Sample records for message passing based

  1. Theoretic derivation of directed acyclic subgraph algorithm and comparisons with message passing algorithm

    NASA Astrophysics Data System (ADS)

    Ha, Jeongmok; Jeong, Hong

    2016-07-01

    This study investigates the directed acyclic subgraph (DAS) algorithm, which is used to solve discrete labeling problems much more rapidly than other Markov-random-field-based inference methods but at a competitive accuracy. However, the mechanism by which the DAS algorithm simultaneously achieves competitive accuracy and fast execution speed, has not been elucidated by a theoretical derivation. We analyze the DAS algorithm by comparing it with a message passing algorithm. Graphical models, inference methods, and energy-minimization frameworks are compared between DAS and message passing algorithms. Moreover, the performances of DAS and other message passing methods [sum-product belief propagation (BP), max-product BP, and tree-reweighted message passing] are experimentally compared.

  2. MPF: A portable message passing facility for shared memory multiprocessors

    NASA Technical Reports Server (NTRS)

    Malony, Allen D.; Reed, Daniel A.; Mcguire, Patrick J.

    1987-01-01

    The design, implementation, and performance evaluation of a message passing facility (MPF) for shared memory multiprocessors are presented. The MPF is based on a message passing model conceptually similar to conversations. Participants (parallel processors) can enter or leave a conversation at any time. The message passing primitives for this model are implemented as a portable library of C function calls. The MPF is currently operational on a Sequent Balance 21000, and several parallel applications were developed and tested. Several simple benchmark programs are presented to establish interprocess communication performance for common patterns of interprocess communication. Finally, performance figures are presented for two parallel applications, linear systems solution, and iterative solution of partial differential equations.

  3. 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.

  4. 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.

  5. Statistics of Epidemics in Networks by Passing Messages

    NASA Astrophysics Data System (ADS)

    Shrestha, Munik Kumar

    Epidemic processes are common out-of-equilibrium phenomena of broad interdisciplinary interest. In this thesis, we show how message-passing approach can be a helpful tool for simulating epidemic models in disordered medium like networks, and in particular for estimating the probability that a given node will become infectious at a particular time. The sort of dynamics we consider are stochastic, where randomness can arise from the stochastic events or from the randomness of network structures. As in belief propagation, variables or messages in message-passing approach are defined on the directed edges of a network. However, unlike belief propagation, where the posterior distributions are updated according to Bayes' rule, in message-passing approach we write differential equations for the messages over time. It takes correlations between neighboring nodes into account while preventing causal signals from backtracking to their immediate source, and thus avoids "echo chamber effects" where a pair of adjacent nodes each amplify the probability that the other is infectious. In our first results, we develop a message-passing approach to threshold models of behavior popular in sociology. These are models, first proposed by Granovetter, where individuals have to hear about a trend or behavior from some number of neighbors before adopting it themselves. In thermodynamic limit of large random networks, we provide an exact analytic scheme while calculating the time dependence of the probabilities and thus learning about the whole dynamics of bootstrap percolation, which is a simple model known in statistical physics for exhibiting discontinuous phase transition. As an application, we apply a similar model to financial networks, studying when bankruptcies spread due to the sudden devaluation of shared assets in overlapping portfolios. We predict that although diversification may be good for individual institutions, it can create dangerous systemic effects, and as a result financial contagion gets worse with too much diversification. We also predict that financial system exhibits "robust yet fragile" behavior, with regions of the parameter space where contagion is rare but catastrophic whenever it occurs. In further results, we develop a message-passing approach to recurrent state epidemics like susceptible-infectious-susceptible and susceptible-infectious-recovered-susceptible where nodes can return to previously inhabited states and multiple waves of infection can pass through the population. Given that message-passing has been applied exclusively to models with one-way state changes like susceptible-infectious and susceptible-infectious-recovered, we develop message-passing for recurrent epidemics based on a new class of differential equations and demonstrate that our approach is simple and efficiently approximates results obtained from Monte Carlo simulation, and that the accuracy of message-passing is often superior to the pair approximation (which also takes second-order correlations into account).

  6. PRAIS: Distributed, real-time knowledge-based systems made easy

    NASA Technical Reports Server (NTRS)

    Goldstein, David G.

    1990-01-01

    This paper discusses an architecture for real-time, distributed (parallel) knowledge-based systems called the Parallel Real-time Artificial Intelligence System (PRAIS). PRAIS strives for transparently parallelizing production (rule-based) systems, even when under real-time constraints. PRAIS accomplishes these goals 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.

  7. Intel NX to PVM 3.2 message passing conversion library

    NASA Technical Reports Server (NTRS)

    Arthur, Trey; Nelson, Michael L.

    1993-01-01

    NASA Langley Research Center has developed a library that allows Intel NX message passing codes to be executed under the more popular and widely supported Parallel Virtual Machine (PVM) message passing library. PVM was developed at Oak Ridge National Labs and has become the defacto standard for message passing. This library will allow the many programs that were developed on the Intel iPSC/860 or Intel Paragon in a Single Program Multiple Data (SPMD) design to be ported to the numerous architectures that PVM (version 3.2) supports. Also, the library adds global operations capability to PVM. A familiarity with Intel NX and PVM message passing is assumed.

  8. 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.

  9. Efficient Data Generation and Publication as a Test Tool

    NASA Technical Reports Server (NTRS)

    Einstein, Craig Jakob

    2017-01-01

    A tool to facilitate the generation and publication of test data was created to test the individual components of a command and control system designed to launch spacecraft. Specifically, this tool was built to ensure messages are properly passed between system components. The tool can also be used to test whether the appropriate groups have access (read/write privileges) to the correct messages. The messages passed between system components take the form of unique identifiers with associated values. These identifiers are alphanumeric strings that identify the type of message and the additional parameters that are contained within the message. The values that are passed with the message depend on the identifier. The data generation tool allows for the efficient creation and publication of these messages. A configuration file can be used to set the parameters of the tool and also specify which messages to pass.

  10. 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.

  11. 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.

  12. 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.

  13. Efficiently passing messages in distributed spiking neural network simulation.

    PubMed

    Thibeault, Corey M; Minkovich, Kirill; O'Brien, Michael J; Harris, Frederick C; Srinivasa, Narayan

    2013-01-01

    Efficiently passing spiking messages in a neural model is an important aspect of high-performance simulation. As the scale of networks has increased so has the size of the computing systems required to simulate them. In addition, the information exchange of these resources has become more of an impediment to performance. In this paper we explore spike message passing using different mechanisms provided by the Message Passing Interface (MPI). A specific implementation, MVAPICH, designed for high-performance clusters with Infiniband hardware is employed. The focus is on providing information about these mechanisms for users of commodity high-performance spiking simulators. In addition, a novel hybrid method for spike exchange was implemented and benchmarked.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Verification of Faulty Message Passing Systems with Continuous State Space in PVS

    NASA Technical Reports Server (NTRS)

    Pilotto, Concetta; White, Jerome

    2010-01-01

    We present a library of Prototype Verification System (PVS) meta-theories that verifies a class of distributed systems in which agent commu nication is through message-passing. The theoretic work, outlined in, consists of iterative schemes for solving systems of linear equations , such as message-passing extensions of the Gauss and Gauss-Seidel me thods. We briefly review that work and discuss the challenges in formally verifying it.

  20. Users manual for the Chameleon parallel programming tools

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

    Gropp, W.; Smith, B.

    1993-06-01

    Message passing is a common method for writing programs for distributed-memory parallel computers. Unfortunately, the lack of a standard for message passing has hampered the construction of portable and efficient parallel programs. In an attempt to remedy this problem, a number of groups have developed their own message-passing systems, each with its own strengths and weaknesses. Chameleon is a second-generation system of this type. Rather than replacing these existing systems, Chameleon is meant to supplement them by providing a uniform way to access many of these systems. Chameleon`s goals are to (a) be very lightweight (low over-head), (b) be highlymore » portable, and (c) help standardize program startup and the use of emerging message-passing operations such as collective operations on subsets of processors. Chameleon also provides a way to port programs written using PICL or Intel NX message passing to other systems, including collections of workstations. Chameleon is tracking the Message-Passing Interface (MPI) draft standard and will provide both an MPI implementation and an MPI transport layer. Chameleon provides support for heterogeneous computing by using p4 and PVM. Chameleon`s support for homogeneous computing includes the portable libraries p4, PICL, and PVM and vendor-specific implementation for Intel NX, IBM EUI (SP-1), and Thinking Machines CMMD (CM-5). Support for Ncube and PVM 3.x is also under development.« less

  1. 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.

  2. 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

  3. Implementing Multidisciplinary and Multi-Zonal Applications Using MPI

    NASA Technical Reports Server (NTRS)

    Fineberg, Samuel A.

    1995-01-01

    Multidisciplinary and multi-zonal applications are an important class of applications in the area of Computational Aerosciences. In these codes, two or more distinct parallel programs or copies of a single program are utilized to model a single problem. To support such applications, it is common to use a programming model where a program is divided into several single program multiple data stream (SPMD) applications, each of which solves the equations for a single physical discipline or grid zone. These SPMD applications are then bound together to form a single multidisciplinary or multi-zonal program in which the constituent parts communicate via point-to-point message passing routines. Unfortunately, simple message passing models, like Intel's NX library, only allow point-to-point and global communication within a single system-defined partition. This makes implementation of these applications quite difficult, if not impossible. In this report it is shown that the new Message Passing Interface (MPI) standard is a viable portable library for implementing the message passing portion of multidisciplinary applications. Further, with the extension of a portable loader, fully portable multidisciplinary application programs can be developed. Finally, the performance of MPI is compared to that of some native message passing libraries. This comparison shows that MPI can be implemented to deliver performance commensurate with native message libraries.

  4. 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.

  5. 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.

  6. Efficient Implementation of Multigrid Solvers on Message-Passing Parrallel Systems

    NASA Technical Reports Server (NTRS)

    Lou, John

    1994-01-01

    We discuss our implementation strategies for finite difference multigrid partial differential equation (PDE) solvers on message-passing systems. Our target parallel architecture is Intel parallel computers: the Delta and Paragon system.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Dispatching packets on a global combining network of a parallel computer

    DOEpatents

    Almasi, Gheorghe [Ardsley, NY; Archer, Charles J [Rochester, MN

    2011-07-19

    Methods, apparatus, and products are disclosed for dispatching packets on a global combining network of a parallel computer comprising a plurality of nodes connected for data communications using the network capable of performing collective operations and point to point operations that include: receiving, by an origin system messaging module on an origin node from an origin application messaging module on the origin node, a storage identifier and an operation identifier, the storage identifier specifying storage containing an application message for transmission to a target node, and the operation identifier specifying a message passing operation; packetizing, by the origin system messaging module, the application message into network packets for transmission to the target node, each network packet specifying the operation identifier and an operation type for the message passing operation specified by the operation identifier; and transmitting, by the origin system messaging module, the network packets to the target node.

  14. MPIRUN: A Portable Loader for Multidisciplinary and Multi-Zonal Applications

    NASA Technical Reports Server (NTRS)

    Fineberg, Samuel A.; Woodrow, Thomas S. (Technical Monitor)

    1994-01-01

    Multidisciplinary and multi-zonal applications are an important class of applications in the area of Computational Aerosciences. In these codes, two or more distinct parallel programs or copies of a single program are utilized to model a single problem. To support such applications, it is common to use a programming model where a program is divided into several single program multiple data stream (SPMD) applications, each of which solves the equations for a single physical discipline or grid zone. These SPMD applications are then bound together to form a single multidisciplinary or multi-zonal program in which the constituent parts communicate via point-to-point message passing routines. One method for implementing the message passing portion of these codes is with the new Message Passing Interface (MPI) standard. Unfortunately, this standard only specifies the message passing portion of an application, but does not specify any portable mechanisms for loading an application. MPIRUN was developed to provide a portable means for loading MPI programs, and was specifically targeted at multidisciplinary and multi-zonal applications. Programs using MPIRUN for loading and MPI for message passing are then portable between all machines supported by MPIRUN. MPIRUN is currently implemented for the Intel iPSC/860, TMC CM5, IBM SP-1 and SP-2, Intel Paragon, and workstation clusters. Further, MPIRUN is designed to be simple enough to port easily to any system supporting MPI.

  15. 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.

  16. 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.

  17. DMA engine for repeating communication patterns

    DOEpatents

    Chen, Dong; Gara, Alan G.; Giampapa, Mark E.; Heidelberger, Philip; Steinmacher-Burow, Burkhard; Vranas, Pavlos

    2010-09-21

    A parallel computer system is constructed as a network of interconnected compute nodes to operate a global message-passing application for performing communications across the network. Each of the compute nodes includes one or more individual processors with memories which run local instances of the global message-passing application operating at each compute node to carry out local processing operations independent of processing operations carried out at other compute nodes. Each compute node also includes a DMA engine constructed to interact with the application via Injection FIFO Metadata describing multiple Injection FIFOs where each Injection FIFO may containing an arbitrary number of message descriptors in order to process messages with a fixed processing overhead irrespective of the number of message descriptors included in the Injection FIFO.

  18. 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.

  19. 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.

  20. 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.

  1. Message Passing vs. Shared Address Space on a Cluster of SMPs

    NASA Technical Reports Server (NTRS)

    Shan, Hongzhang; Singh, Jaswinder Pal; Oliker, Leonid; Biswas, Rupak

    2000-01-01

    The convergence of scalable computer architectures using clusters of PCs (or PC-SMPs) with commodity networking has become an attractive platform for high end scientific computing. Currently, message-passing and shared address space (SAS) are the two leading programming paradigms for these systems. Message-passing has been standardized with MPI, and is the most common and mature programming approach. However message-passing code development can be extremely difficult, especially for irregular 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 programming effort, required for six applications under both programming models on a 32 CPU PC-SMP cluster. Our application suite consists of codes that typically do not exhibit high efficiency under shared memory programming. due to their high communication to computation ratios and complex communication patterns. Results indicate that SAS can achieve about half the parallel efficiency of MPI for most of our applications: however, on certain classes of problems SAS performance is competitive with MPI. We also present new algorithms for improving the PC cluster performance of MPI collective operations.

  2. Simple Algorithms for Distributed Leader Election in Anonymous Synchronous Rings and Complete Networks Inspired by Neural Development in Fruit Flies.

    PubMed

    Xu, Lei; Jeavons, Peter

    2015-11-01

    Leader election in anonymous rings and complete networks is a very practical problem in distributed computing. Previous algorithms for this problem are generally designed for a classical message passing model where complex messages are exchanged. However, the need to send and receive complex messages makes such algorithms less practical for some real applications. We present some simple synchronous algorithms for distributed leader election in anonymous rings and complete networks that are inspired by the development of the neural system of the fruit fly. Our leader election algorithms all assume that only one-bit messages are broadcast by nodes in the network and processors are only able to distinguish between silence and the arrival of one or more messages. These restrictions allow implementations to use a simpler message-passing architecture. Even with these harsh restrictions our algorithms are shown to achieve good time and message complexity both analytically and experimentally.

  3. 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

  4. 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.

  5. 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.

  6. A message passing kernel for the hypercluster parallel processing test bed

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    A Message-Passing Kernel (MPK) for the Hypercluster parallel-processing test bed is described. The Hypercluster is being developed at the NASA Lewis Research Center to support investigations of parallel algorithms and architectures for computational fluid and structural mechanics applications. The Hypercluster resembles the hypercube architecture except that each node consists of multiple processors communicating through shared memory. The MPK efficiently routes information through the Hypercluster, using a message-passing protocol when necessary and faster shared-memory communication whenever possible. The MPK also interfaces all of the processors with the Hypercluster operating system (HYCLOPS), which runs on a Front-End Processor (FEP). This approach distributes many of the I/O tasks to the Hypercluster processors and eliminates the need for a separate I/O support program on the FEP.

  7. 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)

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. An implementation and performance measurement of the progressive retry technique

    NASA Technical Reports Server (NTRS)

    Suri, Gaurav; Huang, Yennun; Wang, Yi-Min; Fuchs, W. Kent; Kintala, Chandra

    1995-01-01

    This paper describes a recovery technique called progressive retry for bypassing software faults in message-passing applications. The technique is implemented as reusable modules to provide application-level software fault tolerance. The paper describes the implementation of the technique and presents results from the application of progressive retry to two telecommunications systems. the results presented show that the technique is helpful in reducing the total recovery time for message-passing applications.

  14. 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.

  15. 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

  16. Design of a network for concurrent message passing systems

    NASA Astrophysics Data System (ADS)

    Song, Paul Y.

    1988-08-01

    We describe the design of the network design frame (NDF), a self-timed routing chip for a message-passing concurrent computer. The NDF uses a partitioned data path, low-voltage output drivers, and a distributed token-passing arbiter to provide a bandwidth of 450 Mbits/sec into the network. Wormhole routing and bidirectional virtual channels are used to provide low latency communications, less than 2us latency to deliver a 216 bit message across the diameter of a 1K node mess-connected machine. To support concurrent software systems, the NDF provides two logical networks, one for user messages and one for system messages. The two networks share the same set of physical wires. To facilitate the development of network nodes, the NDF is a design frame. The NDF circuitry is integrated into the pad frame of a chip leaving the center of the chip uncommitted. We define an analytic framework in which to study the effects of network size, network buffering capacity, bidirectional channels, and traffic on this class of networks. The response of the network to various combinations of these parameters are obtained through extensive simulation of the network model. Through simulation, we are able to observe the macro behavior of the network as opposed to the micro behavior of the NDF routing controller.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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)…

  2. 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.

  3. 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

  4. Critical field-exponents for secure message-passing in modular networks

    NASA Astrophysics Data System (ADS)

    Shekhtman, Louis M.; Danziger, Michael M.; Bonamassa, Ivan; Buldyrev, Sergey V.; Caldarelli, Guido; Zlatić, Vinko; Havlin, Shlomo

    2018-05-01

    We study secure message-passing in the presence of multiple adversaries in modular networks. We assume a dominant fraction of nodes in each module have the same vulnerability, i.e., the same entity spying on them. We find both analytically and via simulations that the links between the modules (interlinks) have effects analogous to a magnetic field in a spin-system in that for any amount of interlinks the system no longer undergoes a phase transition. We then define the exponents δ, which relates the order parameter (the size of the giant secure component) at the critical point to the field strength (average number of interlinks per node), and γ, which describes the susceptibility near criticality. These are found to be δ = 2 and γ = 1 (with the scaling of the order parameter near the critical point given by β = 1). When two or more vulnerabilities are equally present in a module we find δ = 1 and γ = 0 (with β ≥ 2). Apart from defining a previously unidentified universality class, these exponents show that increasing connections between modules is more beneficial for security than increasing connections within modules. We also measure the correlation critical exponent ν, and the upper critical dimension d c , finding that ν {d}c=3 as for ordinary percolation, suggesting that for secure message-passing d c = 6. These results provide an interesting analogy between secure message-passing in modular networks and the physics of magnetic spin-systems.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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).

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.…

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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".

  3. 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/.

  4. 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/.

  5. 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.

  6. 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.

  7. 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.

  8. 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!

  9. 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 ...

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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:

  5. 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

  6. 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.

  7. 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.

  8. 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

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

    Demeure, I.M.

    The research presented here is concerned with representation techniques and tools to support the design, prototyping, simulation, and evaluation of message-based parallel, distributed computations. The author describes ParaDiGM-Parallel, Distributed computation Graph Model-a visual representation technique for parallel, message-based distributed computations. ParaDiGM provides several views of a computation depending on the aspect of concern. It is made of two complementary submodels, the DCPG-Distributed Computing Precedence Graph-model, and the PAM-Process Architecture Model-model. DCPGs are precedence graphs used to express the functionality of a computation in terms of tasks, message-passing, and data. PAM graphs are used to represent the partitioning of a computationmore » into schedulable units or processes, and the pattern of communication among those units. There is a natural mapping between the two models. He illustrates the utility of ParaDiGM as a representation technique by applying it to various computations (e.g., an adaptive global optimization algorithm, the client-server model). ParaDiGM representations are concise. They can be used in documenting the design and the implementation of parallel, distributed computations, in describing such computations to colleagues, and in comparing and contrasting various implementations of the same computation. He then describes VISA-VISual Assistant, a software tool to support the design, prototyping, and simulation of message-based parallel, distributed computations. VISA is based on the ParaDiGM model. In particular, it supports the editing of ParaDiGM graphs to describe the computations of interest, and the animation of these graphs to provide visual feedback during simulations. The graphs are supplemented with various attributes, simulation parameters, and interpretations which are procedures that can be executed by VISA.« less

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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:

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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:

  20. 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:

  1. 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:

  2. 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.

  3. 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.

  4. 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.

  5. Application of decentralized cooperative problem solving in dynamic flexible scheduling

    NASA Astrophysics Data System (ADS)

    Guan, Zai-Lin; Lei, Ming; Wu, Bo; Wu, Ya; Yang, Shuzi

    1995-08-01

    The object of this study is to discuss an intelligent solution to the problem of task-allocation in shop floor scheduling. For this purpose, the technique of distributed artificial intelligence (DAI) is applied. Intelligent agents (IAs) are used to realize decentralized cooperation, and negotiation is realized by using message passing based on the contract net model. Multiple agents, such as manager agents, workcell agents, and workstation agents, make game-like decisions based on multiple criteria evaluations. This procedure of decentralized cooperative problem solving makes local scheduling possible. And by integrating such multiple local schedules, dynamic flexible scheduling for the whole shop floor production can be realized.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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:

  15. 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.

  16. 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.

  17. 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:

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. MPI_XSTAR: MPI-based parallelization of XSTAR program

    NASA Astrophysics Data System (ADS)

    Danehkar, A.

    2017-12-01

    MPI_XSTAR parallelizes execution of multiple XSTAR runs using Message Passing Interface (MPI). XSTAR (ascl:9910.008), part of the HEASARC's HEAsoft (ascl:1408.004) package, calculates the physical conditions and emission spectra of ionized gases. MPI_XSTAR invokes XSTINITABLE from HEASoft to generate a job list of XSTAR commands for given physical parameters. The job list is used to make directories in ascending order, where each individual XSTAR is spawned on each processor and outputs are saved. HEASoft's XSTAR2TABLE program is invoked upon the contents of each directory in order to produce table model FITS files for spectroscopy analysis tools.

  4. Role of Edges in Complex Network Epidemiology

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Jiang, Zhi-Hong; Wang, Hui; Xie, Fei; Chen, Chao

    2012-09-01

    In complex network epidemiology, diseases spread along contacting edges between individuals and different edges may play different roles in epidemic outbreaks. Quantifying the efficiency of edges is an important step towards arresting epidemics. In this paper, we study the efficiency of edges in general susceptible-infected-recovered models, and introduce the transmission capability to measure the efficiency of edges. Results show that deleting edges with the highest transmission capability will greatly decrease epidemics on scale-free networks. Basing on the message passing approach, we get exact mathematical solution on configuration model networks with edge deletion in the large size limit.

  5. 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

  6. 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:

  7. 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

  8. 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:

  9. 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.

  10. 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 \

  11. 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

  12. 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.

  13. 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.

  14. 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:

  15. 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…

  16. 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:

  17. 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:

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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/.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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:

  11. 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.

  12. 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!

  13. 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:

  14. 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:

  15. 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…

  16. 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.

  17. 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."

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. HYDRA : High-speed simulation architecture for precision spacecraft formation simulation

    NASA Technical Reports Server (NTRS)

    Martin, Bryan J.; Sohl, Garett.

    2003-01-01

    e Hierarchical Distributed Reconfigurable Architecture- is a scalable simulation architecture that provides flexibility and ease-of-use which take advantage of modern computation and communication hardware. It also provides the ability to implement distributed - or workstation - based simulations and high-fidelity real-time simulation from a common core. Originally designed to serve as a research platform for examining fundamental challenges in formation flying simulation for future space missions, it is also finding use in other missions and applications, all of which can take advantage of the underlying Object-Oriented structure to easily produce distributed simulations. Hydra automates the process of connecting disparate simulation components (Hydra Clients) through a client server architecture that uses high-level descriptions of data associated with each client to find and forge desirable connections (Hydra Services) at run time. Services communicate through the use of Connectors, which abstract messaging to provide single-interface access to any desired communication protocol, such as from shared-memory message passing to TCP/IP to ACE and COBRA. Hydra shares many features with the HLA, although providing more flexibility in connectivity services and behavior overriding.

  12. Research for the design of visual fatigue based on the computer visual communication

    NASA Astrophysics Data System (ADS)

    Deng, Hu-Bin; Ding, Bao-min

    2013-03-01

    With the era of rapid development of computer networks. The role of network communication in the social, economic, political, become more and more important and suggested their special role. The computer network communicat ion through the modern media and byway of the visual communication effect the public of the emotional, spiritual, career and other aspects of the life. While its rapid growth also brought some problems, It is that their message across to the public, its design did not pass a relat ively perfect manifestation to express the informat ion. So this not only leads to convey the error message, but also to cause the physical and psychological fatigue for the audiences. It is said that the visual fatigue. In order to reduce the fatigue when people obtain the useful information in using computer. Let the audience in a short time to obtain the most useful informat ion, this article gave a detailed account of its causes, and propose effective solutions and, through the specific examples to explain it, also in the future computer design visual communicat ion applications development prospect.

  13. 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

  14. 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:

  15. 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.

  16. 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:

  17. 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…

  18. 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,…

  19. 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:

  20. 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:

  1. 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…

  2. Aircraft Engine Noise Scattering - A Discontinuous Spectral Element Approach

    NASA Technical Reports Server (NTRS)

    Stanescu, D.; Hussaini, M. Y.; Farassat, F.

    2002-01-01

    The paper presents a time-domain method for computation of sound radiation from aircraft engine sources to the far-field. The effects of nonuniform flow around the aircraft and scattering of sound by fuselage and wings are accounted for in the formulation. Our approach is based on the discretization of the inviscid flow equations through a collocation form of the Discontinuous Galerkin spectral element method. An isoparametric representation of the underlying geometry is used in order to take full advantage of the spectral accuracy of the method. Largescale computations are made possible by a parallel implementation based on message passing. Results obtained for radiation from an axisymmetric nacelle alone are compared with those obtained when the same nacelle is installed in a generic con.guration, with and without a wing.

  3. Aircraft Engine Noise Scattering By Fuselage and Wings: A Computational Approach

    NASA Technical Reports Server (NTRS)

    Stanescu, D.; Hussaini, M. Y.; Farassat, F.

    2003-01-01

    The paper presents a time-domain method for computation of sound radiation from aircraft engine sources to the far-field. The effects of nonuniform flow around the aircraft and scattering of sound by fuselage and wings are accounted for in the formulation. The approach is based on the discretization of the inviscid flow equations through a collocation form of the Discontinuous Galerkin spectral element method. An isoparametric representation of the underlying geometry is used in order to take full advantage of the spectral accuracy of the method. Large-scale computations are made possible by a parallel implementation based on message passing. Results obtained for radiation from an axisymmetric nacelle alone are compared with those obtained when the same nacelle is installed in a generic configuration, with and without a wing.

  4. Aircraft Engine Noise Scattering by Fuselage and Wings: A Computational Approach

    NASA Technical Reports Server (NTRS)

    Stanescu, D.; Hussaini, M. Y.; Farassat, F.

    2003-01-01

    The paper presents a time-domain method for computation of sound radiation from aircraft engine sources to the far-field. The effects of nonuniform flow around the aircraft and scattering of sound by fuselage and wings are accounted for in the formulation. The approach is based on the discretization of the inviscid flow equations through a collocation form of the Discontinuous Galerkin spectral element method. An isoparametric representation of the underlying geometry is used in order to take full advantage of the spectral accuracy of the method. Large-scale computations are made possible by a parallel implementation based on message passing. Results obtained for radiation from an axisymmetric nacelle alone are compared with those obtained when the same nacelle is installed in a generic configuration, with and without a wing.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. [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.

  11. 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.

  12. 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

  13. A Note on Alternating Minimization Algorithm for the Matrix Completion Problem

    DOE PAGES

    Gamarnik, David; Misra, Sidhant

    2016-06-06

    Here, we consider the problem of reconstructing a low-rank matrix from a subset of its entries and analyze two variants of the so-called alternating minimization algorithm, which has been proposed in the past.We establish that when the underlying matrix has rank one, has positive bounded entries, and the graph underlying the revealed entries has diameter which is logarithmic in the size of the matrix, both algorithms succeed in reconstructing the matrix approximately in polynomial time starting from an arbitrary initialization.We further provide simulation results which suggest that the second variant which is based on the message passing type updates performsmore » significantly better.« less

  14. 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 .

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. Bidirectional chaos communication between two outer semiconductor lasers coupled mutually with a central semiconductor laser.

    PubMed

    Li, Ping; Wu, Jia-Gui; Wu, Zheng-Mao; Lin, Xiao-Dong; Deng, Dao; Liu, Yu-Ran; Xia, Guang-Qiong

    2011-11-21

    Based on a linear chain composed of a central semiconductor laser and two outer semiconductor lasers, chaos synchronization and bidirectional communication between two outer lasers have been investigated under the case that the central laser and the two outer lasers are coupled mutually, whereas there exists no coupling between the two outer lasers. The simulation results show that high-quality and stable isochronal synchronization between the two outer lasers can be achieved, while the cross-correlation coefficients between the two outer lasers and the central laser are very low under proper operation condition. Based on the high performance chaos synchronization between the two outer lasers, message bidirectional transmissions of bit rates up to 20 Gbit/s can be realized through adopting a novel decoding scheme which is different from that based on chaos pass filtering effect. Furthermore, the security of bidirectional communication is also analyzed. © 2011 Optical Society of America

  5. 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.

  6. 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.

  7. The influence of affective and cognitive arguments on message judgement and attitude change: The moderating effects of meta-bases and structural bases.

    PubMed

    Keer, Mario; van den Putte, Bas; Neijens, Peter; de Wit, John

    2013-01-01

    This study investigated whether the efficacy of affective vs. cognitive persuasive messages was moderated by (1) individuals' subjective assessments of whether their attitudes were based on affect or cognition (i.e. meta-bases) and (2) the degree individuals' attitudes were correlated with affect and cognition (i.e. structural bases). Participants (N = 97) were randomly exposed to a message containing either affective or cognitive arguments discouraging binge drinking. The results demonstrated that meta-bases and not structural bases moderated the influence of argument type on message judgement. Affective (cognitive) messages were judged more positively when individuals' meta-bases were more affective (cognitive). In contrast, structural bases and not meta-bases moderated the influence of argument type on attitude and intention change following exposure to the message. Surprisingly, change was greater among individuals who read a message that mismatched their structural attitude base. Affective messages were more effective as attitudes were more cognition-based, and vice versa. Thus, although individuals prefer messages that match their meta-base, attitude and intention change regarding binge drinking are best established by mismatching their structural base.

  8. MPI Runtime Error Detection with MUST: Advances in Deadlock Detection

    DOE PAGES

    Hilbrich, Tobias; Protze, Joachim; Schulz, Martin; ...

    2013-01-01

    The widely used Message Passing Interface (MPI) is complex and rich. As a result, application developers require automated tools to avoid and to detect MPI programming errors. We present the Marmot Umpire Scalable Tool (MUST) that detects such errors with significantly increased scalability. We present improvements to our graph-based deadlock detection approach for MPI, which cover future MPI extensions. Our enhancements also check complex MPI constructs that no previous graph-based detection approach handled correctly. Finally, we present optimizations for the processing of MPI operations that reduce runtime deadlock detection overheads. Existing approaches often require ( p ) analysis time permore » MPI operation, for p processes. We empirically observe that our improvements lead to sub-linear or better analysis time per operation for a wide range of real world applications.« less

  9. Aircraft Engine Noise Scattering by Fuselage and Wings: A Computational Approach

    NASA Technical Reports Server (NTRS)

    Farassat, F.; Stanescu, D.; Hussaini, M. Y.

    2003-01-01

    The paper presents a time-domain method for computation of sound radiation from aircraft engine sources to the far field. The effects of non-uniform flow around the aircraft and scattering of sound by fuselage and wings are accounted for in the formulation. The approach is based on the discretization of the inviscid flow equations through a collocation form of the discontinuous Galerkin spectral element method. An isoparametric representation of the underlying geometry is used in order to take full advantage of the spectral accuracy of the method. Large-scale computations are made possible by a parallel implementation based on message passing. Results obtained for radiation from an axisymmetric nacelle alone are compared with those obtained when the same nacelle is installed in a generic configuration, with and without a wing. 0 2002 Elsevier Science Ltd. All rights reserved.

  10. Analysis of multigrid methods on massively parallel computers: Architectural implications

    NASA Technical Reports Server (NTRS)

    Matheson, Lesley R.; Tarjan, Robert E.

    1993-01-01

    We study the potential performance of multigrid algorithms running on massively parallel computers with the intent of discovering whether presently envisioned machines will provide an efficient platform for such algorithms. We consider the domain parallel version of the standard V cycle algorithm on model problems, discretized using finite difference techniques in two and three dimensions on block structured grids of size 10(exp 6) and 10(exp 9), respectively. Our models of parallel computation were developed to reflect the computing characteristics of the current generation of massively parallel multicomputers. These models are based on an interconnection network of 256 to 16,384 message passing, 'workstation size' processors executing in an SPMD mode. The first model accomplishes interprocessor communications through a multistage permutation network. The communication cost is a logarithmic function which is similar to the costs in a variety of different topologies. The second model allows single stage communication costs only. Both models were designed with information provided by machine developers and utilize implementation derived parameters. With the medium grain parallelism of the current generation and the high fixed cost of an interprocessor communication, our analysis suggests an efficient implementation requires the machine to support the efficient transmission of long messages, (up to 1000 words) or the high initiation cost of a communication must be significantly reduced through an alternative optimization technique. Furthermore, with variable length message capability, our analysis suggests the low diameter multistage networks provide little or no advantage over a simple single stage communications network.

  11. 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

  12. 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…

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. Barista: A Framework for Concurrent Speech Processing by USC-SAIL

    PubMed Central

    Can, Doğan; Gibson, James; Vaz, Colin; Georgiou, Panayiotis G.; Narayanan, Shrikanth S.

    2016-01-01

    We present Barista, an open-source framework for concurrent speech processing based on the Kaldi speech recognition toolkit and the libcppa actor library. With Barista, we aim to provide an easy-to-use, extensible framework for constructing highly customizable concurrent (and/or distributed) networks for a variety of speech processing tasks. Each Barista network specifies a flow of data between simple actors, concurrent entities communicating by message passing, modeled after Kaldi tools. Leveraging the fast and reliable concurrency and distribution mechanisms provided by libcppa, Barista lets demanding speech processing tasks, such as real-time speech recognizers and complex training workflows, to be scheduled and executed on parallel (and/or distributed) hardware. Barista is released under the Apache License v2.0. PMID:27610047

  18. 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.

  19. Sequentially Executed Model Evaluation Framework

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

    2015-10-20

    Provides a message passing framework between generic input, model and output drivers, and specifies an API for developing such drivers. Also provides batch and real-time controllers which step the model and I/O through the time domain (or other discrete domain), and sample I/O drivers. This is a library framework, and does not, itself, solve any problems or execute any modeling. The SeMe framework aids in development of models which operate on sequential information, such as time-series, where evaluation is based on prior results combined with new data for this iteration. Has applications in quality monitoring, and was developed as partmore » of the CANARY-EDS software, where real-time water quality data is being analyzed for anomalies.« less

  20. Barista: A Framework for Concurrent Speech Processing by USC-SAIL.

    PubMed

    Can, Doğan; Gibson, James; Vaz, Colin; Georgiou, Panayiotis G; Narayanan, Shrikanth S

    2014-05-01

    We present Barista, an open-source framework for concurrent speech processing based on the Kaldi speech recognition toolkit and the libcppa actor library. With Barista, we aim to provide an easy-to-use, extensible framework for constructing highly customizable concurrent (and/or distributed) networks for a variety of speech processing tasks. Each Barista network specifies a flow of data between simple actors, concurrent entities communicating by message passing, modeled after Kaldi tools. Leveraging the fast and reliable concurrency and distribution mechanisms provided by libcppa, Barista lets demanding speech processing tasks, such as real-time speech recognizers and complex training workflows, to be scheduled and executed on parallel (and/or distributed) hardware. Barista is released under the Apache License v2.0.

  1. Encouraging children to eat more fruit and vegetables: Health vs. descriptive social norm-based messages.

    PubMed

    Sharps, Maxine; Robinson, Eric

    2016-05-01

    Traditional intervention approaches to promote fruit and vegetable consumption outline the health benefits of eating fruit and vegetables. More recently, social norm-based messages describing the healthy eating habits of others have been shown to increase fruit and vegetable intake in adults. Here we report two experimental studies which investigated whether exposure to descriptive social norm-based messages about the behaviour of other children and health-based messages increased fruit and vegetable intake in young children. In both studies children were exposed to messages whilst playing a board-game. After exposure to the messages, children were able to consume fruit and vegetables, as well as high calorie snack foods. Although findings were inconsistent across the two individual studies, in a pooled analysis we found evidence that both health messages and descriptive social norm-based messages increased children's fruit and vegetable intake, relative to control condition messages (p < .05). Whether descriptive social norm-based messages can be used to promote meaningful changes to children's dietary behaviour warrants further study. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Encouraging children to eat more fruit and vegetables: Health vs. descriptive social norm-based messages

    PubMed Central

    Sharps, Maxine; Robinson, Eric

    2016-01-01

    Traditional intervention approaches to promote fruit and vegetable consumption outline the health benefits of eating fruit and vegetables. More recently, social norm-based messages describing the healthy eating habits of others have been shown to increase fruit and vegetable intake in adults. Here we report two experimental studies which investigated whether exposure to descriptive social norm-based messages about the behaviour of other children and health-based messages increased fruit and vegetable intake in young children. In both studies children were exposed to messages whilst playing a board-game. After exposure to the messages, children were able to consume fruit and vegetables, as well as high calorie snack foods. Although findings were inconsistent across the two individual studies, in a pooled analysis we found evidence that both health messages and descriptive social norm-based messages increased children's fruit and vegetable intake, relative to control condition messages (p < .05). Whether descriptive social norm-based messages can be used to promote meaningful changes to children's dietary behaviour warrants further study. PMID:26820776

  3. Pass the popcorn: "obesogenic" behaviors and stigma in children's movies.

    PubMed

    Throop, Elizabeth M; Skinner, Asheley Cockrell; Perrin, Andrew J; Steiner, Michael J; Odulana, Adebowale; Perrin, Eliana M

    2014-07-01

    To determine the prevalence of obesity-related behaviors and attitudes in children's movies. A mixed-methods study of the top-grossing G- and PG-rated movies, 2006-2010 (4 per year) was performed. For each 10-min movie segment, the following were assessed: 1) prevalence of key nutrition and physical activity behaviors corresponding to the American Academy of Pediatrics obesity prevention recommendations for families; 2) prevalence of weight stigma; 3) assessment as healthy, unhealthy, or neutral; 3) free-text interpretations of stigma. Agreement between coders was >85% (Cohen's kappa = 0.7), good for binary responses. Segments with food depicted: exaggerated portion size (26%); unhealthy snacks (51%); sugar-sweetened beverages (19%). Screen time was also prevalent (40% of movies showed television; 35% computer; 20% video games). Unhealthy segments outnumbered healthy segments 2:1. Most (70%) of the movies included weight-related stigmatizing content (e.g., "That fat butt! Flabby arms! And this ridiculous belly!"). These popular children's movies had significant "obesogenic" content, and most contained weight-based stigma. They present a mixed message to children, promoting unhealthy behaviors while stigmatizing the behaviors' possible effects. Further research is needed to determine the effects of such messages on children. Copyright © 2013 The Obesity Society.

  4. Live chat alternative security protocol

    NASA Astrophysics Data System (ADS)

    Rahman, J. P. R.; Nugraha, E.; Febriany, A.

    2018-05-01

    Indonesia is one of the largest e-commerce markets in Southeast Asia, as many as 5 million people do transactions in e-commerce, therefore more and more people use live chat service to communicate with customer service. In live chat, the customer service often asks customers’ data such as, full name, address, e-mail, transaction id, which aims to verify the purchase of the product. One of the risks that will happen is sniffing which will lead to the theft of confidential information that will cause huge losses to the customer. The anticipation that will be done is build an alternative security protocol for user interaction in live chat by using a cryptographic algorithm that is useful for protecting confidential messages. Live chat requires confidentiality and data integration with encryption and hash functions. The used algorithm are Rijndael 256 bits, RSA, and SHA256. To increase the complexity, the Rijndael algorithm will be modified in the S-box and ShiftRow sections based on the shannon principle rule, the results show that all pass the Randomness test, but the modification in Shiftrow indicates a better avalanche effect. Therefore the message will be difficult to be stolen or changed.

  5. 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

  6. 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.

  7. Addressing the challenges of standalone multi-core simulations in molecular dynamics

    NASA Astrophysics Data System (ADS)

    Ocaya, R. O.; Terblans, J. J.

    2017-07-01

    Computational modelling in material science involves mathematical abstractions of force fields between particles with the aim to postulate, develop and understand materials by simulation. The aggregated pairwise interactions of the material's particles lead to a deduction of its macroscopic behaviours. For practically meaningful macroscopic scales, a large amount of data are generated, leading to vast execution times. Simulation times of hours, days or weeks for moderately sized problems are not uncommon. The reduction of simulation times, improved result accuracy and the associated software and hardware engineering challenges are the main motivations for many of the ongoing researches in the computational sciences. This contribution is concerned mainly with simulations that can be done on a "standalone" computer based on Message Passing Interfaces (MPI), parallel code running on hardware platforms with wide specifications, such as single/multi- processor, multi-core machines with minimal reconfiguration for upward scaling of computational power. The widely available, documented and standardized MPI library provides this functionality through the MPI_Comm_size (), MPI_Comm_rank () and MPI_Reduce () functions. A survey of the literature shows that relatively little is written with respect to the efficient extraction of the inherent computational power in a cluster. In this work, we discuss the main avenues available to tap into this extra power without compromising computational accuracy. We also present methods to overcome the high inertia encountered in single-node-based computational molecular dynamics. We begin by surveying the current state of the art and discuss what it takes to achieve parallelism, efficiency and enhanced computational accuracy through program threads and message passing interfaces. Several code illustrations are given. The pros and cons of writing raw code as opposed to using heuristic, third-party code are also discussed. The growing trend towards graphical processor units and virtual computing clouds for high-performance computing is also discussed. Finally, we present the comparative results of vacancy formation energy calculations using our own parallelized standalone code called Verlet-Stormer velocity (VSV) operating on 30,000 copper atoms. The code is based on the Sutton-Chen implementation of the Finnis-Sinclair pairwise embedded atom potential. A link to the code is also given.

  8. Priority Queue Based Reactive Buffer Management Policy for Delay Tolerant Network under City Based Environments.

    PubMed

    Ayub, Qaisar; Ngadi, Asri; Rashid, Sulma; Habib, Hafiz Adnan

    2018-01-01

    Delay Tolerant Network (DTN) multi-copy routing protocols are privileged to create and transmit multiple copies of each message that causes congestion and some messages are dropped. This process is known as reactive drop because messages were dropped re-actively to overcome buffer overflows. The existing reactive buffer management policies apply a single metric to drop source, relay and destine messages. Hereby, selection to drop a message is dubious because each message as source, relay or destine may have consumed dissimilar magnitude of network resources. Similarly, DTN has included time to live (ttl) parameter which defines lifetime of message. Hence, when ttl expires then message is automatically destroyed from relay nodes. However, time-to-live (ttl) is not applicable on messages reached at their destinations. Moreover, nodes keep replicating messages till ttl expires even-though large number of messages has already been dispersed. In this paper, we have proposed Priority Queue Based Reactive Buffer Management Policy (PQB-R) for DTN under City Based Environments. The PQB-R classifies buffered messages into source, relay and destine queues. Moreover, separate drop metric has been applied on individual queue. The experiment results prove that proposed PQB-R has reduced number of messages transmissions, message drop and increases delivery ratio.

  9. Priority Queue Based Reactive Buffer Management Policy for Delay Tolerant Network under City Based Environments

    PubMed Central

    Ngadi, Asri; Rashid, Sulma; Habib, Hafiz Adnan

    2018-01-01

    Delay Tolerant Network (DTN) multi-copy routing protocols are privileged to create and transmit multiple copies of each message that causes congestion and some messages are dropped. This process is known as reactive drop because messages were dropped re-actively to overcome buffer overflows. The existing reactive buffer management policies apply a single metric to drop source, relay and destine messages. Hereby, selection to drop a message is dubious because each message as source, relay or destine may have consumed dissimilar magnitude of network resources. Similarly, DTN has included time to live (ttl) parameter which defines lifetime of message. Hence, when ttl expires then message is automatically destroyed from relay nodes. However, time-to-live (ttl) is not applicable on messages reached at their destinations. Moreover, nodes keep replicating messages till ttl expires even-though large number of messages has already been dispersed. In this paper, we have proposed Priority Queue Based Reactive Buffer Management Policy (PQB-R) for DTN under City Based Environments. The PQB-R classifies buffered messages into source, relay and destine queues. Moreover, separate drop metric has been applied on individual queue. The experiment results prove that proposed PQB-R has reduced number of messages transmissions, message drop and increases delivery ratio. PMID:29438438

  10. 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).

  11. A knowledge base architecture for distributed knowledge agents

    NASA Technical Reports Server (NTRS)

    Riedesel, Joel; Walls, Bryan

    1990-01-01

    A tuple space based object oriented model for knowledge base representation and interpretation is presented. An architecture for managing distributed knowledge agents is then implemented within the model. The general model is based upon a database implementation of a tuple space. Objects are then defined as an additional layer upon the database. The tuple space may or may not be distributed depending upon the database implementation. A language for representing knowledge and inference strategy is defined whose implementation takes advantage of the tuple space. The general model may then be instantiated in many different forms, each of which may be a distinct knowledge agent. Knowledge agents may communicate using tuple space mechanisms as in the LINDA model as well as using more well known message passing mechanisms. An implementation of the model is presented describing strategies used to keep inference tractable without giving up expressivity. An example applied to a power management and distribution network for Space Station Freedom is given.

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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:

  17. 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

  18. 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.

  19. "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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Distributed computing for membrane-based modeling of action potential propagation.

    PubMed

    Porras, D; Rogers, J M; Smith, W M; Pollard, A E

    2000-08-01

    Action potential propagation simulations with physiologic membrane currents and macroscopic tissue dimensions are computationally expensive. We, therefore, analyzed distributed computing schemes to reduce execution time in workstation clusters by parallelizing solutions with message passing. Four schemes were considered in two-dimensional monodomain simulations with the Beeler-Reuter membrane equations. Parallel speedups measured with each scheme were compared to theoretical speedups, recognizing the relationship between speedup and code portions that executed serially. A data decomposition scheme based on total ionic current provided the best performance. Analysis of communication latencies in that scheme led to a load-balancing algorithm in which measured speedups at 89 +/- 2% and 75 +/- 8% of theoretical speedups were achieved in homogeneous and heterogeneous clusters of workstations. Speedups in this scheme with the Luo-Rudy dynamic membrane equations exceeded 3.0 with eight distributed workstations. Cluster speedups were comparable to those measured during parallel execution on a shared memory machine.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. Event Driven Messaging with Role-Based Subscriptions

    NASA Technical Reports Server (NTRS)

    Bui, Tung; Bui, Bach; Malhotra, Shantanu; Chen, Fannie; Kim, rachel; Allen, Christopher; Luong, Ivy; Chang, George; Zendejas, Silvino; Sadaqathulla, Syed

    2009-01-01

    Event Driven Messaging with Role-Based Subscriptions (EDM-RBS) is a framework integrated into the Service Management Database (SMDB) to allow for role-based and subscription-based delivery of synchronous and asynchronous messages over JMS (Java Messaging Service), SMTP (Simple Mail Transfer Protocol), or SMS (Short Messaging Service). This allows for 24/7 operation with users in all parts of the world. The software classifies messages by triggering data type, application source, owner of data triggering event (mission), classification, sub-classification and various other secondary classifying tags. Messages are routed to applications or users based on subscription rules using a combination of the above message attributes. This program provides a framework for identifying connected users and their applications for targeted delivery of messages over JMS to the client applications the user is logged into. EDMRBS provides the ability to send notifications over e-mail or pager rather than having to rely on a live human to do it. It is implemented as an Oracle application that uses Oracle relational database management system intrinsic functions. It is configurable to use Oracle AQ JMS API or an external JMS provider for messaging. It fully integrates into the event-logging framework of SMDB (Subnet Management Database).

  12. Developing and Pretesting a Text Messaging Program for Health Behavior Change: Recommended Steps.

    PubMed

    Abroms, Lorien C; Whittaker, Robyn; Free, Caroline; Mendel Van Alstyne, Judith; Schindler-Ruwisch, Jennifer M

    2015-12-21

    A growing body of evidence demonstrates that text messaging-based programs (short message service [SMS]) on mobile phones can help people modify health behaviors. Most of these programs have consisted of automated and sometimes interactive text messages that guide a person through the process of behavior change. This paper provides guidance on how to develop text messaging programs aimed at changing health behaviors. Based on their collective experience in designing, developing, and evaluating text messaging programs and a review of the literature, the authors drafted the guide. One author initially drafted the guide and the others provided input and review. Steps for developing a text messaging program include conducting formative research for insights into the target audience and health behavior, designing the text messaging program, pretesting the text messaging program concept and messages, and revising the text messaging program. The steps outlined in this guide may help in the development of SMS-based behavior change programs.

  13. How lay people respond to messages about genetics, health, and race.

    PubMed

    Condit, C; Bates, B

    2005-08-01

    There is a growing movement in medical genetics to develop, implement, and promote a model of race-based medicine. Although race-based medicine may become a widely disseminated standard of care, messages that advocate race-based selection for diagnosing, screening and prescribing drugs may exacerbate health disparities. These messages are present in clinical genetic counseling sessions, mass media, and everyday talk. Messages promoting linkages among genes, race, and health and messages emphasizing genetic causation may promote both general racism and genetically based racism. This mini-review examines research in three areas: studies that address the effects of these messages about genetics on levels of genetic determinism and genetic discrimination; studies that address the effects of these messages on attitudes about race; and, studies of the impacts of race-specific genetic messages on recipients. Following an integration of this research, this mini-review suggests that the current literature appears fragmented because of methodological and measurement issues and offers strategies for future research. Finally, the authors offer a path model to help organize future research examining the effects of messages about genetics on socioculturally based racism, genetically based racism, and unaccounted for racism. Research in this area is needed to understand and mitigate the negative attitudinal effects of messages that link genes, race, and health and/or emphasize genetic causation.

  14. Development of patient-centric linguistically tailored psychoeducational messages to support nutrition and medication self-management in type 2 diabetes: a feasibility study

    PubMed Central

    Ellis, Rebecca J Bartlett; Connor, Ulla; Marshall, James

    2014-01-01

    Purpose This study evaluated the feasibility of developing linguistically tailored educational messages designed to match the linguistic styles of patients segmented into types with the Descriptor™, and to determine patient preferences for tailored or standard messages based on their segments. Patients and methods Twenty patients with type 2 diabetes (T2DM) were recruited from a diabetes health clinic. Participants were segmented using the Descriptor™, a language-based questionnaire, to identify patient types based on their control orientation (internal/external), agency (high/low), and affect (positive/negative), which are well studied constructs related to T2DM self-management. Two of the seven self-care behaviors described by the American Association of Diabetes Educators (healthy eating and taking medication) were used to develop standard messages and then linguistically tailored using features of the six different construct segment types of the Descriptor™. A subset of seven participants each provided feedback on their preference for standard or linguistically tailored messages; 12 comparisons between standard and tailored messages were made. Results Overall, the tailored messages were preferred to the standard messages. When the messages were matched to specific construct segment types, the tailored messages were preferred over the standard messages, although this was not statistically significant. Conclusion Linguistically tailoring messages based on construct segments is feasible. Furthermore, tailored messages were more often preferred over standard messages. This study provides some preliminary evidence for tailoring messages based on the linguistic features of control orientation, agency, and affect. The messages developed in this study should be tested in a larger more representative sample. The present study did not explore whether tailored messages were better understood. This research will serve as preliminary evidence to develop future studies with the ultimate goal to design intervention studies to investigate if linguistically tailoring communication within the context of patient education influences patient knowledge, motivation, and activation toward making healthy behavior changes in T2DM self-management. PMID:25336928

  15. Response efficacy: the key to minimizing rejection and maximizing acceptance of emotion-based anti-speeding messages.

    PubMed

    Lewis, I M; Watson, B; White, K M

    2010-03-01

    This study sought to improve understanding of the persuasive process of emotion-based appeals not only in relation to negative, fear-based appeals but also for appeals based upon positive emotions. In particular, the study investigated whether response efficacy, as a cognitive construct, mediated outcome measures of message effectiveness in terms of both acceptance and rejection of negative and positive emotion-based messages. Licensed drivers (N=406) participated via the completion of an on-line survey. Within the survey, participants received either a negative (fear-based) appeal or one of the two possible positive appeals (pride or humor-based). Overall, the study's findings confirmed the importance of emotional and cognitive components of persuasive health messages and identified response efficacy as a key cognitive construct influencing the effectiveness of not only fear-based messages but also positive emotion-based messages. Interestingly, however, the results suggested that response efficacy's influence on message effectiveness may differ for positive and negative emotion-based appeals such that significant indirect (and mediational) effects were found with both acceptance and rejection of the positive appeals yet only with rejection of the fear-based appeal. As such, the study's findings provide an important extension to extant literature and may inform future advertising message design. Copyright 2009 Elsevier Ltd. All rights reserved.

  16. A weighted belief-propagation algorithm for estimating volume-related properties of random polytopes

    NASA Astrophysics Data System (ADS)

    Font-Clos, Francesc; Massucci, Francesco Alessandro; Pérez Castillo, Isaac

    2012-11-01

    In this work we introduce a novel weighted message-passing algorithm based on the cavity method for estimating volume-related properties of random polytopes, properties which are relevant in various research fields ranging from metabolic networks, to neural networks, to compressed sensing. We propose, as opposed to adopting the usual approach consisting in approximating the real-valued cavity marginal distributions by a few parameters, using an algorithm to faithfully represent the entire marginal distribution. We explain various alternatives for implementing the algorithm and benchmarking the theoretical findings by showing concrete applications to random polytopes. The results obtained with our approach are found to be in very good agreement with the estimates produced by the Hit-and-Run algorithm, known to produce uniform sampling.

  17. An Application-Based Performance Characterization of the Columbia Supercluster

    NASA Technical Reports Server (NTRS)

    Biswas, Rupak; Djomehri, Jahed M.; Hood, Robert; Jin, Hoaqiang; Kiris, Cetin; Saini, Subhash

    2005-01-01

    Columbia is a 10,240-processor supercluster consisting of 20 Altix nodes with 512 processors each, and currently ranked as the second-fastest computer in the world. In this paper, we present the performance characteristics of Columbia obtained on up to four computing nodes interconnected via the InfiniBand and/or NUMAlink4 communication fabrics. We evaluate floating-point performance, memory bandwidth, message passing communication speeds, and compilers using a subset of the HPC Challenge benchmarks, and some of the NAS Parallel Benchmarks including the multi-zone versions. We present detailed performance results for three scientific applications of interest to NASA, one from molecular dynamics, and two from computational fluid dynamics. Our results show that both the NUMAlink4 and the InfiniBand hold promise for application scaling to a large number of processors.

  18. 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.

  19. MPI_XSTAR: MPI-based Parallelization of the XSTAR Photoionization Program

    NASA Astrophysics Data System (ADS)

    Danehkar, Ashkbiz; Nowak, Michael A.; Lee, Julia C.; Smith, Randall K.

    2018-02-01

    We describe a program for the parallel implementation of multiple runs of XSTAR, a photoionization code that is used to predict the physical properties of an ionized gas from its emission and/or absorption lines. The parallelization program, called MPI_XSTAR, has been developed and implemented in the C++ language by using the Message Passing Interface (MPI) protocol, a conventional standard of parallel computing. We have benchmarked parallel multiprocessing executions of XSTAR, using MPI_XSTAR, against a serial execution of XSTAR, in terms of the parallelization speedup and the computing resource efficiency. Our experience indicates that the parallel execution runs significantly faster than the serial execution, however, the efficiency in terms of the computing resource usage decreases with increasing the number of processors used in the parallel computing.

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. Extending the explanatory utility of the EPPM beyond fear-based persuasion.

    PubMed

    Lewis, Ioni; Watson, Barry; White, Katherine M

    2013-01-01

    In the 20 years since its inception, the Extended Parallel Process Model (EPPM) has attracted much empirical support. Currently, and unsurprisingly, given that is a model of fear-based persuasion, the EPPM's explanatory utility has been based only upon fear-based messages. However, an argument is put forth herein that draws upon existing evidence that the EPPM may be an efficacious framework for explaining the persuasive process and outcomes of emotion-based messages more broadly when such messages are addressing serious health topics. For the current study, four different types of emotional appeals were purposefully devised and included a fear-, an annoyance/agitation-, a pride-, and a humor-based message. All messages addressed the serious health issue of road safety, and in particular the risky behavior of speeding. Participants (n = 551) were exposed to only one of the four messages and subsequently provided responses within a survey. A series of 2 (threat: low, high) × 2 (efficacy: low, high) analysis of variance was conducted for each of the appeals based on the EPPM's message outcomes of acceptance and rejection. Support was found for the EPPM with a number of main effects of threat and efficacy emerging, reflecting that, irrespective of emotional appeal type, high levels of threat and efficacy enhanced message outcomes via maximizing acceptance and minimizing rejection. Theoretically, the findings provide support for the explanatory utility of the EPPM for emotion-based health messages more broadly. In an applied sense, the findings highlight the value of adopting the EPPM as a framework when devising and evaluating emotion-based health messages for serious health topics.

  5. MPI, HPF or OpenMP: A Study with the NAS Benchmarks

    NASA Technical Reports Server (NTRS)

    Jin, Hao-Qiang; Frumkin, Michael; Hribar, Michelle; Waheed, Abdul; Yan, Jerry; Saini, Subhash (Technical Monitor)

    1999-01-01

    Porting applications to new high performance parallel and distributed platforms is a challenging task. Writing parallel code by hand is time consuming and costly, but the task can be simplified by high level languages and would even better be automated by parallelizing tools and compilers. The definition of HPF (High Performance Fortran, based on data parallel model) and OpenMP (based on shared memory parallel model) standards has offered great opportunity in this respect. Both provide simple and clear interfaces to language like FORTRAN and simplify many tedious tasks encountered in writing message passing programs. In our study we implemented the parallel versions of the NAS Benchmarks with HPF and OpenMP directives. Comparison of their performance with the MPI implementation and pros and cons of different approaches will be discussed along with experience of using computer-aided tools to help parallelize these benchmarks. Based on the study,potentials of applying some of the techniques to realistic aerospace applications will be presented

  6. MPI, HPF or OpenMP: A Study with the NAS Benchmarks

    NASA Technical Reports Server (NTRS)

    Jin, H.; Frumkin, M.; Hribar, M.; Waheed, A.; Yan, J.; Saini, Subhash (Technical Monitor)

    1999-01-01

    Porting applications to new high performance parallel and distributed platforms is a challenging task. Writing parallel code by hand is time consuming and costly, but this task can be simplified by high level languages and would even better be automated by parallelizing tools and compilers. The definition of HPF (High Performance Fortran, based on data parallel model) and OpenMP (based on shared memory parallel model) standards has offered great opportunity in this respect. Both provide simple and clear interfaces to language like FORTRAN and simplify many tedious tasks encountered in writing message passing programs. In our study, we implemented the parallel versions of the NAS Benchmarks with HPF and OpenMP directives. Comparison of their performance with the MPI implementation and pros and cons of different approaches will be discussed along with experience of using computer-aided tools to help parallelize these benchmarks. Based on the study, potentials of applying some of the techniques to realistic aerospace applications will be presented.

  7. 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.

  8. 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.

  9. Friendly-Sharing: Improving the Performance of City Sensoring through Contact-Based Messaging Applications.

    PubMed

    Herrera-Tapia, Jorge; Hernández-Orallo, Enrique; Tomás, Andrés; Manzoni, Pietro; Tavares Calafate, Carlos; Cano, Juan-Carlos

    2016-09-18

    Regular citizens equipped with smart devices are being increasingly used as "sensors" by Smart Cities applications. Using contacts among users, data in the form of messages is obtained and shared. Contact-based messaging applications are based on establishing a short-range communication directly between mobile devices, and on storing the messages in these devices for subsequent delivery to cloud-based services. An effective way to increase the number of messages that can be shared is to increase the contact duration. We thus introduce the Friendly-Sharing diffusion approach, where, during a contact, the users are aware of the time needed to interchange the messages stored in their buffers, and they can thus decide to wait more time in order to increase the message sharing probability. The performance of this approach is anyway closely related to the size of the buffer in the device. We therefore compare various policies either for the message selection at forwarding times and for message dropping when the buffer is full. We evaluate our proposal with a modified version of the Opportunistic Networking Environment (ONE) simulator and using real human mobility traces.

  10. Randomized controlled trial of a messaging intervention to increase fruit and vegetable intake in adolescents: Affective versus instrumental messages.

    PubMed

    Carfora, Valentina; Caso, Daniela; Conner, Mark

    2016-11-01

    The present research aimed to test the efficacy of affective and instrumental text messages compared with a no-message control as a strategy to increase fruit and vegetable intake (FVI) in adolescents. A randomized controlled trial was used test impact of different text messages compared with no message on FVI over a 2-week period. A total of 1,065 adolescents (14-19 years) from a high school of the South of Italy completed the baseline questionnaire and were randomly allocated to one of three conditions: instrumental messages (N = 238), affective messages (N = 300), and no messages (N = 521). Students in the message conditions received one message each day over a 2-week period. The messages targeted affective (affective benefits) or instrumental (instrumental benefits) information about FVI. Self-reported FVI at 2 weeks was the key dependent variable. Analyses were based on the N = 634 who completed all aspects of the study. Findings showed that messages significantly increased FVI, particularly in the affective condition and this effect was partially mediated by changes in affective attitude and intentions towards FVI. Text messages can be used to increase FVI in adolescents. Text messages based on affective benefits are more effective than text messages based on instrumental benefits. Statement of contribution What is already known on this subject? Text messages have been shown to promote positive change in health behaviours. However, the most appropriate target for such text messages is less clear although targeting attitudes may be effective. What does this study add? This randomized controlled study shows that text messages targeting instrumental or affective attitudes produce changes in fruit and vegetable intake (FVI) in adolescents. Text messages targeting affective attitudes are shown to be more effective than text messages targeting instrumental attitudes. The effect of affective text messages on FVI was partially mediated by changes in affective attitudes. © 2016 The British Psychological Society.

  11. 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.

  12. Pass the Popcorn: “Obesogenic” Behaviors and Stigma in Children’s Movies

    PubMed Central

    Throop, Elizabeth M.; Skinner, Asheley Cockrell; Perrin, Andrew J.; Steiner, Michael J.; Odulana, Adebowale; Perrin, Eliana M.

    2014-01-01

    Objective To determine the prevalence of obesity-related behaviors and attitudes in children’s movies. Design and Methods We performed a mixed-methods study of the top-grossing G- and PG-rated movies, 2006–2010 (4 per year). For each 10-minute movie segment the following were assessed: 1) prevalence of key nutrition and physical activity behaviors corresponding to the American Academy of Pediatrics obesity prevention recommendations for families; 2) prevalence of weight stigma; 3) assessment as healthy, unhealthy, or neutral; 3) free-text interpretations of stigma. Results Agreement between coders was greater than 85% (Cohen’s kappa=0.7), good for binary responses. Segments with food depicted: exaggerated portion size (26%); unhealthy snacks (51%); sugar-sweetened beverages (19%). Screen time was also prevalent (40% of movies showed television; 35% computer; 20% video games). Unhealthy segments outnumbered healthy segments 2:1. Most (70%) of the movies included weight-related stigmatizing content (e.g. “That fat butt! Flabby arms! And this ridiculous belly!”). Conclusions These popular children’s movies had significant “obesogenic” content, and most contained weight-based stigma. They present a mixed message to children: promoting unhealthy behaviors while stigmatizing the behaviors’ possible effects. Further research is needed to determine the effects of such messages on children. PMID:24311390

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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).

  20. 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.

  1. "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

  2. 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.

  3. DMS message design workshops.

    DOT National Transportation Integrated Search

    2009-03-01

    This report summarizes the training conducted statewide regarding the design and display of messages on : dynamic message signs. The training is based on the Dynamic Message Sign Message Design and Display : Manual (0-4023-P3). Researchers developed ...

  4. 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.

  5. Improving the Effectiveness of Fundraising Messages: The Impact of Charity Goal Attainment, Message Framing, and Evidence on Persuasion

    ERIC Educational Resources Information Center

    Das, Enny; Kerkhof, Peter; Kuiper, Joyce

    2008-01-01

    This experimental study assessed the effectiveness of fundraising messages. Based on recent findings regarding the effects of message framing and evidence, effective fundraising messages should combine abstract, statistical information with a negative message frame and anecdotal evidence with a positive message frame. In addition, building on…

  6. Friendly-Sharing: Improving the Performance of City Sensoring through Contact-Based Messaging Applications

    PubMed Central

    Herrera-Tapia, Jorge; Hernández-Orallo, Enrique; Tomás, Andrés; Manzoni, Pietro; Tavares Calafate, Carlos; Cano, Juan-Carlos

    2016-01-01

    Regular citizens equipped with smart devices are being increasingly used as “sensors” by Smart Cities applications. Using contacts among users, data in the form of messages is obtained and shared. Contact-based messaging applications are based on establishing a short-range communication directly between mobile devices, and on storing the messages in these devices for subsequent delivery to cloud-based services. An effective way to increase the number of messages that can be shared is to increase the contact duration. We thus introduce the Friendly-Sharing diffusion approach, where, during a contact, the users are aware of the time needed to interchange the messages stored in their buffers, and they can thus decide to wait more time in order to increase the message sharing probability. The performance of this approach is anyway closely related to the size of the buffer in the device. We therefore compare various policies either for the message selection at forwarding times and for message dropping when the buffer is full. We evaluate our proposal with a modified version of the Opportunistic Networking Environment (ONE) simulator and using real human mobility traces. PMID:27649209

  7. 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.

  8. 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.

  9. 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.

  10. Can anti-speeding messages based on protection motivation theory influence reported speeding intentions?

    PubMed

    Glendon, A Ian; Walker, Britta L

    2013-08-01

    The study investigated the effects of anti-speeding messages based on protection motivation theory (PMT) components: severity, vulnerability, rewards, self-efficacy, response efficacy, and response cost, on reported speeding intentions. Eighty-three participants aged 18-25 years holding a current Australian driver's license completed a questionnaire measuring their reported typical and recent speeding behaviors. Comparisons were made between 18 anti-speeding messages used on Australian roads and 18 new anti-speeding messages developed from the PMT model. Participants reported their reactions to the 36 messages on the perceived effectiveness of the message for themselves and for the general population of drivers, and also the likelihood of themselves and other drivers driving within the speed limit after viewing each message. Overall the PMT model-derived anti-speeding messages were better than jurisdiction-use anti-speeding messages in influencing participants' reported intention to drive within the speed limit. Severity and vulnerability were the most effective PMT components for developing anti-speeding messages. Male participants reported significantly lower intention to drive within the speed limit than did female participants. However, males reported significantly higher intention to drive within the speed limit for PMT-derived messages compared with jurisdiction-based messages. Third-person effects were that males reported anti-speeding messages to be more effective for the general driving population than for themselves. Females reported the opposite effect - that all messages would be more effective for themselves than for the general driving population. Findings provided support for using a sound conceptual basis as an effective foundation for anti-speeding message development as well as for evaluating proposed anti-speeding messages on the target driver population. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. 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.

  12. 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.

  13. Role of Narrative Perspective and Modality in the Persuasiveness of Public Service Advertisements Promoting HPV Vaccination.

    PubMed

    Nan, Xiaoli; Futerfas, Michelle; Ma, Zexin

    2017-03-01

    In the context of public service advertisements promoting human papillomavirus (HPV) vaccination, the current research examines 1) the relative persuasiveness of narrative vs. non-narrative messages and 2) the influence of narrative perspective (first- vs. third-person) and modality (text-based vs. audio-based) on message effectiveness. Results of a controlled experiment (N = 121) suggested that both a non-narrative message and a first-person narrative message led to greater perceived risk of getting HPV than a third-person narrative message. There was no difference in risk perception between the non-narrative and first-person narrative conditions. These findings were confined to the text-based condition, however. When the messages were audio-based, no differential message effects were detected. The analysis also provided partial evidence for an indirect effect of narrative perspective on intentions to vaccinate against HPV through HPV risk perception. Theoretical and practical implications of the findings are discussed.

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. Drawing Lines with Light in Holographic Space

    NASA Astrophysics Data System (ADS)

    Chang, Yin-Ren; Richardson, Martin

    2013-02-01

    This paper explores the dynamic and expressive possibilities of holographic art through a comparison of art history and technical media such as photography, film and holographic technologies. Examples of modern art and creative expression of time and motions are examined using the early 20th century art movement, Cubism, where subjects are portrayed to be seen simultaneously from different angles. Folding space is represented as subject matter as it can depict space from multiple points of time. The paper also investigates the way holographic art has explored time and space. The lenticular lens-based media reveal a more subjective poetic art in the form of the lyrical images and messages as spectators pass through time, or walk along with the piece of work through an interactive process. It is argued that photographic practice is another example of artistic representation in the form of aesthetic medium of time movement and as such shares a common ground with other dynamic expression that require time based interaction.

  9. Optimal deployment of resources for maximizing impact in spreading processes

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

    Lokhov, Andrey Y.; Saad, David

    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 distributionmore » of available resources hence results from an interplay between network topology and spreading dynamics. Here, 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.« less

  10. Optimal deployment of resources for maximizing impact in spreading processes

    DOE PAGES

    Lokhov, Andrey Y.; Saad, David

    2017-09-12

    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 distributionmore » of available resources hence results from an interplay between network topology and spreading dynamics. Here, 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.« less

  11. Parallel implementation of a Lagrangian-based model on an adaptive mesh in C++: Application to sea-ice

    NASA Astrophysics Data System (ADS)

    Samaké, Abdoulaye; Rampal, Pierre; Bouillon, Sylvain; Ólason, Einar

    2017-12-01

    We present a parallel implementation framework for a new dynamic/thermodynamic sea-ice model, called neXtSIM, based on the Elasto-Brittle rheology and using an adaptive mesh. The spatial discretisation of the model is done using the finite-element method. The temporal discretisation is semi-implicit and the advection is achieved using either a pure Lagrangian scheme or an Arbitrary Lagrangian Eulerian scheme (ALE). The parallel implementation presented here focuses on the distributed-memory approach using the message-passing library MPI. The efficiency and the scalability of the parallel algorithms are illustrated by the numerical experiments performed using up to 500 processor cores of a cluster computing system. The performance obtained by the proposed parallel implementation of the neXtSIM code is shown being sufficient to perform simulations for state-of-the-art sea ice forecasting and geophysical process studies over geographical domain of several millions squared kilometers like the Arctic region.

  12. Design and implementation of a hybrid MPI-CUDA model for the Smith-Waterman algorithm.

    PubMed

    Khaled, Heba; Faheem, Hossam El Deen Mostafa; El Gohary, Rania

    2015-01-01

    This paper provides a novel hybrid model for solving the multiple pair-wise sequence alignment problem combining message passing interface and CUDA, the parallel computing platform and programming model invented by NVIDIA. The proposed model targets homogeneous cluster nodes equipped with similar Graphical Processing Unit (GPU) cards. The model consists of the Master Node Dispatcher (MND) and the Worker GPU Nodes (WGN). The MND distributes the workload among the cluster working nodes and then aggregates the results. The WGN performs the multiple pair-wise sequence alignments using the Smith-Waterman algorithm. We also propose a modified implementation to the Smith-Waterman algorithm based on computing the alignment matrices row-wise. The experimental results demonstrate a considerable reduction in the running time by increasing the number of the working GPU nodes. The proposed model achieved a performance of about 12 Giga cell updates per second when we tested against the SWISS-PROT protein knowledge base running on four nodes.

  13. 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.

  14. Employing multi-GPU power for molecular dynamics simulation: an extension of GALAMOST

    NASA Astrophysics Data System (ADS)

    Zhu, You-Liang; Pan, Deng; Li, Zhan-Wei; Liu, Hong; Qian, Hu-Jun; Zhao, Yang; Lu, Zhong-Yuan; Sun, Zhao-Yan

    2018-04-01

    We describe the algorithm of employing multi-GPU power on the basis of Message Passing Interface (MPI) domain decomposition in a molecular dynamics code, GALAMOST, which is designed for the coarse-grained simulation of soft matters. The code of multi-GPU version is developed based on our previous single-GPU version. In multi-GPU runs, one GPU takes charge of one domain and runs single-GPU code path. The communication between neighbouring domains takes a similar algorithm of CPU-based code of LAMMPS, but is optimised specifically for GPUs. We employ a memory-saving design which can enlarge maximum system size at the same device condition. An optimisation algorithm is employed to prolong the update period of neighbour list. We demonstrate good performance of multi-GPU runs on the simulation of Lennard-Jones liquid, dissipative particle dynamics liquid, polymer and nanoparticle composite, and two-patch particles on workstation. A good scaling of many nodes on cluster for two-patch particles is presented.

  15. Photo-sharing social media for eHealth: analysing perceived message effectiveness of sexual health information on Instagram.

    PubMed

    O'Donnell, Nicole Hummel; Willoughby, Jessica Fitts

    2017-10-01

    Health professionals increasingly use social media to communicate health information, but it is unknown how visual message presentation on these platforms affects message reception. This study used an experiment to analyse how young adults (n = 839) perceive sexual health messages on Instagram. Participants were exposed to one of four conditions based on visual message presentation. Messages with embedded health content had the highest perceived message effectiveness ratings. Additionally, message sensation value, attitudes and systematic information processing were significant predictors of perceived message effectiveness. Implications for visual message design for electronic health are discussed.

  16. Announcement/Subscription/Publication: Message Based Communication for Heterogeneous Mobile Environments

    NASA Astrophysics Data System (ADS)

    Ristau, Henry

    Many tasks in smart environments can be implemented using message based communication paradigms that decouple applications in time, space, synchronization and semantics. Current solutions for decoupled message based communication either do not support message processing and thus semantic decoupling or rely on clearly defined network structures. In this paper we present ASP, a novel concept for such communication that can directly operate on neighbor relations between brokers and does not rely on a homogeneous addressing scheme or anymore than simple link layer communication. We show by simulation that ASP performs well in a heterogeneous scenario with mobile nodes and decreases network or processor load significantly compared to message flooding.

  17. Using Visual Metaphors in Health Messages: A Strategy to Increase Effectiveness for Mental Illness Communication.

    PubMed

    Lazard, Allison J; Bamgbade, Benita A; Sontag, Jennah M; Brown, Carolyn

    2016-12-01

    Depression is highly prevalent among college students. Although treatment is often available on university campuses, many stigma-based barriers prevent students from seeking help. Communication strategies, such as the use of metaphors, are needed to reduce barriers. Specially, the use of visual metaphors, as a strategic message design tactic, may be an effective communication strategy to increase message appeal and engagement. Using a 2-phase approach, this study first identified common metaphors students use to conceptualize mental illness. Messages incorporating conceptual and visual metaphors were then designed and tested to determine their potential in reducing stigma. Participants (n = 256) were randomly assigned to 1 of 4 conditions in a between-subjects experiment: messages with visual and textual metaphors, messages with straightforward visuals and textual metaphors, text-based metaphor messages, or a control group. Overall, metaphorical messages are appealing, the use of visual metaphors leads to greater message engagement, and messages based on conceptual metaphors have the potential to reduce stigma. The use of conceptual and visual metaphors in campaign design is an effective strategy to communicate about a complex health topic, such as mental illness, and should be considered for use in campaigns to reduce barriers for help-seeking behavior.

  18. A systematic review of three approaches for constructing physical activity messages: What messages work and what improvements are needed?

    PubMed Central

    2010-01-01

    Background To motivate individuals to adhere to a regular physical activity regime, guidelines must be supplemented with persuasive messages that are disseminated widely. While substantial research has examined effective strategies for disseminating physical activity messages, there has been no systematic effort to examine optimal message content. This paper reviews studies that evaluate the effectiveness of three approaches for constructing physical activity messages including tailoring messages to suit individual characteristics of message recipients (message tailoring), framing messages in terms of gains versus losses (message framing), and targeting messages to affect change in self-efficacy (i.e., a theoretical determinant of behavior change). Methods We searched the MEDLINE, PsycINFO, EMBASE and CINAHL databases up to July 2008. Relevant reference lists also were searched. We included intervention trials, field experiments, and laboratory-based studies that aimed to test the efficacy or effectiveness of tailored messages, framed messages and self-efficacy change messages among healthy adults. We used a descriptive approach to analyze emerging patterns in research findings. Based on this evidence we made recommendations for practice and future research. Results Twenty-two studies were identified. Twelve studies evaluated message tailoring. In 10 of these studies, tailored messages resulted in greater physical activity than a control message. Six studies evaluated framed messages. Five of these studies demonstrated that gain-framed messages lead to stronger intentions to be active compared to a control message. Moreover, a gain-frame advantage was evident in three of the four studies that assessed physical activity. Four studies evaluated self-efficacy change messages. The two studies that used an experimental design provide a clear indication that individuals' beliefs can be affected by messages that incorporate types of information known to be determinants of self-efficacy. Overall, strong evidence to support definitive recommendations for optimal message content and structure was lacking. Conclusions Additional research testing the optimal content of messages used to supplement physical activity guidelines is needed. Tailored messages, gain-framed messages, and self-efficacy change messages hold promise as strategies for constructing physical activity messages and should be a focus of future research. PMID:20459779

  19. Evaluation of smoking prevention television messages based on the elaboration likelihood model

    PubMed Central

    Flynn, Brian S.; Worden, John K.; Bunn, Janice Yanushka; Connolly, Scott W.; Dorwaldt, Anne L.

    2011-01-01

    Progress in reducing youth smoking may depend on developing improved methods to communicate with higher risk youth. This study explored the potential of smoking prevention messages based on the Elaboration Likelihood Model (ELM) to address these needs. Structured evaluations of 12 smoking prevention messages based on three strategies derived from the ELM were conducted in classroom settings among a diverse sample of non-smoking middle school students in three states (n = 1771). Students categorized as likely to have higher involvement in a decision to initiate cigarette smoking reported relatively high ratings on a cognitive processing indicator for messages focused on factual arguments about negative consequences of smoking than for messages with fewer or no direct arguments. Message appeal ratings did not show greater preference for this message type among higher involved versus lower involved students. Ratings from students reporting lower academic achievement suggested difficulty processing factual information presented in these messages. The ELM may provide a useful strategy for reaching adolescents at risk for smoking initiation, but particular attention should be focused on lower academic achievers to ensure that messages are appropriate for them. This approach should be explored further before similar strategies could be recommended for large-scale implementation. PMID:21885672

  20. Evaluation of smoking prevention television messages based on the elaboration likelihood model.

    PubMed

    Flynn, Brian S; Worden, John K; Bunn, Janice Yanushka; Connolly, Scott W; Dorwaldt, Anne L

    2011-12-01

    Progress in reducing youth smoking may depend on developing improved methods to communicate with higher risk youth. This study explored the potential of smoking prevention messages based on the Elaboration Likelihood Model (ELM) to address these needs. Structured evaluations of 12 smoking prevention messages based on three strategies derived from the ELM were conducted in classroom settings among a diverse sample of non-smoking middle school students in three states (n = 1771). Students categorized as likely to have higher involvement in a decision to initiate cigarette smoking reported relatively high ratings on a cognitive processing indicator for messages focused on factual arguments about negative consequences of smoking than for messages with fewer or no direct arguments. Message appeal ratings did not show greater preference for this message type among higher involved versus lower involved students. Ratings from students reporting lower academic achievement suggested difficulty processing factual information presented in these messages. The ELM may provide a useful strategy for reaching adolescents at risk for smoking initiation, but particular attention should be focused on lower academic achievers to ensure that messages are appropriate for them. This approach should be explored further before similar strategies could be recommended for large-scale implementation.

  1. 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.

  2. Long-range AIS message analysis based on the TianTuo-3 micro satellite

    NASA Astrophysics Data System (ADS)

    Li, Shiyou; Chen, Lihu; Chen, Xiaoqian; Zhao, Yong; Bai, Yuzhu

    2017-07-01

    The "Type-27 AIS message" is the long-range AIS broadcast message, which is primarily intended for the long-range detection of AIS typically by satellite. The TT3-AIS uses a four-frequency receiver scheme which includes two frequency channels conventionally applied by the AIS system and two new frequency channels allocated to the long-range AIS broadcast message. To the end of April 2016, the TT3-AIS has already received more than 11,400 packets of Type-27 AIS messages. In this paper, a detailed analysis of the Type-27 AIS messages is performed. Firstly, an eavesdropper diagram of the space-borne AIS received from the worldwide vessels is obtained. Secondly, the analysis to the trend of the number and the ratio of the new-type vessels is performed based on the Type-27 AIS message. The detection probability of the new-type vessels is also discussed. The result would be helpful on the usage of the long-range AIS message both for data application and for the improvement in designing the next space-based AIS receiver.

  3. Evaluation of emotion-based messages designed to motivate Hispanic and Asian parents of early adolescents to engage in calcium-rich food and beverage parenting practices.

    PubMed

    Banna, Jinan Corinne; Reicks, Marla; Gunther, Carolyn; Richards, Rickelle; Bruhn, Christine; Cluskey, Mary; Wong, Siew Sun; Misner, Scottie; Hongu, Nobuko; Johnston, N Paul

    2016-08-01

    Setting healthful beverage expectations, making calcium-rich foods and beverages (CRF/B) available, and role modeling are parenting practices promoting calcium intake among early adolescents. This study aimed to evaluate emotion-based messages designed to motivate parents of early adolescents to perform these practices. Emotion-based messages were developed for each parenting practice and tested in 35 parents from 5 states. Findings were used to modify messages and develop a survey administered via Amazon MechanicalTurk to a convenience sample of Asian (n = 166) and Hispanic (n = 184) parents of children 10-13 years. Main outcome measures were message comprehension, motivation, relevance, acceptability, and novelty. Engagement in the parenting practices was also assessed. Message comprehension was acceptable for the majority of parents. Most also agreed that messages were motivational (setting healthful beverage expectations (69.0%), making CRF/B available (67.4%), and role modeling (80.0%)), relevant and acceptable. About 30-50% indicated they had not seen the information before. Many parents indicated they were already engaging in the practices (> 70%). No racial/ethnic differences were observed for responses to messages or engaging in parenting practices. Results indicate that emotion-based messages designed to motivate parents to engage in parenting practices that promote calcium intake among early adolescents were motivating, relevant, and acceptable.

  4. Evaluation of Smoking Prevention Television Messages Based on the Elaboration Likelihood Model

    ERIC Educational Resources Information Center

    Flynn, Brian S.; Worden, John K.; Bunn, Janice Yanushka; Connolly, Scott W.; Dorwaldt, Anne L.

    2011-01-01

    Progress in reducing youth smoking may depend on developing improved methods to communicate with higher risk youth. This study explored the potential of smoking prevention messages based on the Elaboration Likelihood Model (ELM) to address these needs. Structured evaluations of 12 smoking prevention messages based on three strategies derived from…

  5. Simplifying HL7 Version 3 messages.

    PubMed

    Worden, Robert; Scott, Philip

    2011-01-01

    HL7 Version 3 offers a semantically robust method for healthcare interoperability but has been criticized as overly complex to implement. This paper reviews initiatives to simplify HL7 Version 3 messaging and presents a novel approach based on semantic mapping. Based on user-defined definitions, precise transforms between simple and full messages are automatically generated. Systems can be interfaced with the simple messages and achieve interoperability with full Version 3 messages through the transforms. This reduces the costs of HL7 interfacing and will encourage better uptake of HL7 Version 3 and CDA.

  6. 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.

  7. Balancing Conflicting Requirements for Grid and Particle Decomposition in Continuum-Lagrangian Solvers

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

    Sitaraman, Hariswaran; Grout, Ray

    2015-10-30

    The load balancing strategies for hybrid solvers that involve grid based partial differential equation solution coupled with particle tracking are presented in this paper. A typical Message Passing Interface (MPI) based parallelization of grid based solves are done using a spatial domain decomposition while particle tracking is primarily done using either of the two techniques. One of the techniques is to distribute the particles to MPI ranks to whose grid they belong to while the other is to share the particles equally among all ranks, irrespective of their spatial location. The former technique provides spatial locality for field interpolation butmore » cannot assure load balance in terms of number of particles, which is achieved by the latter. The two techniques are compared for a case of particle tracking in a homogeneous isotropic turbulence box as well as a turbulent jet case. We performed a strong scaling study for more than 32,000 cores, which results in particle densities representative of anticipated exascale machines. The use of alternative implementations of MPI collectives and efficient load equalization strategies are studied to reduce data communication overheads.« less

  8. Passing the baton: Community-based ethnography to design a randomized clinical trial on the effectiveness of oral pre-exposure prophylaxis for HIV prevention among Black men who have sex with men.

    PubMed

    Garcia, Jonathan; Colson, Paul W; Parker, Caroline; Hirsch, Jennifer S

    2015-11-01

    Although HIV interventions and clinical trials increasingly report the use of mixed methods, studies have not reported on the process through which ethnographic or qualitative findings are incorporated into RCT designs. We conducted a community-based ethnography on social and structural factors that may affect the acceptance of and adherence to oral pre-exposure prophylaxis (PrEP) among Black men who have sex with men (BMSM). We then devised the treatment arm of an adherence clinical trial drawing on findings from the community-based ethnography. This article describes how ethnographic findings informed the RCT and identifies distilled themes and findings that could be included as part of an RCT. The enhanced intervention includes in-person support groups, online support groups, peer navigation, and text message reminders. By describing key process-related facilitators and barriers to conducting meaningful mixed methods research, we provide important insights for the practice of designing clinical trials for 'real-world' community settings. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Passing the Baton: Community-based ethnography to design a randomized clinical trial on the effectiveness of oral pre-exposure prophylaxis for HIV prevention among Black men who have sex with men

    PubMed Central

    Garcia, Jonathan; Colson, Paul W.; Parker, Caroline; Hirsch, Jennifer S.

    2015-01-01

    Although HIV interventions and clinical trials increasingly report the use of mixed methods, studies have not reported on the process through which ethnographic or qualitative findings are incorporated into RCT designs. We conducted a community-based ethnography on social and structural factors that may affect the acceptance of and adherence to oral pre-exposure prophylaxis (PrEP) among Black men who have sex with men (BMSM). We then devised the treatment arm of an adherence clinical trial drawing on findings from the community-based ethnography. This article describes how ethnographic findings informed the RCT and identifies distilled themes and findings that could be included as part of an RCT. The enhanced intervention includes in-person support groups, online support groups, peer navigation, and text message reminders. By describing key process-related facilitators and barriers to conducting meaningful mixed methods research, we provide important insights for the practice of designing clinical trials for ‘real-world’ community settings. PMID:26476286

  10. 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.

  11. Explaining the Efficacy of Pre-exposure Prophylaxis (PrEP) for HIV Prevention: A Qualitative Study of Message Framing and Messaging Preferences Among US Men Who have Sex with Men.

    PubMed

    Underhill, Kristen; Morrow, Kathleen M; Colleran, Christopher; Calabrese, Sarah K; Operario, Don; Salovey, Peter; Mayer, Kenneth H

    2016-07-01

    We investigated message comprehension and message framing preferences for communicating about PrEP efficacy with US MSM. We conducted eight focus groups (n = 38) and n = 56 individual interviews with MSM in Providence, RI. Facilitators probed comprehension, credibility, and acceptability of efficacy messages, including percentages, non-numerical paraphrases, efficacy ranges versus point estimates, and success- versus failure-framed messages. Our findings indicated a range of comprehension and operational understandings of efficacy messages. Participants tended to prefer percentage-based and success-framed messages, although preferences varied for communicating about efficacy using a single percentage versus a range. Participants reported uncertainty about how to interpret numerical estimates, and many questioned whether trial results would predict personal effectiveness. These results suggest that providers and researchers implementing PrEP may face challenges in communicating with users about efficacy. Efforts to educate MSM about PrEP should incorporate percentage-based information, and message framing decisions may influence message credibility and overall PrEP acceptability.

  12. Paradigms and strategies for scientific computing on distributed memory concurrent computers

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

    Foster, I.T.; Walker, D.W.

    1994-06-01

    In this work we examine recent advances in parallel languages and abstractions that have the potential for improving the programmability and maintainability of large-scale, parallel, scientific applications running on high performance architectures and networks. This paper focuses on Fortran M, a set of extensions to Fortran 77 that supports the modular design of message-passing programs. We describe the Fortran M implementation of a particle-in-cell (PIC) plasma simulation application, and discuss issues in the optimization of the code. The use of two other methodologies for parallelizing the PIC application are considered. The first is based on the shared object abstraction asmore » embodied in the Orca language. The second approach is the Split-C language. In Fortran M, Orca, and Split-C the ability of the programmer to control the granularity of communication is important is designing an efficient implementation.« less

  13. A pervasive parallel framework for visualization: final report for FWP 10-014707

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

    Moreland, Kenneth D.

    2014-01-01

    We are on the threshold of a transformative change in the basic architecture of highperformance computing. The use of accelerator processors, characterized by large core counts, shared but asymmetrical memory, and heavy thread loading, is quickly becoming the norm in high performance computing. These accelerators represent significant challenges in updating our existing base of software. An intrinsic problem with this transition is a fundamental programming shift from message passing processes to much more fine thread scheduling with memory sharing. Another problem is the lack of stability in accelerator implementation; processor and compiler technology is currently changing rapidly. This report documentsmore » the results of our three-year ASCR project to address these challenges. Our project includes the development of the Dax toolkit, which contains the beginnings of new algorithms for a new generation of computers and the underlying infrastructure to rapidly prototype and build further algorithms as necessary.« less

  14. A 3D staggered-grid finite difference scheme for poroelastic wave equation

    NASA Astrophysics Data System (ADS)

    Zhang, Yijie; Gao, Jinghuai

    2014-10-01

    Three dimensional numerical modeling has been a viable tool for understanding wave propagation in real media. The poroelastic media can better describe the phenomena of hydrocarbon reservoirs than acoustic and elastic media. However, the numerical modeling in 3D poroelastic media demands significantly more computational capacity, including both computational time and memory. In this paper, we present a 3D poroelastic staggered-grid finite difference (SFD) scheme. During the procedure, parallel computing is implemented to reduce the computational time. Parallelization is based on domain decomposition, and communication between processors is performed using message passing interface (MPI). Parallel analysis shows that the parallelized SFD scheme significantly improves the simulation efficiency and 3D decomposition in domain is the most efficient. We also analyze the numerical dispersion and stability condition of the 3D poroelastic SFD method. Numerical results show that the 3D numerical simulation can provide a real description of wave propagation.

  15. Regularization with numerical extrapolation for finite and UV-divergent multi-loop integrals

    NASA Astrophysics Data System (ADS)

    de Doncker, E.; Yuasa, F.; Kato, K.; Ishikawa, T.; Kapenga, J.; Olagbemi, O.

    2018-03-01

    We give numerical integration results for Feynman loop diagrams such as those covered by Laporta (2000) and by Baikov and Chetyrkin (2010), and which may give rise to loop integrals with UV singularities. We explore automatic adaptive integration using multivariate techniques from the PARINT package for multivariate integration, as well as iterated integration with programs from the QUADPACK package, and a trapezoidal method based on a double exponential transformation. PARINT is layered over MPI (Message Passing Interface), and incorporates advanced parallel/distributed techniques including load balancing among processes that may be distributed over a cluster or a network/grid of nodes. Results are included for 2-loop vertex and box diagrams and for sets of 2-, 3- and 4-loop self-energy diagrams with or without UV terms. Numerical regularization of integrals with singular terms is achieved by linear and non-linear extrapolation methods.

  16. 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.

  17. 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.

  18. 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.

  19. Degree sequence in message transfer

    NASA Astrophysics Data System (ADS)

    Yamuna, M.

    2017-11-01

    Message encryption is always an issue in current communication scenario. Methods are being devised using various domains. Graphs satisfy numerous unique properties which can be used for message transfer. In this paper, I propose a message encryption method based on degree sequence of graphs.

  20. 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.

  1. Promoting stair use: single versus multiple stair-riser messages.

    PubMed

    Webb, Oliver J; Eves, Frank F

    2005-09-01

    Message banners attached to stair risers produced a significant increase in pedestrian stair use, exceeding effects previously reported for conventional posters. Multiple instances of the same message banner, however, were as effective as banners featuring different messages. Therefore, greater visibility, rather than message variety, appears to account for the superiority of the banner format. Our findings indicate the feasibility of simple stair-use promotion campaigns based around the repetition of a single message.

  2. Feasibility and Acceptability of a Text Message-Based Smoking Cessation Program for Young Adults in Lima, Peru: Pilot Study

    PubMed Central

    Zevallos, Karine; Samolski, M Reuven; Requena, David; Velarde, Chaska; Briceño, Patricia; Piazza, Marina; Ybarra, Michele L

    2017-01-01

    Background In Peru’s urban communities, tobacco smoking generally starts during adolescence and smoking prevalence is highest among young adults. Each year, many attempt to quit, but access to smoking cessation programs is limited. Evidence-based text messaging smoking cessation programs are an alternative that has been successfully implemented in high-income countries, but not yet in middle- and low-income countries with limited tobacco control policies. Objective The objective was to assess the feasibility and acceptability of an short message service (SMS) text message-based cognitive behavioral smoking cessation program for young adults in Lima, Peru. Methods Recruitment included using flyers and social media ads to direct young adults interested in quitting smoking to a website where interested participants completed a Google Drive survey. Inclusion criteria were being between ages 18 and 25 years, smoking at least four cigarettes per day at least 6 days per week, willing to quit in the next 30 days, owning a mobile phone, using SMS text messaging at least once in past year, and residing in Lima. Participants joined one of three phases: (1) focus groups and in-depth interviews whose feedback was used to develop the SMS text messages, (2) validating the SMS text messages, and (3) a pilot of the SMS text message-based smoking cessation program to test its feasibility and acceptability among young adults in Lima. The outcome measures included adherence to the SMS text message-based program, acceptability of content, and smoking abstinence self-report on days 2, 7, and 30 after quitting. Results Of 639 participants who completed initial online surveys, 42 met the inclusion criteria and 35 agreed to participate (focus groups and interviews: n=12; validate SMS text messages: n=8; program pilot: n=15). Common quit practices and beliefs emerged from participants in the focus groups and interviews informed the content, tone, and delivery schedule of the messages used in the SMS text message smoking cessation program. A small randomized controlled pilot trial was performed to test the program’s feasibility and acceptability; nine smokers were assigned to the SMS text message smoking cessation program and six to a SMS text message nutrition program. Participant retention was high: 93% (14/15) remained until day 30 after quit day. In all, 56% of participants (5/9) in the SMS text message smoking cessation program reported remaining smoke-free until day 30 after quit day and 17% of participants (1/6) in the SMS text message nutrition program reported remaining smoke-free during the entire program. The 14 participants who completed the pilot reported that they received valuable health information and approved the delivery schedule of the SMS text messages. Conclusions This study provides initial evidence that a SMS text message smoking cessation program is feasible and acceptable for young adults residing in Lima. PMID:28778850

  3. 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

  4. Receptivity of African American Adolescents to an HIV-Prevention Curriculum Enhanced by Text Messaging

    PubMed Central

    Cornelius, Judith B.; St Lawrence, Janet S.

    2013-01-01

    PURPOSE This study assessed African American adolescents’ receptivity to an HIV-prevention curriculum enhanced by text messaging. DESIGN AND METHODS Two focus groups were conducted with 14 African American adolescents regarding how an HIV-prevention curriculum could be enhanced for text messaging delivery. RESULTS The adolescents were receptive to the idea of text messaging HIV-prevention information but wanted to receive a maximum of three messages per day during the hours of 4:00–6:00 p.m. PRACTICE IMPLICATIONS By taking the findings of this study, nurses, other healthcare providers, and community-based organizations can adapt evidence-based interventions for text messaging delivery to individuals at high risk for HIV infection. PMID:19356206

  5. Competing with big business: a randomised experiment testing the effects of messages to promote alcohol and sugary drink control policy.

    PubMed

    Scully, Maree; Brennan, Emily; Durkin, Sarah; Dixon, Helen; Wakefield, Melanie; Barry, Colleen L; Niederdeppe, Jeff

    2017-12-28

    Evidence-based policies encouraging healthy behaviours are often strongly opposed by well-funded industry groups. As public support is crucial for policy change, public health advocates need to be equipped with strategies to offset the impact of anti-policy messages. In this study, we aimed to investigate the effectiveness of theory-based public health advocacy messages in generating public support for sugary drink/alcohol policies (increased taxes; sport sponsorship bans) and improving resistance to subsequent anti-policy messages typical of the sugary drink/alcohol industry. We conducted a two-wave randomised online experiment assigning Australian adults to one of four health policies (sugary drink tax; sugary drink industry sports sponsorship ban; alcohol tax; alcohol industry sports sponsorship ban). Within each health policy, we randomised participants to one of five message conditions: (i) non-advocacy based message about the size and seriousness of the relevant health issue (control); (ii) standard pro-policy arguments alone; (iii) standard pro-policy arguments combined with an inoculation message (forewarning and directly refuting anti-policy arguments from the opposition); (iv) standard pro-policy arguments combined with a narrative message (a short, personal story about an individual's experience of the health issue); or (v) standard pro-policy arguments combined with a composite inoculation and narrative message. At time 1, we exposed participants (n = 6000) to their randomly assigned message. Around two weeks later, we re-contacted participants (n = 3285) and exposed them to an anti-policy message described as being from a representative of the sugary drink/alcohol industry. Generalised linear models tested for differences between conditions in policy support and anti-industry beliefs at both time points. Only the standard argument plus narrative message increased policy support relative to control at time 1. The standard argument plus narrative and standard argument plus inoculation messages were effective at increasing resistance to the persuasive impact of anti-policy messages relative to control at time 2. Dissemination of advocacy messages using inoculation or narrative components can help strengthen public resistance to subsequent anti-policy messages from industry groups.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Event-Based Stereo Depth Estimation Using Belief Propagation.

    PubMed

    Xie, Zhen; Chen, Shengyong; Orchard, Garrick

    2017-01-01

    Compared to standard frame-based cameras, biologically-inspired event-based sensors capture visual information with low latency and minimal redundancy. These event-based sensors are also far less prone to motion blur than traditional cameras, and still operate effectively in high dynamic range scenes. However, classical framed-based algorithms are not typically suitable for these event-based data and new processing algorithms are required. This paper focuses on the problem of depth estimation from a stereo pair of event-based sensors. A fully event-based stereo depth estimation algorithm which relies on message passing is proposed. The algorithm not only considers the properties of a single event but also uses a Markov Random Field (MRF) to consider the constraints between the nearby events, such as disparity uniqueness and depth continuity. The method is tested on five different scenes and compared to other state-of-art event-based stereo matching methods. The results show that the method detects more stereo matches than other methods, with each match having a higher accuracy. The method can operate in an event-driven manner where depths are reported for individual events as they are received, or the network can be queried at any time to generate a sparse depth frame which represents the current state of the network.

  12. The Allure of Privacy or the Desire for Self-Expression? Identifying Users' Gratifications for Ephemeral, Photograph-Based Communication.

    PubMed

    Waddell, T Franklin

    2016-07-01

    Temporary messaging programs continue to rise in popularity, due in large part to the perceived privacy that they afford. However, recent controversies have revealed that messages shared on ephemeral messaging services are persistent and potentially retrieval, thus undermining the privacy they are assumed to provide. Given this paradox, why are temporary messaging services so popular? Does the allure of privacy still motivate the use of temporary messaging programs? Or, if privacy is no longer afforded by ephemeral messaging, what other psychological gratifications do these applications fulfill that might account for their continued use? Informed by the Modality-Agency-Interactivity-Navigability (MAIN) model and the uses and gratifications tradition, the current study conducted qualitative interviews to identify the gratifications that individuals derive from the popular ephemeral messaging application, Snapchat. Study results show that the visual affordances of ephemeral messaging have legitimized photographic communication, providing self-expression and relational gratifications that are unfulfilled by text-based applications. By comparison, users report low levels of trust in the privacy affordances of ephemeral messaging, and instead projecting negative effects of temporary messaging on other users rather than self. Theoretical and practical implications of these results are discussed.

  13. 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.

  14. Application of a Tsunami Warning Message Metric to refine NOAA NWS Tsunami Warning Messages

    NASA Astrophysics Data System (ADS)

    Gregg, C. E.; Johnston, D.; Sorensen, J.; Whitmore, P.

    2013-12-01

    In 2010, the U.S. National Weather Service (NWS) funded a three year project to integrate social science into their Tsunami Program. One of three primary requirements of the grant was to make improvements to tsunami warning messages of the NWS' two Tsunami Warning Centers- the West Coast/Alaska Tsunami Warning Center (WCATWC) in Palmer, Alaska and the Pacific Tsunami Warning Center (PTWC) in Ewa Beach, Hawaii. We conducted focus group meetings with a purposive sample of local, state and Federal stakeholders and emergency managers in six states (AK, WA, OR, CA, HI and NC) and two US Territories (US Virgin Islands and American Samoa) to qualitatively asses information needs in tsunami warning messages using WCATWC tsunami messages for the March 2011 Tohoku earthquake and tsunami event. We also reviewed research literature on behavioral response to warnings to develop a tsunami warning message metric that could be used to guide revisions to tsunami warning messages of both warning centers. The message metric is divided into categories of Message Content, Style, Order and Formatting and Receiver Characteristics. A message is evaluated by cross-referencing the message with the operational definitions of metric factors. Findings are then used to guide revisions of the message until the characteristics of each factor are met. Using findings from this project and findings from a parallel NWS Warning Tiger Team study led by T. Nicolini, the WCATWC implemented the first of two phases of revisions to their warning messages in November 2012. A second phase of additional changes, which will fully implement the redesign of messages based on the metric, is in progress. The resulting messages will reflect current state-of-the-art knowledge on warning message effectiveness. Here we present the message metric; evidence-based rational for message factors; and examples of previous, existing and proposed messages.

  15. 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.

  16. Assessing college students' attitudes toward responsible drinking messages to identify promising binge drinking intervention strategies.

    PubMed

    Pilling, Valerie K; Brannon, Laura A

    2007-01-01

    Health communication appeals were utilized through a Web site simulation to evaluate the potential effectiveness of 3 intervention approaches to promote responsible drinking among college students. Within the Web site simulation, participants were exposed to a persuasive message designed to represent either the generalized social norms advertising approach (based on others' behavior), the personalized behavioral feedback approach (tailored to the individual's behavior), or the schema-based approach (tailored to the individual's self-schema, or personality). A control group was exposed to a message that was designed to be neutral (it was designed to discourage heavy drinking, but it did not represent any of the previously mentioned approaches). It was hypothesized that the more personalized the message was to the individual, the more favorable college students' attitudes would be toward the responsible drinking message. Participants receiving the more personalized messages did report more favorable attitudes toward the responsible drinking message.

  17. A Research Protocol to Test the Effectiveness of Text Messaging and Reminder Calls to Increase Service Use Referrals in a Community Engagement Program.

    PubMed

    Varma, Deepthi Satheesa; Hart, Mark; McIntyre, Denise Sonya; Kwiatkowski, Evan; Cottler, Linda Bauer

    2016-06-28

    Mobile phoned-based interventions have been increasingly used in clinical populations to improve health and health care delivery. The literature has shown that mobile phone-based text messages (short message service, SMS) are instantaneous, cost effective, and have less chance of being misplaced. Studies using mobile phone based-text messages have reported text messages as effective reminders that have resulted in increased appointment attendance, adherence to treatment, and better self-management. There have been no reports of adverse events when using text messaging in terms of misreading or misinterpreting data, transmitting inaccurate data, losing verbal or nonverbal communication cues, privacy issues, or failure or delay in message delivery. However, the literature has cited a need for personalized messages that are more responsive to individual needs. In addition, there has been a dearth of information on the use of reminders in nonclinical populations. The goal of this study is to assess the effectiveness of adding reminders in the form of text messaging versus reminder calls versus text messages and reminder calls to increase use of service referrals provided through community outreach. A total of 300 participants will be recruited for the study. Each participant will be randomized to one of three arms: a group that receives only reminder calls (CALLSONLY); a group that receives only text message reminders (TEXTONLY); and a group that receives both reminder calls and text messages (CALLS+TEXT). All groups will receive their reminder intervention on the 15th and 45th day after baseline when they receive medical and social service referrals from the community health workers (CHWs). A standard script will be used to administer the call and text reminders and a 15-item telephone-based satisfaction survey will be administered to assess the participant satisfaction with the process of receiving periodic reminders. The study is in the recruitment and follow-up phase. The authors anticipate completion of recruitment, interventions, and data entry by July 2016. Preliminary results are expected to be available by September 2016. This study will provide an opportunity to test the effectiveness of mobile-based interventions on nonclinical, community-recruited populations. In particular, such a protocol would increase the effectiveness of a community-based engagement program by instating a formal reminder system for all program members who receive social and/or medical service referrals during outreach in the community. Findings from this study would guide the development and implementation of reminder protocols for community-based engagement programs nationwide.

  18. Low Power LDPC Code Decoder Architecture Based on Intermediate Message Compression Technique

    NASA Astrophysics Data System (ADS)

    Shimizu, Kazunori; Togawa, Nozomu; Ikenaga, Takeshi; Goto, Satoshi

    Reducing the power dissipation for LDPC code decoder is a major challenging task to apply it to the practical digital communication systems. In this paper, we propose a low power LDPC code decoder architecture based on an intermediate message-compression technique which features as follows: (i) An intermediate message compression technique enables the decoder to reduce the required memory capacity and write power dissipation. (ii) A clock gated shift register based intermediate message memory architecture enables the decoder to decompress the compressed messages in a single clock cycle while reducing the read power dissipation. The combination of the above two techniques enables the decoder to reduce the power dissipation while keeping the decoding throughput. The simulation results show that the proposed architecture improves the power efficiency up to 52% and 18% compared to that of the decoder based on the overlapped schedule and the rapid convergence schedule without the proposed techniques respectively.

  19. Message propagation in the network based on node credibility

    NASA Astrophysics Data System (ADS)

    Nian, Fuzhong; Dang, Zhongkai

    2018-04-01

    In the propagation efficiency point of view, the node credibility is introduced in this paper. For the message receiver, the node would partially believe the message according to the credibility of the propagator. For a node, the credibility is variable. The more the true message spread, the higher the credibility, and vice versa, the credibility becomes smaller. Based on the idea, a new network was established with the node credibility. Finally, a comparing experiment between the fully trusted network and the network with the node credibility was implemented. The results indicate that the spread effect of messages is better in the network with the node credibility.

  20. Views of Somali women and men on the use of faith-based messages promoting breast and cervical cancer screening for Somali women: a focus-group study.

    PubMed

    Pratt, Rebekah; Mohamed, Sharif; Dirie, Wali; Ahmed, Nimo; VanKeulen, Michael; Ahmed, Huda; Raymond, Nancy; Okuyemi, Kola

    2017-03-20

    Screening rates for breast and cervical cancer for Muslim women in the United States are low, particularly for first-generation immigrants. Interpretations of the Muslim faith represent some of the barriers for breast and cervical cancer screening. Working to understand how faith influences breast and cervical screening for Somali women, and working with the community to identify and utilize faith-based assets for promoting screening, may lead to life-saving changes in screening behaviors. We partnered with an Imam to develop faith-based messages addressing the concerns of modesty and predetermination and promoting cancer testing and screening. A total of five focus groups were convened, with 34 Somali women (three groups) and 20 Somali men (two groups). Each focus group first discussed participant views of breast and cervical cancer screening in general and then viewed and discussed video clips of the Imam delivering the faith-based messages. Both Somali women and men had an overwhelmingly positive response to the faith-based messages promoting breast and cervical cancer screening. The faith-based messages appeared to reinforce the views of those who were already inclined to see screening positively, with participants describing increased confidence to engage in screening. For those who had reservations about screening, there was feedback that the faith-based messages had meaningfully influenced their views. Somali immigrant women and men found faith-based messages addressing topics of predestination and modesty and encouraging the use of screening and treatment to be both acceptable and influential. Faith can play an important role as an asset to promote breast and cervical cancer screening, and there may be substantial benefits to adding faith-based messaging to other interventions that focus on improving screening uptake. This may help to address health disparities for Somali women in this area.

  1. 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.

  2. 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.

  3. [The scientific information that the pharmaceutical industry provides to family doctors].

    PubMed

    Rivera Casares, F; Richart Rufino, M J; Navas Cutanda, J; Rodríguez Górriz, E; Gómez Moruno, C; Gómez García, B

    2005-06-15

    To check whether the information in the written publicity that the pharmaceutical industry gives to family doctors really is based on the scientific studies that support it. Cross-sectional study. Health centre on the outskirts of a big city. Over a year, all the scientific studies that laboratory reps gave family doctors along with the advertising for medicines were collected. A total of 63 paired studies and advertising pieces were obtained. 1-3 advertising messages with each supporting study were selected and reviewed in a structured fashion. Then whether or not the messages selected were based on the study was appraised. 44.5% of the advertising messages were not based on the accompanying study; 29.9% clearly were based on the study; and in the rest there was a half-and-half relationship. There was a significant relationship between the evaluation of the advertising messages and the kind of study, masking and the kind of result variable. A high proportion of advertising messages are not based on the study that is reputed to support them. A critique of these studies has to be undertaken before the advertising messages can be looked at.

  4. How effective are messages and their characteristics in changing behavioural intentions to substitute plant-based foods for red meat? The mediating role of prior beliefs.

    PubMed

    Vainio, Annukka; Irz, Xavier; Hartikainen, Hanna

    2018-06-01

    By means of a population-based survey experiment, we analysed the effectiveness of two message characteristics - message framing and the refutation of misinformation - in persuading respondents to reduce their consumption of red meat and increase that of plant-based alternatives. We also tested whether the effects of those two message characteristics were moderated by prior beliefs about the health and climate impacts of red meat consumption. The data were collected with an online survey of the adult population living in Finland (N = 1279). We found that messages had a small but desired effect on intentions when the effect of prior beliefs was taken into account, but that that effect was strongly moderated by prior beliefs. In particular, messages changed behavioural intentions among the "meat-sceptics" (i.e., those believing relatively strongly in the negative health and climate effects of meat consumption) but not among the "meat believers" (defined symmetrically). The combination of frames and refutation of misinformation were not found to be more effective strategies than the provision of information through single-framed, one-sided messages. We found limited evidence that the way a message was formulated determined its effectiveness in changing behaviours. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Designing Anti-Binge Drinking Prevention Messages: Message Framing vs. Evidence Type.

    PubMed

    Kang, Hannah; Lee, Moon J

    2017-09-27

    We investigated whether presenting anti-binge drinking health campaign messages in different message framing and evidence types influences college students' intention to avoid binge drinking, based on prospect theory (PT) and exemplification theory. A 2 (message framing: loss-framed message/gain-framed message) X 2 (evidence type: statistical/narrative) between-subjects factorial design with a control group was conducted with 156 college students. College students who were exposed to the loss-framed message condition exhibited a higher level of intention to avoid binge drinking in the near future than those who did not see any messages (the control group). This finding was mainly among non-binge drinkers. Regardless of evidence type, those who were exposed to the messages exhibited a higher level of intention to avoid binge drinking than those in the control group. This is also mainly among non-binge drinkers. We also found the main effects of message framing and evidence type on attitude toward the message and the main effect of message framing on attitude toward drinking.

  6. Rapid Growth in Surgeons’ Use of Secure Messaging in a Patient Portal

    PubMed Central

    Shenson, Jared A.; Cronin, Robert M.; Davis, Sharon E.; Chen, Qingxia; Jackson, Gretchen Purcell

    2016-01-01

    Background Use of secure messaging through patient portals has risen substantially in recent years due to provider incentives and consumer demand. Secure messaging may increase patient satisfaction and improve outcomes, but also adds to physician workload. Most prior studies of secure messaging focused on primary care and medical specialties. We examined surgeons’ use of secure messaging and the contribution of messaging to outpatient interactions in a broadly-deployed patient portal. Methods We determined the number of clinic visits and secure messages for surgical providers in the first three years (2008–10) after patient portal deployment at an academic medical center. We calculated the proportion of outpatient interaction conducted through messaging for each specialty. Logistic regression models compared the likelihood of message-based versus clinic outpatient interaction across surgical specialties. Results Over the study period, surgical providers delivered care in 648,200 clinic visits and received 83,912 messages, with more than 200% growth in monthly message volume. Surgical specialties receiving the most messages were orthopedics/podiatry (25.1%), otolaryngology (20.1%), urology (10.8%), and general surgery (9.6%); vascular surgery (0.8%) and pediatric general surgery (0.2%) received the fewest. The proportion of outpatient interactions conducted through secure messaging increased significantly from 5.4% in 2008 to 15.3% in 2010 (p<0.001) with all specialties experiencing growth. Heart/lung transplantation (74.9%), liver/kidney/pancreas transplantation (69.5%), and general surgery (48.7%) had the highest proportion of message-based outpatient interaction by the end of the study. Conclusions This study demonstrates rapid adoption of online secure messaging across surgical specialties with significant growth in its use for outpatient interaction. Some specialties, particularly those with long-term follow-up, interacted with patients more through secure messaging than in person. As surgeons devote more time to secure messaging, additional research will be needed to understand the care delivered through online interactions and to develop models for reimbursement. PMID:26123340

  7. Developing anti-tobacco messages for Australian Aboriginal and Torres Strait Islander peoples: evidence from a national cross-sectional survey.

    PubMed

    Gould, Gillian S; Watt, Kerrianne; Stevenson, Leah; McEwen, Andy; Cadet-James, Yvonne; Clough, Alan R

    2014-03-13

    Smoking rates in Australian Aboriginal and Torres Strait Islander peoples remain high, with limited impact of government measures for many subgroups. The aim of this cross-sectional study was to investigate differences in organisational practice for developing anti-tobacco messages for these target populations. Telephone interviews were conducted with 47 organisation representatives using a structured questionnaire based on health communication and health promotion frameworks. Responses were coded into phases of message development, message types (educational, threat, positive or advocacy), target groups, message recommendations, and evaluations undertaken. Cultural sensitivity for message development was divided into surface structure (use of images, language, demographics) and deep structure (use of socio-cultural values). A categorical principal component analysis explored the key dimensions of the findings and their component relationships. Among organisations interviewed, a community-orientated, bottom-up approach for developing anti-tobacco messages was reported by 47% (n=24); 55% based message development on a theoretical framework; 87% used a positive benefit appeal; 38% used threat messages. More Aboriginal Medical Services (AMSs) targeted youth (p<0.005) and advised smokers to quit (p<0.05) than other types of organisations. AMSs were significantly more likely to report using deep structure in tailoring messages compared with non-government (p<0.05) and government organisations (p<0.05). Organisations that were oriented to the general population were more likely to evaluate their programs (p<0.05). A two-dimensional non-linear principal component analysis extracted components interpreted as "cultural understanding" (bottom-up, community-based approaches, deep structures) and "rigour" (theoretical frameworks, and planned/completed evaluations), and accounted for 53% of the variability in the data. Message features, associated with successful campaigns in other populations, are starting to be used for Aboriginal and Torres Strait Islander peoples. A model is proposed to facilitate the development of targeted anti-tobacco messages for Aboriginal and Torres Strait Islander peoples. Organisations could consider incorporating both components of cultural understanding-rigour to enable the growth of evidence-based practice.

  8. Developing anti-tobacco messages for Australian Aboriginal and Torres Strait Islander peoples: evidence from a national cross-sectional survey

    PubMed Central

    2014-01-01

    Background Smoking rates in Australian Aboriginal and Torres Strait Islander peoples remain high, with limited impact of government measures for many subgroups. The aim of this cross-sectional study was to investigate differences in organisational practice for developing anti-tobacco messages for these target populations. Methods Telephone interviews were conducted with 47 organisation representatives using a structured questionnaire based on health communication and health promotion frameworks. Responses were coded into phases of message development, message types (educational, threat, positive or advocacy), target groups, message recommendations, and evaluations undertaken. Cultural sensitivity for message development was divided into surface structure (use of images, language, demographics) and deep structure (use of socio-cultural values). A categorical principal component analysis explored the key dimensions of the findings and their component relationships. Results Among organisations interviewed, a community-orientated, bottom-up approach for developing anti-tobacco messages was reported by 47% (n = 24); 55% based message development on a theoretical framework; 87% used a positive benefit appeal; 38% used threat messages. More Aboriginal Medical Services (AMSs) targeted youth (p < 0.005) and advised smokers to quit (p < 0.05) than other types of organisations. AMSs were significantly more likely to report using deep structure in tailoring messages compared with non-government (p < 0.05) and government organisations (p < 0.05). Organisations that were oriented to the general population were more likely to evaluate their programs (p < 0.05). A two-dimensional non-linear principal component analysis extracted components interpreted as “cultural understanding” (bottom-up, community-based approaches, deep structures) and “rigour” (theoretical frameworks, and planned/completed evaluations), and accounted for 53% of the variability in the data. Conclusion Message features, associated with successful campaigns in other populations, are starting to be used for Aboriginal and Torres Strait Islander peoples. A model is proposed to facilitate the development of targeted anti-tobacco messages for Aboriginal and Torres Strait Islander peoples. Organisations could consider incorporating both components of cultural understanding-rigour to enable the growth of evidence-based practice. PMID:24625235

  9. 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.

  10. 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.

  11. An Evaluation of Two Methods for Generating Synthetic HL7 Segments Reflecting Real-World Health Information Exchange Transactions

    PubMed Central

    Mwogi, Thomas S.; Biondich, Paul G.; Grannis, Shaun J.

    2014-01-01

    Motivated by the need for readily available data for testing an open-source health information exchange platform, we developed and evaluated two methods for generating synthetic messages. The methods used HL7 version 2 messages obtained from the Indiana Network for Patient Care. Data from both methods were analyzed to assess how effectively the output reflected original ‘real-world’ data. The Markov Chain method (MCM) used an algorithm based on transitional probability matrix while the Music Box model (MBM) randomly selected messages of particular trigger type from the original data to generate new messages. The MBM was faster, generated shorter messages and exhibited less variation in message length. The MCM required more computational power, generated longer messages with more message length variability. Both methods exhibited adequate coverage, producing a high proportion of messages consistent with original messages. Both methods yielded similar rates of valid messages. PMID:25954458

  12. 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

  13. SmartVeh: Secure and Efficient Message Access Control and Authentication for Vehicular Cloud Computing.

    PubMed

    Huang, Qinlong; Yang, Yixian; Shi, Yuxiang

    2018-02-24

    With the growing number of vehicles and popularity of various services in vehicular cloud computing (VCC), message exchanging among vehicles under traffic conditions and in emergency situations is one of the most pressing demands, and has attracted significant attention. However, it is an important challenge to authenticate the legitimate sources of broadcast messages and achieve fine-grained message access control. In this work, we propose SmartVeh, a secure and efficient message access control and authentication scheme in VCC. A hierarchical, attribute-based encryption technique is utilized to achieve fine-grained and flexible message sharing, which ensures that vehicles whose persistent or dynamic attributes satisfy the access policies can access the broadcast message with equipped on-board units (OBUs). Message authentication is enforced by integrating an attribute-based signature, which achieves message authentication and maintains the anonymity of the vehicles. In order to reduce the computations of the OBUs in the vehicles, we outsource the heavy computations of encryption, decryption and signing to a cloud server and road-side units. The theoretical analysis and simulation results reveal that our secure and efficient scheme is suitable for VCC.

  14. SmartVeh: Secure and Efficient Message Access Control and Authentication for Vehicular Cloud Computing

    PubMed Central

    Yang, Yixian; Shi, Yuxiang

    2018-01-01

    With the growing number of vehicles and popularity of various services in vehicular cloud computing (VCC), message exchanging among vehicles under traffic conditions and in emergency situations is one of the most pressing demands, and has attracted significant attention. However, it is an important challenge to authenticate the legitimate sources of broadcast messages and achieve fine-grained message access control. In this work, we propose SmartVeh, a secure and efficient message access control and authentication scheme in VCC. A hierarchical, attribute-based encryption technique is utilized to achieve fine-grained and flexible message sharing, which ensures that vehicles whose persistent or dynamic attributes satisfy the access policies can access the broadcast message with equipped on-board units (OBUs). Message authentication is enforced by integrating an attribute-based signature, which achieves message authentication and maintains the anonymity of the vehicles. In order to reduce the computations of the OBUs in the vehicles, we outsource the heavy computations of encryption, decryption and signing to a cloud server and road-side units. The theoretical analysis and simulation results reveal that our secure and efficient scheme is suitable for VCC. PMID:29495269

  15. Creating and testing regulatory focus messages to enhance medication adherence.

    PubMed

    O'Connor, Ashley; Ladebue, Amy; Peterson, Jamie; Davis, Ryan; Jung Grant, Susan; McCreight, Marina; Lambert-Kerzner, Anne

    2018-01-01

    Objectives Strategies were explored to improve patient adherence to cardioprotective medications by borrowing from a motivational framework used in psychology, regulatory focus theory. The current study is part of a larger randomized control trial and was aimed at understanding what written educational messages, based on patients' regulatory focus tendency, resonated with each individual as a potential reminder to take medications. This study was also aimed at understanding why messages resonated with the patients. Methods Twenty veterans were tested for regulatory fitand presented with messages dependent on focus tendency. In-person semi-structured interviews were conducted to collect feedback of messages. An iterative analysis drawing primarily on matrix and reflexive team analyses was conducted. Result Six promotion and six prevention messages emerged, such as "team up with your provider to create a combination of medications to prevent illness" and "Live your best life - Take your medications". Five themes related to types of health messages that spoke to patients' regulatory fit were discovered: relatability; empowerment and control; philosophy on life; relationship with provider and medications; and vocabulary effect on the impact of messages. Discussion Motivational messages based on regulatory fit may be useful in improving patient medication adherence, leading to improved cardiovascular outcomes.

  16. 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.

  17. 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.

  18. 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…

  19. Use of Qualitative Research to Inform Development of Nutrition Messages for Low-Income Mothers of Preschool Children

    ERIC Educational Resources Information Center

    White, Alicie H.; Wilson, Judy F.; Burns, Adam; Blum-Kemelor, Donna; Singh, Anita; Race, Patricia O.; Soto, Valery; Lockett, Alice F.

    2011-01-01

    Objective: To develop and test nutrition messages and supporting content with low-income mothers for use with theory-based interventions addressing fruit and vegetable consumption and child-feeding practices. Design: Six formative and 6 evaluative focus groups explored message concepts and tested messages, respectively. Setting: Research…

  20. Computer-Supported Feedback Message Tailoring for Healthcare Providers in Malawi: Proof-of-Concept.

    PubMed

    Landis-Lewis, Zach; Douglas, Gerald P; Hochheiser, Harry; Kam, Matthew; Gadabu, Oliver; Bwanali, Mwatha; Jacobson, Rebecca S

    2015-01-01

    Although performance feedback has the potential to help clinicians improve the quality and safety of care, healthcare organizations generally lack knowledge about how this guidance is best provided. In low-resource settings, tools for theory-informed feedback tailoring may enhance limited clinical supervision resources. Our objectives were to establish proof-of-concept for computer-supported feedback message tailoring in Malawi, Africa. We conducted this research in five stages: clinical performance measurement, modeling the influence of feedback on antiretroviral therapy (ART) performance, creating a rule-based message tailoring process, generating tailored messages for recipients, and finally analysis of performance and message tailoring data. We retrospectively generated tailored messages for 7,448 monthly performance reports from 11 ART clinics. We found that tailored feedback could be routinely generated for four guideline-based performance indicators, with 35% of reports having messages prioritized to optimize the effect of feedback. This research establishes proof-of-concept for a novel approach to improving the use of clinical performance feedback in low-resource settings and suggests possible directions for prospective evaluations comparing alternative designs of feedback messages.

  1. A cryptographic hash function based on chaotic network automata

    NASA Astrophysics Data System (ADS)

    Machicao, Jeaneth; Bruno, Odemir M.

    2017-12-01

    Chaos theory has been used to develop several cryptographic methods relying on the pseudo-random properties extracted from simple nonlinear systems such as cellular automata (CA). Cryptographic hash functions (CHF) are commonly used to check data integrity. CHF “compress” arbitrary long messages (input) into much smaller representations called hash values or message digest (output), designed to prevent the ability to reverse the hash values into the original message. This paper proposes a chaos-based CHF inspired on an encryption method based on chaotic CA rule B1357-S2468. Here, we propose an hybrid model that combines CA and networks, called network automata (CNA), whose chaotic spatio-temporal outputs are used to compute a hash value. Following the Merkle and Damgård model of construction, a portion of the message is entered as the initial condition of the network automata, so that the rest parts of messages are iteratively entered to perturb the system. The chaotic network automata shuffles the message using flexible control parameters, so that the generated hash value is highly sensitive to the message. As demonstrated in our experiments, the proposed model has excellent pseudo-randomness and sensitivity properties with acceptable performance when compared to conventional hash functions.

  2. Validation of persuasive messages for the promotion of physical activity among people with coronary heart disease.

    PubMed

    Mendez, Roberto Della Rosa; Rodrigues, Roberta Cunha Matheus; Spana, Thaís Moreira; Cornélio, Marília Estevam; Gallani, Maria Cecília Bueno Jayme; Pérez-Nebra, Amalia Raquel

    2012-01-01

    to validate the content of persuasive messages for promoting walking among patients with coronary heart disease (CHD). The messages were constructed to strengthen or change patients' attitudes to walking. the selection of persuasive arguments was based on behavioral beliefs (determinants of attitude) related to walking. The messages were constructed based in the Elaboration Likelihood Model and were submitted to content validation. the data was analyzed with the content validity index and by the importance which the patients attributed to the messages' persuasive arguments. Positive behavioral beliefs (i.e. positive and negative reinforcement) and self-efficacy were the appeals which the patients considered important. The messages with validation evidence will be tested in an intervention study for the promotion of the practice of physical activity among patients with CHD.

  3. Predictive Validity of an Empirical Approach for Selecting Promising Message Topics: A Randomized-Controlled Study

    PubMed Central

    Lee, Stella Juhyun; Brennan, Emily; Gibson, Laura Anne; Tan, Andy S. L.; Kybert-Momjian, Ani; Liu, Jiaying; Hornik, Robert

    2016-01-01

    Several message topic selection approaches propose that messages based on beliefs pretested and found to be more strongly associated with intentions will be more effective in changing population intentions and behaviors when used in a campaign. This study aimed to validate the underlying causal assumption of these approaches which rely on cross-sectional belief–intention associations. We experimentally tested whether messages addressing promising themes as identified by the above criterion were more persuasive than messages addressing less promising themes. Contrary to expectations, all messages increased intentions. Interestingly, mediation analyses showed that while messages deemed promising affected intentions through changes in targeted promising beliefs, messages deemed less promising also achieved persuasion by influencing nontargeted promising beliefs. Implications for message topic selection are discussed. PMID:27867218

  4. CDC MessageWorks: Designing and Validating a Social Marketing Tool to Craft and Defend Effective Messages.

    PubMed

    Cole, Galen E; Keller, Punam A; Reynolds, Jennifer; Schaur, Michelle; Krause, Diane

    2016-03-01

    The Centers for Disease Control and Prevention's Division of Cancer Prevention and Control, in partnership with Oak Ridge Associated Universities, designed an online social marketing strategy tool, MessageWorks, to help health communicators effectively formulate messages aimed at changing health behaviors and evaluate message tactics and audience characteristics. MessageWorks is based on the advisor for risk communication model that identifies 10 variables that can be used to predict target audience intentions to comply with health recommendations. This article discusses the value of the MessageWorks tool to health communicators and to the field of social marketing by (1) describing the scientific evidence supporting use of MessageWorks to improve health communication practice and (2) summarizing how to use MessageWorks and interpret the results it produces.

  5. "Obesity is a disease": examining the self-regulatory impact of this public-health message.

    PubMed

    Hoyt, Crystal L; Burnette, Jeni L; Auster-Gussman, Lisa

    2014-04-01

    In the current work, we examined the impact of the American Medical Association's recent classification of obesity as a disease on weight-management processes. Across three experimental studies, we highlighted the potential hidden costs associated with labeling obesity as a disease, showing that this message, presented in an actual New York Times article, undermined beneficial weight-loss self-regulatory processes. A disease-based, relative to an information-based, weight-management message weakened the importance placed on health-focused dieting and reduced concerns about weight among obese individuals--the very people whom such public-health messages are targeting. Further, the decreased concern about weight predicted higher-calorie food choices. In addition, the disease message, relative to a message that obesity is not a disease, lowered body-image dissatisfaction, but this too predicted higher-calorie food choices. Thus, although defining obesity as a disease may be beneficial for body image, results from the current work emphasize the negative implications of this message for self-regulation.

  6. The message development tool: a case for effective operationalization of messaging in social marketing practice.

    PubMed

    Mattson, Marifran; Basu, Ambar

    2010-07-01

    That messages are essential, if not the most critical component of any communicative process, seems like an obvious claim. More so when the communication is about health--one of the most vital and elemental of human experiences (Babrow & Mattson, 2003). Any communication campaign that aims to change a target audience's health behaviors needs to centralize messages. Even though messaging strategies are an essential component of social marketing and are a widely used campaign model, health campaigns based on this framework have not always been able to effectively operationalize this key component, leading to cases where initiating and sustaining prescribed health behavior has been difficult (MacStravic, 2000). Based on an examination of the VERB campaign and an Australian breastfeeding promotion campaign, we propose a message development tool within the ambit of the social marketing framework that aims to extend the framework and ensure that the messaging component of the model is contextualized at the core of planning, implementation, and evaluation efforts.

  7. Parallel SOR methods with a parabolic-diffusion acceleration technique for solving an unstructured-grid Poisson equation on 3D arbitrary geometries

    NASA Astrophysics Data System (ADS)

    Zapata, M. A. Uh; Van Bang, D. Pham; Nguyen, K. D.

    2016-05-01

    This paper presents a parallel algorithm for the finite-volume discretisation of the Poisson equation on three-dimensional arbitrary geometries. The proposed method is formulated by using a 2D horizontal block domain decomposition and interprocessor data communication techniques with message passing interface. The horizontal unstructured-grid cells are reordered according to the neighbouring relations and decomposed into blocks using a load-balanced distribution to give all processors an equal amount of elements. In this algorithm, two parallel successive over-relaxation methods are presented: a multi-colour ordering technique for unstructured grids based on distributed memory and a block method using reordering index following similar ideas of the partitioning for structured grids. In all cases, the parallel algorithms are implemented with a combination of an acceleration iterative solver. This solver is based on a parabolic-diffusion equation introduced to obtain faster solutions of the linear systems arising from the discretisation. Numerical results are given to evaluate the performances of the methods showing speedups better than linear.

  8. Performance Analysis of a Hybrid Overset Multi-Block Application on Multiple Architectures

    NASA Technical Reports Server (NTRS)

    Djomehri, M. Jahed; Biswas, Rupak

    2003-01-01

    This paper presents a detailed performance analysis of a multi-block overset grid compu- tational fluid dynamics app!ication on multiple state-of-the-art computer architectures. The application is implemented using a hybrid MPI+OpenMP programming paradigm that exploits both coarse and fine-grain parallelism; the former via MPI message passing and the latter via OpenMP directives. The hybrid model also extends the applicability of multi-block programs to large clusters of SNIP nodes by overcoming the restriction that the number of processors be less than the number of grid blocks. A key kernel of the application, namely the LU-SGS linear solver, had to be modified to enhance the performance of the hybrid approach on the target machines. Investigations were conducted on cacheless Cray SX6 vector processors, cache-based IBM Power3 and Power4 architectures, and single system image SGI Origin3000 platforms. Overall results for complex vortex dynamics simulations demonstrate that the SX6 achieves the highest performance and outperforms the RISC-based architectures; however, the best scaling performance was achieved on the Power3.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. FAST: a framework for simulation and analysis of large-scale protein-silicon biosensor circuits.

    PubMed

    Gu, Ming; Chakrabartty, Shantanu

    2013-08-01

    This paper presents a computer aided design (CAD) framework for verification and reliability analysis of protein-silicon hybrid circuits used in biosensors. It is envisioned that similar to integrated circuit (IC) CAD design tools, the proposed framework will be useful for system level optimization of biosensors and for discovery of new sensing modalities without resorting to laborious fabrication and experimental procedures. The framework referred to as FAST analyzes protein-based circuits by solving inverse problems involving stochastic functional elements that admit non-linear relationships between different circuit variables. In this regard, FAST uses a factor-graph netlist as a user interface and solving the inverse problem entails passing messages/signals between the internal nodes of the netlist. Stochastic analysis techniques like density evolution are used to understand the dynamics of the circuit and estimate the reliability of the solution. As an example, we present a complete design flow using FAST for synthesis, analysis and verification of our previously reported conductometric immunoassay that uses antibody-based circuits to implement forward error-correction (FEC).

  14. LBMD : a layer-based mesh data structure tailored for generic API infrastructures.

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

    Ebeida, Mohamed S.; Knupp, Patrick Michael

    2010-11-01

    A new mesh data structure is introduced for the purpose of mesh processing in Application Programming Interface (API) infrastructures. This data structure utilizes a reduced mesh representation to increase its ability to handle significantly larger meshes compared to full mesh representation. In spite of the reduced representation, each mesh entity (vertex, edge, face, and region) is represented using a unique handle, with no extra storage cost, which is a crucial requirement in most API libraries. The concept of mesh layers makes the data structure more flexible for mesh generation and mesh modification operations. This flexibility can have a favorable impactmore » in solver based queries of finite volume and multigrid methods. The capabilities of LBMD make it even more attractive for parallel implementations using Message Passing Interface (MPI) or Graphics Processing Units (GPUs). The data structure is associated with a new classification method to relate mesh entities to their corresponding geometrical entities. The classification technique stores the related information at the node level without introducing any ambiguities. Several examples are presented to illustrate the strength of this new data structure.« less

  15. Alcohol Messages in Prime-Time Television Series

    PubMed Central

    RUSSELL, CRISTEL ANTONIA; RUSSELL, DALE W.

    2010-01-01

    Alcohol messages contained in television programming serve as sources of information about drinking. To better understand the ways embedded messages about alcohol are communicated, it is crucial to objectively monitor and analyze television alcohol depictions. This article presents a content analysis of an eight-week sample of eighteen prime-time programs. Alcohol messages were coded based on modalities of presentation, level of plot connection, and valence. The analysis reveals that mixed messages about alcohol often coexist but the ways in which they are presented differ: whereas negative messages are tied to the plot and communicated verbally, positive messages are associated with subtle visual portrayals. PMID:21188281

  16. 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.

  17. A Comparison Between Phone-Based Psychotherapy With and Without Text Messaging Support In Between Sessions for Crisis Patients

    PubMed Central

    2014-01-01

    Background Few studies have tested whether individually tailored text messaging interventions have an effect on clinical outcomes when used to supplement traditional psychotherapy. This is despite the potential to improve outcomes through symptom monitoring, prompts for between-session activities, and psychoeducation. Objective The intent of the study was to explore the use of individually tailored between-session text messaging, or short message service (SMS), as an adjunct to telephone-based psychotherapy for consumers who present to the Emergency Department (ED) in situational and/or emotional crises. Methods Over a 4-month period, two therapists offered 68 prospective consumers of a telephone-based psychotherapy service individually tailored between-session text messaging alongside their telephone-based psychotherapy. Attendance and clinical outcomes (depression, anxiety, functional impairment) of those receiving messages were compared against a historical control group (n=157) who received telephone psychotherapy only. Results A total of 66% (45/68) of the consumers offered SMS accepted the intervention. A total of 432 messages were sent over the course of the trial, the majority involving some kind of psychoeducation or reminders to engage in therapy goals. There were no significant differences in clinical outcomes between consumers who received the SMS and those in the control group. There was a trend for participants in the intervention group to attend fewer sessions than those in the control group (mean 3.7, SD 1.9 vs mean 4.4, SD 2.3). Conclusions Both groups showed significant improvement over time. Individually tailored SMS were not found to improve clinical outcomes in consumers receiving telephone-based psychotherapy, but the study was underpowered, given the effect sizes noted and the significance level chosen. Given the ease of implementation and positive feedback from therapists and clients, individually tailored text messages should be explored further in future trials with a focus on enhancing the clinical impact of the tailored text messages, and utilizing designs with additional power to test for between-group effects. PMID:25295667

  18. A comparison between phone-based psychotherapy with and without text messaging support in between sessions for crisis patients.

    PubMed

    Furber, Gareth; Jones, Gabrielle Margaret; Healey, David; Bidargaddi, Niranjan

    2014-10-08

    Few studies have tested whether individually tailored text messaging interventions have an effect on clinical outcomes when used to supplement traditional psychotherapy. This is despite the potential to improve outcomes through symptom monitoring, prompts for between-session activities, and psychoeducation. The intent of the study was to explore the use of individually tailored between-session text messaging, or short message service (SMS), as an adjunct to telephone-based psychotherapy for consumers who present to the Emergency Department (ED) in situational and/or emotional crises. Over a 4-month period, two therapists offered 68 prospective consumers of a telephone-based psychotherapy service individually tailored between-session text messaging alongside their telephone-based psychotherapy. Attendance and clinical outcomes (depression, anxiety, functional impairment) of those receiving messages were compared against a historical control group (n=157) who received telephone psychotherapy only. A total of 66% (45/68) of the consumers offered SMS accepted the intervention. A total of 432 messages were sent over the course of the trial, the majority involving some kind of psychoeducation or reminders to engage in therapy goals. There were no significant differences in clinical outcomes between consumers who received the SMS and those in the control group. There was a trend for participants in the intervention group to attend fewer sessions than those in the control group (mean 3.7, SD 1.9 vs mean 4.4, SD 2.3). Both groups showed significant improvement over time. Individually tailored SMS were not found to improve clinical outcomes in consumers receiving telephone-based psychotherapy, but the study was underpowered, given the effect sizes noted and the significance level chosen. Given the ease of implementation and positive feedback from therapists and clients, individually tailored text messages should be explored further in future trials with a focus on enhancing the clinical impact of the tailored text messages, and utilizing designs with additional power to test for between-group effects.

  19. Optimising text messaging to improve adherence to web-based smoking cessation treatment: a randomised control trial protocol

    PubMed Central

    Graham, Amanda L; Jacobs, Megan A; Cohn, Amy M; Cha, Sarah; Abroms, Lorien C; Papandonatos, George D; Whittaker, Robyn

    2016-01-01

    Introduction Millions of smokers use the Internet for smoking cessation assistance each year; however, most smokers engage minimally with even the best designed websites. The ubiquity of mobile devices and their effectiveness in promoting adherence in other areas of health behaviour change make them a promising tool to address adherence in Internet smoking cessation interventions. Text messaging is used by most adults, and messages can proactively encourage use of a web-based intervention. Text messaging can also be integrated with an Internet intervention to facilitate the use of core Internet intervention components. Methods and analysis We identified four aspects of a text message intervention that may enhance its effectiveness in promoting adherence to a web-based smoking cessation programme: personalisation, integration, dynamic tailoring and message intensity. Phase I will use a two-level full factorial design to test the impact of these four experimental features on adherence to a web-based intervention. The primary outcome is a composite metric of adherence that incorporates general utilisation metrics (eg, logins, page views) and specific feature utilisation shown to predict abstinence. Participants will be N=860 adult smokers who register on an established Internet cessation programme and enrol in its text message programme. Phase II will be a two-arm randomised trial to compare the efficacy of the web-based cessation programme alone and in conjunction with the optimised text messaging intervention on 30-day point prevalence abstinence at 9 months. Phase II participants will be N=600 adult smokers who register to use an established Internet cessation programme and enrol in text messaging. Secondary analyses will explore whether adherence mediates the effect of treatment condition on outcome. Ethics and dissemination This protocol was approved by Chesapeake IRB. We will disseminate study results through peer-reviewed manuscripts and conference presentations related to the methods and design, outcomes and exploratory analyses. Trial registration number NCT02585206. PMID:27029775

  20. Development of a replicable process for translating science into practical health education messages.

    PubMed

    Tyus, Nadra C; Freeman, Randall J; Gibbons, M Christopher

    2006-09-01

    There has been considerable discussion about translating science into practical messages, especially among urban minority and "hard-to-reach" populations. Unfortunately, many research findings rarely make it back in useful format to the general public. Few innovative techniques have been established that provide researchers with a systematic process for developing health awareness and prevention messages for priority populations. The purpose of this paper is to describe the early development and experience of a unique community-based participatory process used to develop health promotion messages for a predominantly low-income, black and African-American community in Baltimore, MD. Scientific research findings from peer-reviewed literature were identified by academic researchers. Researchers then taught the science to graphic design students and faculty. The graphic design students and faculty then worked with both community residents and researchers to transform this information into evidence-based public health education messages. The final products were culturally and educationally appropriate, health promotion messages reflecting urban imagery that were eagerly desired by the community. This early outcome is in contrast to many previously developed messages and materials created through processes with limited community involvement and by individuals with limited practical knowledge of local community culture or expertise in marketing or mass communication. This process may potentially be utilized as a community-based participatory approach to enhance the translation of scientific research into desirable and appropriate health education messages.

  1. 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.

  2. 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.

  3. Recruitment and retention in an SMS-based health education program: Lessons learned from Text2BHealthy.

    PubMed

    Speirs, Katherine E; Grutzmacher, Stephanie K; Munger, Ashley L; Messina, Lauren A

    2016-09-01

    While text messages or short messaging service programs are increasingly utilized for delivering health education, few studies have explored the unique challenges of recruiting and retaining participants in such programs. This study utilizes survey and focus group data from Text2BHealthy, a short messaging service-based nutrition and physical activity promotion program, to examine barriers to enrollment and facilitators of retention among parents of elementary school students. Results show that participants were hard to reach with recruitment materials, had difficulty with self-enrollment, and were apprehensive about program costs. However, 89-90 percent of participants were retained. Results suggest that providing manual enrollment options, alternative program delivery methods (e.g. email messages), and opportunities to reenroll may facilitate participation in short messaging service-based health education and promotion programs. © The Author(s) 2015.

  4. A Content Analysis of E-mail Communication between Patients and Their Providers: Patients Get the Message

    PubMed Central

    White, Casey B.; Moyer, Cheryl A.; Stern, David T.; Katz, Steven J.

    2004-01-01

    Objective: E-mail use in the clinical setting has been slow to diffuse for several reasons, including providers' concerns about patients' inappropriate and inefficient use of the technology. This study examined the content of a random sample of patient–physician e-mail messages to determine the validity of those concerns. Design: A qualitative analysis of patient–physician e-mail messages was performed. Measurements: A total of 3,007 patient–physician e-mail messages were collected over 11 months as part of a randomized, controlled trial of a triage-based e-mail system in two primary care centers (including 98 physicians); 10% of messages were randomly selected for review. Messages were coded across such domains as message type, number of requests per e-mail, inclusion of sensitive content, necessity of a physician response, and message tone. Results: The majority (82.8%) of messages addressed a single issue. The most common message types included information updates to the physicians (41.4%), prescription renewals (24.2%), health questions (13.2%), questions about test results (10.9%), referrals (8.8%), “other” (including thank yous, apologies) (8.8%), appointments (5.4%), requests for non-health-related information (4.8%), and billing questions (0.3%). Overall, messages were concise, formal, and medically relevant. Very few (5.1%) included sensitive content, and none included urgent messages. Less than half (43.2%) required a physician response. Conclusion: A triage-based e-mail system promoted e-mail exchanges appropriate for primary care. Most patients adhered to guidelines aimed at focusing content, limiting the number of requests per message, and avoiding urgent requests or highly sensitive content. Thus, physicians' concerns about the content of patients' e-mails may be unwarranted. PMID:15064295

  5. 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.

  6. Communicating with the workforce during emergencies: developing an employee text messaging program in a local public health setting.

    PubMed

    Karasz, Hilary N; Bogan, Sharon; Bosslet, Lindsay

    2014-01-01

    Short message service (SMS) text messaging can be useful for communicating information to public health employees and improving workforce situational awareness during emergencies. We sought to understand how the 1,500 employees at Public Health--Seattle & King County, Washington, perceived barriers to and benefits of participation in a voluntary, employer-based SMS program. Based on employee feedback, we developed the system, marketed it, and invited employees to opt in. The system was tested during an ice storm in January 2012. Employee concerns about opting into an SMS program included possible work encroachment during non-work time and receiving excessive irrelevant messages. Employees who received messages during the weather event reported high levels of satisfaction and perceived utility from the program. We conclude that text messaging is a feasible form of communication with employees during emergencies. Care should be taken to design and deploy a program that maximizes employee satisfaction.

  7. CDC MessageWorks: Designing and Validating a Social Marketing Tool to Craft and Defend Effective Messages

    PubMed Central

    Cole, Galen E.; Keller, Punam A.; Reynolds, Jennifer; Schaur, Michelle; Krause, Diane

    2016-01-01

    The Centers for Disease Control and Prevention’s Division of Cancer Prevention and Control, in partnership with Oak Ridge Associated Universities, designed an online social marketing strategy tool, MessageWorks, to help health communicators effectively formulate messages aimed at changing health behaviors and evaluate message tactics and audience characteristics. MessageWorks is based on the advisor for risk communication model that identifies 10 variables that can be used to predict target audience intentions to comply with health recommendations. This article discusses the value of the MessageWorks tool to health communicators and to the field of social marketing by (1) describing the scientific evidence supporting use of MessageWorks to improve health communication practice and (2) summarizing how to use MessageWorks and interpret the results it produces. PMID:26877714

  8. Parallel Implementation of Triangular Cellular Automata for Computing Two-Dimensional Elastodynamic Response on Arbitrary Domains

    NASA Astrophysics Data System (ADS)

    Leamy, Michael J.; Springer, Adam C.

    In this research we report parallel implementation of a Cellular Automata-based simulation tool for computing elastodynamic response on complex, two-dimensional domains. Elastodynamic simulation using Cellular Automata (CA) has recently been presented as an alternative, inherently object-oriented technique for accurately and efficiently computing linear and nonlinear wave propagation in arbitrarily-shaped geometries. The local, autonomous nature of the method should lead to straight-forward and efficient parallelization. We address this notion on symmetric multiprocessor (SMP) hardware using a Java-based object-oriented CA code implementing triangular state machines (i.e., automata) and the MPI bindings written in Java (MPJ Express). We use MPJ Express to reconfigure our existing CA code to distribute a domain's automata to cores present on a dual quad-core shared-memory system (eight total processors). We note that this message passing parallelization strategy is directly applicable to computer clustered computing, which will be the focus of follow-on research. Results on the shared memory platform indicate nearly-ideal, linear speed-up. We conclude that the CA-based elastodynamic simulator is easily configured to run in parallel, and yields excellent speed-up on SMP hardware.

  9. Monte Carlo-based fluorescence molecular tomography reconstruction method accelerated by a cluster of graphic processing units.

    PubMed

    Quan, Guotao; Gong, Hui; Deng, Yong; Fu, Jianwei; Luo, Qingming

    2011-02-01

    High-speed fluorescence molecular tomography (FMT) reconstruction for 3-D heterogeneous media is still one of the most challenging problems in diffusive optical fluorescence imaging. In this paper, we propose a fast FMT reconstruction method that is based on Monte Carlo (MC) simulation and accelerated by a cluster of graphics processing units (GPUs). Based on the Message Passing Interface standard, we modified the MC code for fast FMT reconstruction, and different Green's functions representing the flux distribution in media are calculated simultaneously by different GPUs in the cluster. A load-balancing method was also developed to increase the computational efficiency. By applying the Fréchet derivative, a Jacobian matrix is formed to reconstruct the distribution of the fluorochromes using the calculated Green's functions. Phantom experiments have shown that only 10 min are required to get reconstruction results with a cluster of 6 GPUs, rather than 6 h with a cluster of multiple dual opteron CPU nodes. Because of the advantages of high accuracy and suitability for 3-D heterogeneity media with refractive-index-unmatched boundaries from the MC simulation, the GPU cluster-accelerated method provides a reliable approach to high-speed reconstruction for FMT imaging.

  10. Distributed memory compiler design for sparse problems

    NASA Technical Reports Server (NTRS)

    Wu, Janet; Saltz, Joel; Berryman, Harry; Hiranandani, Seema

    1991-01-01

    A compiler and runtime support mechanism is described and demonstrated. The methods presented are capable of solving a wide range of sparse and unstructured problems in scientific computing. The compiler takes as input a FORTRAN 77 program enhanced with specifications for distributing data, and the compiler outputs a message passing program that runs on a distributed memory computer. The runtime support for this compiler is a library of primitives designed to efficiently support irregular patterns of distributed array accesses and irregular distributed array partitions. A variety of Intel iPSC/860 performance results obtained through the use of this compiler are presented.

  11. A Scalable Architecture of a Structured LDPC Decoder

    NASA Technical Reports Server (NTRS)

    Lee, Jason Kwok-San; Lee, Benjamin; Thorpe, Jeremy; Andrews, Kenneth; Dolinar, Sam; Hamkins, Jon

    2004-01-01

    We present a scalable decoding architecture for a certain class of structured LDPC codes. The codes are designed using a small (n,r) protograph that is replicated Z times to produce a decoding graph for a (Z x n, Z x r) code. Using this architecture, we have implemented a decoder for a (4096,2048) LDPC code on a Xilinx Virtex-II 2000 FPGA, and achieved decoding speeds of 31 Mbps with 10 fixed iterations. The implemented message-passing algorithm uses an optimized 3-bit non-uniform quantizer that operates with 0.2dB implementation loss relative to a floating point decoder.

  12. ''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.

  13. 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.

  14. Chronology of the birth and death of a health bill.

    PubMed

    Jacks, J C; Jacks, L

    1995-01-01

    A two-year attempt by the Clinton administration to develop and pass a health care reform bill was from the beginning destined for failure. The health care reform plan was developed in secret, leaving the plan open for special interest suspect. It was overly complex and difficult to understand. Congress and the general public initially supported the effort, but wavered under pressure and negative messages generated by special interest groups. After a year of intense debate, health care reform was declared dead, with very little hope of resurrection in the 1994 election year, which saw Republicans make significant gains in Congress.

  15. Distributed-Memory Computing With the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA)

    NASA Technical Reports Server (NTRS)

    Riley, Christopher J.; Cheatwood, F. McNeil

    1997-01-01

    The Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA), a Navier-Stokes solver, has been modified for use in a parallel, distributed-memory environment using the Message-Passing Interface (MPI) standard. A standard domain decomposition strategy is used in which the computational domain is divided into subdomains with each subdomain assigned to a processor. Performance is examined on dedicated parallel machines and a network of desktop workstations. The effect of domain decomposition and frequency of boundary updates on performance and convergence is also examined for several realistic configurations and conditions typical of large-scale computational fluid dynamic analysis.

  16. Overview of Sparse Graph for Multiple Access in Future Mobile Networks

    NASA Astrophysics Data System (ADS)

    Lei, Jing; Li, Baoguo; Li, Erbao; Gong, Zhenghui

    2017-10-01

    Multiple access via sparse graph, such as low density signature (LDS) and sparse code multiple access (SCMA), is a promising technique for future wireless communications. This survey presents an overview of the developments in this burgeoning field, including transmitter structures, extrinsic information transform (EXIT) chart analysis and comparisons with existing multiple access techniques. Such technique enables multiple access under overloaded conditions to achieve a satisfactory performance. Message passing algorithm is utilized for multi-user detection in the receiver, and structures of the sparse graph are illustrated in detail. Outlooks and challenges of this technique are also presented.

  17. Design and Multi-Country Validation of Text Messages for an mHealth Intervention for Primary Prevention of Progression to Hypertension in Latin America.

    PubMed

    Diez-Canseco, Francisco; Zavala-Loayza, J Alfredo; Beratarrechea, Andrea; Kanter, Rebecca; Ramirez-Zea, Manuel; Rubinstein, Adolfo; Martinez, Homero; Miranda, J Jaime

    2015-02-18

    Mobile health (mHealth) has been posited to contribute to the reduction in health gaps and has shown fast and widespread growth in developing countries. This growth demands understanding of, and preparedness for, local cultural contexts. To describe the design and validation of text messages (short message service, SMS) that will be used for an mHealth behavioral change intervention to prevent hypertension in three Latin American countries: Argentina, Guatemala, and Peru. An initial set of 64 SMS text messages were designed to promote healthy lifestyles among individuals in different stages of behavior change, addressing four key domains: salt and sodium intake, fruit and vegetable intake, consumption of high fat and sugar foods, and physical activity. The 64 SMS text messages were organized into nine subsets for field validation. In each country 36 people were recruited, half of them being male. Of the participants, 4 per country evaluated each subset of SMS text messages, which contained between 6 and 8 SMS text messages regarding different key domains and stages of change. The understanding and appeal of each SMS text message was assessed using a 7-item questionnaire. The understanding and appeal ratings were used to reach a final set of 56 SMS text messages. Overall, each of the 64 SMS text messages received a total of 12 evaluations (4 per country). The majority of evaluations-742 out of a total of 767 (96.7%) valid responses-revealed an adequate understanding of the key idea contained in the SMS text message. On a scale from 1 to 10, the average appeal score was 8.7 points, with a range of 4 to 10 points. Based on their low scores, 8 SMS text messages per country were discarded. Once the final set of 56 SMS text messages was established, and based on feedback obtained in the field, wording and content of some SMS text messages were improved. Of the final set, 9, 8, and 16 of the SMS text messages were improved based on participant evaluations from Argentina, Guatemala, and Peru, respectively. Most SMS text messages selected for the final set (49/56, 88%) were the same in all countries, except for small wording differences. The final set of SMS text messages produced had very high rates of understanding and appeal in three different Latin American countries. This study highlights the importance of developing and validating a package of simple, preventative SMS text messages, grounded in evidence and theory, across three different Latin American countries with active engagement of end users.

  18. Design and Multi-Country Validation of Text Messages for an mHealth Intervention for Primary Prevention of Progression to Hypertension in Latin America

    PubMed Central

    Diez-Canseco, Francisco; Zavala-Loayza, J Alfredo; Beratarrechea, Andrea; Kanter, Rebecca; Ramirez-Zea, Manuel; Rubinstein, Adolfo; Martinez, Homero

    2015-01-01

    Background Mobile health (mHealth) has been posited to contribute to the reduction in health gaps and has shown fast and widespread growth in developing countries. This growth demands understanding of, and preparedness for, local cultural contexts. Objective To describe the design and validation of text messages (short message service, SMS) that will be used for an mHealth behavioral change intervention to prevent hypertension in three Latin American countries: Argentina, Guatemala, and Peru. Methods An initial set of 64 SMS text messages were designed to promote healthy lifestyles among individuals in different stages of behavior change, addressing four key domains: salt and sodium intake, fruit and vegetable intake, consumption of high fat and sugar foods, and physical activity. The 64 SMS text messages were organized into nine subsets for field validation. In each country 36 people were recruited, half of them being male. Of the participants, 4 per country evaluated each subset of SMS text messages, which contained between 6 and 8 SMS text messages regarding different key domains and stages of change. The understanding and appeal of each SMS text message was assessed using a 7-item questionnaire. The understanding and appeal ratings were used to reach a final set of 56 SMS text messages. Results Overall, each of the 64 SMS text messages received a total of 12 evaluations (4 per country). The majority of evaluations—742 out of a total of 767 (96.7%) valid responses—revealed an adequate understanding of the key idea contained in the SMS text message. On a scale from 1 to 10, the average appeal score was 8.7 points, with a range of 4 to 10 points. Based on their low scores, 8 SMS text messages per country were discarded. Once the final set of 56 SMS text messages was established, and based on feedback obtained in the field, wording and content of some SMS text messages were improved. Of the final set, 9, 8, and 16 of the SMS text messages were improved based on participant evaluations from Argentina, Guatemala, and Peru, respectively. Most SMS text messages selected for the final set (49/56, 88%) were the same in all countries, except for small wording differences. Conclusions The final set of SMS text messages produced had very high rates of understanding and appeal in three different Latin American countries. This study highlights the importance of developing and validating a package of simple, preventative SMS text messages, grounded in evidence and theory, across three different Latin American countries with active engagement of end users. PMID:25693595

  19. Faster Isn't Smarter: Messages about Math, Teaching, and Learning in the 21st Century

    ERIC Educational Resources Information Center

    Seeley, Cathy L.

    2009-01-01

    NCTM Past President Cathy L. Seeley shares her messages on today's most relevant topics and issues in education. Based on Cathy L. Seeley's award-winning NCTM President's Messages, and including dozens of new messages, this must-have K-12 resource offers straight talk and common sense about some of today's most important, thought-provoking issues…

  20. Monitoring Receptivity to Online Health Messages by Tracking Daily Web Traffic Engagement Patterns: A Review of More than 13 Million US Web Exposures over 1,235 Days.

    PubMed

    Seeman, Neil; Seeman, Bob

    2017-01-01

    Reaching the recipient of online health messages is necessary to Web-based health promotion applications. To measure willingness to adhere to a health-related Web message, we explored the frequency with which more than 13 million Web users ignored or opted to receive a random inbound message. The findings suggest declining curiosity among Web users about online messages, and that certain days may be more propitious than others for communicating with users. This approach can be modified to gather more granular insights into how messages, including timing and design features, can be tailored to promote improved public health messaging.

  1. Evaluators' Perceptions of Teachers' Use of Behavior Alteration Techniques.

    ERIC Educational Resources Information Center

    Allen, Terre; Edwards, Renee

    1988-01-01

    Examines which message-based behavior alteration techniques (BATs) teacher evaluators perceive as commonly used by good, average, and poor teachers. Reports that principals equate reward-type messages with effective teaching and punishment-type messages with ineffective teaching. (MM)

  2. Reactions to a health threat: dispositional threat orientations and message characteristics.

    PubMed

    Thompson, Suzanne C; Schlehofer, Michèle M; Gonzalez, Amelia; Denison, Elizabeth

    2011-05-01

    This study explored the interactive effects of dispositional threat orientation, type of message, and having children on reactions to a message about exposure to bisphenol A (BPA) in plastics. The study used a 2 (message: Fear Arousal or Plain)×2 (parenting status: child or no child)×2 (threat orientation: high or low) mixed factorial design. Adults (N= 200) recruited via the Internet completed measures of threat orientations, reported whether they were a parent, and read either a low or high fear-arousal message about the risks of BPA exposure. They then completed measures of reactions to the message (perceived susceptibility to BPA effects, negative emotions, and behavioural intentions to engage in protection). Depending on threat orientations, the fear arousal version of the message and parenthood had strikingly different effects, ranging from no effect (for those high in a control-based approach) to prompting change (for those low in a control-based approach) to counterproductive (for those high in an optimistic denial approach). These findings suggest that considering individual differences and their interactions with situational factors could improve both the predictive ability of threat protection theories and the delivery of messages intended to change behaviour. ©2010 The British Psychological Society.

  3. Mobile phone short message service messaging for behaviour modification in a community-based weight control programme in Korea.

    PubMed

    Joo, Nam-Seok; Kim, Bom-Taeck

    2007-01-01

    We conducted a community-based anti-obesity programme using mobile phone short message service (SMS) messaging. A total of 927 participants were recruited and visited a public health centre for initial assessment. Mobile phones were used to deliver short messages about diet, exercise and behaviour modification once a week. After a 12-week anti-obesity programme they visited the public health centre again. Four hundred and thirty-three subjects (47%) successfully completed their weight control programme. There were mean reductions of weight, waist circumference and body mass index of 1.6 kg (P < 0.001), 4.3 cm (P < 0.001) and 0.6 kg/m(2) (P < 0.001), respectively. Over two-thirds of the subjects had a reduction in waist circumference of 5-7.5 cm. A post-intervention survey showed that the majority of participants were satisfied with the weekly SMS messages and information brochures delivered by post. SMS messaging may be an effective method of behaviour modification in weight control and anti-obesity health education programmes when promoted by community health centres.

  4. LSB Based Quantum Image Steganography Algorithm

    NASA Astrophysics Data System (ADS)

    Jiang, Nan; Zhao, Na; Wang, Luo

    2016-01-01

    Quantum steganography is the technique which hides a secret message into quantum covers such as quantum images. In this paper, two blind LSB steganography algorithms in the form of quantum circuits are proposed based on the novel enhanced quantum representation (NEQR) for quantum images. One algorithm is plain LSB which uses the message bits to substitute for the pixels' LSB directly. The other is block LSB which embeds a message bit into a number of pixels that belong to one image block. The extracting circuits can regain the secret message only according to the stego cover. Analysis and simulation-based experimental results demonstrate that the invisibility is good, and the balance between the capacity and the robustness can be adjusted according to the needs of applications.

  5. Validation of mobile phone text messages for nicotine and tobacco risk communication among college students: A content analysis.

    PubMed

    Khalil, Georges E; Calabro, Karen S; Crook, Brittani; Machado, Tamara C; Perry, Cheryl L; Prokhorov, Alexander V

    2018-02-01

    In the United States, young adults have the highest prevalence of tobacco use. The dissemination of mobile phone text messages is a growing strategy for tobacco risk communication among young adults. However, little has been done concerning the design and validation of such text messages. The Texas Tobacco Center of Regulatory Science (Texas-TCORS) has developed a library of messages based on framing (gain- or loss-framed), depth (simple or complex) and appeal (emotional or rational). This study validated the library based on depth and appeal, identified text messages that may need improvement, and explored new themes. The library formed the study sample (N=976 messages). The Linguistic Inquiry and Word Count (LIWC) software of 2015 was used to code for word count, word length and frequency of emotional and cognitive words. Analyses of variance, logistic regression and scatter plots were conducted for validation. In all, 874 messages agreed with LIWC-coding. Several messages did not agree with LIWC. Ten messages designed to be complex indicated simplicity, while 51 messages designed to be rational exhibited no cognitive words. New relevant themes were identified, such as health (e.g. 'diagnosis', 'cancer'), death (e.g. 'dead', 'lethal') and social connotations (e.g. 'parents', 'friends'). Nicotine and tobacco researchers can safely use, for young adults, messages from the Texas-TCORS library to convey information in the intended style. Future work may expand upon the new themes. Findings will be utilized to develop new campaigns, so that risks of nicotine and tobacco products can be widely disseminated.

  6. Fundamentals for Future Mobile-Health (mHealth): A Systematic Review of Mobile Phone and Web-Based Text Messaging in Mental Health

    PubMed Central

    Baca-García, Enrique; Brandt, Sara; Walter, Michel; Courtet, Philippe

    2016-01-01

    Background Mobile phone text messages (short message service, SMS) are used pervasively as a form of communication. Almost 100% of the population uses text messaging worldwide and this technology is being suggested as a promising tool in psychiatry. Text messages can be sent either from a classic mobile phone or a web-based application. Reviews are needed to better understand how text messaging can be used in mental health care and other fields of medicine. Objective The objective of the study was to review the literature regarding the use of mobile phone text messaging in mental health care. Methods We conducted a thorough literature review of studies involving text messaging in health care management. Searches included PubMed, PsycINFO, Cochrane, Scopus, Embase and Web of Science databases on May 25, 2015. Studies reporting the use of text messaging as a tool in managing patients with mental health disorders were included. Given the heterogeneity of studies, this review was summarized using a descriptive approach. Results From 677 initial citations, 36 studies were included in the review. Text messaging was used in a wide range of mental health situations, notably substance abuse (31%), schizophrenia (22%), and affective disorders (17%). We identified four ways in which text messages were used: reminders (14%), information (17%), supportive messages (42%), and self-monitoring procedures (42%). Applications were sometimes combined. Conclusions We report growing interest in text messaging since 2006. Text messages have been proposed as a health care tool in a wide spectrum of psychiatric disorders including substance abuse, schizophrenia, affective disorders, and suicide prevention. Most papers described pilot studies, while some randomized clinical trials (RCTs) were also reported. Overall, a positive attitude toward text messages was reported. RCTs reported improved treatment adherence and symptom surveillance. Other positive points included an increase in appointment attendance and in satisfaction with management and health care services. Insight into message content, preventative strategies, and innovative approaches derived from the mental health field may be applicable in other medical specialties. PMID:27287668

  7. Fundamentals for Future Mobile-Health (mHealth): A Systematic Review of Mobile Phone and Web-Based Text Messaging in Mental Health.

    PubMed

    Berrouiguet, Sofian; Baca-García, Enrique; Brandt, Sara; Walter, Michel; Courtet, Philippe

    2016-06-10

    Mobile phone text messages (short message service, SMS) are used pervasively as a form of communication. Almost 100% of the population uses text messaging worldwide and this technology is being suggested as a promising tool in psychiatry. Text messages can be sent either from a classic mobile phone or a web-based application. Reviews are needed to better understand how text messaging can be used in mental health care and other fields of medicine. The objective of the study was to review the literature regarding the use of mobile phone text messaging in mental health care. We conducted a thorough literature review of studies involving text messaging in health care management. Searches included PubMed, PsycINFO, Cochrane, Scopus, Embase and Web of Science databases on May 25, 2015. Studies reporting the use of text messaging as a tool in managing patients with mental health disorders were included. Given the heterogeneity of studies, this review was summarized using a descriptive approach. From 677 initial citations, 36 studies were included in the review. Text messaging was used in a wide range of mental health situations, notably substance abuse (31%), schizophrenia (22%), and affective disorders (17%). We identified four ways in which text messages were used: reminders (14%), information (17%), supportive messages (42%), and self-monitoring procedures (42%). Applications were sometimes combined. We report growing interest in text messaging since 2006. Text messages have been proposed as a health care tool in a wide spectrum of psychiatric disorders including substance abuse, schizophrenia, affective disorders, and suicide prevention. Most papers described pilot studies, while some randomized clinical trials (RCTs) were also reported. Overall, a positive attitude toward text messages was reported. RCTs reported improved treatment adherence and symptom surveillance. Other positive points included an increase in appointment attendance and in satisfaction with management and health care services. Insight into message content, preventative strategies, and innovative approaches derived from the mental health field may be applicable in other medical specialties.

  8. Roadside-based communication system and method

    NASA Technical Reports Server (NTRS)

    Bachelder, Aaron D. (Inventor)

    2007-01-01

    A roadside-based communication system providing backup communication between emergency mobile units and emergency command centers. In the event of failure of a primary communication, the mobile units transmit wireless messages to nearby roadside controllers that may take the form of intersection controllers. The intersection controllers receive the wireless messages, convert the messages into standard digital streams, and transmit the digital streams along a citywide network to a destination intersection or command center.

  9. One-way versus two-way text messaging on improving medication adherence: meta-analysis of randomized trials.

    PubMed

    Wald, David S; Butt, Shahena; Bestwick, Jonathan P

    2015-10-01

    Mobile telephone text messaging is a simple potential solution to the failure to take medications as directed. There is uncertainty over the effectiveness of 1-way text messaging (sending text message reminders only) compared with 2-way text messaging (sending reminders and receiving replies confirming whether medication has been taken) as a means of improving medication adherence. A meta-analysis of 8 randomized trials (1994 patients) that tested the effectiveness of text messaging on medication adherence was performed. The trials were divided into 2 groups: trials using 1-way text messaging versus no text messaging and trials using 2-way text messaging versus no text messaging. The summary estimates of the effect of the 2 methods of text messaging (1-way or 2-way) were compared. The summary relative risk estimate was 1.04 (95% confidence interval, 0.97-1.11) for 1-way text messaging and 1.23 (95% confidence interval, 1.13-1.35) for 2-way text messaging. The difference in effect between the 2 methods was statistically significant (P = .007). Two-way text messaging is associated with substantially improved medication adherence compared with 1-way text messaging. This has important implications in the provision of mobile-based messaging in the management of patients taking medication for the prevention of chronic disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Comparing Tailored and Untailored Text Messages for Smoking Cessation: A Randomized Controlled Trial among Adolescent and Young Adult Smokers

    ERIC Educational Resources Information Center

    Skov-Ettrup, L. S.; Ringgaard, L. W.; Dalum, P.; Flensborg-Madsen, T.; Thygesen, L. C.; Tolstrup, J. S.

    2014-01-01

    The aim was to compare the effectiveness of untailored text messages for smoking cessation to tailored text messages delivered at a higher frequency. From February 2007 to August 2009, 2030 users of an internet-based smoking cessation program with optional text message support aged 15-25 years were consecutively randomized to versions of the…

  11. Message framing in social networking sites.

    PubMed

    Kao, Danny Tengti; Chuang, Shih-Chieh; Wang, Sui-Min; Zhang, Lei

    2013-10-01

    Online social networking sites represent significant new opportunities for Internet advertisers. However, results based on the real world cannot be generalized to all virtual worlds. In this research, the moderating effects of need for cognition (NFC) and knowledge were applied to examine the impact of message framing on attitudes toward social networking sites. A total of 216 undergraduates participated in the study. Results reveal that for social networking sites, while high-NFC individuals form more favorable attitudes toward negatively framed messages than positively framed messages, low-NFC individuals form more favorable attitudes toward positively framed messages than negatively framed messages. In addition, low-knowledge individuals demonstrate more favorable attitudes toward negatively framed messages than positively framed messages; however, the framing effect does not differentially affect the attitudes of high-knowledge individuals. Furthermore, the framing effect does not differentially affect the attitudes of high-NFC individuals with high knowledge. In contrast, low-NFC individuals with low knowledge hold more favorable attitudes toward positively framed messages than negatively framed messages.

  12. Mood and threat to attitudinal freedom: delineating the role of mood congruency and hedonic contingency in counterattitudinal message processing.

    PubMed

    Ziegler, Rene; Schlett, Christian; Aydinli, Arzu

    2013-08-01

    The present research examined when happy individuals' processing of a counterattitudinal message is guided by mood-congruent expectancies versus hedonic considerations. Recipients in positive, neutral, or negative mood read a strong or weak counterattitudinal message which either contained a threat to attitudinal freedom or did not contain such a threat. As expected, a freedom-threatening counterattitudinal message was more mood threatening than a counterattitudinal message not threatening freedom. Furthermore, as predicted by the mood-congruent expectancies approach, people in positive mood processed a nonthreatening counterattitudinal message more thoroughly than people in negative mood. Message processing in neutral mood lay in between. In contrast, as predicted by the hedonic-contingency view, a threatening counterattitudinal message was processed less thoroughly in positive mood than in neutral mood. In negative mood, processing of a threatening counterattitudinal message was as low as in positive mood. These findings suggest that message processing is determined by mood congruency unless hedonic considerations override expectancy-based processing inclinations.

  13. Regional-scale calculation of the LS factor using parallel processing

    NASA Astrophysics Data System (ADS)

    Liu, Kai; Tang, Guoan; Jiang, Ling; Zhu, A.-Xing; Yang, Jianyi; Song, Xiaodong

    2015-05-01

    With the increase of data resolution and the increasing application of USLE over large areas, the existing serial implementation of algorithms for computing the LS factor is becoming a bottleneck. In this paper, a parallel processing model based on message passing interface (MPI) is presented for the calculation of the LS factor, so that massive datasets at a regional scale can be processed efficiently. The parallel model contains algorithms for calculating flow direction, flow accumulation, drainage network, slope, slope length and the LS factor. According to the existence of data dependence, the algorithms are divided into local algorithms and global algorithms. Parallel strategy are designed according to the algorithm characters including the decomposition method for maintaining the integrity of the results, optimized workflow for reducing the time taken for exporting the unnecessary intermediate data and a buffer-communication-computation strategy for improving the communication efficiency. Experiments on a multi-node system show that the proposed parallel model allows efficient calculation of the LS factor at a regional scale with a massive dataset.

  14. Static analysis techniques for semiautomatic synthesis of message passing software skeletons

    DOE PAGES

    Sottile, Matthew; Dagit, Jason; Zhang, Deli; ...

    2015-06-29

    The design of high-performance computing architectures demands performance analysis of large-scale parallel applications to derive various parameters concerning hardware design and software development. The process of performance analysis and benchmarking an application can be done in several ways with varying degrees of fidelity. One of the most cost-effective ways is to do a coarse-grained study of large-scale parallel applications through the use of program skeletons. The concept of a “program skeleton” that we discuss in this article is an abstracted program that is derived from a larger program where source code that is determined to be irrelevant is removed formore » the purposes of the skeleton. In this work, we develop a semiautomatic approach for extracting program skeletons based on compiler program analysis. Finally, we demonstrate correctness of our skeleton extraction process by comparing details from communication traces, as well as show the performance speedup of using skeletons by running simulations in the SST/macro simulator.« less

  15. High Performance Geostatistical Modeling of Biospheric Resources

    NASA Astrophysics Data System (ADS)

    Pedelty, J. A.; Morisette, J. T.; Smith, J. A.; Schnase, J. L.; Crosier, C. S.; Stohlgren, T. J.

    2004-12-01

    We are using parallel geostatistical codes to study spatial relationships among biospheric resources in several study areas. For example, spatial statistical models based on large- and small-scale variability have been used to predict species richness of both native and exotic plants (hot spots of diversity) and patterns of exotic plant invasion. However, broader use of geostastics in natural resource modeling, especially at regional and national scales, has been limited due to the large computing requirements of these applications. To address this problem, we implemented parallel versions of the kriging spatial interpolation algorithm. The first uses the Message Passing Interface (MPI) in a master/slave paradigm on an open source Linux Beowulf cluster, while the second is implemented with the new proprietary Xgrid distributed processing system on an Xserve G5 cluster from Apple Computer, Inc. These techniques are proving effective and provide the basis for a national decision support capability for invasive species management that is being jointly developed by NASA and the US Geological Survey.

  16. 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

  17. 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

  18. Parallel Fortran-MPI software for numerical inversion of the Laplace transform and its application to oscillatory water levels in groundwater environments

    USGS Publications Warehouse

    Zhan, X.

    2005-01-01

    A parallel Fortran-MPI (Message Passing Interface) software for numerical inversion of the Laplace transform based on a Fourier series method is developed to meet the need of solving intensive computational problems involving oscillatory water level's response to hydraulic tests in a groundwater environment. The software is a parallel version of ACM (The Association for Computing Machinery) Transactions on Mathematical Software (TOMS) Algorithm 796. Running 38 test examples indicated that implementation of MPI techniques with distributed memory architecture speedups the processing and improves the efficiency. Applications to oscillatory water levels in a well during aquifer tests are presented to illustrate how this package can be applied to solve complicated environmental problems involved in differential and integral equations. The package is free and is easy to use for people with little or no previous experience in using MPI but who wish to get off to a quick start in parallel computing. ?? 2004 Elsevier Ltd. All rights reserved.

  19. 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.

  20. Charon Toolkit for Parallel, Implicit Structured-Grid Computations: Functional Design

    NASA Technical Reports Server (NTRS)

    VanderWijngaart, Rob F.; Kutler, Paul (Technical Monitor)

    1997-01-01

    In a previous report the design concepts of Charon were presented. Charon is a toolkit that aids engineers in developing scientific programs for structured-grid applications to be run on MIMD parallel computers. It constitutes an augmentation of the general-purpose MPI-based message-passing layer, and provides the user with a hierarchy of tools for rapid prototyping and validation of parallel programs, and subsequent piecemeal performance tuning. Here we describe the implementation of the domain decomposition tools used for creating data distributions across sets of processors. We also present the hierarchy of parallelization tools that allows smooth translation of legacy code (or a serial design) into a parallel program. Along with the actual tool descriptions, we will present the considerations that led to the particular design choices. Many of these are motivated by the requirement that Charon must be useful within the traditional computational environments of Fortran 77 and C. Only the Fortran 77 syntax will be presented in this report.

  1. 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.

  2. 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.

  3. Bistatic scattering from a three-dimensional object above a two-dimensional randomly rough surface modeled with the parallel FDTD approach.

    PubMed

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

    2009-11-01

    We present an investigation of the electromagnetic scattering from a three-dimensional (3-D) object above a two-dimensional (2-D) randomly rough surface. A Message Passing Interface-based parallel finite-difference time-domain (FDTD) approach is used, and the uniaxial perfectly matched layer (UPML) medium is adopted for truncation of the 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 number of processors is illustrated for one rough surface realization and shows that the computation time of our parallel FDTD algorithm is dramatically reduced relative to a single-processor implementation. Finally, the composite scattering coefficients versus scattered and azimuthal angle are presented and analyzed for different conditions, including the surface roughness, the dielectric constants, the polarization, and the size of the 3-D object.

  4. Automated Generation of Message-Passing Programs: An Evaluation Using CAPTools

    NASA Technical Reports Server (NTRS)

    Hribar, Michelle R.; Jin, Haoqiang; Yan, Jerry C.; Saini, Subhash (Technical Monitor)

    1998-01-01

    Scientists at NASA Ames Research Center have been developing computational aeroscience applications on highly parallel architectures over the past ten years. During that same time period, a steady transition of hardware and system software also occurred, forcing us to expend great efforts into migrating and re-coding our applications. As applications and machine architectures become increasingly complex, the cost and time required for this process will become prohibitive. In this paper, we present the first set of results in our evaluation of interactive parallelization tools. In particular, we evaluate CAPTool's ability to parallelize computational aeroscience applications. CAPTools was tested on serial versions of the NAS Parallel Benchmarks and ARC3D, a computational fluid dynamics application, on two platforms: the SGI Origin 2000 and the Cray T3E. This evaluation includes performance, amount of user interaction required, limitations and portability. Based on these results, a discussion on the feasibility of computer aided parallelization of aerospace applications is presented along with suggestions for future work.

  5. "Please Don't Send Us Spam!" A Participative, Theory-Based Methodology for Developing an mHealth Intervention.

    PubMed

    Toefy, Yoesrie; Skinner, Donald; Thomsen, Sarah

    2016-08-17

    Mobile health solutions have the potential of reducing burdens on health systems and empowering patients with important information. However, there is a lack of theory-based mHealth interventions. The purpose of our study was to develop a participative, theory-based, mobile phone, audio messaging intervention attractive to recently circumcised men at voluntary medical male circumcision (VMMC) clinics in the Cape Town area in South Africa. We aimed to shift some of the tasks related to postoperative counselling on wound management and goal setting on safe sex. We place an emphasis on describing the full method of message generation to allow for replication. We developed an mHealth intervention using a staggered qualitative methodology: (1) focus group discussions with 52 recently circumcised men and their partners to develop initial voice messages they felt were relevant and appropriate, (2) thematic analysis and expert consultation to select the final messages for pilot testing, and (3) cognitive interviews with 12 recent VMMC patients to judge message comprehension and rank the messages. Message content and phasing were guided by the theory of planned behavior and the health action process approach. Patients and their partners came up with 245 messages they thought would help men during the wound-healing period. Thematic analysis revealed 42 different themes. Expert review and cognitive interviews with more patients resulted in 42 messages with a clear division in terms of needs and expectations between the initial wound-healing recovery phase (weeks 1-3) and the adjustment phase (weeks 4-6). Discussions with patients also revealed potential barriers to voice messaging, such as lack of technical knowledge of mobile phones and concerns about the invasive nature of the intervention. Patients' own suggested messages confirmed Ajzen's theory of planned behavior that if a health promotion intervention can build trust and be relevant to the recipient's needs in the first contacts, then the same recipients will perceive subsequent motivational messages more favorably. The health action process approach was also a useful tool for guiding the phasing of the messages. Participants were more positive and salutogenic than public health experts. The system showed how a process of consultation can work with a set of potential recipients of an mHealth service to ensure that their needs are included. Classic behavioral theories can and should be used to design modern mHealth interventions. We also believe that patients are the best source of messaging, ensuring that messages are culturally relevant and interesting to the recipient.

  6. Acceptability, Language, and Structure of Text Message-Based Behavioral Interventions for High-Risk Adolescent Females: A Qualitative Study

    PubMed Central

    Ranney, Megan L.; Choo, Esther K.; Cunningham, Rebecca M.; Spirito, Anthony; Thorsen, Margaret; Mello, Michael J.; Morrow, Kathleen

    2014-01-01

    Purpose To elucidate key elements surrounding acceptability/feasibility, language, and structure of a text message-based preventive intervention for high-risk adolescent females. Methods We recruited high-risk 13- to 17-year-old females screening positive for past-year peer violence and depressive symptoms, during emergency department visits for any chief complaint. Participants completed semistructured interviews exploring preferences around text message preventive interventions. Interviews were conducted by trained interviewers, audio-recorded, and transcribed verbatim. A coding structure was iteratively developed using thematic and content analysis. Each transcript was double coded. NVivo 10 was used to facilitate analysis. Results Saturation was reached after 20 interviews (mean age 15.4; 55% white; 40% Hispanic; 85% with cell phone access). (1) Acceptability/feasibility themes: A text-message intervention was felt to support and enhance existing coping strategies. Participants had a few concerns about privacy and cost. Peer endorsement may increase uptake. (2) Language themes: Messages should be simple and positive. Tone should be conversational but not slang filled. (3) Structural themes: Messages may be automated but must be individually tailored on a daily basis. Both predetermined (automatic) and as-needed messages are requested. Dose and timing of content should be varied according to participants’ needs. Multimedia may be helpful but is not necessary. Conclusions High-risk adolescent females seeking emergency department care are enthusiastic about a text message-based preventive intervention. Incorporating thematic results on language and structure can inform development of future text messaging interventions for adolescent girls. Concerns about cost and privacy may be able to be addressed through the process of recruitment and introduction to the intervention. PMID:24559973

  7. Mobile Phone Messaging During Unobserved "Home" Induction to Buprenorphine.

    PubMed

    Tofighi, Babak; Grossman, Ellie; Sherman, Scott; Nunes, Edward V; Lee, Joshua D

    2016-01-01

    The deployment of health information technologies promises to optimize clinical outcomes for populations with substance use disorders. Electronic health records, web-based counseling interventions, and mobile phone applications enhance the delivery of evidence-based behavioral and pharmacological treatments, with minimal burden to clinical personnel, infrastructure, and work flows. This clinical case shares a recent experience utilizing mobile phone text messaging between an office-based buprenorphine provider in a safety net ambulatory clinic and a patient seeking buprenorphine treatment for opioid use disorder. The case highlights the use of text message-based physician-patient communication to facilitate unobserved "home" induction onto buprenorphine.

  8. Implementation of a Message Passing Interface into a Cloud-Resolving Model for Massively Parallel Computing

    NASA Technical Reports Server (NTRS)

    Juang, Hann-Ming Henry; Tao, Wei-Kuo; Zeng, Xi-Ping; Shie, Chung-Lin; Simpson, Joanne; Lang, Steve

    2004-01-01

    The capability for massively parallel programming (MPP) using a message passing interface (MPI) has been implemented into a three-dimensional version of the Goddard Cumulus Ensemble (GCE) model. The design for the MPP with MPI uses the concept of maintaining similar code structure between the whole domain as well as the portions after decomposition. Hence the model follows the same integration for single and multiple tasks (CPUs). Also, it provides for minimal changes to the original code, so it is easily modified and/or managed by the model developers and users who have little knowledge of MPP. The entire model domain could be sliced into one- or two-dimensional decomposition with a halo regime, which is overlaid on partial domains. The halo regime requires that no data be fetched across tasks during the computational stage, but it must be updated before the next computational stage through data exchange via MPI. For reproducible purposes, transposing data among tasks is required for spectral transform (Fast Fourier Transform, FFT), which is used in the anelastic version of the model for solving the pressure equation. The performance of the MPI-implemented codes (i.e., the compressible and anelastic versions) was tested on three different computing platforms. The major results are: 1) both versions have speedups of about 99% up to 256 tasks but not for 512 tasks; 2) the anelastic version has better speedup and efficiency because it requires more computations than that of the compressible version; 3) equal or approximately-equal numbers of slices between the x- and y- directions provide the fastest integration due to fewer data exchanges; and 4) one-dimensional slices in the x-direction result in the slowest integration due to the need for more memory relocation for computation.

  9. 3D unstructured-mesh radiation transport codes

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

    Morel, J.

    1997-12-31

    Three unstructured-mesh radiation transport codes are currently being developed at Los Alamos National Laboratory. The first code is ATTILA, which uses an unstructured tetrahedral mesh in conjunction with standard Sn (discrete-ordinates) angular discretization, standard multigroup energy discretization, and linear-discontinuous spatial differencing. ATTILA solves the standard first-order form of the transport equation using source iteration in conjunction with diffusion-synthetic acceleration of the within-group source iterations. DANTE is designed to run primarily on workstations. The second code is DANTE, which uses a hybrid finite-element mesh consisting of arbitrary combinations of hexahedra, wedges, pyramids, and tetrahedra. DANTE solves several second-order self-adjoint forms of the transport equation including the even-parity equation, the odd-parity equation, and a new equation called the self-adjoint angular flux equation. DANTE also offers three angular discretization options:more » $$S{_}n$$ (discrete-ordinates), $$P{_}n$$ (spherical harmonics), and $$SP{_}n$$ (simplified spherical harmonics). DANTE is designed to run primarily on massively parallel message-passing machines, such as the ASCI-Blue machines at LANL and LLNL. The third code is PERICLES, which uses the same hybrid finite-element mesh as DANTE, but solves the standard first-order form of the transport equation rather than a second-order self-adjoint form. DANTE uses a standard $$S{_}n$$ discretization in angle in conjunction with trilinear-discontinuous spatial differencing, and diffusion-synthetic acceleration of the within-group source iterations. PERICLES was initially designed to run on workstations, but a version for massively parallel message-passing machines will be built. The three codes will be described in detail and computational results will be presented.« less

  10. 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.

  11. A Multi-Level Parallelization Concept for High-Fidelity Multi-Block Solvers

    NASA Technical Reports Server (NTRS)

    Hatay, Ferhat F.; Jespersen, Dennis C.; Guruswamy, Guru P.; Rizk, Yehia M.; Byun, Chansup; Gee, Ken; VanDalsem, William R. (Technical Monitor)

    1997-01-01

    The integration of high-fidelity Computational Fluid Dynamics (CFD) analysis tools with the industrial design process benefits greatly from the robust implementations that are transportable across a wide range of computer architectures. In the present work, a hybrid domain-decomposition and parallelization concept was developed and implemented into the widely-used NASA multi-block Computational Fluid Dynamics (CFD) packages implemented in ENSAERO and OVERFLOW. The new parallel solver concept, PENS (Parallel Euler Navier-Stokes Solver), employs both fine and coarse granularity in data partitioning as well as data coalescing to obtain the desired load-balance characteristics on the available computer platforms. This multi-level parallelism implementation itself introduces no changes to the numerical results, hence the original fidelity of the packages are identically preserved. The present implementation uses the Message Passing Interface (MPI) library for interprocessor message passing and memory accessing. By choosing an appropriate combination of the available partitioning and coalescing capabilities only during the execution stage, the PENS solver becomes adaptable to different computer architectures from shared-memory to distributed-memory platforms with varying degrees of parallelism. The PENS implementation on the IBM SP2 distributed memory environment at the NASA Ames Research Center obtains 85 percent scalable parallel performance using fine-grain partitioning of single-block CFD domains using up to 128 wide computational nodes. Multi-block CFD simulations of complete aircraft simulations achieve 75 percent perfect load-balanced executions using data coalescing and the two levels of parallelism. SGI PowerChallenge, SGI Origin 2000, and a cluster of workstations are the other platforms where the robustness of the implementation is tested. The performance behavior on the other computer platforms with a variety of realistic problems will be included as this on-going study progresses.

  12. Message passing interface and multithreading hybrid for parallel molecular docking of large databases on petascale high performance computing machines.

    PubMed

    Zhang, Xiaohua; Wong, Sergio E; Lightstone, Felice C

    2013-04-30

    A mixed parallel scheme that combines message passing interface (MPI) and multithreading was implemented in the AutoDock Vina molecular docking program. The resulting program, named VinaLC, was tested on the petascale high performance computing (HPC) machines at Lawrence Livermore National Laboratory. To exploit the typical cluster-type supercomputers, thousands of docking calculations were dispatched by the master process to run simultaneously on thousands of slave processes, where each docking calculation takes one slave process on one node, and within the node each docking calculation runs via multithreading on multiple CPU cores and shared memory. Input and output of the program and the data handling within the program were carefully designed to deal with large databases and ultimately achieve HPC on a large number of CPU cores. Parallel performance analysis of the VinaLC program shows that the code scales up to more than 15K CPUs with a very low overhead cost of 3.94%. One million flexible compound docking calculations took only 1.4 h to finish on about 15K CPUs. The docking accuracy of VinaLC has been validated against the DUD data set by the re-docking of X-ray ligands and an enrichment study, 64.4% of the top scoring poses have RMSD values under 2.0 Å. The program has been demonstrated to have good enrichment performance on 70% of the targets in the DUD data set. An analysis of the enrichment factors calculated at various percentages of the screening database indicates VinaLC has very good early recovery of actives. Copyright © 2013 Wiley Periodicals, Inc.

  13. Constrained low-rank matrix estimation: phase transitions, approximate message passing and applications

    NASA Astrophysics Data System (ADS)

    Lesieur, Thibault; Krzakala, Florent; Zdeborová, Lenka

    2017-07-01

    This article is an extended version of previous work of Lesieur et al (2015 IEEE Int. Symp. on Information Theory Proc. pp 1635-9 and 2015 53rd Annual Allerton Conf. on Communication, Control and Computing (IEEE) pp 680-7) on low-rank matrix estimation in the presence of constraints on the factors into which the matrix is factorized. Low-rank matrix factorization is one of the basic methods used in data analysis for unsupervised learning of relevant features and other types of dimensionality reduction. We present a framework to study the constrained low-rank matrix estimation for a general prior on the factors, and a general output channel through which the matrix is observed. We draw a parallel with the study of vector-spin glass models—presenting a unifying way to study a number of problems considered previously in separate statistical physics works. We present a number of applications for the problem in data analysis. We derive in detail a general form of the low-rank approximate message passing (Low-RAMP) algorithm, that is known in statistical physics as the TAP equations. We thus unify the derivation of the TAP equations for models as different as the Sherrington-Kirkpatrick model, the restricted Boltzmann machine, the Hopfield model or vector (xy, Heisenberg and other) spin glasses. The state evolution of the Low-RAMP algorithm is also derived, and is equivalent to the replica symmetric solution for the large class of vector-spin glass models. In the section devoted to result we study in detail phase diagrams and phase transitions for the Bayes-optimal inference in low-rank matrix estimation. We present a typology of phase transitions and their relation to performance of algorithms such as the Low-RAMP or commonly used spectral methods.

  14. Optimising text messaging to improve adherence to web-based smoking cessation treatment: a randomised control trial protocol.

    PubMed

    Graham, Amanda L; Jacobs, Megan A; Cohn, Amy M; Cha, Sarah; Abroms, Lorien C; Papandonatos, George D; Whittaker, Robyn

    2016-03-30

    Millions of smokers use the Internet for smoking cessation assistance each year; however, most smokers engage minimally with even the best designed websites. The ubiquity of mobile devices and their effectiveness in promoting adherence in other areas of health behaviour change make them a promising tool to address adherence in Internet smoking cessation interventions. Text messaging is used by most adults, and messages can proactively encourage use of a web-based intervention. Text messaging can also be integrated with an Internet intervention to facilitate the use of core Internet intervention components. We identified four aspects of a text message intervention that may enhance its effectiveness in promoting adherence to a web-based smoking cessation programme: personalisation, integration, dynamic tailoring and message intensity. Phase I will use a two-level full factorial design to test the impact of these four experimental features on adherence to a web-based intervention. The primary outcome is a composite metric of adherence that incorporates general utilisation metrics (eg, logins, page views) and specific feature utilisation shown to predict abstinence. Participants will be N=860 adult smokers who register on an established Internet cessation programme and enrol in its text message programme. Phase II will be a two-arm randomised trial to compare the efficacy of the web-based cessation programme alone and in conjunction with the optimised text messaging intervention on 30-day point prevalence abstinence at 9 months. Phase II participants will be N=600 adult smokers who register to use an established Internet cessation programme and enrol in text messaging. Secondary analyses will explore whether adherence mediates the effect of treatment condition on outcome. This protocol was approved by Chesapeake IRB. We will disseminate study results through peer-reviewed manuscripts and conference presentations related to the methods and design, outcomes and exploratory analyses. NCT02585206. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  15. A lightweight messaging-based distributed processing and workflow execution framework for real-time and big data analysis

    NASA Astrophysics Data System (ADS)

    Laban, Shaban; El-Desouky, Aly

    2014-05-01

    To achieve a rapid, simple and reliable parallel processing of different types of tasks and big data processing on any compute cluster, a lightweight messaging-based distributed applications processing and workflow execution framework model is proposed. The framework is based on Apache ActiveMQ and Simple (or Streaming) Text Oriented Message Protocol (STOMP). ActiveMQ , a popular and powerful open source persistence messaging and integration patterns server with scheduler capabilities, acts as a message broker in the framework. STOMP provides an interoperable wire format that allows framework programs to talk and interact between each other and ActiveMQ easily. In order to efficiently use the message broker a unified message and topic naming pattern is utilized to achieve the required operation. Only three Python programs and simple library, used to unify and simplify the implementation of activeMQ and STOMP protocol, are needed to use the framework. A watchdog program is used to monitor, remove, add, start and stop any machine and/or its different tasks when necessary. For every machine a dedicated one and only one zoo keeper program is used to start different functions or tasks, stompShell program, needed for executing the user required workflow. The stompShell instances are used to execute any workflow jobs based on received message. A well-defined, simple and flexible message structure, based on JavaScript Object Notation (JSON), is used to build any complex workflow systems. Also, JSON format is used in configuration, communication between machines and programs. The framework is platform independent. Although, the framework is built using Python the actual workflow programs or jobs can be implemented by any programming language. The generic framework can be used in small national data centres for processing seismological and radionuclide data received from the International Data Centre (IDC) of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). Also, it is possible to extend the use of the framework in monitoring the IDC pipeline. The detailed design, implementation,conclusion and future work of the proposed framework will be presented.

  16. Testing a social cognitive theory-based model of indoor tanning: implications for skin cancer prevention messages.

    PubMed

    Noar, Seth M; Myrick, Jessica Gall; Zeitany, Alexandra; Kelley, Dannielle; Morales-Pico, Brenda; Thomas, Nancy E

    2015-01-01

    The lack of a theory-based understanding of indoor tanning is a major impediment to the development of effective messages to prevent or reduce this behavior. This study applied the Comprehensive Indoor Tanning Expectations (CITE) scale in an analysis of indoor tanning behavior among sorority women (total N = 775). Confirmatory factor analyses indicated that CITE positive and negative expectations were robust, multidimensional factors and that a hierarchical structure fit the data well. Social cognitive theory-based structural equation models demonstrated that appearance-oriented variables were significantly associated with outcome expectations. Outcome expectations were, in turn, significantly associated with temptations to tan, intention to tan indoors, and indoor tanning behavior. The implications of these findings for the development of messages to prevent and reduce indoor tanning behavior are discussed in two domains: (a) messages that attempt to change broader societal perceptions about tan skin, and (b) messages that focus more narrowly on indoor tanning-challenging positive expectations, enhancing negative expectations, and encouraging substitution of sunless tanning products.

  17. ConformRank: A conformity-based rank for finding top-k influential users

    NASA Astrophysics Data System (ADS)

    Wang, Qiyao; Jin, Yuehui; Cheng, Shiduan; Yang, Tan

    2017-05-01

    Finding influential users is a hot topic in social networks. For example, advertisers identify influential users to make a successful campaign. Retweeters forward messages from original users, who originally publish messages. This action is referred to as retweeting. Retweeting behaviors generate influence. Original users have influence on retweeters. Whether retweeters keep the same sentiment as original users is taken into consideration in this study. Influence is calculated based on conformity from emotional perspective after retweeting. A conformity-based algorithm, called ConformRank, is proposed to find top-k influential users, who make the most users keep the same sentiment after retweeting messages. Emotional conformity is introduced to denote how users conform to original users from the emotional perspective. Conforming weights are introduced to denote how two users keep the same sentiment after retweeting messages. Emotional conformity is applied for users and conforming weights are used for relations. Experiments were conducted on Sina Weibo. Experimental results show that users have larger influence when they publish positive messages.

  18. [Effects of attitude formation, persuasive message, and source expertise on attitude change: an examination based on the Elaboration Likelihood Model and the Attitude Formation Theory].

    PubMed

    Nakamura, M; Saito, K; Wakabayashi, M

    1990-04-01

    The purpose of this study was to investigate how attitude change is generated by the recipient's degree of attitude formation, evaluative-emotional elements contained in the persuasive messages, and source expertise as a peripheral cue in the persuasion context. Hypotheses based on the Attitude Formation Theory of Mizuhara (1982) and the Elaboration Likelihood Model of Petty and Cacioppo (1981, 1986) were examined. Eighty undergraduate students served as subjects in the experiment, the first stage of which involving manipulating the degree of attitude formation with respect to nuclear power development. Then, the experimenter presented persuasive messages with varying combinations of evaluative-emotional elements from a source with either high or low expertise on the subject. Results revealed a significant interaction effect on attitude change among attitude formation, persuasive message and the expertise of the message source. That is, high attitude formation subjects resisted evaluative-emotional persuasion from the high expertise source while low attitude formation subjects changed their attitude when exposed to the same persuasive message from a low expertise source. Results exceeded initial predictions based on the Attitude Formation Theory and the Elaboration Likelihood Model.

  19. Theory-Based Formative Research on an Anti-Cyberbullying Victimization Intervention Message.

    PubMed

    Savage, Matthew W; Deiss, Douglas M; Roberto, Anthony J; Aboujaoude, Elias

    2017-02-01

    Cyberbullying is a common byproduct of the digital revolution with serious consequences to victims. Unfortunately, there is a dearth of empirically based methods to confront it. This study used social cognitive theory to design and test an intervention message aimed at persuading college students to abstain from retaliation, seek social support, save evidence, and notify authorities-important victim responses identified and recommended in previous research. Using a posttest-only control group design, this study tested the effectiveness of an intervention message in changing college students' perceived susceptibility to and perceived severity of cyberbullying as well as their self-efficacy, response efficacy, attitudes, and behavioral intentions toward each recommended response in future episodes of cyberbullying. Results indicated that the intervention message caused participants in the experimental condition to report significantly higher susceptibility, but not perceived severity, to cyberbullying than those in the control condition. The intervention message also caused expected changes in all outcomes except self-efficacy for not retaliating and in all outcomes for seeking social support, saving evidence, and notifying an authority. Implications for message design and future research supporting evidence-based anti-cyberbullying health communication campaigns are discussed.

  20. Relational Messages Associated with Nonverbal Behaviors.

    ERIC Educational Resources Information Center

    Burgoon, Judee K.; And Others

    Based on the assumptions that relational messages are multidimensional and that they are largely communicated by nonverbal cues, this experiment manipulated five nonverbal cues--eye contact, proximity, body lean, smiling, and touch--to determine what meanings they convey along four relational message dimensions: emotionality/arousal/composure,…

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