth time interval and to messages with priority state p during an (n+1) th time interval. The messages that are awarded priority are output on an output path toward the addressed output message processor. Thus, no message remains in the network for a time longer than T. 4 figures.

Eliminating livelock by assigning the same priority state to each message that is inputted into a flushable routing system during N time intervals

DOEpatents

Faber, Vance

1994-01-01

Livelock-free message routing is provided in a network of interconnected nodes that is flushable in time T. An input message processor generates sequences of at least N time intervals, each of duration T. An input register provides for receiving and holding each input message, where the message is assigned a priority state p during an nth one of the N time intervals. At each of the network nodes a message processor reads the assigned priority state and awards priority to messages with priority state (p-1) during an nth time interval and to messages with priority state p during an (n+1) th time interval. The messages that are awarded priority are output on an output path toward the addressed output message processor. Thus, no message remains in the network for a time longer than T.

Productivity and cost of conventional understory biomass harvesting systems

Treesearch

Douglas E. Miller; Thomas J. Straka; Bryce J. Stokes; William Watson

1987-01-01

Conventional harvesting equipment was tested for removing forest understory biomass (energywood) for use as fuel. Two types of systems were tested--a one-pass system and a two-pass system. In the one-pass system, the energywood and pulpwood were harvested simultaneously. In the two-pass system, the energywood was harvested in a first pass through the stand, and the...

First results of electron temperature measurements by the use of multi-pass Thomson scattering system in GAMMA 10

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoshikawa, M., E-mail: yosikawa@prc.tsukuba.ac.jp; Nagasu, K.; Shimamura, Y.

2014-11-15

A multi-pass Thomson scattering (TS) has the advantage of enhancing scattered signals. We constructed a multi-pass TS system for a polarisation-based system and an image relaying system modelled on the GAMMA 10 TS system. We undertook Raman scattering experiments both for the multi-pass setting and for checking the optical components. Moreover, we applied the system to the electron temperature measurements in the GAMMA 10 plasma for the first time. The integrated scattering signal was magnified by approximately three times by using the multi-pass TS system with four passes. The electron temperature measurement accuracy is improved by using this multi-pass system.

First results of electron temperature measurements by the use of multi-pass Thomson scattering system in GAMMA 10.

PubMed

Yoshikawa, M; Yasuhara, R; Nagasu, K; Shimamura, Y; Shima, Y; Kohagura, J; Sakamoto, M; Nakashima, Y; Imai, T; Ichimura, M; Yamada, I; Funaba, H; Kawahata, K; Minami, T

2014-11-01

A multi-pass Thomson scattering (TS) has the advantage of enhancing scattered signals. We constructed a multi-pass TS system for a polarisation-based system and an image relaying system modelled on the GAMMA 10 TS system. We undertook Raman scattering experiments both for the multi-pass setting and for checking the optical components. Moreover, we applied the system to the electron temperature measurements in the GAMMA 10 plasma for the first time. The integrated scattering signal was magnified by approximately three times by using the multi-pass TS system with four passes. The electron temperature measurement accuracy is improved by using this multi-pass system.

SMS Security System on Mobile Devices Using Tiny Encryption Algorithm

NASA Astrophysics Data System (ADS)

Novelan, M. S.; Husein, A. M.; Harahap, M.; Aisyah, S.

2018-04-01

The development of telecommunications technology is so rapid has given such great benefits. With the telecommunication technology, distance and time no longer be a significant obstacle. One of the results of telecommunications technology that is well known is the Short Message Service. In this study developed an application on the mobile phone to modify the SMS message into ciphertext so that the information content of the SMS is not known by others. SMS delivery system for encrypting messages into ciphertext using a key that is entered by the sender then sends to the destination number. SMS reception system to decrypt it to others via SMS without the fear of information from these messages will be known by others. The method used in the system encrypt and decrypt the message is the algorithm Tiny Encryption Algorithm and implemented using the Java programming language. JDK 1.7 as the Java programming language ciphertext into plaintext using the key entered by the receiver and displays the original message to the recipient. This application can be used by someone who wants to send a confidential information and the Java compiler. Eclipse, a Java SDK and the Android SDK as a Java source code editor.

A system for de-identifying medical message board text.

PubMed

Benton, Adrian; Hill, Shawndra; Ungar, Lyle; Chung, Annie; Leonard, Charles; Freeman, Cristin; Holmes, John H

2011-06-09

There are millions of public posts to medical message boards by users seeking support and information on a wide range of medical conditions. It has been shown that these posts can be used to gain a greater understanding of patients' experiences and concerns. As investigators continue to explore large corpora of medical discussion board data for research purposes, protecting the privacy of the members of these online communities becomes an important challenge that needs to be met. Extant entity recognition methods used for more structured text are not sufficient because message posts present additional challenges: the posts contain many typographical errors, larger variety of possible names, terms and abbreviations specific to Internet posts or a particular message board, and mentions of the authors' personal lives. The main contribution of this paper is a system to de-identify the authors of message board posts automatically, taking into account the aforementioned challenges. We demonstrate our system on two different message board corpora, one on breast cancer and another on arthritis. We show that our approach significantly outperforms other publicly available named entity recognition and de-identification systems, which have been tuned for more structured text like operative reports, pathology reports, discharge summaries, or newswire.

Fixing convergence of Gaussian belief propagation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Jason K; Bickson, Danny; Dolev, Danny

Gaussian belief propagation (GaBP) is an iterative message-passing algorithm for inference in Gaussian graphical models. It is known that when GaBP converges it converges to the correct MAP estimate of the Gaussian random vector and simple sufficient conditions for its convergence have been established. In this paper we develop a double-loop algorithm for forcing convergence of GaBP. Our method computes the correct MAP estimate even in cases where standard GaBP would not have converged. We further extend this construction to compute least-squares solutions of over-constrained linear systems. We believe that our construction has numerous applications, since the GaBP algorithm ismore » linked to solution of linear systems of equations, which is a fundamental problem in computer science and engineering. As a case study, we discuss the linear detection problem. We show that using our new construction, we are able to force convergence of Montanari's linear detection algorithm, in cases where it would originally fail. As a consequence, we are able to increase significantly the number of users that can transmit concurrently.« less

Massively parallel algorithm and implementation of RI-MP2 energy calculation for peta-scale many-core supercomputers.

PubMed

Katouda, Michio; Naruse, Akira; Hirano, Yukihiko; Nakajima, Takahito

2016-11-15

A new parallel algorithm and its implementation for the RI-MP2 energy calculation utilizing peta-flop-class many-core supercomputers are presented. Some improvements from the previous algorithm (J. Chem. Theory Comput. 2013, 9, 5373) have been performed: (1) a dual-level hierarchical parallelization scheme that enables the use of more than 10,000 Message Passing Interface (MPI) processes and (2) a new data communication scheme that reduces network communication overhead. A multi-node and multi-GPU implementation of the present algorithm is presented for calculations on a central processing unit (CPU)/graphics processing unit (GPU) hybrid supercomputer. Benchmark results of the new algorithm and its implementation using the K computer (CPU clustering system) and TSUBAME 2.5 (CPU/GPU hybrid system) demonstrate high efficiency. The peak performance of 3.1 PFLOPS is attained using 80,199 nodes of the K computer. The peak performance of the multi-node and multi-GPU implementation is 514 TFLOPS using 1349 nodes and 4047 GPUs of TSUBAME 2.5. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A hybrid parallel framework for the cellular Potts model simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Yi; He, Kejing; Dong, Shoubin

2009-01-01

The Cellular Potts Model (CPM) has been widely used for biological simulations. However, most current implementations are either sequential or approximated, which can't be used for large scale complex 3D simulation. In this paper we present a hybrid parallel framework for CPM simulations. The time-consuming POE solving, cell division, and cell reaction operation are distributed to clusters using the Message Passing Interface (MPI). The Monte Carlo lattice update is parallelized on shared-memory SMP system using OpenMP. Because the Monte Carlo lattice update is much faster than the POE solving and SMP systems are more and more common, this hybrid approachmore » achieves good performance and high accuracy at the same time. Based on the parallel Cellular Potts Model, we studied the avascular tumor growth using a multiscale model. The application and performance analysis show that the hybrid parallel framework is quite efficient. The hybrid parallel CPM can be used for the large scale simulation ({approx}10{sup 8} sites) of complex collective behavior of numerous cells ({approx}10{sup 6}).« less

Reconstruction of financial networks for robust estimation of systemic risk

NASA Astrophysics Data System (ADS)

Mastromatteo, Iacopo; Zarinelli, Elia; Marsili, Matteo

2012-03-01

In this paper we estimate the propagation of liquidity shocks through interbank markets when the information about the underlying credit network is incomplete. We show that techniques such as maximum entropy currently used to reconstruct credit networks severely underestimate the risk of contagion by assuming a trivial (fully connected) topology, a type of network structure which can be very different from the one empirically observed. We propose an efficient message-passing algorithm to explore the space of possible network structures and show that a correct estimation of the network degree of connectedness leads to more reliable estimations for systemic risk. Such an algorithm is also able to produce maximally fragile structures, providing a practical upper bound for the risk of contagion when the actual network structure is unknown. We test our algorithm on ensembles of synthetic data encoding some features of real financial networks (sparsity and heterogeneity), finding that more accurate estimations of risk can be achieved. Finally we find that this algorithm can be used to control the amount of information that regulators need to require from banks in order to sufficiently constrain the reconstruction of financial networks.

Advanced CLIPS capabilities

NASA Technical Reports Server (NTRS)

Riley, Gary

1991-01-01

The C Language Integrated Production System (CLIPS) is a forward chaining rule based language developed by NASA. CLIPS was designed specifically to provide high portability, low cost, and easy integration with external systems. The current release of CLIPS, version 4.3, is being used by over 2500 users throughout the public and private community. The primary addition to the next release of CLIPS, version 5.0, will be the CLIPS Object Oriented Language (COOL). The major capabilities of COOL are: class definition with multiple inheritance and no restrictions on the number, types, or cardinality of slots; message passing which allows procedural code bundled with an object to be executed; and query functions which allow groups of instances to be examined and manipulated. In addition to COOL, numerous other enhancements were added to CLIPS including: generic functions (which allow different pieces of procedural code to be executed depending upon the types or classes of the arguments); integer and double precision data type support; multiple conflict resolution strategies; global variables; logical dependencies; type checking on facts; full ANSI compiler support; and incremental reset for rules.

Message-adjusted network (MAN) hypothesis in gastro-entero-pancreatic (GEP) endocrine system.

PubMed

Aykan, N Faruk

2007-01-01

Several types of communication coordinate body functions to maintain homeostasis. Clarifying intercellular communication systems is as important as intracellular signal mechanisms. In this study, we propose an intercellular network model to establish novel targets in GEP-endocrine system, based on up-to-date information from medical publications. As materials, two physiologic events which are Pavlov's sham-feeding assay and bicarbonate secretion into the duodenum from pancreas were explored by new biologic data from the literature. Major key words used in Pub-Med were modes of regulations (autocrine, paracrine, endocrine, neurocrine, juxtacrine, lumencrine), GEP cells, hormones, peptides and neuro-transmitters. In these two examples of physiologic events, we can design a model of network to clarify transmission of a message. When we take a simple, unique message, we can observe a complete intercellular network. In our examples, these messages are "food is coming" and "hydrogen ions are increasing" in human language (humanese). We need to find molecular counterparts of these unique messages in cell language (cellese). In this network (message-adjusted network; MAN), message is an input which can affect the physiologic equilibrium, mission is an output to improve the disequilibrium and aim is always maintenance of homeostasis. If we orientate to a transmission of a unique message we can distinguish that different cells use different chemical messengers in different modes of regulations to transmit the same message. This study also supports Shannon's information theory and cell language theories such as von Neumann-Patte principles. After human genome project (HU-GO) and protein organisations (HU-PO), finding true messages and the establishment of their networks (in our model HU-MAN project) can be a novel and exciting field in cell biology. We established an intercellular network model to understand intercellular communication in the physiology of GEP endocrine system. This model could help to explain complex physiologic events as well as to generate new treatment concepts.

Nonblocking and orphan free message logging protocols

NASA Technical Reports Server (NTRS)

Alvisi, Lorenzo; Hoppe, Bruce; Marzullo, Keith

1992-01-01

Currently existing message logging protocols demonstrate a classic pessimistic vs. optimistic tradeoff. We show that the optimistic-pessimistic tradeoff is not inherent to the problem of message logging. We construct a message-logging protocol that has the positive features of both optimistic and pessimistic protocol: our protocol prevents orphans and allows simple failure recovery; however, it requires no blocking in failure-free runs. Furthermore, this protocol does not introduce any additional message overhead as compared to one implemented for a system in which messages may be lost but processes do not crash.

Nonblocking and orphan free message logging protocols

NASA Astrophysics Data System (ADS)

Alvisi, Lorenzo; Hoppe, Bruce; Marzullo, Keith

1992-12-01

Currently existing message logging protocols demonstrate a classic pessimistic vs. optimistic tradeoff. We show that the optimistic-pessimistic tradeoff is not inherent to the problem of message logging. We construct a message-logging protocol that has the positive features of both optimistic and pessimistic protocol: our protocol prevents orphans and allows simple failure recovery; however, it requires no blocking in failure-free runs. Furthermore, this protocol does not introduce any additional message overhead as compared to one implemented for a system in which messages may be lost but processes do not crash.

Increasing the Automation and Autonomy for Spacecraft Operations with Criteria Action Table

NASA Technical Reports Server (NTRS)

Li, Zhen-Ping; Savki, Cetin

2005-01-01

The Criteria Action Table (CAT) is an automation tool developed for monitoring real time system messages for specific events and processes in order to take user defined actions based on a set of user-defined rules. CAT was developed by Lockheed Martin Space Operations as a part of a larger NASA effort at the Goddard Space Flight Center (GSFC) to create a component-based, middleware-based, and standard-based general purpose ground system architecture referred as GMSEC - the GSFC Mission Services Evolution Center. CAT has been integrated into the upgraded ground systems for Tropical Rainfall Measuring Mission (TRMM) and Small Explorer (SMEX) satellites and it plays the central role in their automation effort to reduce the cost and increase the reliability for spacecraft operations. The GMSEC architecture provides a standard communication interface and protocol for components to publish/describe messages to an information bus. It also provides a standard message definition so components can send and receive messages to the bus interface rather than each other, thus reducing the component-to-component coupling, interface, protocols, and link (socket) management. With the GMSEC architecture, components can publish standard event messages to the bus for all nominal, significant, and surprising events in regard to satellite, celestial, ground system, or any other activity. In addition to sending standard event messages, each GMSEC compliant component is required to accept and process GMSEC directive request messages.

Convergence of Health Level Seven Version 2 Messages to Semantic Web Technologies for Software-Intensive Systems in Telemedicine Trauma Care.

PubMed

Menezes, Pedro Monteiro; Cook, Timothy Wayne; Cavalini, Luciana Tricai

2016-01-01

To present the technical background and the development of a procedure that enriches the semantics of Health Level Seven version 2 (HL7v2) messages for software-intensive systems in telemedicine trauma care. This study followed a multilevel model-driven approach for the development of semantically interoperable health information systems. The Pre-Hospital Trauma Life Support (PHTLS) ABCDE protocol was adopted as the use case. A prototype application embedded the semantics into an HL7v2 message as an eXtensible Markup Language (XML) file, which was validated against an XML schema that defines constraints on a common reference model. This message was exchanged with a second prototype application, developed on the Mirth middleware, which was also used to parse and validate both the original and the hybrid messages. Both versions of the data instance (one pure XML, one embedded in the HL7v2 message) were equally validated and the RDF-based semantics recovered by the receiving side of the prototype from the shared XML schema. This study demonstrated the semantic enrichment of HL7v2 messages for intensive-software telemedicine systems for trauma care, by validating components of extracts generated in various computing environments. The adoption of the method proposed in this study ensures the compliance of the HL7v2 standard in Semantic Web technologies.

Getting the Message? Native Reactive Electrophiles Pass Two Out of Three Thresholds to be Bona Fide Signaling Mediators.

PubMed

Poganik, Jesse R; Long, Marcus J C; Aye, Yimon

2018-05-01

Precision cell signaling activities of reactive electrophilic species (RES) are arguably among the most poorly-understood means to transmit biological messages. Latest research implicates native RES to be a chemically-distinct subset of endogenous redox signals that influence cell decision making through non-enzyme-assisted modifications of specific proteins. Yet, fundamental questions remain regarding the role of RES as bona fide second messengers. Here, we lay out three sets of criteria we feel need to be met for RES to be considered as true cellular signals that directly mediate information transfer by modifying "first-responding" sensor proteins. We critically assess the available evidence and define the extent to which each criterion has been fulfilled. Finally, we offer some ideas on the future trajectories of the electrophile signaling field taking inspiration from work that has been done to understand canonical signaling mediators. Also see the video abstract here: https://youtu.be/rG7o0clVP0c. © 2018 WILEY Periodicals, Inc.

Messages about appearance, food, weight and exercise in "tween" television.

PubMed

Simpson, Courtney C; Kwitowski, Melissa; Boutte, Rachel; Gow, Rachel W; Mazzeo, Suzanne E

2016-12-01

Tweens (children ages ~8-14years) are a relatively recently defined age group, increasingly targeted by marketers. Individuals in this age group are particularly vulnerable to opinions and behaviors presented in media messages, given their level of cognitive and social development. However, little research has examined messages about appearance, food, weight, and exercise in television specifically targeting tweens, despite the popularity of this media type among this age group. This study used a content analytic approach to explore these messages in the five most popular television shows for tweens on the Disney Channel (as of 2015). Using a multiple-pass approach, relevant content in episodes from the most recently completed seasons of each show was coded. Appearance related incidents occurred in every episode; these most frequently mentioned attractiveness/beauty. Food related incidents were also present in every episode; typically, these situations were appearance and weight neutral. Exercise related incidents occurred in 53.3% of episodes; the majority expressed resistance to exercise. Weight related incidents occurred in 40.0% of the episodes; the majority praised the muscular ideal. Women were more likely to initiate appearance incidents, and men were more likely to initiate exercise incidents. These results suggest that programs specifically marketed to tweens reinforce appearance ideals, including stereotypes about female attractiveness and male athleticism, two constructs linked to eating pathology and body dissatisfaction. Given the developmental vulnerability of the target group, these findings are concerning, and highlight potential foci for prevention programming, including media literacy, for tweens. Copyright © 2016 Elsevier Ltd. All rights reserved.

Patient-to-physician messaging: volume nearly tripled as more patients joined system, but per capita rate plateaued.

PubMed

Crotty, Bradley H; Tamrat, Yonas; Mostaghimi, Arash; Safran, Charles; Landon, Bruce E

2014-10-01

Patients want to be able to communicate with their physicians by e-mail. However, physicians are often concerned about the impact that such communications will have on their time, productivity, and reimbursement. Typically, physicians are not reimbursed for time spent communicating with patients electronically. But under federal meaningful-use criteria for information technology, physicians can receive a modest incentive for such communications. Little is known about trends in secure e-mail messaging between physicians and patients. To understand these trends, we analyzed the volume of messages in a large academic health system's patient portal in the period 2001-10. At the end of 2010, 49,778 patients (22.7 percent of all patients seen within the system) had enrolled in the portal, and 36.9 percent of enrolled patients (8.4 percent of all patients) had sent at least one message to a physician. Physicians in the aggregate saw a near tripling of e-mail messages during the study period. However, the number of messages per hundred patients per month stabilized between 2005 and 2010, at an average of 18.9 messages. As physician reimbursement moves toward global payments, physicians' and patients' participation in secure messaging will likely increase, and electronic communication should be considered part of physicians' job descriptions. Project HOPE—The People-to-People Health Foundation, Inc.

Lessons learned from the implementation of clinical messaging systems.

PubMed

Barnes, Mike

2007-10-11

The Regenstrief Institute has designed and implemented two clinical messaging systems over the past six years, both called DOCS4DOCS. These systems receive HL7 messages from data sources and deliver results to clinicians via the web, fax, or as HL7 directed to an EMR. This paper focuses on some of the lessons we have learned, both good and bad. We discuss important issues in clinical messaging including provider mapping, document delivery and duplicate prevention, creating uniform HL7 outbound feeds, user authentication, the problems of allowing Active-X controls, why automatic printing of documents is not important although a frequently requested feature, and assorted other pearls of wisdom we have acquired.