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.
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.
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
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.
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.
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.
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.
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.
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.
Ordering Traces Logically to Identify Lateness in Message Passing Programs
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
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.
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.
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.
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.
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.
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.
WinHPC System Programming | High-Performance Computing | NREL
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
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.
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.
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.
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.
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.
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.
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.
Advanced Numerical Techniques of Performance Evaluation. Volume 2
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
Terrorism Risk Insurance Program Reauthorization Act of 2014
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:
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.
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.
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.
Efficiently passing messages in distributed spiking neural network simulation.
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.
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.
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).
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.
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
The serial message-passing schedule for LDPC decoding algorithms
NASA Astrophysics Data System (ADS)
Liu, Mingshan; Liu, Shanshan; Zhou, Yuan; Jiang, Xue
2015-12-01
The conventional message-passing schedule for LDPC decoding algorithms is the so-called flooding schedule. It has the disadvantage that the updated messages cannot be used until next iteration, thus reducing the convergence speed . In this case, the Layered Decoding algorithm (LBP) based on serial message-passing schedule is proposed. In this paper the decoding principle of LBP algorithm is briefly introduced, and then proposed its two improved algorithms, the grouped serial decoding algorithm (Grouped LBP) and the semi-serial decoding algorithm .They can improve LBP algorithm's decoding speed while maintaining a good decoding performance.
A Model for Speedup of Parallel Programs
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
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.
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.
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.
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
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.
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.
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.
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.
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.
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
Message passing with parallel queue traversal
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.
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
Neighbourhood-consensus message passing and its potentials in image processing applications
NASA Astrophysics Data System (ADS)
Ružic, Tijana; Pižurica, Aleksandra; Philips, Wilfried
2011-03-01
In this paper, a novel algorithm for inference in Markov Random Fields (MRFs) is presented. Its goal is to find approximate maximum a posteriori estimates in a simple manner by combining neighbourhood influence of iterated conditional modes (ICM) and message passing of loopy belief propagation (LBP). We call the proposed method neighbourhood-consensus message passing because a single joint message is sent from the specified neighbourhood to the central node. The message, as a function of beliefs, represents the agreement of all nodes within the neighbourhood regarding the labels of the central node. This way we are able to overcome the disadvantages of reference algorithms, ICM and LBP. On one hand, more information is propagated in comparison with ICM, while on the other hand, the huge amount of pairwise interactions is avoided in comparison with LBP by working with neighbourhoods. The idea is related to the previously developed iterated conditional expectations algorithm. Here we revisit it and redefine it in a message passing framework in a more general form. The results on three different benchmarks demonstrate that the proposed technique can perform well both for binary and multi-label MRFs without any limitations on the model definition. Furthermore, it manifests improved performance over related techniques either in terms of quality and/or speed.
Foundations for a healthy future.
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.
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.
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…
Dispatching packets on a global combining network of a parallel computer
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.
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.
Cellular automata with object-oriented features for parallel molecular network modeling.
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.
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.
DMA engine for repeating communication patterns
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.
IMPETUS - Interactive MultiPhysics Environment for Unified Simulations.
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.
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.
Statistical Inference in Graphical Models
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
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.
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.
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.
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.
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)
Saguaro: A Distributed Operating System Based on Pools of Servers.
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
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
Sutton, Jeannette; Gibson, C. Ben; Spiro, Emma S.; League, Cedar; Fitzhugh, Sean M.; Butts, Carter T.
2015-01-01
Message retransmission is a central aspect of information diffusion. In a disaster context, the passing on of official warning messages by members of the public also serves as a behavioral indicator of message salience, suggesting that particular messages are (or are not) perceived by the public to be both noteworthy and valuable enough to share with others. This study provides the first examination of terse message retransmission of official warning messages in response to a domestic terrorist attack, the Boston Marathon Bombing in 2013. Using messages posted from public officials’ Twitter accounts that were active during the period of the Boston Marathon bombing and manhunt, we examine the features of messages that are associated with their retransmission. We focus on message content, style, and structure, as well as the networked relationships of message senders to answer the question: what characteristics of a terse message sent under conditions of imminent threat predict its retransmission among members of the public? We employ a negative binomial model to examine how message characteristics affect message retransmission. We find that, rather than any single effect dominating the process, retransmission of official Tweets during the Boston bombing response was jointly influenced by various message content, style, and sender characteristics. These findings suggest the need for more work that investigates impact of multiple factors on the allocation of attention and on message retransmission during hazard events. PMID:26295584
The Edge-Disjoint Path Problem on Random Graphs by Message-Passing.
Altarelli, Fabrizio; Braunstein, Alfredo; Dall'Asta, Luca; De Bacco, Caterina; Franz, Silvio
2015-01-01
We present a message-passing algorithm to solve a series of edge-disjoint path problems on graphs based on the zero-temperature cavity equations. Edge-disjoint paths problems are important in the general context of routing, that can be defined by incorporating under a unique framework both traffic optimization and total path length minimization. The computation of the cavity equations can be performed efficiently by exploiting a mapping of a generalized edge-disjoint path problem on a star graph onto a weighted maximum matching problem. We perform extensive numerical simulations on random graphs of various types to test the performance both in terms of path length minimization and maximization of the number of accommodated paths. In addition, we test the performance on benchmark instances on various graphs by comparison with state-of-the-art algorithms and results found in the literature. Our message-passing algorithm always outperforms the others in terms of the number of accommodated paths when considering non trivial instances (otherwise it gives the same trivial results). Remarkably, the largest improvement in performance with respect to the other methods employed is found in the case of benchmarks with meshes, where the validity hypothesis behind message-passing is expected to worsen. In these cases, even though the exact message-passing equations do not converge, by introducing a reinforcement parameter to force convergence towards a sub optimal solution, we were able to always outperform the other algorithms with a peak of 27% performance improvement in terms of accommodated paths. On random graphs, we numerically observe two separated regimes: one in which all paths can be accommodated and one in which this is not possible. We also investigate the behavior of both the number of paths to be accommodated and their minimum total length.
The Edge-Disjoint Path Problem on Random Graphs by Message-Passing
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
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.
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.
Supporting shared data structures on distributed memory architectures
NASA Technical Reports Server (NTRS)
Koelbel, Charles; Mehrotra, Piyush; Vanrosendale, John
1990-01-01
Programming nonshared memory systems is more difficult than programming shared memory systems, since there is no support for shared data structures. Current programming languages for distributed memory architectures force the user to decompose all data structures into separate pieces, with each piece owned by one of the processors in the machine, and with all communication explicitly specified by low-level message-passing primitives. A new programming environment is presented for distributed memory architectures, providing a global name space and allowing direct access to remote parts of data values. The analysis and program transformations required to implement this environment are described, and the efficiency of the resulting code on the NCUBE/7 and IPSC/2 hypercubes are described.
Message passing with a limited number of DMA byte counters
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.
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."
Public-channel cryptography based on mutual chaos pass filters.
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.
A Survey of Rollback-Recovery Protocols in Message-Passing Systems
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
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
Parallelization of a hydrological model using the message passing interface
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.
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.
Belief propagation decoding of quantum channels by passing quantum messages
NASA Astrophysics Data System (ADS)
Renes, Joseph M.
2017-07-01
The belief propagation (BP) algorithm is a powerful tool in a wide range of disciplines from statistical physics to machine learning to computational biology, and is ubiquitous in decoding classical error-correcting codes. The algorithm works by passing messages between nodes of the factor graph associated with the code and enables efficient decoding of the channel, in some cases even up to the Shannon capacity. Here we construct the first BP algorithm which passes quantum messages on the factor graph and is capable of decoding the classical-quantum channel with pure state outputs. This gives explicit decoding circuits whose number of gates is quadratic in the code length. We also show that this decoder can be modified to work with polar codes for the pure state channel and as part of a decoder for transmitting quantum information over the amplitude damping channel. These represent the first explicit capacity-achieving decoders for non-Pauli channels.
LCAMP: Location Constrained Approximate Message Passing for Compressed Sensing MRI
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
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.
Eigensolver for a Sparse, Large Hermitian Matrix
NASA Technical Reports Server (NTRS)
Tisdale, E. Robert; Oyafuso, Fabiano; Klimeck, Gerhard; Brown, R. Chris
2003-01-01
A parallel-processing computer program finds a few eigenvalues in a sparse Hermitian matrix that contains as many as 100 million diagonal elements. This program finds the eigenvalues faster, using less memory, than do other, comparable eigensolver programs. This program implements a Lanczos algorithm in the American National Standards Institute/ International Organization for Standardization (ANSI/ISO) C computing language, using the Message Passing Interface (MPI) standard to complement an eigensolver in PARPACK. [PARPACK (Parallel Arnoldi Package) is an extension, to parallel-processing computer architectures, of ARPACK (Arnoldi Package), which is a collection of Fortran 77 subroutines that solve large-scale eigenvalue problems.] The eigensolver runs on Beowulf clusters of computers at the Jet Propulsion Laboratory (JPL).
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.
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.
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.
The graphical brain: Belief propagation and active inference
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
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.
Design and Implementation of an Operations Module for the ARGOS paperless Ship System
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
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.
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)…
Inference in the brain: Statistics flowing in redundant population codes
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
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.
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.
NASA Technical Reports Server (NTRS)
Lawson, Gary; Poteat, Michael; Sosonkina, Masha; Baurle, Robert; Hammond, Dana
2016-01-01
In this work, several mini-apps have been created to enhance a real-world application performance, namely the VULCAN code for complex flow analysis developed at the NASA Langley Research Center. These mini-apps explore hybrid parallel programming paradigms with Message Passing Interface (MPI) for distributed memory access and either Shared MPI (SMPI) or OpenMP for shared memory accesses. Performance testing shows that MPI+SMPI yields the best execution performance, while requiring the largest number of code changes. A maximum speedup of 23X was measured for MPI+SMPI, but only 10X was measured for MPI+OpenMP.
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.
Gene-network inference by message passing
NASA Astrophysics Data System (ADS)
Braunstein, A.; Pagnani, A.; Weigt, M.; Zecchina, R.
2008-01-01
The inference of gene-regulatory processes from gene-expression data belongs to the major challenges of computational systems biology. Here we address the problem from a statistical-physics perspective and develop a message-passing algorithm which is able to infer sparse, directed and combinatorial regulatory mechanisms. Using the replica technique, the algorithmic performance can be characterized analytically for artificially generated data. The algorithm is applied to genome-wide expression data of baker's yeast under various environmental conditions. We find clear cases of combinatorial control, and enrichment in common functional annotations of regulated genes and their regulators.
Optimal mapping of neural-network learning on message-passing multicomputers
NASA Technical Reports Server (NTRS)
Chu, Lon-Chan; Wah, Benjamin W.
1992-01-01
A minimization of learning-algorithm completion time is sought in the present optimal-mapping study of the learning process in multilayer feed-forward artificial neural networks (ANNs) for message-passing multicomputers. A novel approximation algorithm for mappings of this kind is derived from observations of the dominance of a parallel ANN algorithm over its communication time. Attention is given to both static and dynamic mapping schemes for systems with static and dynamic background workloads, as well as to experimental results obtained for simulated mappings on multicomputers with dynamic background workloads.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shipman, Galen M.
These are the slides for a presentation on programming models in HPC, at the Los Alamos National Laboratory's Parallel Computing Summer School. The following topics are covered: Flynn's Taxonomy of computer architectures; single instruction single data; single instruction multiple data; multiple instruction multiple data; address space organization; definition of Trinity (Intel Xeon-Phi is a MIMD architecture); single program multiple data; multiple program multiple data; ExMatEx workflow overview; definition of a programming model, programming languages, runtime systems; programming model and environments; MPI (Message Passing Interface); OpenMP; Kokkos (Performance Portable Thread-Parallel Programming Model); Kokkos abstractions, patterns, policies, and spaces; RAJA, a systematicmore » approach to node-level portability and tuning; overview of the Legion Programming Model; mapping tasks and data to hardware resources; interoperability: supporting task-level models; Legion S3D execution and performance details; workflow, integration of external resources into the programming model.« less
An interactive parallel programming environment applied in atmospheric science
NASA Technical Reports Server (NTRS)
vonLaszewski, G.
1996-01-01
This article introduces an interactive parallel programming environment (IPPE) that simplifies the generation and execution of parallel programs. One of the tasks of the environment is to generate message-passing parallel programs for homogeneous and heterogeneous computing platforms. The parallel programs are represented by using visual objects. This is accomplished with the help of a graphical programming editor that is implemented in Java and enables portability to a wide variety of computer platforms. In contrast to other graphical programming systems, reusable parts of the programs can be stored in a program library to support rapid prototyping. In addition, runtime performance data on different computing platforms is collected in a database. A selection process determines dynamically the software and the hardware platform to be used to solve the problem in minimal wall-clock time. The environment is currently being tested on a Grand Challenge problem, the NASA four-dimensional data assimilation system.
Gauge-free cluster variational method by maximal messages and moment matching.
Domínguez, Eduardo; Lage-Castellanos, Alejandro; Mulet, Roberto; Ricci-Tersenghi, Federico
2017-04-01
We present an implementation of the cluster variational method (CVM) as a message passing algorithm. The kind of message passing algorithm used for CVM, usually named generalized belief propagation (GBP), is a generalization of the belief propagation algorithm in the same way that CVM is a generalization of the Bethe approximation for estimating the partition function. However, the connection between fixed points of GBP and the extremal points of the CVM free energy is usually not a one-to-one correspondence because of the existence of a gauge transformation involving the GBP messages. Our contribution is twofold. First, we propose a way of defining messages (fields) in a generic CVM approximation, such that messages arrive on a given region from all its ancestors, and not only from its direct parents, as in the standard parent-to-child GBP. We call this approach maximal messages. Second, we focus on the case of binary variables, reinterpreting the messages as fields enforcing the consistency between the moments of the local (marginal) probability distributions. We provide a precise rule to enforce all consistencies, avoiding any redundancy, that would otherwise lead to a gauge transformation on the messages. This moment matching method is gauge free, i.e., it guarantees that the resulting GBP is not gauge invariant. We apply our maximal messages and moment matching GBP to obtain an analytical expression for the critical temperature of the Ising model in general dimensions at the level of plaquette CVM. The values obtained outperform Bethe estimates, and are comparable with loop corrected belief propagation equations. The method allows for a straightforward generalization to disordered systems.
Gauge-free cluster variational method by maximal messages and moment matching
NASA Astrophysics Data System (ADS)
Domínguez, Eduardo; Lage-Castellanos, Alejandro; Mulet, Roberto; Ricci-Tersenghi, Federico
2017-04-01
We present an implementation of the cluster variational method (CVM) as a message passing algorithm. The kind of message passing algorithm used for CVM, usually named generalized belief propagation (GBP), is a generalization of the belief propagation algorithm in the same way that CVM is a generalization of the Bethe approximation for estimating the partition function. However, the connection between fixed points of GBP and the extremal points of the CVM free energy is usually not a one-to-one correspondence because of the existence of a gauge transformation involving the GBP messages. Our contribution is twofold. First, we propose a way of defining messages (fields) in a generic CVM approximation, such that messages arrive on a given region from all its ancestors, and not only from its direct parents, as in the standard parent-to-child GBP. We call this approach maximal messages. Second, we focus on the case of binary variables, reinterpreting the messages as fields enforcing the consistency between the moments of the local (marginal) probability distributions. We provide a precise rule to enforce all consistencies, avoiding any redundancy, that would otherwise lead to a gauge transformation on the messages. This moment matching method is gauge free, i.e., it guarantees that the resulting GBP is not gauge invariant. We apply our maximal messages and moment matching GBP to obtain an analytical expression for the critical temperature of the Ising model in general dimensions at the level of plaquette CVM. The values obtained outperform Bethe estimates, and are comparable with loop corrected belief propagation equations. The method allows for a straightforward generalization to disordered systems.
Multiple node remote messaging
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).
Parallel Programming Strategies for Irregular Adaptive Applications
NASA Technical Reports Server (NTRS)
Biswas, Rupak; Biegel, Bryan (Technical Monitor)
2001-01-01
Achieving scalable performance for dynamic irregular applications is eminently challenging. Traditional message-passing approaches have been making steady progress towards this goal; however, they suffer from complex implementation requirements. The use of a global address space greatly simplifies the programming task, but can degrade the performance for such computations. In this work, we examine two typical irregular adaptive applications, Dynamic Remeshing and N-Body, under competing programming methodologies and across various parallel architectures. The Dynamic Remeshing application simulates flow over an airfoil, and refines localized regions of the underlying unstructured mesh. The N-Body experiment models two neighboring Plummer galaxies that are about to undergo a merger. Both problems demonstrate dramatic changes in processor workloads and interprocessor communication with time; thus, dynamic load balancing is a required component.
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.
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...
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.
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.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gropp, W.D.; Keyes, D.E.
1988-03-01
The authors discuss the parallel implementation of preconditioned conjugate gradient (PCG)-based domain decomposition techniques for self-adjoint elliptic partial differential equations in two dimensions on several architectures. The complexity of these methods is described on a variety of message-passing parallel computers as a function of the size of the problem, number of processors and relative communication speeds of the processors. They show that communication startups are very important, and that even the small amount of global communication in these methods can significantly reduce the performance of many message-passing architectures.
n-body simulations using message passing parallel computers.
NASA Astrophysics Data System (ADS)
Grama, A. Y.; Kumar, V.; Sameh, A.
The authors present new parallel formulations of the Barnes-Hut method for n-body simulations on message passing computers. These parallel formulations partition the domain efficiently incurring minimal communication overhead. This is in contrast to existing schemes that are based on sorting a large number of keys or on the use of global data structures. The new formulations are augmented by alternate communication strategies which serve to minimize communication overhead. The impact of these communication strategies is experimentally studied. The authors report on experimental results obtained from an astrophysical simulation on an nCUBE2 parallel computer.
Implementation of a 3D mixing layer code on parallel computers
NASA Technical Reports Server (NTRS)
Roe, K.; Thakur, R.; Dang, T.; Bogucz, E.
1995-01-01
This paper summarizes our progress and experience in the development of a Computational-Fluid-Dynamics code on parallel computers to simulate three-dimensional spatially-developing mixing layers. In this initial study, the three-dimensional time-dependent Euler equations are solved using a finite-volume explicit time-marching algorithm. The code was first programmed in Fortran 77 for sequential computers. The code was then converted for use on parallel computers using the conventional message-passing technique, while we have not been able to compile the code with the present version of HPF compilers.
High-energy physics software parallelization using database techniques
NASA Astrophysics Data System (ADS)
Argante, E.; van der Stok, P. D. V.; Willers, I.
1997-02-01
A programming model for software parallelization, called CoCa, is introduced that copes with problems caused by typical features of high-energy physics software. By basing CoCa on the database transaction paradimg, the complexity induced by the parallelization is for a large part transparent to the programmer, resulting in a higher level of abstraction than the native message passing software. CoCa is implemented on a Meiko CS-2 and on a SUN SPARCcenter 2000 parallel computer. On the CS-2, the performance is comparable with the performance of native PVM and MPI.
Tolerant (parallel) Programming
NASA Technical Reports Server (NTRS)
DiNucci, David C.; Bailey, David H. (Technical Monitor)
1997-01-01
In order to be truly portable, a program must be tolerant of a wide range of development and execution environments, and a parallel program is just one which must be tolerant of a very wide range. This paper first defines the term "tolerant programming", then describes many layers of tools to accomplish it. The primary focus is on F-Nets, a formal model for expressing computation as a folded partial-ordering of operations, thereby providing an architecture-independent expression of tolerant parallel algorithms. For implementing F-Nets, Cooperative Data Sharing (CDS) is a subroutine package for implementing communication efficiently in a large number of environments (e.g. shared memory and message passing). Software Cabling (SC), a very-high-level graphical programming language for building large F-Nets, possesses many of the features normally expected from today's computer languages (e.g. data abstraction, array operations). Finally, L2(sup 3) is a CASE tool which facilitates the construction, compilation, execution, and debugging of SC programs.
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
Developing and Pretesting a Text Messaging Program for Health Behavior Change: Recommended Steps.
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.
Messages about appearance, food, weight and exercise in "tween" television.
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.
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.
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.
ms2: A molecular simulation tool for thermodynamic properties
NASA Astrophysics Data System (ADS)
Deublein, Stephan; Eckl, Bernhard; Stoll, Jürgen; Lishchuk, Sergey V.; Guevara-Carrion, Gabriela; Glass, Colin W.; Merker, Thorsten; Bernreuther, Martin; Hasse, Hans; Vrabec, Jadran
2011-11-01
This work presents the molecular simulation program ms2 that is designed for the calculation of thermodynamic properties of bulk fluids in equilibrium consisting of small electro-neutral molecules. ms2 features the two main molecular simulation techniques, molecular dynamics (MD) and Monte-Carlo. It supports the calculation of vapor-liquid equilibria of pure fluids and multi-component mixtures described by rigid molecular models on the basis of the grand equilibrium method. Furthermore, it is capable of sampling various classical ensembles and yields numerous thermodynamic properties. To evaluate the chemical potential, Widom's test molecule method and gradual insertion are implemented. Transport properties are determined by equilibrium MD simulations following the Green-Kubo formalism. ms2 is designed to meet the requirements of academia and industry, particularly achieving short response times and straightforward handling. It is written in Fortran90 and optimized for a fast execution on a broad range of computer architectures, spanning from single processor PCs over PC-clusters and vector computers to high-end parallel machines. The standard Message Passing Interface (MPI) is used for parallelization and ms2 is therefore easily portable to different computing platforms. Feature tools facilitate the interaction with the code and the interpretation of input and output files. The accuracy and reliability of ms2 has been shown for a large variety of fluids in preceding work. Program summaryProgram title:ms2 Catalogue identifier: AEJF_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJF_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Special Licence supplied by the authors No. of lines in distributed program, including test data, etc.: 82 794 No. of bytes in distributed program, including test data, etc.: 793 705 Distribution format: tar.gz Programming language: Fortran90 Computer: The simulation tool ms2 is usable on a wide variety of platforms, from single processor machines over PC-clusters and vector computers to vector-parallel architectures. (Tested with Fortran compilers: gfortran, Intel, PathScale, Portland Group and Sun Studio.) Operating system: Unix/Linux, Windows Has the code been vectorized or parallelized?: Yes. Message Passing Interface (MPI) protocol Scalability. Excellent scalability up to 16 processors for molecular dynamics and >512 processors for Monte-Carlo simulations. RAM:ms2 runs on single processors with 512 MB RAM. The memory demand rises with increasing number of processors used per node and increasing number of molecules. Classification: 7.7, 7.9, 12 External routines: Message Passing Interface (MPI) Nature of problem: Calculation of application oriented thermodynamic properties for rigid electro-neutral molecules: vapor-liquid equilibria, thermal and caloric data as well as transport properties of pure fluids and multi-component mixtures. Solution method: Molecular dynamics, Monte-Carlo, various classical ensembles, grand equilibrium method, Green-Kubo formalism. Restrictions: No. The system size is user-defined. Typical problems addressed by ms2 can be solved by simulating systems containing typically 2000 molecules or less. Unusual features: Feature tools are available for creating input files, analyzing simulation results and visualizing molecular trajectories. Additional comments: Sample makefiles for multiple operation platforms are provided. Documentation is provided with the installation package and is available at http://www.ms-2.de. Running time: The running time of ms2 depends on the problem set, the system size and the number of processes used in the simulation. Running four processes on a "Nehalem" processor, simulations calculating VLE data take between two and twelve hours, calculating transport properties between six and 24 hours.
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.
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.…
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.
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.
Automated Instrumentation, Monitoring and Visualization of PVM Programs Using AIMS
NASA Technical Reports Server (NTRS)
Mehra, Pankaj; VanVoorst, Brian; Yan, Jerry; Lum, Henry, Jr. (Technical Monitor)
1994-01-01
We present views and analysis of the execution of several PVM (Parallel Virtual Machine) codes for Computational Fluid Dynamics on a networks of Sparcstations, including: (1) NAS Parallel Benchmarks CG and MG; (2) a multi-partitioning algorithm for NAS Parallel Benchmark SP; and (3) an overset grid flowsolver. These views and analysis were obtained using our Automated Instrumentation and Monitoring System (AIMS) version 3.0, a toolkit for debugging the performance of PVM programs. We will describe the architecture, operation and application of AIMS. The AIMS toolkit contains: (1) Xinstrument, which can automatically instrument various computational and communication constructs in message-passing parallel programs; (2) Monitor, a library of runtime trace-collection routines; (3) VK (Visual Kernel), an execution-animation tool with source-code clickback; and (4) Tally, a tool for statistical analysis of execution profiles. Currently, Xinstrument can handle C and Fortran 77 programs using PVM 3.2.x; Monitor has been implemented and tested on Sun 4 systems running SunOS 4.1.2; and VK uses XIIR5 and Motif 1.2. Data and views obtained using AIMS clearly illustrate several characteristic features of executing parallel programs on networked workstations: (1) the impact of long message latencies; (2) the impact of multiprogramming overheads and associated load imbalance; (3) cache and virtual-memory effects; and (4) significant skews between workstation clocks. Interestingly, AIMS can compensate for constant skew (zero drift) by calibrating the skew between a parent and its spawned children. In addition, AIMS' skew-compensation algorithm can adjust timestamps in a way that eliminates physically impossible communications (e.g., messages going backwards in time). Our current efforts are directed toward creating new views to explain the observed performance of PVM programs. Some of the features planned for the near future include: (1) ConfigView, showing the physical topology of the virtual machine, inferred using specially formatted IP (Internet Protocol) packets: and (2) LoadView, synchronous animation of PVM-program execution and resource-utilization patterns.
Asbestos: Securing Untrusted Software with Interposition
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
Mars Global Reference Atmospheric Model (Mars-GRAM 3.34): Programmer's Guide
NASA Technical Reports Server (NTRS)
Justus, C. G.; James, Bonnie F.; Johnson, Dale L.
1996-01-01
This is a programmer's guide for the Mars Global Reference Atmospheric Model (Mars-GRAM 3.34). Included are a brief history and review of the model since its origin in 1988 and a technical discussion of recent additions and modifications. Examples of how to run both the interactive and batch (subroutine) forms are presented. Instructions are provided on how to customize output of the model for various parameters of the Mars atmosphere. Detailed descriptions are given of the main driver programs, subroutines, and associated computational methods. Lists and descriptions include input, output, and local variables in the programs. These descriptions give a summary of program steps and 'map' of calling relationships among the subroutines. Definitions are provided for the variables passed between subroutines through common lists. Explanations are provided for all diagnostic and progress messages generated during execution of the program. A brief outline of future plans for Mars-GRAM is also presented.
User-Defined Data Distributions in High-Level Programming Languages
NASA Technical Reports Server (NTRS)
Diaconescu, Roxana E.; Zima, Hans P.
2006-01-01
One of the characteristic features of today s high performance computing systems is a physically distributed memory. Efficient management of locality is essential for meeting key performance requirements for these architectures. The standard technique for dealing with this issue has involved the extension of traditional sequential programming languages with explicit message passing, in the context of a processor-centric view of parallel computation. This has resulted in complex and error-prone assembly-style codes in which algorithms and communication are inextricably interwoven. This paper presents a high-level approach to the design and implementation of data distributions. Our work is motivated by the need to improve the current parallel programming methodology by introducing a paradigm supporting the development of efficient and reusable parallel code. This approach is currently being implemented in the context of a new programming language called Chapel, which is designed in the HPCS project Cascade.
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.
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
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.
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.
Static analysis techniques for semiautomatic synthesis of message passing software skeletons
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
DOE Office of Scientific and Technical Information (OSTI.GOV)
Littlefield, R.J.
1990-02-01
To implement an efficient data-parallel program on a non-shared memory MIMD multicomputer, data and computations must be properly partitioned to achieve good load balance and locality of reference. Programs with irregular data reference patterns often require irregular partitions. Although good partitions may be easy to determine, they can be difficult or impossible to implement in programming languages that provide only regular data distributions, such as blocked or cyclic arrays. We are developing Onyx, a programming system that provides a shared memory model of distributed data structures and extends the concept of data distribution to include irregular and dynamic distributions. Thismore » provides a powerful means to specify irregular partitions. Perhaps surprisingly, programs using it can also execute efficiently. In this paper, we describe and evaluate the Onyx implementation of a model problem that repeatedly executes an irregular but fixed data reference pattern. On an NCUBE hypercube, the speed of the Onyx implementation is comparable to that of carefully handwritten message-passing code.« less
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.
2013-08-20
Earth observation taken during day pass by an Expedition 36 crew member on board the International Space Station (ISS). Per Twitter message: Looking southwest over northern Africa. Libya, Algeria, Niger.
Application of a distributed network in computational fluid dynamic simulations
NASA Technical Reports Server (NTRS)
Deshpande, Manish; Feng, Jinzhang; Merkle, Charles L.; Deshpande, Ashish
1994-01-01
A general-purpose 3-D, incompressible Navier-Stokes algorithm is implemented on a network of concurrently operating workstations using parallel virtual machine (PVM) and compared with its performance on a CRAY Y-MP and on an Intel iPSC/860. The problem is relatively computationally intensive, and has a communication structure based primarily on nearest-neighbor communication, making it ideally suited to message passing. Such problems are frequently encountered in computational fluid dynamics (CDF), and their solution is increasingly in demand. The communication structure is explicitly coded in the implementation to fully exploit the regularity in message passing in order to produce a near-optimal solution. Results are presented for various grid sizes using up to eight processors.
Approximate message passing with restricted Boltzmann machine priors
NASA Astrophysics Data System (ADS)
Tramel, Eric W.; Drémeau, Angélique; Krzakala, Florent
2016-07-01
Approximate message passing (AMP) has been shown to be an excellent statistical approach to signal inference and compressed sensing problems. The AMP framework provides modularity in the choice of signal prior; here we propose a hierarchical form of the Gauss-Bernoulli prior which utilizes a restricted Boltzmann machine (RBM) trained on the signal support to push reconstruction performance beyond that of simple i.i.d. priors for signals whose support can be well represented by a trained binary RBM. We present and analyze two methods of RBM factorization and demonstrate how these affect signal reconstruction performance within our proposed algorithm. Finally, using the MNIST handwritten digit dataset, we show experimentally that using an RBM allows AMP to approach oracle-support performance.
High Performance Fortran for Aerospace Applications
NASA Technical Reports Server (NTRS)
Mehrotra, Piyush; Zima, Hans; Bushnell, Dennis M. (Technical Monitor)
2000-01-01
This paper focuses on the use of High Performance Fortran (HPF) for important classes of algorithms employed in aerospace applications. HPF is a set of Fortran extensions designed to provide users with a high-level interface for programming data parallel scientific applications, while delegating to the compiler/runtime system the task of generating explicitly parallel message-passing programs. We begin by providing a short overview of the HPF language. This is followed by a detailed discussion of the efficient use of HPF for applications involving multiple structured grids such as multiblock and adaptive mesh refinement (AMR) codes as well as unstructured grid codes. We focus on the data structures and computational structures used in these codes and on the high-level strategies that can be expressed in HPF to optimally exploit the parallelism in these algorithms.
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.
MPI implementation of PHOENICS: A general purpose computational fluid dynamics code
NASA Astrophysics Data System (ADS)
Simunovic, S.; Zacharia, T.; Baltas, N.; Spalding, D. B.
1995-03-01
PHOENICS is a suite of computational analysis programs that are used for simulation of fluid flow, heat transfer, and dynamical reaction processes. The parallel version of the solver EARTH for the Computational Fluid Dynamics (CFD) program PHOENICS has been implemented using Message Passing Interface (MPI) standard. Implementation of MPI version of PHOENICS makes this computational tool portable to a wide range of parallel machines and enables the use of high performance computing for large scale computational simulations. MPI libraries are available on several parallel architectures making the program usable across different architectures as well as on heterogeneous computer networks. The Intel Paragon NX and MPI versions of the program have been developed and tested on massively parallel supercomputers Intel Paragon XP/S 5, XP/S 35, and Kendall Square Research, and on the multiprocessor SGI Onyx computer at Oak Ridge National Laboratory. The preliminary testing results of the developed program have shown scalable performance for reasonably sized computational domains.
MPI implementation of PHOENICS: A general purpose computational fluid dynamics code
DOE Office of Scientific and Technical Information (OSTI.GOV)
Simunovic, S.; Zacharia, T.; Baltas, N.
1995-04-01
PHOENICS is a suite of computational analysis programs that are used for simulation of fluid flow, heat transfer, and dynamical reaction processes. The parallel version of the solver EARTH for the Computational Fluid Dynamics (CFD) program PHOENICS has been implemented using Message Passing Interface (MPI) standard. Implementation of MPI version of PHOENICS makes this computational tool portable to a wide range of parallel machines and enables the use of high performance computing for large scale computational simulations. MPI libraries are available on several parallel architectures making the program usable across different architectures as well as on heterogeneous computer networks. Themore » Intel Paragon NX and MPI versions of the program have been developed and tested on massively parallel supercomputers Intel Paragon XP/S 5, XP/S 35, and Kendall Square Research, and on the multiprocessor SGI Onyx computer at Oak Ridge National Laboratory. The preliminary testing results of the developed program have shown scalable performance for reasonably sized computational domains.« less
Passing messages between biological networks to refine predicted interactions.
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.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sayan Ghosh, Jeff Hammond
OpenSHMEM is a community effort to unifyt and standardize the SHMEM programming model. MPI (Message Passing Interface) is a well-known community standard for parallel programming using distributed memory. The most recen t release of MPI, version 3.0, was designed in part to support programming models like SHMEM.OSHMPI is an implementation of the OpenSHMEM standard using MPI-3 for the Linux operating system. It is the first implementation of SHMEM over MPI one-sided communication and has the potential to be widely adopted due to the portability and widely availability of Linux and MPI-3. OSHMPI has been tested on a variety of systemsmore » and implementations of MPI-3, includingInfiniBand clusters using MVAPICH2 and SGI shared-memory supercomputers using MPICH. Current support is limited to Linux but may be extended to Apple OSX if there is sufficient interest. The code is opensource via https://github.com/jeffhammond/oshmpi« less
Evaluating and extending user-level fault tolerance in MPI applications
Laguna, Ignacio; Richards, David F.; Gamblin, Todd; ...
2016-01-11
The user-level failure mitigation (ULFM) interface has been proposed to provide fault-tolerant semantics in the Message Passing Interface (MPI). Previous work presented performance evaluations of ULFM; yet questions related to its programability and applicability, especially to non-trivial, bulk synchronous applications, remain unanswered. In this article, we present our experiences on using ULFM in a case study with a large, highly scalable, bulk synchronous molecular dynamics application to shed light on the advantages and difficulties of this interface to program fault-tolerant MPI applications. We found that, although ULFM is suitable for master–worker applications, it provides few benefits for more common bulkmore » synchronous MPI applications. Furthermore, to address these limitations, we introduce a new, simpler fault-tolerant interface for complex, bulk synchronous MPI programs with better applicability and support than ULFM for application-level recovery mechanisms, such as global rollback.« less
Earth observation taken by the Expedition 46 crew
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".
Automated Instrumentation, Monitoring and Visualization of PVM Programs Using AIMS
NASA Technical Reports Server (NTRS)
Mehra, Pankaj; VanVoorst, Brian; Yan, Jerry; Tucker, Deanne (Technical Monitor)
1994-01-01
We present views and analysis of the execution of several PVM codes for Computational Fluid Dynamics on a network of Sparcstations, including (a) NAS Parallel benchmarks CG and MG (White, Alund and Sunderam 1993); (b) a multi-partitioning algorithm for NAS Parallel Benchmark SP (Wijngaart 1993); and (c) an overset grid flowsolver (Smith 1993). These views and analysis were obtained using our Automated Instrumentation and Monitoring System (AIMS) version 3.0, a toolkit for debugging the performance of PVM programs. We will describe the architecture, operation and application of AIMS. The AIMS toolkit contains (a) Xinstrument, which can automatically instrument various computational and communication constructs in message-passing parallel programs; (b) Monitor, a library of run-time trace-collection routines; (c) VK (Visual Kernel), an execution-animation tool with source-code clickback; and (d) Tally, a tool for statistical analysis of execution profiles. Currently, Xinstrument can handle C and Fortran77 programs using PVM 3.2.x; Monitor has been implemented and tested on Sun 4 systems running SunOS 4.1.2; and VK uses X11R5 and Motif 1.2. Data and views obtained using AIMS clearly illustrate several characteristic features of executing parallel programs on networked workstations: (a) the impact of long message latencies; (b) the impact of multiprogramming overheads and associated load imbalance; (c) cache and virtual-memory effects; and (4significant skews between workstation clocks. Interestingly, AIMS can compensate for constant skew (zero drift) by calibrating the skew between a parent and its spawned children. In addition, AIMS' skew-compensation algorithm can adjust timestamps in a way that eliminates physically impossible communications (e.g., messages going backwards in time). Our current efforts are directed toward creating new views to explain the observed performance of PVM programs. Some of the features planned for the near future include: (a) ConfigView, showing the physical topology of the virtual machine, inferred using specially formatted IP (Internet Protocol) packets; and (b) LoadView, synchronous animation of PVM-program execution and resource-utilization patterns.
NASA Astrophysics Data System (ADS)
Bellerby, Tim
2015-04-01
PM (Parallel Models) is a new parallel programming language specifically designed for writing environmental and geophysical models. The language is intended to enable implementers to concentrate on the science behind the model rather than the details of running on parallel hardware. At the same time PM leaves the programmer in control - all parallelisation is explicit and the parallel structure of any given program may be deduced directly from the code. This paper describes a PM implementation based on the Message Passing Interface (MPI) and Open Multi-Processing (OpenMP) standards, looking at issues involved with translating the PM parallelisation model to MPI/OpenMP protocols and considering performance in terms of the competing factors of finer-grained parallelisation and increased communication overhead. In order to maximise portability, the implementation stays within the MPI 1.3 standard as much as possible, with MPI-2 MPI-IO file handling the only significant exception. Moreover, it does not assume a thread-safe implementation of MPI. PM adopts a two-tier abstract representation of parallel hardware. A PM processor is a conceptual unit capable of efficiently executing a set of language tasks, with a complete parallel system consisting of an abstract N-dimensional array of such processors. PM processors may map to single cores executing tasks using cooperative multi-tasking, to multiple cores or even to separate processing nodes, efficiently sharing tasks using algorithms such as work stealing. While tasks may move between hardware elements within a PM processor, they may not move between processors without specific programmer intervention. Tasks are assigned to processors using a nested parallelism approach, building on ideas from Reyes et al. (2009). The main program owns all available processors. When the program enters a parallel statement then either processors are divided out among the newly generated tasks (number of new tasks < number of processors) or tasks are divided out among the available processors (number of tasks > number of processors). Nested parallel statements may further subdivide the processor set owned by a given task. Tasks or processors are distributed evenly by default, but uneven distributions are possible under programmer control. It is also possible to explicitly enable child tasks to migrate within the processor set owned by their parent task, reducing load unbalancing at the potential cost of increased inter-processor message traffic. PM incorporates some programming structures from the earlier MIST language presented at a previous EGU General Assembly, while adopting a significantly different underlying parallelisation model and type system. PM code is available at www.pm-lang.org under an unrestrictive MIT license. Reference Ruymán Reyes, Antonio J. Dorta, Francisco Almeida, Francisco de Sande, 2009. Automatic Hybrid MPI+OpenMP Code Generation with llc, Recent Advances in Parallel Virtual Machine and Message Passing Interface, Lecture Notes in Computer Science Volume 5759, 185-195
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.
2013-08-03
Earth observation taken during day pass by an Expedition 36 crew member on board the International Space Station (ISS). Per Twitter message: Perhaps a dandelion losing its seeds in the wind? Love clouds!
Paralysis 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 ...
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.
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.
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.
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
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.
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.
Trellis Tone Modulation Multiple-Access for Peer Discovery in D2D Networks
Lim, Chiwoo; Kim, Sang-Hyo
2018-01-01
In this paper, a new non-orthogonal multiple-access scheme, trellis tone modulation multiple-access (TTMMA), is proposed for peer discovery of distributed device-to-device (D2D) communication. The range and capacity of discovery are important performance metrics in peer discovery. The proposed trellis tone modulation uses single-tone transmission and achieves a long discovery range due to its low Peak-to-Average Power Ratio (PAPR). The TTMMA also exploits non-orthogonal resource assignment to increase the discovery capacity. For the multi-user detection of superposed multiple-access signals, a message-passing algorithm with supplementary schemes are proposed. With TTMMA and its message-passing demodulation, approximately 1.5 times the number of devices are discovered compared to the conventional frequency division multiple-access (FDMA)-based discovery. PMID:29673167
Statistical physics of hard combinatorial optimization: Vertex cover problem
NASA Astrophysics Data System (ADS)
Zhao, Jin-Hua; Zhou, Hai-Jun
2014-07-01
Typical-case computation complexity is a research topic at the boundary of computer science, applied mathematics, and statistical physics. In the last twenty years, the replica-symmetry-breaking mean field theory of spin glasses and the associated message-passing algorithms have greatly deepened our understanding of typical-case computation complexity. In this paper, we use the vertex cover problem, a basic nondeterministic-polynomial (NP)-complete combinatorial optimization problem of wide application, as an example to introduce the statistical physical methods and algorithms. We do not go into the technical details but emphasize mainly the intuitive physical meanings of the message-passing equations. A nonfamiliar reader shall be able to understand to a large extent the physics behind the mean field approaches and to adjust the mean field methods in solving other optimization problems.
Trellis Tone Modulation Multiple-Access for Peer Discovery in D2D Networks.
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.
Moghadasi, Mohammad; Kozakov, Dima; Mamonov, Artem B.; Vakili, Pirooz; Vajda, Sandor; Paschalidis, Ioannis Ch.
2013-01-01
We introduce a message-passing algorithm to solve the Side Chain Positioning (SCP) problem. SCP is a crucial component of protein docking refinement, which is a key step of an important class of problems in computational structural biology called protein docking. We model SCP as a combinatorial optimization problem and formulate it as a Maximum Weighted Independent Set (MWIS) problem. We then employ a modified and convergent belief-propagation algorithm to solve a relaxation of MWIS and develop randomized estimation heuristics that use the relaxed solution to obtain an effective MWIS feasible solution. Using a benchmark set of protein complexes we demonstrate that our approach leads to more accurate docking predictions compared to a baseline algorithm that does not solve the SCP. PMID:23515575
Multi-partitioning for ADI-schemes on message passing architectures
NASA Technical Reports Server (NTRS)
Vanderwijngaart, Rob F.
1994-01-01
A kind of discrete-operator splitting called Alternating Direction Implicit (ADI) has been found to be useful in simulating fluid flow problems. In particular, it is being used to study the effects of hot exhaust jets from high performance aircraft on landing surfaces. Decomposition techniques that minimize load imbalance and message-passing frequency are described. Three strategies that are investigated for implementing the NAS Scalar Penta-diagonal Parallel Benchmark (SP) are transposition, pipelined Gaussian elimination, and multipartitioning. The multipartitioning strategy, which was used on Ethernet, was found to be the most efficient, although it was considered only a moderate success because of Ethernet's limited communication properties. The efficiency derived largely from the coarse granularity of the strategy, which reduced latencies and allowed overlap of communication and computation.
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
Ultrascalable petaflop parallel supercomputer
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.
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
A concurrent distributed system for aircraft tactical decision generation
NASA Technical Reports Server (NTRS)
Mcmanus, John W.
1990-01-01
A research program investigating the use of AI techniques to aid in the development of a tactical decision generator (TDG) for within visual range (WVR) air combat engagements is discussed. The application of AI programming and problem-solving methods in the development and implementation of a concurrent version of the computerized logic for air-to-air warfare simulations (CLAWS) program, a second-generation TDG, is presented. Concurrent computing environments and programming approaches are discussed, and the design and performance of prototype concurrent TDG system (Cube CLAWS) are presented. It is concluded that the Cube CLAWS has provided a useful testbed to evaluate the development of a distributed blackboard system. The project has shown that the complexity of developing specialized software on a distributed, message-passing architecture such as the Hypercube is not overwhelming, and that reasonable speedups and processor efficiency can be achieved by a distributed blackboard system. The project has also highlighted some of the costs of using a distributed approach to designing a blackboard system.
Automated Performance Prediction of Message-Passing Parallel Programs
NASA Technical Reports Server (NTRS)
Block, Robert J.; Sarukkai, Sekhar; Mehra, Pankaj; Woodrow, Thomas S. (Technical Monitor)
1995-01-01
The increasing use of massively parallel supercomputers to solve large-scale scientific problems has generated a need for tools that can predict scalability trends of applications written for these machines. Much work has been done to create simple models that represent important characteristics of parallel programs, such as latency, network contention, and communication volume. But many of these methods still require substantial manual effort to represent an application in the model's format. The NIK toolkit described in this paper is the result of an on-going effort to automate the formation of analytic expressions of program execution time, with a minimum of programmer assistance. In this paper we demonstrate the feasibility of our approach, by extending previous work to detect and model communication patterns automatically, with and without overlapped computations. The predictions derived from these models agree, within reasonable limits, with execution times of programs measured on the Intel iPSC/860 and Paragon. Further, we demonstrate the use of MK in selecting optimal computational grain size and studying various scalability metrics.
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.
NASA Technical Reports Server (NTRS)
Oliker, Leonid; Heber, Gerd; Biswas, Rupak
2000-01-01
The Conjugate Gradient (CG) algorithm is perhaps the best-known iterative technique to solve sparse linear systems that are symmetric and positive definite. A sparse matrix-vector multiply (SPMV) usually accounts for most of the floating-point operations within a CG iteration. In this paper, we investigate the effects of various ordering and partitioning strategies on the performance of parallel CG and SPMV using different programming paradigms and architectures. Results show that for this class of applications, ordering significantly improves overall performance, that cache reuse may be more important than reducing communication, and that it is possible to achieve message passing performance using shared memory constructs through careful data ordering and distribution. However, a multi-threaded implementation of CG on the Tera MTA does not require special ordering or partitioning to obtain high efficiency and scalability.
Performance and Application of Parallel OVERFLOW Codes on Distributed and Shared Memory Platforms
NASA Technical Reports Server (NTRS)
Djomehri, M. Jahed; Rizk, Yehia M.
1999-01-01
The presentation discusses recent studies on the performance of the two parallel versions of the aerodynamics CFD code, OVERFLOW_MPI and _MLP. Developed at NASA Ames, the serial version, OVERFLOW, is a multidimensional Navier-Stokes flow solver based on overset (Chimera) grid technology. The code has recently been parallelized in two ways. One is based on the explicit message-passing interface (MPI) across processors and uses the _MPI communication package. This approach is primarily suited for distributed memory systems and workstation clusters. The second, termed the multi-level parallel (MLP) method, is simple and uses shared memory for all communications. The _MLP code is suitable on distributed-shared memory systems. For both methods, the message passing takes place across the processors or processes at the advancement of each time step. This procedure is, in effect, the Chimera boundary conditions update, which is done in an explicit "Jacobi" style. In contrast, the update in the serial code is done in more of the "Gauss-Sidel" fashion. The programming efforts for the _MPI code is more complicated than for the _MLP code; the former requires modification of the outer and some inner shells of the serial code, whereas the latter focuses only on the outer shell of the code. The _MPI version offers a great deal of flexibility in distributing grid zones across a specified number of processors in order to achieve load balancing. The approach is capable of partitioning zones across multiple processors or sending each zone and/or cluster of several zones into a single processor. The message passing across the processors consists of Chimera boundary and/or an overlap of "halo" boundary points for each partitioned zone. The MLP version is a new coarse-grain parallel concept at the zonal and intra-zonal levels. A grouping strategy is used to distribute zones into several groups forming sub-processes which will run in parallel. The total volume of grid points in each group are approximately balanced. A proper number of threads are initially allocated to each group, and in subsequent iterations during the run-time, the number of threads are adjusted to achieve load balancing across the processes. Each process exploits the multitasking directives already established in Overflow.
Passing Messages between Biological Networks to Refine Predicted Interactions
Glass, Kimberly; Huttenhower, Curtis; Quackenbush, John; Yuan, Guo-Cheng
2013-01-01
Regulatory network reconstruction is a fundamental problem in computational biology. There are significant limitations to such reconstruction using individual datasets, and increasingly people attempt to construct networks using multiple, independent datasets obtained from complementary sources, but methods for this integration are lacking. We developed PANDA (Passing Attributes between Networks for Data Assimilation), a message-passing model using multiple sources of information to predict regulatory relationships, and used it to integrate protein-protein interaction, gene expression, and sequence motif data to reconstruct genome-wide, condition-specific regulatory networks in yeast as a model. The resulting networks were not only more accurate than those produced using individual data sets and other existing methods, but they also captured information regarding specific biological mechanisms and pathways that were missed using other methodologies. PANDA is scalable to higher eukaryotes, applicable to specific tissue or cell type data and conceptually generalizable to include a variety of regulatory, interaction, expression, and other genome-scale data. An implementation of the PANDA algorithm is available at www.sourceforge.net/projects/panda-net. PMID:23741402
Applications of Probabilistic Combiners on Linear Feedback Shift Register Sequences
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
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.
Sen. Alexander, Lamar [R-TN
2011-07-28
Senate - 12/19/2012 Message on House action received in Senate and at desk: House amendments to Senate bill. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:
Electronic Cigarettes on Twitter – Spreading the Appeal of Flavors
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
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.
NASA Astrophysics Data System (ADS)
Min, Byungjoon
2018-01-01
Identifying the most influential spreaders is one of outstanding problems in physics of complex systems. So far, many approaches have attempted to rank the influence of nodes but there is still the lack of accuracy to single out influential spreaders. Here, we directly tackle the problem of finding important spreaders by solving analytically the expected size of epidemic outbreaks when spreading originates from a single seed. We derive and validate a theory for calculating the size of epidemic outbreaks with a single seed using a message-passing approach. In addition, we find that the probability to occur epidemic outbreaks is highly dependent on the location of the seed but the size of epidemic outbreaks once it occurs is insensitive to the seed. We also show that our approach can be successfully adapted into weighted networks.
The design of multi-core DSP parallel model based on message passing and multi-level pipeline
NASA Astrophysics Data System (ADS)
Niu, Jingyu; Hu, Jian; He, Wenjing; Meng, Fanrong; Li, Chuanrong
2017-10-01
Currently, the design of embedded signal processing system is often based on a specific application, but this idea is not conducive to the rapid development of signal processing technology. In this paper, a parallel processing model architecture based on multi-core DSP platform is designed, and it is mainly suitable for the complex algorithms which are composed of different modules. This model combines the ideas of multi-level pipeline parallelism and message passing, and summarizes the advantages of the mainstream model of multi-core DSP (the Master-Slave model and the Data Flow model), so that it has better performance. This paper uses three-dimensional image generation algorithm to validate the efficiency of the proposed model by comparing with the effectiveness of the Master-Slave and the Data Flow model.
Generalized hypercube structures and hyperswitch communication network
NASA Technical Reports Server (NTRS)
Young, Steven D.
1992-01-01
This paper discusses an ongoing study that uses a recent development in communication control technology to implement hybrid hypercube structures. These architectures are similar to binary hypercubes, but they also provide added connectivity between the processors. This added connectivity increases communication reliability while decreasing the latency of interprocessor message passing. Because these factors directly determine the speed that can be obtained by multiprocessor systems, these architectures are attractive for applications such as remote exploration and experimentation, where high performance and ultrareliability are required. This paper describes and enumerates these architectures and discusses how they can be implemented with a modified version of the hyperswitch communication network (HCN). The HCN is analyzed because it has three attractive features that enable these architectures to be effective: speed, fault tolerance, and the ability to pass multiple messages simultaneously through the same hyperswitch controller.
Effective Compiler Error Message Enhancement for Novice Programming Students
ERIC Educational Resources Information Center
Becker, Brett A.; Glanville, Graham; Iwashima, Ricardo; McDonnell, Claire; Goslin, Kyle; Mooney, Catherine
2016-01-01
Programming is an essential skill that many computing students are expected to master. However, programming can be difficult to learn. Successfully interpreting compiler error messages (CEMs) is crucial for correcting errors and progressing toward success in programming. Yet these messages are often difficult to understand and pose a barrier to…
Austin, L S; Husted, K
1998-06-01
Mass media campaigns to influence public attitudes and behaviors in the area of mental health must consider cost-effectiveness, which is based on actual costs, the number of people reached (exposures), and the impact of the program on the individual. Cost per exposure is a critical factor. The authors review their experience in developing media programs in several broadcast formats and in print. Their experience suggests that an effective television production has a very high per-exposure cost and that radio is a more cost-effective way to present health messages. Radio programs also have the advantage of reaching people in their homes or cars or at work. Brief segments may be particularly cost-effective because they can be can be inserted between programs during prime-time hours. Print media--newspapers, magazines, and newsletters--can be cost-effective if magazine or newspaper space is free, but newsletters can be costly due to fixed postage costs. One advantage of print is that it can be reread, clipped out, copied, and passed on.
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.
2013-07-21
Earth observation taken during night pass by an Expedition 36 crew member on board the International Space Station (ISS). Per Twitter message this is labeled as : Tehran, Iran. Lights along the coast of the Caspian Sea visible through clouds. July 21.
Whistleblower Protection Enhancement Act of 2010
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:
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
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.
A contest to create media messages aimed at recruiting adolescents for stop smoking programs.
Croghan, Ivana T; Campbell, Heather M; Patten, Christi A; Croghan, Gary A; Schroeder, Darrell R; Novotny, Paul J
2004-10-01
This project engaged adolescents in a contest to create advertising messages aimed at recruiting teens for stop smoking programs. Middle school students were invited to design a media message for television, radio, Web, or print (newspaper or billboard). Of 4,289 students in eight middle schools of Rochester, Minn., 265 (6.2%) developed 172 stop smoking messages. The quality of their work confirmed that teens can design media messages to encourage their smoking adolescent peers to enroll in a program to stop smoking.
Facilitating Co-Design for Extreme-Scale Systems Through Lightweight Simulation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Engelmann, Christian; Lauer, Frank
This work focuses on tools for investigating algorithm performance at extreme scale with millions of concurrent threads and for evaluating the impact of future architecture choices to facilitate the co-design of high-performance computing (HPC) architectures and applications. The approach focuses on lightweight simulation of extreme-scale HPC systems with the needed amount of accuracy. The prototype presented in this paper is able to provide this capability using a parallel discrete event simulation (PDES), such that a Message Passing Interface (MPI) application can be executed at extreme scale, and its performance properties can be evaluated. The results of an initial prototype aremore » encouraging as a simple 'hello world' MPI program could be scaled up to 1,048,576 virtual MPI processes on a four-node cluster, and the performance properties of two MPI programs could be evaluated at up to 16,384 virtual MPI processes on the same system.« less
Multicore Challenges and Benefits for High Performance Scientific Computing
Nielsen, Ida M. B.; Janssen, Curtis L.
2008-01-01
Until recently, performance gains in processors were achieved largely by improvements in clock speeds and instruction level parallelism. Thus, applications could obtain performance increases with relatively minor changes by upgrading to the latest generation of computing hardware. Currently, however, processor performance improvements are realized by using multicore technology and hardware support for multiple threads within each core, and taking full advantage of this technology to improve the performance of applications requires exposure of extreme levels of software parallelism. We will here discuss the architecture of parallel computers constructed from many multicore chips as well as techniques for managing the complexitymore » of programming such computers, including the hybrid message-passing/multi-threading programming model. We will illustrate these ideas with a hybrid distributed memory matrix multiply and a quantum chemistry algorithm for energy computation using Møller–Plesset perturbation theory.« less
Discrete sensitivity derivatives of the Navier-Stokes equations with a parallel Krylov solver
NASA Technical Reports Server (NTRS)
Ajmani, Kumud; Taylor, Arthur C., III
1994-01-01
This paper solves an 'incremental' form of the sensitivity equations derived by differentiating the discretized thin-layer Navier Stokes equations with respect to certain design variables of interest. The equations are solved with a parallel, preconditioned Generalized Minimal RESidual (GMRES) solver on a distributed-memory architecture. The 'serial' sensitivity analysis code is parallelized by using the Single Program Multiple Data (SPMD) programming model, domain decomposition techniques, and message-passing tools. Sensitivity derivatives are computed for low and high Reynolds number flows over a NACA 1406 airfoil on a 32-processor Intel Hypercube, and found to be identical to those computed on a single-processor Cray Y-MP. It is estimated that the parallel sensitivity analysis code has to be run on 40-50 processors of the Intel Hypercube in order to match the single-processor processing time of a Cray Y-MP.
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.
Solving Partial Differential Equations in a data-driven multiprocessor environment
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gaudiot, J.L.; Lin, C.M.; Hosseiniyar, M.
1988-12-31
Partial differential equations can be found in a host of engineering and scientific problems. The emergence of new parallel architectures has spurred research in the definition of parallel PDE solvers. Concurrently, highly programmable systems such as data-how architectures have been proposed for the exploitation of large scale parallelism. The implementation of some Partial Differential Equation solvers (such as the Jacobi method) on a tagged token data-flow graph is demonstrated here. Asynchronous methods (chaotic relaxation) are studied and new scheduling approaches (the Token No-Labeling scheme) are introduced in order to support the implementation of the asychronous methods in a data-driven environment.more » New high-level data-flow language program constructs are introduced in order to handle chaotic operations. Finally, the performance of the program graphs is demonstrated by a deterministic simulation of a message passing data-flow multiprocessor. An analysis of the overhead in the data-flow graphs is undertaken to demonstrate the limits of parallel operations in dataflow PDE program graphs.« less
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
Devine, Sharon; Leeds, Caroline; Shlay, Judith C; Leytem, Amber; Beum, Robert; Bull, Sheana
2015-08-01
Youth are prolific users of cell phone minutes and text messaging. Numerous programs using short message service text messaging (SMS) have been employed to help improve health behaviors and health outcomes. However, we lack information on whether and what type of interaction or engagement with SMS program content is required to realize any benefit. We explored youth engagement with an automated SMS program designed to supplement a 25-session youth development program with demonstrated efficacy for reductions in teen pregnancy. Using two years of program data, we report on youth participation in design of message content and response frequency to messages among youth enrolled in the intervention arm of a randomized controlled trial (RCT) as one indicator of engagement. There were 221 youth between the ages of 14-18 enrolled over two years in the intervention arm of the RCT. Just over half (51%) were female; 56% were Hispanic; and 27% African American. Youth were sent 40,006 messages of which 16,501 were considered bi-directional where youth were asked to text a response. Four-fifths (82%) responded at least once to a text. We found variations in response frequency by gender, age, and ethnicity. The most popular types of messages youth responded to include questions and quizzes. The first two months of the program in each year had the highest response frequency. An important next step is to assess whether higher response to SMS results in greater efficacy. This future work can facilitate greater attention to message design and content to ensure messages are engaging for the intended audience. Copyright © 2015 Elsevier Inc. All rights reserved.
Munro, Sarah; Hui, Amber; Salmons, Vanessa; Solomon, Carolyn; Gemmell, Emily; Torabi, Nahal
2017-01-01
Background We engaged Canadian women in the development of a prenatal education program delivered via one-way text messaging called SmartMom. SmartMom is the first peer-reviewed, evidence-based mHealth program for prenatal education in Canada and the first to be endorsed by the Society of Obstetricians and Gynaecologists of Canada. Objective To explore women’s preferences for a prenatal education program by text messaging. Methods We conducted a qualitative focus group study in three Canadian communities in the Northern Health Authority. Women completed a demographic questionnaire, participated in a guided discussion about their pregnancy information-seeking behavior, reviewed a printed copy of the SmartMom text messages, and then engaged in a moderated discussion about their perceptions of the usability of the SmartMom program. Open-ended questions explored women’s perceptions regarding the message content, acceptability of receiving information by text message, positive health behaviors they might engage in after receiving a message, modifiable program factors, and intention to use the program. Thematic analysis of transcribed audio recordings was undertaken and modifications were made to the SmartMom program based on these findings. Results A total of 40 women participated in seven focus groups in three rural northern communities. The vast majority had a mobile phone (39/40, 98%), used text messages “all the time” (28/40, 70%), and surfed the Internet on their phone (37/40, 93%). Participants perceived SmartMom to be highly acceptable and relevant. The text message modality reflected how participants currently sought pregnancy-related information and provided them with local information tailored to their gestational age, which they had not received through other pregnancy resources. Women recommended adding the opportunity to receive supplemental streams of messages tailored to their individual needs, for example, depression, pregnancy after previous cesarean, >35 years of age, new immigrants, and harm reduction for smoking and alcohol. Conclusions This formative qualitative evaluation provides evidence that a prenatal education program by text messaging, SmartMom, is acceptable to the end users. These findings support the usability of the SmartMom program at a population level and the development of an evaluation program exploring the effects of the text messages on adoption of health-promoting behaviors and maternal-child health outcomes. PMID:28174149
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.
Electronic Message Preservation Act
Rep. Hodes, Paul W. [D-NH-2
2009-03-09
Senate - 03/18/2010 Received in the Senate and Read twice and referred to the Committee on Homeland Security and Governmental Affairs. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:
Federal Financial Assistance Management Improvement Act of 2009
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:
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.
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.
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.
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.
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.
Schnoll, Robert A; Cappella, Joseph; Lerman, Caryn; Pinto, Angela; Patterson, Freda; Wileyto, E Paul; Bigman, Cabral; Leone, Frank
2011-12-01
Most smokers do not utilize approved interventions for nicotine dependence, reducing the probability of cessation. Smoking cessation programs typically use recruitment messages emphasizing the health threats of smoking. Augmenting this threat message by describing the genetic aspects of nicotine addiction may enhance enrollment into a cessation program. During telephone recruitment, 125 treatment-seeking smokers were randomized to receive by phone either a standard threat message or a threat plus genetic prime message and were offered open-label varenicline and counseling. There was a greater rate of enrollment into the cessation program for the threat plus genetic prime participants (51.7%) versus the threat-only participants (37.7%; p = .03). Smokers who self-identified from racial/ethnic minority groups were less likely to enroll in the cessation program (p = .01) versus smokers who self-identified as Caucasian. These preliminary data suggest that a simple, affordable, and transportable communication approach enhances enrollment of smokers into a smoking cessation program. A larger clinical trial to evaluate a genetic prime message for improving recruitment into smoking cessation programs is warranted.
Dane, Pierre; Copley, Charles J; Pienaar, Cara; Parsons, Annie Neo; Engelhard, Matt; Woods, David; Bekker, Marcha; Benjamin, Peter; Pillay, Yogan; Barron, Peter; Mohan, Diwakar
2018-01-01
Despite calls to address broader evidence gaps in linking digital technologies to outcome and impact level health indicators, limited attention has been paid to measuring processes pertaining to the performance of programs. In this paper, we assess the program reach and message exposure of a mobile health information messaging program for mothers (MomConnect) in South Africa. In this descriptive study, we draw from system generated data to measure exposure to the program through registration attempts and conversions, message delivery, opt-outs and drop-outs. Using a logit model, we additionally explore determinants for early registration, opt-outs and drop-outs. From August 2014 to April 2017, 1 159 431 women were registered to MomConnect; corresponding to half of women attending antenatal care 1 (ANC1) and nearly 60% of those attending ANC1 estimated to own a mobile phone. In 2016, 26% of registrations started to get women onto MomConnect did not succeed. If registration attempts were converted to successful registrations, coverage of ANC1 attendees would have been 74% in 2016 and 86% in 2017. When considered as percentage of ANC1 attendees with access to a mobile phone, addressing conversion challenges bring registration coverage to an estimated 83%–89% in 2016 and 97%–100% in 2017. Among women registered, nearly 80% of expected short messaging service messages were received. While registration coverage and message delivery success rates exceed those observed for mobile messaging programs elsewhere, study findings highlight opportunities for program improvement and reinforce the need for rigorous and continuous monitoring of delivery systems. PMID:29713510
LeFevre, Amnesty E; Dane, Pierre; Copley, Charles J; Pienaar, Cara; Parsons, Annie Neo; Engelhard, Matt; Woods, David; Bekker, Marcha; Benjamin, Peter; Pillay, Yogan; Barron, Peter; Seebregts, Christopher John; Mohan, Diwakar
2018-01-01
Despite calls to address broader evidence gaps in linking digital technologies to outcome and impact level health indicators, limited attention has been paid to measuring processes pertaining to the performance of programs. In this paper, we assess the program reach and message exposure of a mobile health information messaging program for mothers (MomConnect) in South Africa. In this descriptive study, we draw from system generated data to measure exposure to the program through registration attempts and conversions, message delivery, opt-outs and drop-outs. Using a logit model, we additionally explore determinants for early registration, opt-outs and drop-outs. From August 2014 to April 2017, 1 159 431 women were registered to MomConnect; corresponding to half of women attending antenatal care 1 (ANC1) and nearly 60% of those attending ANC1 estimated to own a mobile phone. In 2016, 26% of registrations started to get women onto MomConnect did not succeed. If registration attempts were converted to successful registrations, coverage of ANC1 attendees would have been 74% in 2016 and 86% in 2017. When considered as percentage of ANC1 attendees with access to a mobile phone, addressing conversion challenges bring registration coverage to an estimated 83%-89% in 2016 and 97%-100% in 2017. Among women registered, nearly 80% of expected short messaging service messages were received. While registration coverage and message delivery success rates exceed those observed for mobile messaging programs elsewhere, study findings highlight opportunities for program improvement and reinforce the need for rigorous and continuous monitoring of delivery systems.
Media's Moral Messages: Assessing Perceptions of Moral Content in Television Programming
ERIC Educational Resources Information Center
Glover, Rebecca J.; Garmon, Lance C.; Hull, Darrell M.
2011-01-01
This study extends the examination of moral content in the media by exploring moral messages in television programming and viewer characteristics predictive of the ability to perceive such messages. Generalisability analyses confirmed the reliability of the Media's Moral Messages (MMM) rating form for analysing programme content and the existence…
[Series: Medical Applications of the PHITS Code (2): Acceleration by Parallel Computing].
Furuta, Takuya; Sato, Tatsuhiko
2015-01-01
Time-consuming Monte Carlo dose calculation becomes feasible owing to the development of computer technology. However, the recent development is due to emergence of the multi-core high performance computers. Therefore, parallel computing becomes a key to achieve good performance of software programs. A Monte Carlo simulation code PHITS contains two parallel computing functions, the distributed-memory parallelization using protocols of message passing interface (MPI) and the shared-memory parallelization using open multi-processing (OpenMP) directives. Users can choose the two functions according to their needs. This paper gives the explanation of the two functions with their advantages and disadvantages. Some test applications are also provided to show their performance using a typical multi-core high performance workstation.
GenASiS Basics: Object-oriented utilitarian functionality for large-scale physics simulations
Cardall, Christian Y.; Budiardja, Reuben D.
2015-06-11
Aside from numerical algorithms and problem setup, large-scale physics simulations on distributed-memory supercomputers require more basic utilitarian functionality, such as physical units and constants; display to the screen or standard output device; message passing; I/O to disk; and runtime parameter management and usage statistics. Here we describe and make available Fortran 2003 classes furnishing extensible object-oriented implementations of this sort of rudimentary functionality, along with individual `unit test' programs and larger example problems demonstrating their use. Lastly, these classes compose the Basics division of our developing astrophysics simulation code GenASiS (General Astrophysical Simulation System), but their fundamental nature makes themmore » useful for physics simulations in many fields.« less
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.
Simple, efficient allocation of modelling runs on heterogeneous clusters with MPI
Donato, David I.
2017-01-01
In scientific modelling and computation, the choice of an appropriate method for allocating tasks for parallel processing depends on the computational setting and on the nature of the computation. The allocation of independent but similar computational tasks, such as modelling runs or Monte Carlo trials, among the nodes of a heterogeneous computational cluster is a special case that has not been specifically evaluated previously. A simulation study shows that a method of on-demand (that is, worker-initiated) pulling from a bag of tasks in this case leads to reliably short makespans for computational jobs despite heterogeneity both within and between cluster nodes. A simple reference implementation in the C programming language with the Message Passing Interface (MPI) is provided.
Optimization of the design of Gas Cherenkov Detectors for ICF diagnosis
NASA Astrophysics Data System (ADS)
Liu, Bin; Hu, Huasi; Han, Hetong; Lv, Huanwen; Li, Lan
2018-07-01
A design method, which combines a genetic algorithm (GA) with Monte-Carlo simulation, is established and applied to two different types of Cherenkov detectors, namely, Gas Cherenkov Detector (GCD) and Gamma Reaction History (GRH). For accelerating the optimization program, open Message Passing Interface (MPI) is used in the Geant4 simulation. Compared with the traditional optical ray-tracing method, the performances of these detectors have been improved with the optimization method. The efficiency for GCD system, with a threshold of 6.3 MeV, is enhanced by ∼20% and time response improved by ∼7.2%. For the GRH system, with threshold of 10 MeV, the efficiency is enhanced by ∼76% in comparison with previously published results.
Compiled MPI: Cost-Effective Exascale Applications Development
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bronevetsky, G; Quinlan, D; Lumsdaine, A
2012-04-10
The complexity of petascale and exascale machines makes it increasingly difficult to develop applications that can take advantage of them. Future systems are expected to feature billion-way parallelism, complex heterogeneous compute nodes and poor availability of memory (Peter Kogge, 2008). This new challenge for application development is motivating a significant amount of research and development on new programming models and runtime systems designed to simplify large-scale application development. Unfortunately, DoE has significant multi-decadal investment in a large family of mission-critical scientific applications. Scaling these applications to exascale machines will require a significant investment that will dwarf the costs of hardwaremore » procurement. A key reason for the difficulty in transitioning today's applications to exascale hardware is their reliance on explicit programming techniques, such as the Message Passing Interface (MPI) programming model to enable parallelism. MPI provides a portable and high performance message-passing system that enables scalable performance on a wide variety of platforms. However, it also forces developers to lock the details of parallelization together with application logic, making it very difficult to adapt the application to significant changes in the underlying system. Further, MPI's explicit interface makes it difficult to separate the application's synchronization and communication structure, reducing the amount of support that can be provided by compiler and run-time tools. This is in contrast to the recent research on more implicit parallel programming models such as Chapel, OpenMP and OpenCL, which promise to provide significantly more flexibility at the cost of reimplementing significant portions of the application. We are developing CoMPI, a novel compiler-driven approach to enable existing MPI applications to scale to exascale systems with minimal modifications that can be made incrementally over the application's lifetime. It includes: (1) New set of source code annotations, inserted either manually or automatically, that will clarify the application's use of MPI to the compiler infrastructure, enabling greater accuracy where needed; (2) A compiler transformation framework that leverages these annotations to transform the original MPI source code to improve its performance and scalability; (3) Novel MPI runtime implementation techniques that will provide a rich set of functionality extensions to be used by applications that have been transformed by our compiler; and (4) A novel compiler analysis that leverages simple user annotations to automatically extract the application's communication structure and synthesize most complex code annotations.« less
ng: What next-generation languages can teach us about HENP frameworks in the manycore era
NASA Astrophysics Data System (ADS)
Binet, Sébastien
2011-12-01
Current High Energy and Nuclear Physics (HENP) frameworks were written before multicore systems became widely deployed. A 'single-thread' execution model naturally emerged from that environment, however, this no longer fits into the processing model on the dawn of the manycore era. Although previous work focused on minimizing the changes to be applied to the LHC frameworks (because of the data taking phase) while still trying to reap the benefits of the parallel-enhanced CPU architectures, this paper explores what new languages could bring to the design of the next-generation frameworks. Parallel programming is still in an intensive phase of R&D and no silver bullet exists despite the 30+ years of literature on the subject. Yet, several parallel programming styles have emerged: actors, message passing, communicating sequential processes, task-based programming, data flow programming, ... to name a few. We present the work of the prototyping of a next-generation framework in new and expressive languages (python and Go) to investigate how code clarity and robustness are affected and what are the downsides of using languages younger than FORTRAN/C/C++.
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. PMID:25355976
Internet and Mobile Phone Text Messaging Intervention for College Smokers
ERIC Educational Resources Information Center
Riley, William; Obermayer, Jami; Jean-Mary, Jersino
2008-01-01
Objective: The authors developed a smoking cessation program using mobile phone text messaging to provide tailored and stage-specific messages to college smokers. Participants and Methods: The authors recruited 31 daily smokers who desired to quit from a college campus and asked them to use an Internet and mobile phone text messaging program to…
ERIC Educational Resources Information Center
Messner, Mike; Hunt, Darnell; Dunbar, Michele; Chen, Perry; Lapp, Joan; Miller, Patti
Sports programming plays a significant role in the media messages that American boys receive today. To explore the messages that sports programming presents to its audience, this report relates the findings of a study that analyzed a representative selection of sports programs and their accompanying commercials; also presented are findings from a…
Munro, Sarah; Hui, Amber; Salmons, Vanessa; Solomon, Carolyn; Gemmell, Emily; Torabi, Nahal; Janssen, Patricia A
2017-02-07
We engaged Canadian women in the development of a prenatal education program delivered via one-way text messaging called SmartMom. SmartMom is the first peer-reviewed, evidence-based mHealth program for prenatal education in Canada and the first to be endorsed by the Society of Obstetricians and Gynaecologists of Canada. To explore women's preferences for a prenatal education program by text messaging. We conducted a qualitative focus group study in three Canadian communities in the Northern Health Authority. Women completed a demographic questionnaire, participated in a guided discussion about their pregnancy information-seeking behavior, reviewed a printed copy of the SmartMom text messages, and then engaged in a moderated discussion about their perceptions of the usability of the SmartMom program. Open-ended questions explored women's perceptions regarding the message content, acceptability of receiving information by text message, positive health behaviors they might engage in after receiving a message, modifiable program factors, and intention to use the program. Thematic analysis of transcribed audio recordings was undertaken and modifications were made to the SmartMom program based on these findings. A total of 40 women participated in seven focus groups in three rural northern communities. The vast majority had a mobile phone (39/40, 98%), used text messages "all the time" (28/40, 70%), and surfed the Internet on their phone (37/40, 93%). Participants perceived SmartMom to be highly acceptable and relevant. The text message modality reflected how participants currently sought pregnancy-related information and provided them with local information tailored to their gestational age, which they had not received through other pregnancy resources. Women recommended adding the opportunity to receive supplemental streams of messages tailored to their individual needs, for example, depression, pregnancy after previous cesarean, >35 years of age, new immigrants, and harm reduction for smoking and alcohol. This formative qualitative evaluation provides evidence that a prenatal education program by text messaging, SmartMom, is acceptable to the end users. These findings support the usability of the SmartMom program at a population level and the development of an evaluation program exploring the effects of the text messages on adoption of health-promoting behaviors and maternal-child health outcomes. ©Sarah Munro, Amber Hui, Vanessa Salmons, Carolyn Solomon, Emily Gemmell, Nahal Torabi, Patricia A Janssen. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 07.02.2017.
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
Thakkar, Jay; Karthikeyan, Ganesan; Purohit, Gaurav; Thakkar, Swetha; Sharma, Jitender; Verma, Sunilkumar; Parakh, Neeraj; Seth, Sandeep; Mishra, Sundeep; Yadav, Rakesh; Singh, Sandeep; Joshi, Rohina; Thiagalingam, Aravinda; Chow, Clara K; Redfern, Julie
2016-01-01
Background Coronary heart disease (CHD) is a leading cause of morbidity and mortality in India. Text message based prevention programs have demonstrated reduction in cardiovascular risk factors among patients with CHD in selected populations. Customisation is important as behaviour change is influenced by culture and linguistic context. Objectives To customise a mobile phone text message program supporting behaviour and treatment adherence in CHD for delivery in North India. Methods We used an iterative process with mixed methods involving three phases: (1) Initial translation, (2) Review and incorporation of feedback including review by cardiologists in India to assess alignment with local guidelines and by consumers on perceived utility and clarity and (3) Pilot testing of message management software. Results Messages were translated in three ways: symmetrical translation, asymmetrical translation and substitution. Feedback from cardiologists and 25 patients was incorporated to develop the final bank. Patients reported Hinglish messages were easy to understand (93%) and useful (78%). The software located in Australia successfully delivered messages to participants based in Delhi-surrounds (India). Conclusions Our process for customisation of a text message program considered cultural, linguistic and the medical context of potential participants. This is important in optimising intervention fidelity across populations enabling examination of the generalisability of text message programs across populations. We also demonstrated the customised program was acceptable to patients in India and that a centralised cross-country delivery model was feasible. This process could be used as a guide for other groups seeking to customise their programs. Trial registration number TEXTMEDS Australia (Parent study)—ACTRN 12613000793718. PMID:27752288
Davis, LaShara A; Morgan, Susan E; Mobley, Amy R
2016-06-01
Additional strategies to evaluate the impact of community nutrition education programs on low-income individuals are needed. The objective of this qualitative study was to examine the use of the Memorable Messages Framework as an intermediary nutrition education program evaluation tool to determine what fruit and vegetable messages were reported as memorable and the characteristics of those memorable messages. A convenience sample of low-income, primarily African American adults (N = 58) who previously completed a series of community nutrition education lessons within an urban area of Indiana participated in a focus group (N = 8 focus groups). A lead moderator using a semistructured script conducted the focus groups to determine what information about fruits and vegetables was most memorable from the participants' nutrition lessons and why this information was memorable. All focus group audiotapes were transcribed verbatim and ATLAS.ti software was used to code and identify themes within the data. Participants cited quantity, variety, and the positive nutritional impact of eating fruits and vegetables as most memorable. Information given in the form of recipes was also cited as most memorable. For example, participants referred to the recipe demonstrations as not only fun but also key components of the program that helped with message retention and memorability. Key characteristics of memorable messages included personal relevance and message vividness. These findings indicated that the Memorable Messages Framework may serve as an intermediary program evaluation tool to identify what information and messages are most influential to participants in community nutrition education programs. © 2015 Society for Public Health Education.
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.
Domestic Minor Sex Trafficking Deterrence and Victims Support Act of 2010
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:
Alcohol Messages in Prime-Time Television Series
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
Lau, Erica Y; Lau, Patrick W C; Cai, Bo; Archer, Edward
2015-01-01
This study examined the effects of text message content (generic vs. culturally tailored) on the login rate of an Internet physical activity program in Hong Kong Chinese adolescent school children. A convenience sample of 252 Hong Kong secondary school adolescents (51% female, 49% male; M age = 13.17 years, SD = 1.28 years) were assigned to one of 3 treatments for 8 weeks. The control group consisted of an Internet physical activity program. The Internet plus generic text message group consisted of the same Internet physical activity program and included daily generic text messages. The Internet plus culturally tailored text message group consisted of the Internet physical activity program and included daily culturally tailored text messages. Zero-inflated Poisson mixed models showed that the overall effect of the treatment group on the login rates varied significantly across individuals. The login rates over time were significantly higher in the Internet plus culturally tailored text message group than the control group (β = 46.06, 95% CI 13.60, 156.02; p = .002) and the Internet plus generic text message group (β = 15.80, 95% CI 4.81, 51.9; p = .021) after adjusting for covariates. These findings suggest that culturally tailored text messages may be more advantageous than generic text messages on improving adolescents' website login rate, but effects varied significantly across individuals. Our results support the inclusion of culturally tailored messaging in future online physical activity interventions.
Neural correlates of message tailoring and self-relatedness in smoking cessation programming.
Chua, Hannah Faye; Liberzon, Israel; Welsh, Robert C; Strecher, Victor J
2009-01-15
Smoking leads to illnesses including addiction, cancer, and cardiovascular and respiratory diseases. Different intervention programs have become available. In the past decade, providing tailored smoking cessation messages has been shown to be more effective in inducing smoking cessation than one-size-fits-all interventions. However, little is known about the brain responses of smokers when they receive tailored smoking cessation messages. A neuroimaging study using blocked and event-related designs examined neural activity in 24 smokers exposed to high-tailored and low-tailored smoking cessation messages. In both blocked and event-related conditions, rostral medial prefrontal cortex and precuneus/posterior cingulate were engaged more during the processing of high-tailored smoking cessation messages than low-tailored smoking cessation messages. The activation patterns of smokers to tailored cessation messages show involvement of brain areas commonly implicated in self-related processing. Results seem to add support to the suggested role of self-relevance in tailored cessation programs, where previous studies have shown a potential mediating role of self-relevance on smoking abstinence. The findings are relevant to understanding the cognitive mechanisms underlying tailored message processing and might point to new directions for testing response to health communications programming.
Neural correlates of message tailoring and self-relatedness in smoking cessation programming
Chua, Hannah Faye; Liberzon, Israel; Welsh, Robert C.; Strecher, Victor J.
2011-01-01
BACKGROUND Smoking leads to illnesses including addiction, cancer, and cardiovascular and respiratory diseases. Different intervention programs have become available. In the past decade, providing tailored smoking cessation messages has been shown to be more effective in inducing smoking cessation than one-size-fits-all interventions. However, little is known about the brain responses of smokers when they receive tailored smoking cessation messages. METHODS A neuroimaging study using blocked and event-related designs examined neural activity in 24 smokers exposed to high-tailored and low-tailored smoking cessation messages. RESULTS: In both blocked and event-related conditions, rostral medial prefrontal cortex and precuneus/posterior cingulate were engaged more during the processing of high-tailored smoking cessation messages than low-tailored smoking cessation messages. CONCLUSION The activation patterns of smokers to tailored cessation messages show involvement of brain areas commonly implicated in self-related processing. Results seem to add support to the suggested role of self-relevance in tailored cessation programs, where previous studies have shown a potential mediating role of self-relevance on smoking abstinence. The findings are relevant to understanding the cognitive mechanisms underlying tailored message processing and may point to new directions for testing response to health communications programming. PMID:18926523
HealthyhornsTXT: A Text-Messaging Program to Promote College Student Health and Wellness.
Glowacki, Elizabeth M; Kirtz, Susan; Hughes Wagner, Jessica; Cance, Jessica Duncan; Barrera, Denise; Bernhardt, Jay M
2018-01-01
Text-messaging interventions positively affect health behaviors, but their use on college campuses has been limited. Text messaging serves as a relatively affordable way to communicate with large audiences and is one of the preferred modes of communication for young adults. This study examined the feasibility and acceptability of a campus-wide, health text-messaging program. The subscriber pool consisted of approximately 6,000 undergraduate students from a large, southern university. From that pool, 1,095 participants (64% female; 41% White) completed a posttest survey. Text messages covered a range of health topics and information about campus resources. Research was conducted from August through December 2015. Process data were collected throughout the semester; participants' attitudes were assessed via an online survey at the program's conclusion. Students demonstrated engagement with the messages throughout the semester as evidenced by replies to text-back keywords and clicks on website links embedded within messages. Messages about sleep, stress management, and hydration were considered most relevant. The majority of participants (61%) reported increased awareness regarding their health. Text-messaging interventions are a feasible strategy to improve college student health.
Chaos synchronization communication using extremely unsymmetrical bidirectional injections.
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.
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.
Disaster Relief Appropriations Act, 2013
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:
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.
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.
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.
Gallagher, Kristel M
2016-01-01
The benefits of exercise gained by older adults during physical therapy are often not maintained once the program is over. This lack of sustained benefits is thought to be partially the result of poor adherence to the prescribed home exercise program to be continued once therapy is completed. Most of what is known about older adults' adherence to physical therapy and home exercise comes from research seeking to identify and understand predictors of adherence, rather than trying to enhance adherence explicitly. The purpose of this study was to test a theoretically grounded approach to promoting adherence to home exercise programs in older adults. Sixty older adults (M age = 69.3 (6.87) years) in a program of physical therapy received 1 of 2 print messages and magnets promoting adherence to home exercise. The content of the messages was informed by the goal-specific tenets of socioemotional selectivity theory-one message described the emotional and meaningful benefits of home exercise, such as time with loved ones and independence, and one message described facts and information about physiological benefits, such as balance and strength. Adherence to home exercise was measured 2 weeks after participants were discharged from physical therapy by calculating the percentage of the prescribed exercises participants reported completing at home. An analysis of covariance indicated that there was no statistically significant difference in adherence rates between participants receiving either message. However, a 2×2 analysis of covariance did reveal a significant interaction between the type of message participants received and the time at which they received that message. Post hoc analyses separately examined the rates of adherence in participants who received the intervention message with time remaining in their therapy program and participants who received the intervention message on the day of discharge. In the subset of participants who received their intervention message with time remaining in their therapy program, those who received the emotion and meaning message were somewhat more adherent to their home exercise program than those who received the facts and information message (63.6% vs 50.8%; P = .07). Those who received the emotion and meaning message also performed on average more exercises outside of their home exercise program (2.4 vs 1.3; P = .06). Despite lacking a statistically significant difference between message groups, the results of this study suggest that highlighting the emotional and meaningful benefits of home exercise versus providing facts and information about the physiological benefits may encourage older adults to be adherent to their home exercise programs. This may especially be the case if they receive the information while still in therapy. As this was the first study to empirically test an intervention targeting adherence to post-physical therapy home exercise in older adults, future research is needed to better understand what motivates older adults to be adherent.
Abroms, Lorien C; Ahuja, Meenakshi; Kodl, Yvonne; Thaweethai, Lalida; Sims, Justin; Winickoff, Jonathan P; Windsor, Richard A
2012-01-01
Text messaging programs on mobile phones have shown some promise in helping people quit smoking. Text2Quit is an automated, personalized, and interactive mobile health program that sends text messages and e-mails timed around a participant's quit date over the course of 3 months. The text messages include pre- and post-quit educational messages, peer ex-smoker messages, medication reminders and relapse messages, and multiple opportunities for interaction. Study participants were university students (N = 23) enrolled in the Text2Quit program. Participants were surveyed at baseline and at 2 and 4 weeks after enrollment. The majority of participants agreed that they liked the program at 2 and 4 weeks after enrollment (90.5% and 82.3%, respectively). Support for text messages was found to be moderate and higher than that of the e-mail and web components. Of participants, 75% reported reading most or all of the texts. On average, users made 11.8 responses to the texts over a 4-week period, although responses declined after the quit date. The interactive feature for tracking cigarettes was the most used interactive feature, followed by the craving trivia game. This pilot test provides some support for the Text2Quit program. A future iteration of the program will include additional tracking features in both the pre-quit and post-quit protocols and an easier entry into the not-quit protocol. Future studies are recommended that identify the value of the interactive and personalized features that characterize this program.
ABROMS, LORIEN C.; AHUJA, MEENAKSHI; KODL, YVONNE; THAWEETHAI, LALIDA; SIMS, JUSTIN; WINICKOFF, JONATHAN; WINDSOR, RICHARD A.
2012-01-01
Text messaging programs on mobile phones have shown some promise in helping people quit smoking. Text2Quit is an automated, personalized and interactive mobile health program that sends text messages and emails timed around a participant’s quit date over the course of 3 months. The text messages include pre- and post-quit educational messages, peer ex-smoker messages, medication reminders and relapse messages, as well as multiple opportunities for interaction. Study participants were university students (n=23) enrolled in the Text2Quit program. Participants were surveyed at baseline and at 2 and 4 weeks post-enrollment. The vast majority of participants agreed that they liked the program at 2 and 4 weeks post-enrollment (90.5% and 82.3%, respectively). Support for text messages was found to be moderate, and higher than that of the email and web components. Seventy-five percent of participants reported reading most or all of the texts. On average, users made 11.8 responses to the texts over a 4 week period, although responses declined following the quit date. The interactive feature for tracking cigarettes was the most used interactive feature, followed by the craving trivia game. This pilot test provides some support for the Text2Quit program. A future iteration of the program will include additional tracking features in both the pre-quit and post-quit protocol and an easier entry into the not-quit protocol. Future studies are recommended that identify the value of the interactive and personalized features that characterize this program. PMID:22548598
Ybarra, Michele L; Holtrop, Jodi Summers; Prescott, Tonya L; Strong, David
2014-11-01
Report lessons learned in an RCT of Stop My Smoking (SMS) USA, a mHealth smoking cessation program for young adult smokers. 164 18-24-year-olds were recruited nationally, online in 2011. Program evaluation data were provided at 12-week post-Quit Day. (1) Inviting participants to complete a brief text messaging survey and then asking them to complete a longer online survey resulted in the highest response rate (89%). (2) The positive tone of program messages was the most commonly noted program strength. (3) Suggested improvements included more social connectivity and additional assistance overcoming stressful situations. (4) Half of intervention participants moved through the program linearly and half went through various paths that reflected multiple relapses. Suggestions to use pharmacotherapy resulted in 22% of heavy smokers to utilize it. Participant feedback provided concrete ways in which this and other young adult-focused interventions can improve messaging and program features to be even more salient. Future young adult mHealth interventions could: Integrate models that are flexible to different "paths" of behavior change; address stressful life events directly and comprehensively; integrate proactive messaging that promotes pharmacotherapy options; and use text messaging as a gateway to longer online surveys. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
ERIC Educational Resources Information Center
Davis, LaShara A.; Morgan, Susan E.; Mobley, Amy R.
2016-01-01
Additional strategies to evaluate the impact of community nutrition education programs on low-income individuals are needed. The objective of this qualitative study was to examine the use of the Memorable Messages Framework as an intermediary nutrition education program evaluation tool to determine what fruit and vegetable messages were reported…
Recruiting Strategically: Increasing Enrollment in Academic Programs of Agriculture
ERIC Educational Resources Information Center
Baker, Lauri M.; Settle, Quisto; Chiarelli, Christy; Irani, Tracy
2013-01-01
Agriculture continues to struggle to find enough qualified students to advance the industry. Thus, recruiting practice improvement is imperative. This study assessed the efficacy of message strategies, message channels, recruiting materials, and messages for recruiting students into an academic program with low enrollment. Focus groups were…
Enabling Energy Saving Innovations Act
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:
Interstate Recognition of Notarizations Act of 2010
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:
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 \
Message passing for integrating and assessing renewable generation in a redundant power grid
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zdeborova, Lenka; Backhaus, Scott; Chertkov, Michael
2009-01-01
A simplified model of a redundant power grid is used to study integration of fluctuating renewable generation. The grid consists of large number of generator and consumer nodes. The net power consumption is determined by the difference between the gross consumption and the level of renewable generation. The gross consumption is drawn from a narrow distribution representing the predictability of aggregated loads, and we consider two different distributions representing wind and solar resources. Each generator is connected to D consumers, and redundancy is built in by connecting R {le} D of these consumers to other generators. The lines are switchablemore » so that at any instance each consumer is connected to a single generator. We explore the capacity of the renewable generation by determining the level of 'firm' generation capacity that can be displaced for different levels of redundancy R. We also develop message-passing control algorithm for finding switch sellings where no generator is overloaded.« less
Mapping a battlefield simulation onto message-passing parallel architectures
NASA Technical Reports Server (NTRS)
Nicol, David M.
1987-01-01
Perhaps the most critical problem in distributed simulation is that of mapping: without an effective mapping of workload to processors the speedup potential of parallel processing cannot be realized. Mapping a simulation onto a message-passing architecture is especially difficult when the computational workload dynamically changes as a function of time and space; this is exactly the situation faced by battlefield simulations. This paper studies an approach where the simulated battlefield domain is first partitioned into many regions of equal size; typically there are more regions than processors. The regions are then assigned to processors; a processor is responsible for performing all simulation activity associated with the regions. The assignment algorithm is quite simple and attempts to balance load by exploiting locality of workload intensity. The performance of this technique is studied on a simple battlefield simulation implemented on the Flex/32 multiprocessor. Measurements show that the proposed method achieves reasonable processor efficiencies. Furthermore, the method shows promise for use in dynamic remapping of the simulation.
High speed bus technology development
NASA Astrophysics Data System (ADS)
Modrow, Marlan B.; Hatfield, Donald W.
1989-09-01
The development and demonstration of the High Speed Data Bus system, a 50 Million bits per second (Mbps) local data network intended for avionics applications in advanced military aircraft is described. The Advanced System Avionics (ASA)/PAVE PILLAR program provided the avionics architecture concept and basic requirements. Designs for wire and fiber optic media were produced and hardware demonstrations were performed. An efficient, robust token-passing protocol was developed and partially demonstrated. The requirements specifications, the trade-offs made, and the resulting designs for both a coaxial wire media system and a fiber optics design are examined. Also, the development of a message-oriented media access protocol is described, from requirements definition through analysis, simulation and experimentation. Finally, the testing and demonstrations conducted on the breadboard and brassboard hardware is presented.
Boal, Ashley L; Abroms, Lorien C; Simmens, Samuel; Graham, Amanda L; Carpenter, Kelly M
2016-05-01
This study seeks to determine whether comprehensive quitline services combined with text messaging improve smoking cessation rates beyond those achieved by offering comprehensive quitline services alone. The study sample consisted of callers to the Alere Wellbeing, Inc, commercial quitline in 2012. A quasi-experimental design was implemented using propensity score matching to create the intervention and control groups. The intervention group consisted of those who were offered and accepted a text message intervention in addition to usual quitline services, while the control group consisted of those who were not offered the text message intervention. Analyses utilized baseline data collected at intake, program use data (eg, call history and text message use), and reports of smoking behaviors and program satisfaction collected 6 months after intake. Similar rates of 7-day abstinence were reported regardless of whether participants received combined multi-call quitline services plus text messaging (25.3%) or multi-call quitline services in isolation (25.5%), though those who received combined services reported higher treatment satisfaction (P < .05). Among those who received combined services, the number of text messages sent to the text message program predicted 7-day abstinence such that those who sent more text messages were less likely to report 7-day abstinence. Text messaging may not confer additional benefits over and above those received through multi-modal, multi-call quitline programs. Future research should investigate whether text messaging programs improve quit rates when combined with less intensive services such as single-call phone counseling. While the impact of quitline and text messaging services for smoking cessation have been examined in isolation, no study has explored the impact of combined services on smoking outcomes. This study examines the role of text messaging in combination with comprehensive quitline services including multi-call phone counseling, access to an interactive website and nicotine replacement therapy. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Woolford, Susan J.; Barr, Kathryn L.C.; Derry, Holly A.; Jepson, Christina M.; Clark, Sarah J.; Strecher, Victor J.; Resnicow, Kenneth
2011-01-01
Adolescents participating in weight loss programs experience difficulty adhering to behavior change recommendations. Communications technology provides a low cost means to increase the frequency of contact with adolescents which can improve their engagement and also lead to behavior change. Within a larger project on the development of tailored text messages for adolescents enrolled in an existing multidisciplinary weight management program, this study explored participants’ perspectives about message content. A library of messages was developed focused on topics central to weight management. Four focus groups were conducted with a total of 24 participants from the weight management program to gage their reactions to the messages. Detailed notes from the focus groups were analyzed to assess the acceptability of individual messages and to identify overriding themes. Results indicate that participants were very enthusiastic about receiving text messages. They preferred messages that provided recipe ideas, included successful weight loss strategies used by peers, and requested feedback regarding their progress. They preferred positive, encouraging, and direct messages. They were unanimous that messages should include encouraging symbols (e.g., exclamation points and “smiley faces”) as often as possible. They emphasized that any mention of unhealthy foods or behaviors would trigger them to eat those foods or engage in those behaviors. Text messaging acronyms (e.g., LOL) were considered too informal for messages from healthcare providers. This study suggests that including text messages in obesity interventions is acceptable to obese adolescents as a means of supporting their weight loss efforts, and it highlights the need for such messages to be carefully constructed. PMID:21869762
NASA Technical Reports Server (NTRS)
Ierotheou, C.; Johnson, S.; Leggett, P.; Cross, M.; Evans, E.; Jin, Hao-Qiang; Frumkin, M.; Yan, J.; Biegel, Bryan (Technical Monitor)
2001-01-01
The shared-memory programming model is a very effective way to achieve parallelism on shared memory parallel computers. Historically, the lack of a programming standard for using directives and the rather limited performance due to scalability have affected the take-up of this programming model approach. Significant progress has been made in hardware and software technologies, as a result the performance of parallel programs with compiler directives has also made improvements. The introduction of an industrial standard for shared-memory programming with directives, OpenMP, has also addressed the issue of portability. In this study, we have extended the computer aided parallelization toolkit (developed at the University of Greenwich), to automatically generate OpenMP based parallel programs with nominal user assistance. We outline the way in which loop types are categorized and how efficient OpenMP directives can be defined and placed using the in-depth interprocedural analysis that is carried out by the toolkit. We also discuss the application of the toolkit on the NAS Parallel Benchmarks and a number of real-world application codes. This work not only demonstrates the great potential of using the toolkit to quickly parallelize serial programs but also the good performance achievable on up to 300 processors for hybrid message passing and directive-based parallelizations.
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.
Effects of Ordering Strategies and Programming Paradigms on Sparse Matrix Computations
NASA Technical Reports Server (NTRS)
Oliker, Leonid; Li, Xiaoye; Husbands, Parry; Biswas, Rupak; Biegel, Bryan (Technical Monitor)
2002-01-01
The Conjugate Gradient (CG) algorithm is perhaps the best-known iterative technique to solve sparse linear systems that are symmetric and positive definite. For systems that are ill-conditioned, it is often necessary to use a preconditioning technique. In this paper, we investigate the effects of various ordering and partitioning strategies on the performance of parallel CG and ILU(O) preconditioned CG (PCG) using different programming paradigms and architectures. Results show that for this class of applications: ordering significantly improves overall performance on both distributed and distributed shared-memory systems, that cache reuse may be more important than reducing communication, that it is possible to achieve message-passing performance using shared-memory constructs through careful data ordering and distribution, and that a hybrid MPI+OpenMP paradigm increases programming complexity with little performance gains. A implementation of CG on the Cray MTA does not require special ordering or partitioning to obtain high efficiency and scalability, giving it a distinct advantage for adaptive applications; however, it shows limited scalability for PCG due to a lack of thread level parallelism.
Parallel computation and the Basis system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Smith, G.R.
1992-12-16
A software package has been written that can facilitate efforts to develop powerful, flexible, and easy-to-use programs that can run in single-processor, massively parallel, and distributed computing environments. Particular attention has been given to the difficulties posed by a program consisting of many science packages that represent subsystems of a complicated, coupled system. Methods have been found to maintain independence of the packages by hiding data structures without increasing the communication costs in a parallel computing environment. Concepts developed in this work are demonstrated by a prototype program that uses library routines from two existing software systems, Basis and Parallelmore » Virtual Machine (PVM). Most of the details of these libraries have been encapsulated in routines and macros that could be rewritten for alternative libraries that possess certain minimum capabilities. The prototype software uses a flexible master-and-slaves paradigm for parallel computation and supports domain decomposition with message passing for partitioning work among slaves. Facilities are provided for accessing variables that are distributed among the memories of slaves assigned to subdomains. The software is named PROTOPAR.« less
Parallel computation and the basis system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Smith, G.R.
1993-05-01
A software package has been written that can facilitate efforts to develop powerful, flexible, and easy-to use programs that can run in single-processor, massively parallel, and distributed computing environments. Particular attention has been given to the difficulties posed by a program consisting of many science packages that represent subsystems of a complicated, coupled system. Methods have been found to maintain independence of the packages by hiding data structures without increasing the communications costs in a parallel computing environment. Concepts developed in this work are demonstrated by a prototype program that uses library routines from two existing software systems, Basis andmore » Parallel Virtual Machine (PVM). Most of the details of these libraries have been encapsulated in routines and macros that could be rewritten for alternative libraries that possess certain minimum capabilities. The prototype software uses a flexible master-and-slaves paradigm for parallel computation and supports domain decomposition with message passing for partitioning work among slaves. Facilities are provided for accessing variables that are distributed among the memories of slaves assigned to subdomains. The software is named PROTOPAR.« less
McMillan, Libba R; Smith-Hendricks, Constance; Gore, Teresa
2010-01-01
This study examines the use of tailored messages as a learning tool to volunteer citizen servants to promote health and empower Alabama citizens to live healthier lives. Descriptive data of formative and summative questionnaires were analyzed from convenience sampling in this study, which encompassed 12 months. Researchers formed unique partnerships among community service organizations (CSO), faith-based organizations (FBO), author affiliated school of nursing, and community organizations to implement Healthy People 2010 goals. The program provided "health information stations" to focus on delivery of monthly culturally relevant messages to meet the health needs in the community. This program provided tailored health messages to 11 CSO and FBO. Outcome measures include an increase in health promotion knowledge, desire for furtherance and expansion of programs, and improved contacts within the community. The results from this study provide achievement of overall program goals, suggestions for improved evaluation strategies, implementation plans, and examples of specific topical messages. © 2010 Wiley Periodicals, Inc.
47 CFR 11.51 - EAS code and Attention Signal Transmission requirements.
Code of Federal Regulations, 2012 CFR
2012-10-01
... Message (EOM) codes using the EAS Protocol. The Attention Signal must precede any emergency audio message... audio messages. No Attention Signal is required for EAS messages that do not contain audio programming... EAS messages in the main audio channel. All DAB stations shall also transmit EAS messages on all audio...
47 CFR 11.51 - EAS code and Attention Signal Transmission requirements.
Code of Federal Regulations, 2014 CFR
2014-10-01
... Message (EOM) codes using the EAS Protocol. The Attention Signal must precede any emergency audio message... audio messages. No Attention Signal is required for EAS messages that do not contain audio programming... EAS messages in the main audio channel. All DAB stations shall also transmit EAS messages on all audio...
47 CFR 11.51 - EAS code and Attention Signal Transmission requirements.
Code of Federal Regulations, 2013 CFR
2013-10-01
... Message (EOM) codes using the EAS Protocol. The Attention Signal must precede any emergency audio message... audio messages. No Attention Signal is required for EAS messages that do not contain audio programming... EAS messages in the main audio channel. All DAB stations shall also transmit EAS messages on all audio...
NASA Technical Reports Server (NTRS)
Lawson, Gary; Sosonkina, Masha; Baurle, Robert; Hammond, Dana
2017-01-01
In many fields, real-world applications for High Performance Computing have already been developed. For these applications to stay up-to-date, new parallel strategies must be explored to yield the best performance; however, restructuring or modifying a real-world application may be daunting depending on the size of the code. In this case, a mini-app may be employed to quickly explore such options without modifying the entire code. In this work, several mini-apps have been created to enhance a real-world application performance, namely the VULCAN code for complex flow analysis developed at the NASA Langley Research Center. These mini-apps explore hybrid parallel programming paradigms with Message Passing Interface (MPI) for distributed memory access and either Shared MPI (SMPI) or OpenMP for shared memory accesses. Performance testing shows that MPI+SMPI yields the best execution performance, while requiring the largest number of code changes. A maximum speedup of 23 was measured for MPI+SMPI, but only 11 was measured for MPI+OpenMP.
Parallelization of NAS Benchmarks for Shared Memory Multiprocessors
NASA Technical Reports Server (NTRS)
Waheed, Abdul; Yan, Jerry C.; Saini, Subhash (Technical Monitor)
1998-01-01
This paper presents our experiences of parallelizing the sequential implementation of NAS benchmarks using compiler directives on SGI Origin2000 distributed shared memory (DSM) system. Porting existing applications to new high performance parallel and distributed computing platforms is a challenging task. Ideally, a user develops a sequential version of the application, leaving the task of porting to new generations of high performance computing systems to parallelization tools and compilers. Due to the simplicity of programming shared-memory multiprocessors, compiler developers have provided various facilities to allow the users to exploit parallelism. Native compilers on SGI Origin2000 support multiprocessing directives to allow users to exploit loop-level parallelism in their programs. Additionally, supporting tools can accomplish this process automatically and present the results of parallelization to the users. We experimented with these compiler directives and supporting tools by parallelizing sequential implementation of NAS benchmarks. Results reported in this paper indicate that with minimal effort, the performance gain is comparable with the hand-parallelized, carefully optimized, message-passing implementations of the same benchmarks.
Preconditioned implicit solvers for the Navier-Stokes equations on distributed-memory machines
NASA Technical Reports Server (NTRS)
Ajmani, Kumud; Liou, Meng-Sing; Dyson, Rodger W.
1994-01-01
The GMRES method is parallelized, and combined with local preconditioning to construct an implicit parallel solver to obtain steady-state solutions for the Navier-Stokes equations of fluid flow on distributed-memory machines. The new implicit parallel solver is designed to preserve the convergence rate of the equivalent 'serial' solver. A static domain-decomposition is used to partition the computational domain amongst the available processing nodes of the parallel machine. The SPMD (Single-Program Multiple-Data) programming model is combined with message-passing tools to develop the parallel code on a 32-node Intel Hypercube and a 512-node Intel Delta machine. The implicit parallel solver is validated for internal and external flow problems, and is found to compare identically with flow solutions obtained on a Cray Y-MP/8. A peak computational speed of 2300 MFlops/sec has been achieved on 512 nodes of the Intel Delta machine,k for a problem size of 1024 K equations (256 K grid points).
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.
NASA Technical Reports Server (NTRS)
Wallace, Robert
1986-01-01
A major impediment to a systematic attack on Ada software reusability is the lack of an effective taxonomy for software component functions. The scope of all possible applications of Ada software is considered too great to allow the practical development of a working taxonomy. Instead, for the purposes herein, the scope of Ada software application is limited to device and subsystem control in real-time embedded systems. A functional approach is taken in constructing the taxonomy tree for identified Ada domain. The use of modular software functions as a starting point fits well with the object oriented programming philosophy of Ada. Examples of the types of functions represented within the working taxonomy are real time kernels, interrupt service routines, synchronization and message passing, data conversion, digital filtering and signal conditioning, and device control. The constructed taxonomy is proposed as a framework from which a need analysis can be performed to reveal voids in current Ada real-time embedded programming efforts for Space Station.
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.
Kingman and Heritage Islands Act of 2009
Rep. Norton, Eleanor Holmes [D-DC-At Large
2009-04-23
Senate - 09/28/2010 Message on Senate action sent to the House. (All Actions) Notes: For further action, see H.R.6278, which became Public Law 111-328 on 12/22/2010. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:
Distance Learning and Public School Finance.
ERIC Educational Resources Information Center
Monahan, Brian; Wimber, Charles
This discussion of the application of computers and telecommunications technology to distance learning begins by describing a workstation equipped to produce "lessonware" in such formats as audiocassettes, videocassettes, diskettes, and voice messages. Such workstations would be located in classrooms equipped with two-way reverse passes to a cable…
Reducing Flight Delays Act of 2013
Sen. Collins, Susan M. [R-ME
2013-04-25
Senate - 04/30/2013 Message on Senate action sent to the House. (All Actions) Notes: For further action, see H.R.1765, which became Public Law 113-9 on 5/1/2013. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:
Temporary Bankruptcy Judgeships Extension Act of 2011
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:
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.
NASA Astrophysics Data System (ADS)
Wedgwood, Kyle C. A.; Satin, Leslie S.
2018-03-01
In 1967, the social psychologist Stanley Milgram asked how many intermediates would be required for a letter from participants in various U.S. states to be received by a contact in Boston, given that participants were given only basic information about the contact, and were instructed only to pass along the message to someone that might know the intended recipient [27]. The surprising answer was that, in spite of the social and geographical distances covered, on average, only 6 people were required for the message to reach its intended target.
A distributed infrastructure for publishing VO services: an implementation
NASA Astrophysics Data System (ADS)
Cepparo, Francesco; Scagnetto, Ivan; Molinaro, Marco; Smareglia, Riccardo
2016-07-01
This contribution describes both the design and the implementation details of a new solution for publishing VO services, enlightening its maintainable, distributed, modular and scalable architecture. Indeed, the new publisher is multithreaded and multiprocess. Multiple instances of the modules can run on different machines to ensure high performance and high availability, and this will be true both for the interface modules of the services and the back end data access ones. The system uses message passing to let its components communicate through an AMQP message broker that can itself be distributed to provide better scalability and availability.
NASA Astrophysics Data System (ADS)
Gregg, C. E.; Sorensen, J. H.; Vogt Sorensen, B.; Whitmore, P.; Johnston, D. M.
2016-12-01
Spurred in part by world-wide interest in improving warning messaging for and response to tsunamis in the wake of several catastrophic tsunamis since 2004 and growing interest at the US National Weather Service (NWS) to integrate social science into their Tsunami Program, the NWS Tsunami Warning Centers in Alaska and Hawaii have made great progress toward enhancing tsunami messages. These include numerous products, among them being Tsunami Warnings, Tsunami Advisories and Tsunami Watches. Beginning in 2010 we have worked with US National Tsunami Hazard Mitigation Program (NTHMP) Warning Coordination and Mitigation and Education Subcommittee members; Tsunami Program administrators; and NWS Weather Forecast Officers to conduct a series of focus group meetings with stakeholders in coastal areas of Alaska, American Samoa, California, Hawaii, North Carolina, Oregon, US Virgin Islands and Washington to understand end-user perceptions of existing messages and their existing needs in message products. 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, Formatting, and Receiver Characteristics. A sample 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, whether the message is a full length or short message. Incrementally, this work contributed to revisions in the format, content and style of message products issued by the National Tsunami Warning Center (NTWC). Since that time, interest in short warning messages has continued to increase and in May 2016 the NTWC began efforts to revise message products to take advantage of recent NWS policy changes allowing use of mixed-case text format and expanded punctuation, a practice which the NWS first started in 2010. Here we describe our application of a modification of the warning message metric to develop new streamlined messages using mixed-case text. These messages reflect current state-of-the-art knowledge on warning message effectiveness.
Development of a smoking prevention mass media program using diagnostic and formative research.
Worden, J K; Flynn, B S; Geller, B M; Chen, M; Shelton, L G; Secker-Walker, R H; Solomon, D S; Solomon, L J; Couchey, S; Costanza, M C
1988-09-01
The process of developing a mass media campaign to prevent smoking among adolescents is described in detail. This campaign supplements a school smoking prevention program and shares educational objectives with the school program but is otherwise independent. It comprises various television and radio 30- and 60-sec "spot" messages. The campaign development process includes identifying educational objectives and strategies for appealing to young people; conducting diagnostic surveys and focus groups to determine target audience interests and perceptions about smoking and media content; suggesting approaches to producers to create preliminary television and radio messages for testing; conducting formative pretests with target groups to select optimal messages and suggest improvements to those messages; producing final messages for media presentation; and developing a media exposure plan to place messages in local media at optimal times for reception by target audiences. The media campaign is being evaluated in a 5-year project with 5,500 adolescents in four communities to determine the additional effect of mass media over a school program alone in preventing smoking.
NASA electronic message experiment and study: Detailed test plans
NASA Technical Reports Server (NTRS)
1979-01-01
A methodology for evaluating the utility of high speed digital facsimile as a component of the projected NASA-wide electronic message network is presented. Equipment checkout, operator familiarization, pretest calibration, and the development of procedures are addressed. An experimental test program of the facsimile message service which will carry duplicates of the actual messages sent by other means is highlighted. Also, an operational test program during which messages will be sent on a regular basis in order to accumulate the information that will be used to evaluate system performance and project future growth is described.
Design Considerations in Developing a Text Messaging Program Aimed at Smoking Cessation
Holtrop, Jodi Summers; Bağci Bosi, A Tülay; Emri, Salih
2012-01-01
Background Cell phone text messaging is gaining increasing recognition as an important tool that can be harnessed for prevention and intervention programs across a wide variety of health research applications. Despite the growing body of literature reporting positive outcomes, very little is available about the design decisions that scaffold the development of text messaging-based health interventions. What seems to be missing is documentation of the thought process of investigators in the initial stages of protocol and content development. This omission is of particular concern because many researchers seem to view text messaging as the intervention itself instead of simply a delivery mechanism. Certainly, aspects of this technology may increase participant engagement. Like other interventions, however, the content is a central driver of the behavior change. Objective To address this noted gap in the literature, we discuss the protocol decisions and content development for SMS Turkey (or Cebiniz birakin diyor in Turkish), a smoking cessation text messaging program for adult smokers in Turkey. Methods Content was developed in English and translated into Turkish. Efforts were made to ensure that the protocol and content were grounded in evidence-based smoking cessation theory, while also reflective of the cultural aspects of smoking and quitting in Turkey. Results Methodological considerations included whether to provide cell phones and whether to reimburse participants for texting costs; whether to include supplementary intervention resources (eg, personal contact); and whether to utilize unidirectional versus bidirectional messaging. Program design considerations included how messages were tailored to the quitting curve and one’s smoking status after one’s quit date, the number of messages participants received per day, and over what period of time the intervention lasted. Conclusion The content and methods of effective smoking cessation quitline programs were a useful guide in developing SMS Turkey. Proposed guidelines in developing text messaging-based behavior change programs are offered. PMID:22832182
A distributed program composition system
NASA Technical Reports Server (NTRS)
Brown, Robert L.
1989-01-01
A graphical technique for creating distributed computer programs is investigated and a prototype implementation is described which serves as a testbed for the concepts. The type of programs under examination is restricted to those comprising relatively heavyweight parts that intercommunicate by passing messages of typed objects. Such programs are often presented visually as a directed graph with computer program parts as the nodes and communication channels as the edges. This class of programs, called parts-based programs, is not well supported by existing computer systems; much manual work is required to describe the program to the system, establish the communication paths, accommodate the heterogeneity of data types, and to locate the parts of the program on the various systems involved. The work described solves most of these problems by providing an interface for describing parts-based programs in this class in a way that closely models the way programmers think about them: using sketches of diagraphs. Program parts, the computational modes of the larger program system are categorized in libraries and are accessed with browsers. The process of programming has the programmer draw the program graph interactively. Heterogeneity is automatically accommodated by the insertion of type translators where necessary between the parts. Many decisions are necessary in the creation of a comprehensive tool for interactive creation of programs in this class. Possibilities are explored and the issues behind such decisions are presented. An approach to program composition is described, not a carefully implemented programming environment. However, a prototype implementation is described that can demonstrate the ideas presented.
Hirai, Kei; Ishikawa, Yoshiki; Fukuyoshi, Jun; Yonekura, Akio; Harada, Kazuhiro; Shibuya, Daisuke; Yamamoto, Seiichiro; Mizota, Yuri; Hamashima, Chisato; Saito, Hiroshi
2016-05-24
The purpose of this study was to examine the effectiveness and cost-efficiency of a tailored message intervention compared with a non-tailored message intervention for increasing colorectal cancer (CRC) screening rates among a non-adherent population, in a community-based client reminder program. After a baseline survey for psychological segmentation, 2140 eligible individuals were randomly assigned either to a group with a tailored matched-message condition (N = 356), a group with a non-tailored unmatched-message condition (N = 355), or to two control groups, one using a typical message with a professional design (N = 717) and one without a professional design (N = 712). The main outcome measure was attendance rates in a community-organized CRC screening program within five months of receiving a print reminder. There was a significant difference in fecal occult blood test (FOBT) attendance rates at follow-up assessments between the tailored matched-message condition (14.0 %) and the control (9.9 %; OR = 1.48, p = 0.026), while there was no significant difference between the unmatched-message condition (11.0 %) and the control (OR = 1.12, p = 0.558), and between the matched-message condition and the unmatched-message condition (OR = 1.32, p = 0.219). The cost of a one-person increase in FOBT screening was 3,740 JPY for the tailored matched-message condition, while it was 2,747 JPY for the control. A tailored-message intervention for segmented individuals designed to increase CRC screening rates in a community-based client reminder program was significantly effective compared to a usual reminder, but not more effective than an unmatched message in a randomized controlled trial, and was not sufficiently effective to highlight its value from a cost perspective. Therefore, the tailored intervention including target segmentation needs to be improved for future implementation in a CRC screening program for a non-adherent population. UMIN Clinical Trials Registry UMIN000004384 . Date of Registration: March 2011.
Jeong, Erwin W; Feger, Erin; Noble, Harmony K; Kmiec, Magdalen; Prayaga, Ram S
2018-01-01
Background Nonadherence is a major concern in the management of chronic conditions such as hypertension, cardiovascular disease, and diabetes where patients may discontinue or interrupt their medication for a variety of reasons. Text message reminders have been used to improve adherence. However, few programs or studies have explored the benefits of text messaging with older populations and at scale. In this paper, we present a program design using tailored and interactive text messaging to improve refill rates of partially adherent or nonadherent Medicare members of a large integrated health plan. Objective The aim of this 3-month program was to gain an understanding of whether tailored interactive text message dialogues could be used to improve medication refills in Medicare patients with one or more chronic diseases. Methods We used the mPulse Mobile interactive text messaging solution with partially adherent and nonadherent Medicare patients (ie, over age 65 years or younger with disabilities) of Kaiser Permanente Southern California (KP), a large integrated health plan, and compared refill rates of the text messaging group (n=12,272) to a group of partially adherent or nonadherent Medicare patients at KP who did not receive text messages (nontext messaging group, n=76,068). Both groups were exposed to other forms of refill and adherence outreach including phone calls, secure emails, and robo-calls from December 2016 to February 2017. Results The text messaging group and nontext messaging group were compared using an independent samples t test to test difference in group average of refill rates. There was a significant difference in medication refill rates between the 2 groups, with a 14.07 percentage points higher refill rate in the text messaging group (P<.001). Conclusions The results showed a strong benefit of using this text messaging solution to improve medication refill rates among Medicare patients. These findings also support using interactive text messaging as a cost-effective, convenient, and user-friendly solution for patient engagement. Program outcomes and insights can be used to enhance the design of future text-based solutions to improve health outcomes and promote adherence and long-term behavior change. PMID:29382623
Feasibility and Acceptability of a Text Messaging Program for Smoking Cessation in Israel.
Abroms, Lorien; Hershcovitz, Ronit; Boal, Ashley; Levine, Hagai
2015-08-01
Text messaging programs on mobile phones have been shown to promote smoking cessation. This study investigated whether a text-messaging program for smoking cessation, adapted from QuitNowTXT, is feasible in Israel and acceptable to Israeli smokers. Participants (N = 38) were given a baseline assessment, enrolled in the adapted text messaging program, and followed-up with at 2 weeks and 4 weeks after their quit date. The authors used an intent-to-treat analysis and found that 23.7% of participants reported having quit smoking at the 4-week follow-up. Participants sent an average of 12.9 text replies during the study period, and the majority reported reading most or all of the texts. However, 34.2% of participants had unsubscribed by the 4-week follow-up. Moderate levels of satisfaction were reported; more than half agreed that they would recommend the program. Suggestions for improvement included adding advice by an expert counselor, website support, and increased customization. Results indicate that a text messaging smoking cessation program developed by modifying the content of QuitNowTXT is feasible and could be acceptable to smokers in Israel. The experience adapting and pilot testing the program can serve as a model for using QuitNowTXT to develop and implement such programs in other countries.
Bhat, Amritha; Mao, Johnny; Unützer, Jürgen; Reed, Susan; Unger, Jennifer
Mental health care integrated into obstetric settings improves access to perinatal depression treatments. Digital interactions such as text messaging between patient and provider can further improve access. We describe the use of text messaging within a perinatal Collaborative Care (CC) program, and explore the association of text messaging content with perinatal depression outcomes. We analyzed data from an open treatment trial of perinatal CC in a rural obstetric clinic. Twenty five women with Patient Health Questionnaire-9 score of ≥10 enrolled in CC, and used text messaging to communicate with their Care Manager(CM). We used surveys and focus groups to assessacceptability of text messaging with surveys and focus groups. We calculated the number of text messages exchanged, and analyzed content to understand usage patterns. We explored association between text messaging content and depression outcomes. CMs initiated 85.4% messages, and patients responded to 86.9% messages. CMs used text messaging for appointment reminders, and patients used it to obtain obstetric and parenting information. CMs had concerns about the likelihood of boundary violations. Patients appreciated the asynchronous nature of text messaging. Text messaging is feasible and acceptable within a perinatal CC program. We need further research into the effectiveness of text messaging content, and response protocols. Copyright © 2018 Elsevier Inc. All rights reserved.
Abroms, Lorien C; Chiang, Shawn; Macherelli, Laura; Leavitt, Leah; Montgomery, Margaret
2017-10-03
Automated text messages on mobile phones have been found to be effective for smoking cessation in adult smokers. This study aims to test the acceptability and feasibility of SmokefreeMOM, a national smoking cessation text-messaging program for pregnant smokers. Participants were recruited from prenatal care and randomized to receive SmokefreeMOM (n=55), an automated smoking cessation text-messaging program, or a control text message quitline referral (n=44). Participants were surveyed by phone at baseline and at 1 month and 3 months after enrollment. Results indicate that the SmokefreeMOM program was highly rated overall and rated more favorably than the control condition in its helpfulness at 3-month follow-up (P<.01) and in its frequency of messaging at both 1-month and 3-month follow-ups (P<.001, P<.01, respectively). Despite the presence of technical problems, the vast majority of intervention participants read all program messages, and few participants unsubscribed from the program. There were no significant differences between groups on the use of extra treatment resources or on smoking-related outcomes. However, at the 3-month follow-up, some outcomes favored the intervention group. SmokefreeMOM is acceptable for pregnant smokers. It is recommended that SmokefreeMOM be further refined and evaluated. Clinicaltrials.gov NCT02412956; https://clinicaltrials.gov/ct2/show/NCT02412956 (Archived by WebCite at http://www.webcitation.org/6tcmeRnbC). ©Lorien C Abroms, Shawn Chiang, Laura Macherelli, Leah Leavitt, Margaret Montgomery. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 03.10.2017.
Information processing in the CNS: a supramolecular chemistry?
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.
Asynchronous Messaging and Data Transfer in a Spacecraft: An Implementation
NASA Technical Reports Server (NTRS)
Moholt, Joseph M.
2005-01-01
Data transfer and messaging is an important part of a spacecraft. Creating a standard protocol for messaging that can be used for a variety of applications is an extremely beneficial project at the Jet Propulsion Laboratory (JPL). The Asynchronous Messaging Service (AMS) is a protocol outlining how subsystems initialize and conduct communication between each other. There are currently two implementations of AMS in the works. At JPL, my task is to get a working implementation of AMS onto vxWorks as a proof of concept. An Autocoder, a program used to convert visually created state chart diagrams to C++, has also been created to accomplish a part of the implementation. I was assigned to make the program portable on any Unix type environment. Lastly, I was to develop a program to demonstrate messaging between two FireWire cards running vxworks.
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.
MPI Runtime Error Detection with MUST: Advances in Deadlock Detection
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
SKIRT: Hybrid parallelization of radiative transfer simulations
NASA Astrophysics Data System (ADS)
Verstocken, S.; Van De Putte, D.; Camps, P.; Baes, M.
2017-07-01
We describe the design, implementation and performance of the new hybrid parallelization scheme in our Monte Carlo radiative transfer code SKIRT, which has been used extensively for modelling the continuum radiation of dusty astrophysical systems including late-type galaxies and dusty tori. The hybrid scheme combines distributed memory parallelization, using the standard Message Passing Interface (MPI) to communicate between processes, and shared memory parallelization, providing multiple execution threads within each process to avoid duplication of data structures. The synchronization between multiple threads is accomplished through atomic operations without high-level locking (also called lock-free programming). This improves the scaling behaviour of the code and substantially simplifies the implementation of the hybrid scheme. The result is an extremely flexible solution that adjusts to the number of available nodes, processors and memory, and consequently performs well on a wide variety of computing architectures.
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.
NASA Technical Reports Server (NTRS)
Korzennik, Sylvain
1997-01-01
Under the direction of Dr. Rhodes, and the technical supervision of Dr. Korzennik, the data assimilation of high spatial resolution solar dopplergrams has been carried out throughout the program on the Intel Delta Touchstone supercomputer. With the help of a research assistant, partially supported by this grant, and under the supervision of Dr. Korzennik, code development was carried out at SAO, using various available resources. To ensure cross-platform portability, PVM was selected as the message passing library. A parallel implementation of power spectra computation for helioseismology data reduction, using PVM was successfully completed. It was successfully ported to SMP architectures (i.e. SUN), and to some MPP architectures (i.e. the CM5). Due to limitation of the implementation of PVM on the Cray T3D, the port to that architecture was not completed at the time.
A Contest to Create Media Messages Aimed at Recruiting Adolescents for Stop Smoking Programs.
ERIC Educational Resources Information Center
Croghan, Ivana T.; Campbell, Heather M.; Patten, Christi A.; Croghan, Gary A.; Schroeder, Darrell R.; Novotny, Paul J.
2004-01-01
This project engaged adolescents in a contest to create advertising messages aimed at recruiting teens for stop smoking programs. Middle school students were invited to design a media message for television, radio, Web, or print (newspaper or billboard). 0f 4,289 students in eight middle schools of Rochester, Minn., 265 (6.2%) developed 172 stop…
Thiha, Phyo; Pisani, Anthony R; Gurditta, Kunali; Cherry, Erin; Peterson, Derick R; Kautz, Henry; Wyman, Peter A
2016-11-09
Equipping members of a target population to deliver effective public health messaging to peers is an established approach in health promotion. The Sources of Strength program has demonstrated the promise of this approach for "upstream" youth suicide prevention. Text messaging is a well-established medium for promoting behavior change and is the dominant communication medium for youth. In order for peer 'opinion leader' programs like Sources of Strength to use scalable, wide-reaching media such as text messaging to spread peer-to-peer messages, they need techniques for assisting peer opinion leaders in creating effective testimonials to engage peers and match program goals. We developed a Web interface, called Stories of Personal Resilience in Managing Emotions (StoryPRIME), which helps peer opinion leaders write effective, short-form messages that can be delivered to the target population in youth suicide prevention program like Sources of Strength. To determine the efficacy of StoryPRIME, a Web-based interface for remotely eliciting high school peer leaders, and helping them produce high-quality, personal testimonials for use in a text messaging extension of an evidence-based, peer-led suicide prevention program. In a double-blind randomized controlled experiment, 36 high school students wrote testimonials with or without eliciting from the StoryPRIME interface. The interface was created in the context of Sources of Strength-an evidence-based youth suicide prevention program-and 24 ninth graders rated these testimonials on relatability, usefulness/relevance, intrigue, and likability. Testimonials written with the StoryPRIME interface were rated as more relatable, useful/relevant, intriguing, and likable than testimonials written without StoryPRIME, P=.054. StoryPRIME is a promising way to elicit high-quality, personal testimonials from youth for prevention programs that draw on members of a target population to spread public health messages. ©Phyo Thiha, Anthony R Pisani, Kunali Gurditta, Erin Cherry, Derick R Peterson, Henry Kautz, Peter A Wyman. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 09.11.2016.
Gonzales, Rachel; Douglas Anglin, M.; Glik, Deborah C.
2014-01-01
This exploratory study examined treatment involved youth opinions about (i) the utility of using text messaging to support recovery behaviors after treatment; (ii) important types of text messages that could help youth self-manage their substance use behaviors after treatment; and (iii) programmatic or logistical areas associated with text messaging programs. Eight focus groups were conducted with 67 youth (aged 12–24) enrolled in outpatient and residential publicly funded substance abuse treatment programs around Los Angeles County, California. Results highlight that 70% of youth positively endorsed text messaging as a viable method of intervention during aftercare, 20% expressed ambivalent feelings, and 10% conveyed dislike. Thematic data exploration revealed seven themes related to the types of text messages youth recommend for helping youth avoid relapse after treatment, including positive appraisal (90%), lifestyle change tips (85%), motivational reinforcing (80%), coping advice (75%), confidence boosters (65%), inspiration encouragement (55%), and informational resources (50%). Youth opinions about key logistical features of text messaging programs, including frequency, timing, sender, and length are also examined. Findings offer insight for the development and enhancement of recovery support interventions with substance abusing youth. Results imply text messaging may serve as a promising opportunity for recovery support for young people with substance abuse problems. PMID:24038196
Gonzales, Rachel; Douglas Anglin, M; Glik, Deborah C
2014-02-01
This exploratory study examined treatment involved youth opinions about (i) the utility of using text messaging to support recovery behaviors after treatment; (ii) important types of text messages that could help youth self-manage their substance use behaviors after treatment; and (iii) programmatic or logistical areas associated with text messaging programs. Eight focus groups were conducted with 67 youth (aged 12-24) enrolled in outpatient and residential publicly funded substance abuse treatment programs around Los Angeles County, California. Results highlight that 70% of youth positively endorsed text messaging as a viable method of intervention during aftercare, 20% expressed ambivalent feelings, and 10% conveyed dislike. Thematic data exploration revealed seven themes related to the types of text messages youth recommend for helping youth avoid relapse after treatment, including positive appraisal (90%), lifestyle change tips (85%), motivational reinforcing (80%), coping advice (75%), confidence boosters (65%), inspiration encouragement (55%), and informational resources (50%). Youth opinions about key logistical features of text messaging programs, including frequency, timing, sender, and length are also examined. Findings offer insight for the development and enhancement of recovery support interventions with substance abusing youth. Results imply text messaging may serve as a promising opportunity for recovery support for young people with substance abuse problems.
Lang, Jun
2012-01-30
In this paper, we propose a novel secure image sharing scheme based on Shamir's three-pass protocol and the multiple-parameter fractional Fourier transform (MPFRFT), which can safely exchange information with no advance distribution of either secret keys or public keys between users. The image is encrypted directly by the MPFRFT spectrum without the use of phase keys, and information can be shared by transmitting the encrypted image (or message) three times between users. Numerical simulation results are given to verify the performance of the proposed algorithm.
E-mail, decisional styles, and rest breaks.
Baker, James R; Phillips, James G
2007-10-01
E-mail is a common but problematic work application. A scale was created to measure tendencies to use e-mail to take breaks (e-breaking); and self-esteem and decisional style (vigilance, procrastination, buck-passing, hypervigilance) were used to predict the self-reported and actual e-mail behaviors of 133 participants (students and marketing employees). Individuals who were low in defensive avoidance (buck-passing) engaged in more e-mailing per week, both in time spent on e-mail and message volume. E-breakers were more likely to engage in behavioral procrastination and spent more time on personal e-mail.
PyPanda: a Python package for gene regulatory network reconstruction
van IJzendoorn, David G.P.; Glass, Kimberly; Quackenbush, John; Kuijjer, Marieke L.
2016-01-01
Summary: PANDA (Passing Attributes between Networks for Data Assimilation) is a gene regulatory network inference method that uses message-passing to integrate multiple sources of ‘omics data. PANDA was originally coded in C ++. In this application note we describe PyPanda, the Python version of PANDA. PyPanda runs considerably faster than the C ++ version and includes additional features for network analysis. Availability and implementation: The open source PyPanda Python package is freely available at http://github.com/davidvi/pypanda. Contact: mkuijjer@jimmy.harvard.edu or d.g.p.van_ijzendoorn@lumc.nl PMID:27402905
PyPanda: a Python package for gene regulatory network reconstruction.
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.
Using Text Message Surveys to Evaluate a Mobile Sexual Health Question-and-Answer Service.
Willoughby, Jessica Fitts; L'Engle, Kelly Ladin; Jackson, Kennon; Brickman, Jared
2018-01-01
Text message programs for sexual health are becoming increasingly popular as practitioners aim to meet youth on media they use frequently. Two-way mobile health (mHealth) interventions allow for feedback solicitation from participants. This study explores the use of a text message survey to assess demographics and program feedback from users of an adolescent sexual health text message question-and-answer service. Development and feasibility of the short-message service survey are discussed. The text message survey achieved a 43.9% response rate, which is comparable to response rates of surveys conducted via other methods. When compared to respondents who used the service and completed an online in-school questionnaire, text survey respondents were more likely to be female and older. They also reported higher service satisfaction. Results have implications for text message service providers and researchers. This article examines a community application of a new intervention strategy and research methodology.
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:
Earth observation taken by the Expedition 43 crew.
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 âEmerald Isleâ is very green!
New Frontier Congressional Gold Medal Act
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:
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:
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…
Patient Perspectives on a Text Messaging Program to Support Asthma Management: A Qualitative Study.
Doyle, Reina; Albright, Karen; Hurley, Laura P; Chávez, Catia; Stowell, Melanie; Dircksen, Suzanne; Havranek, Edward P; Anderson, Mark
2018-05-01
This study investigated participants' acceptance of a short messaging service (SMS) intervention designed to support asthma management, including suggestions regarding program delivery and message content. Individual and group interviews were conducted with patients from a safety-net health care system in Denver, Colorado. Eligible participants were English or Spanish speakers between the ages of 13 and 40 years, with diagnosed persistent asthma. All individual and group interviews were digitally recorded, transcribed, translated from Spanish to English (where applicable), and analyzed for thematic content by experienced analysts using established qualitative content techniques. The qualitative software package ATLAS.ti was used for data analysis and management. This study included a total of 43 participants. In general, participants were receptive toward the SMS program and supported the use of tailored and interactive messages. Adolescents supported the idea of enhancing care by sending messages to a support person, such as a parent or guardian. However, adults were less receptive toward this idea. Participants also preferred directive educational messages and cues to action, while general messages reminding them of their asthma diagnosis were viewed less favorably. The results from this study will inform a randomized control trial evaluating the efficacy of the SMS intervention.
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
Brar Prayaga, Rena; Jeong, Erwin W; Feger, Erin; Noble, Harmony K; Kmiec, Magdalen; Prayaga, Ram S
2018-01-30
Nonadherence is a major concern in the management of chronic conditions such as hypertension, cardiovascular disease, and diabetes where patients may discontinue or interrupt their medication for a variety of reasons. Text message reminders have been used to improve adherence. However, few programs or studies have explored the benefits of text messaging with older populations and at scale. In this paper, we present a program design using tailored and interactive text messaging to improve refill rates of partially adherent or nonadherent Medicare members of a large integrated health plan. The aim of this 3-month program was to gain an understanding of whether tailored interactive text message dialogues could be used to improve medication refills in Medicare patients with one or more chronic diseases. We used the mPulse Mobile interactive text messaging solution with partially adherent and nonadherent Medicare patients (ie, over age 65 years or younger with disabilities) of Kaiser Permanente Southern California (KP), a large integrated health plan, and compared refill rates of the text messaging group (n=12,272) to a group of partially adherent or nonadherent Medicare patients at KP who did not receive text messages (nontext messaging group, n=76,068). Both groups were exposed to other forms of refill and adherence outreach including phone calls, secure emails, and robo-calls from December 2016 to February 2017. The text messaging group and nontext messaging group were compared using an independent samples t test to test difference in group average of refill rates. There was a significant difference in medication refill rates between the 2 groups, with a 14.07 percentage points higher refill rate in the text messaging group (P<.001). The results showed a strong benefit of using this text messaging solution to improve medication refill rates among Medicare patients. These findings also support using interactive text messaging as a cost-effective, convenient, and user-friendly solution for patient engagement. Program outcomes and insights can be used to enhance the design of future text-based solutions to improve health outcomes and promote adherence and long-term behavior change. ©Rena Brar Prayaga, Erwin W Jeong, Erin Feger, Harmony K Noble, Magdalen Kmiec, Ram S Prayaga. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 30.01.2018.
User preferences for a text message-based smoking cessation intervention.
Bock, Beth C; Heron, Kristin E; Jennings, Ernestine G; Magee, Joshua C; Morrow, Kathleen M
2013-04-01
Younger adults are more likely to smoke and less likely to seek treatment than older smokers. They are also frequent users of communication technology. In the current study, we conducted focus groups to obtain feedback about preferences for a text message-based smoking cessation program from potential users. Participants (N = 21, M age = 25.6 years, age range = 20-33 years) were current or recently quit smokers (M cigarettes/day = 12.8) who used text messaging. Participants completed questionnaires and participated in a 2-hour focus group. Focus groups were conducted using an a priori semistructured interview guide to promote discussion of the content and functionality of the intervention. Major themes from analysis of the focus groups included support for the acceptability of a text-based cessation program, suggestions for a more technologically broad-based program, and adjustments to the program structure. Participants recommended including social networking functions, user control of program output through an online profile, and text message features to promote interaction with the system. Interestingly, many participants suggested the program should begin on individuals' identified quit day, challenging the procedures used in most cessation programs, which begin by preparing participants for a future quit date. Overall, younger adult smokers appear to be interested in participating in a smoking cessation program that uses text messages and web-based elements. Qualitative feedback regarding the perceived optimal features and structure of a technology-based intervention challenged traditional methods of implementing smoking cessation interventions and will inform the development of future programs.
Lewkowitz, Adam K; O'Donnell, Betsy E; Nakagawa, Sanae; Vargas, Juan E; Zlatnik, Marya G
2016-03-01
Text4baby is the only free text-message program for pregnancy available. Our objective was to determine whether content differed between Text4baby and popular pregnancy smart phone applications (apps). Researchers enrolled in Text4baby in 2012 and downloaded the four most-popular free pregnancy smart phone apps in July 2013; content was re-extracted in February 2014. Messages were assigned thematic codes. Two researchers coded messages independently before reviewing all the codes jointly to ensure consistency. Logistic regression modeling determined statistical differences between Text4baby and smart phone apps. About 1399 messages were delivered. Of these, 333 messages had content related to more than one theme and were coded as such, resulting in 1820 codes analyzed. Compared to smart phone apps, Text4baby was significantly more likely to have content regarding Postpartum Planning, Seeking Care, Recruitment and Prevention and significantly less likely to mention Normal Pregnancy Symptoms. No messaging program included content regarding postpartum contraception. To improve content without increasing text message number, Text4baby could replace messages on recruitment with messages regarding normal pregnancy symptoms, fetal development and postpartum contraception.
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.
Message passing with queues and channels
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dozsa, Gabor J; Heidelberger, Philip; Kumar, Sameer
In an embodiment, a reception thread receives a source node identifier, a type, and a data pointer from an application and, in response, creates a receive request. If the source node identifier specifies a source node, the reception thread adds the receive request to a fast-post queue. If a message received from a network does not match a receive request on a posted queue, a polling thread adds a receive request that represents the message to an unexpected queue. If the fast-post queue contains the receive request, the polling thread removes the receive request from the fast-post queue. If themore » receive request that was removed from the fast-post queue does not match the receive request on the unexpected queue, the polling thread adds the receive request that was removed from the fast-post queue to the posted queue. The reception thread and the polling thread execute asynchronously from each other.« less
Secure Web-Site Access with Tickets and Message-Dependent Digests
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.
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.
Versteeg, Roelof J.; Few, Douglas A.; Kinoshita, Robert A.; Johnson, Douglas; Linda, Ondrej
2015-12-15
Methods, computer readable media, and apparatuses provide robotic explosive hazard detection. A robot intelligence kernel (RIK) includes a dynamic autonomy structure with two or more autonomy levels between operator intervention and robot initiative A mine sensor and processing module (ESPM) operating separately from the RIK perceives environmental variables indicative of a mine using subsurface perceptors. The ESPM processes mine information to determine a likelihood of a presence of a mine. A robot can autonomously modify behavior responsive to an indication of a detected mine. The behavior is modified between detection of mines, detailed scanning and characterization of the mine, developing mine indication parameters, and resuming detection. Real time messages are passed between the RIK and the ESPM. A combination of ESPM bound messages and RIK bound messages cause the robot platform to switch between modes including a calibration mode, the mine detection mode, and the mine characterization mode.
Machine-checked proofs of the design and implementation of a fault-tolerant circuit
NASA Technical Reports Server (NTRS)
Bevier, William R.; Young, William D.
1990-01-01
A formally verified implementation of the 'oral messages' algorithm of Pease, Shostak, and Lamport is described. An abstract implementation of the algorithm is verified to achieve interactive consistency in the presence of faults. This abstract characterization is then mapped down to a hardware level implementation which inherits the fault-tolerant characteristics of the abstract version. All steps in the proof were checked with the Boyer-Moore theorem prover. A significant results is the demonstration of a fault-tolerant device that is formally specified and whose implementation is proved correct with respect to this specification. A significant simplifying assumption is that the redundant processors behave synchronously. A mechanically checked proof that the oral messages algorithm is 'optimal' in the sense that no algorithm which achieves agreement via similar message passing can tolerate a larger proportion of faulty processor is also described.
Action languages: Dimensions, effects
NASA Technical Reports Server (NTRS)
Hayes, Daniel G.; Streeter, Gordon
1989-01-01
Dimensions of action languages are discussed for communication between humans and machines, and the message handling capabilities of object oriented programming systems are examined. Design of action languages is seen to be very contextual. Economical and effective design will depend on features of situations, the tasks intended to be accomplished, and the nature of the devices themselves. Current object oriented systems turn out to have fairly simple and straightforward message handling facilities, which in themselves do little to buffer action or even in some cases to handle competing messages. Even so, it is possible to program a certain amount of discretion about how they react to messages. Such thoughtfulness and perhaps relative autonomy of program modules seems prerequisite to future systems to handle complex interactions in changing situations.
Method for distributed agent-based non-expert simulation of manufacturing process behavior
Ivezic, Nenad; Potok, Thomas E.
2004-11-30
A method for distributed agent based non-expert simulation of manufacturing process behavior on a single-processor computer comprises the steps of: object modeling a manufacturing technique having a plurality of processes; associating a distributed agent with each the process; and, programming each the agent to respond to discrete events corresponding to the manufacturing technique, wherein each discrete event triggers a programmed response. The method can further comprise the step of transmitting the discrete events to each agent in a message loop. In addition, the programming step comprises the step of conditioning each agent to respond to a discrete event selected from the group consisting of a clock tick message, a resources received message, and a request for output production message.
A text message intervention for alcohol risk reduction among community college students: TMAP.
Bock, Beth C; Barnett, Nancy P; Thind, Herpreet; Rosen, Rochelle; Walaska, Kristen; Traficante, Regina; Foster, Robert; Deutsch, Chris; Fava, Joseph L; Scott-Sheldon, Lori A J
2016-12-01
Students at community colleges comprise nearly half of all U.S. college students and show higher risk of heavy drinking and related consequences compared to students at 4-year colleges, but no alcohol safety programs currently target this population. To examine the feasibility, acceptability, and preliminary efficacy of an alcohol risk-reduction program delivered through text messaging designed for community college (CC) students. Heavy drinking adult CC students (N=60) were enrolled and randomly assigned to the six-week active intervention (Text Message Alcohol Program: TMAP) or a control condition of general motivational (not alcohol related) text messages. TMAP text messages consisted of alcohol facts, strategies to limit alcohol use and related risks, and motivational messages. Assessments were conducted at baseline, week 6 (end of treatment) and week 12 (follow up). Most participants (87%) completed all follow up assessments. Intervention messages received an average rating of 6.8 (SD=1.5) on a 10-point scale. At week six, TMAP participants were less likely than controls to report heavy drinking and negative alcohol consequences. The TMAP group also showed significant increases in self-efficacy to resist drinking in high risk situations between baseline and week six, with no such increase among controls. Results were maintained through the week 12 follow up. The TMAP alcohol risk reduction program was feasible and highly acceptable indicated by high retention rates through the final follow up assessment and good ratings for the text message content. Reductions in multiple outcomes provide positive indications of intervention efficacy. Copyright © 2016. Published by Elsevier Ltd.
Falcone, John L; Gonzalo, Jed D
2014-01-19
To determine Internal Medicine residency program compliance with the Accreditation Council for Graduate Medical Education 80% pass-rate standard and the correlation between residency program size and performance on the American Board of Internal Medicine Certifying Examination. Using a cross-sectional study design from 2010-2012 American Board of Internal Medicine Certifying Examination data of all Internal Medicine residency pro-grams, comparisons were made between program pass rates to the Accreditation Council for Graduate Medical Education pass-rate standard. To assess the correlation between program size and performance, a Spearman's rho was calculated. To evaluate program size and its relationship to the pass-rate standard, receiver operative characteristic curves were calculated. Of 372 Internal Medicine residency programs, 276 programs (74%) achieved a pass rate of =80%, surpassing the Accreditation Council for Graduate Medical Education minimum standard. A weak correlation was found between residency program size and pass rate for the three-year period (p=0.19, p<0.001). The area underneath the receiver operative characteristic curve was 0.69 (95% Confidence Interval [0.63-0.75]), suggesting programs with less than 12 examinees/year are less likely to meet the minimum Accreditation Council for Graduate Medical Education pass-rate standard (sensitivity 63.8%, specificity 60.4%, positive predictive value 82.2%, p<0.001). Although a majority of Internal Medicine residency programs complied with Accreditation Council for Graduate Medical Education pass-rate standards, a quarter of the programs failed to meet this requirement. Program size is positively but weakly associated with American Board of Internal Medicine Certifying Examination performance, suggesting other unidentified variables significantly contribute to program performance.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-04
.... Need and Use of Information Collection: This is a request for clearance to pretest messages, materials... information programs; and (2) pretest these health messages, products, strategies, and program components...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-11-17
.... Need and Use of Information Collection: This is a request for clearance to pretest messages, materials... information programs; and (2) pretest these health messages, products, strategies, and program components...
Participation Rates in a Worksite Wellness Program Using E-Mail Wellness Messages
ERIC Educational Resources Information Center
Anenson, Larry W.; Brunt, Ardith; Terbizan, Donna J.; Christensen, Bryan
2014-01-01
The purpose of this study was to determine which days of the work week had the largest rate of opened e-health messages, whether detailed or basic e-health messages were more likely to be opened, if motivation influenced the rate of message opening, and if the rate of opening messages declined over time. Ninety-one city employees (52 male and 39…
A Struggle for Dominance: Relational Communication Messages in Television Programming.
ERIC Educational Resources Information Center
Barbatsis, Gretchen S.; And Others
Television's messages about sex role behavior were analyzed by collecting and coding spot samples of the ten top ranked programs in prime viewing time and proportionate numbers of daytime soap operas and Saturday morning children's programs. The content analysis was based on a relational coding system developed to assess interpersonal…
Admission Volunteer Programs: Are They Really Worth the Effort?
ERIC Educational Resources Information Center
Symmonds, Ian
2002-01-01
Developing and using volunteers in the admission process is an age-old topic for those in the admission field. A good volunteer program allows an institution to provide more audience-based marketing messages rather than institutional-based marketing messages. Such programs can mean a more engaged, supportive, and enthusiastic set of key…
Promoting Quality of Program Delivery via an Internet Message Delivery System
ERIC Educational Resources Information Center
Bishop, Dana C.; Dusenbury, Linda; Pankratz, Melinda M.; Hansen, William B.
2013-01-01
This article presents results from a study that evaluated an online message system designed to improve the delivery of prevention programs. We conducted a quasi-experimental study with 32 agencies and schools that implemented substance use prevention programs and examined differences between the comparison and intervention groups. We also examined…
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…
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:
Emergency Border Security Supplemental Appropriations Act, 2010
Rep. Price, David E. [D-NC-4
2010-07-27
Senate - 09/23/2010 Message received in the Senate: Returned to the Senate pursuant to the provisions of H.Res. 1653. (All Actions) Notes: For further action, see H.R.6080, which became Public Law 111-230 on 8/13/2010. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:
LDPC Codes--Structural Analysis and Decoding Techniques
ERIC Educational Resources Information Center
Zhang, Xiaojie
2012-01-01
Low-density parity-check (LDPC) codes have been the focus of much research over the past decade thanks to their near Shannon limit performance and to their efficient message-passing (MP) decoding algorithms. However, the error floor phenomenon observed in MP decoding, which manifests itself as an abrupt change in the slope of the error-rate curve,…
Comprehensive Iran Sanctions, Accountability, and Divestment Act of 2009
Sen. Dodd, Christopher J. [D-CT
2009-11-19
Senate - 09/23/2010 Message received in the Senate: Returned to the Senate pursuant to the provisions of H.Res. 1653. (All Actions) Notes: For further action, see H.R.2194, which became Public Law 111-195 on 7/1/2010. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:
Federal Aviation Administration Extension Act of 2010
Sen. Rockefeller, John D., IV [D-WV
2010-03-25
Senate - 09/23/2010 Message received in the Senate: Returned to the Senate pursuant to the provisions of H.Res. 1653. (All Actions) Notes: For further action, see H.R.5147, which became Public Law 111-161 on 4/30/2010. Tracker: This bill has the status Passed SenateHere are the steps for Status of Legislation:
Minority Journalists Push Media to Maintain Diversity Commitment
ERIC Educational Resources Information Center
Anderson, Michelle D.
2008-01-01
In a media advisory released earlier this month, the National Association of Black Journalists (NABJ) had an urgent message for the newspaper industry: Diversity should not be treated like a passing fad and it should continue to be a top priority. The advocacy organization, where a majority of its 4,000 members are Black print journalists, warned…
Post-acute crisis text messaging outreach for suicide prevention: a pilot study.
Berrouiguet, Sofian; Gravey, Michel; Le Galudec, Mickaël; Alavi, Zarrin; Walter, Michel
2014-07-30
Several post-suicide prevention strategies such as sending postcards or making phone calls have been used to keep in contact with suicide attempters. The continuity of care has been beneficial to the prevention of post-acute suicidal behaviors. The aim of the study was to evaluate the technical feasibility and acceptability of text messaging outreach in post-acute suicide attempters. Eighteen post-suicidal patients were included in a prospective, monocentric, open-label, 2 months pilot study. The text messages were sent from the intranet program that we specially developed for the study. Technical feasibility of this text message intervention was evaluated by the analysis of text message reports. Acceptability of such intervention was evaluated by a standardized phone interview. Our study showed that receiving text messages sent from an intranet program after a suicide attempt is technically possible. This post-crisis outreach program was accepted by the patients who found it to have a positive preventive impact. Text messaging outreach offers several advantages such as lower cost, and easier utilization compared to current post-acute care strategies. We suggest further randomized controlled trials in a large sample of suicidal patients to assess the efficacy of this novel outreach tool for prevention of post-acute suicide. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Signaling communication events in a computer network
Bender, Carl A.; DiNicola, Paul D.; Gildea, Kevin J.; Govindaraju, Rama K.; Kim, Chulho; Mirza, Jamshed H.; Shah, Gautam H.; Nieplocha, Jaroslaw
2000-01-01
A method, apparatus and program product for detecting a communication event in a distributed parallel data processing system in which a message is sent from an origin to a target. A low-level application programming interface (LAPI) is provided which has an operation for associating a counter with a communication event to be detected. The LAPI increments the counter upon the occurrence of the communication event. The number in the counter is monitored, and when the number increases, the event is detected. A completion counter in the origin is associated with the completion of a message being sent from the origin to the target. When the message is completed, LAPI increments the completion counter such that monitoring the completion counter detects the completion of the message. The completion counter may be used to insure that a first message has been sent from the origin to the target and completed before a second message is sent.
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.
From Our Practices to Yours: Key Messages for the Journey to Integrated Behavioral Health.
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.
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.
NASA Technical Reports Server (NTRS)
Spuler, Linda M.; Ford, Patricia K.; Skeete, Darren C.; Hershman, Scot; Raviprakash, Pushpa; Arnold, John W.; Tran, Victor; Haenze, Mary Alice
2005-01-01
"Close Call Action Log Form" ("CCALF") is the name of both a computer program and a Web-based service provided by the program for creating an enhanced database of close calls (in the colloquial sense of mishaps that were avoided by small margins) assigned to the Center Operations Directorate (COD) at Johnson Space Center. CCALF provides a single facility for on-line collaborative review of close calls. Through CCALF, managers can delegate responses to employees. CCALF utilizes a pre-existing e-mail system to notify managers that there are close calls to review, but eliminates the need for the prior practices of passing multiple e-mail messages around the COD, then collecting and consolidating them into final responses: CCALF now collects comments from all responders for incorporation into reports that it generates. Also, whereas it was previously necessary to manually calculate metrics (e.g., numbers of maintenance-work orders necessitated by close calls) for inclusion in the reports, CCALF now computes the metrics, summarizes them, and displays them in graphical form. The reports and all pertinent information used to generate the reports are logged, tracked, and retained by CCALF for historical purposes.
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.
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.
Procacci, Piero
2016-06-27
We present a new release (6.0β) of the ORAC program [Marsili et al. J. Comput. Chem. 2010, 31, 1106-1116] with a hybrid OpenMP/MPI (open multiprocessing message passing interface) multilevel parallelism tailored for generalized ensemble (GE) and fast switching double annihilation (FS-DAM) nonequilibrium technology aimed at evaluating the binding free energy in drug-receptor system on high performance computing platforms. The production of the GE or FS-DAM trajectories is handled using a weak scaling parallel approach on the MPI level only, while a strong scaling force decomposition scheme is implemented for intranode computations with shared memory access at the OpenMP level. The efficiency, simplicity, and inherent parallel nature of the ORAC implementation of the FS-DAM algorithm, project the code as a possible effective tool for a second generation high throughput virtual screening in drug discovery and design. The code, along with documentation, testing, and ancillary tools, is distributed under the provisions of the General Public License and can be freely downloaded at www.chim.unifi.it/orac .
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
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
Portable Parallel Programming for the Dynamic Load Balancing of Unstructured Grid Applications
NASA Technical Reports Server (NTRS)
Biswas, Rupak; Das, Sajal K.; Harvey, Daniel; Oliker, Leonid
1999-01-01
The ability to dynamically adapt an unstructured -rid (or mesh) is a powerful tool for solving computational problems with evolving physical features; however, an efficient parallel implementation is rather difficult, particularly from the view point of portability on various multiprocessor platforms We address this problem by developing PLUM, tin automatic anti architecture-independent framework for adaptive numerical computations in a message-passing environment. Portability is demonstrated by comparing performance on an SP2, an Origin2000, and a T3E, without any code modifications. We also present a general-purpose load balancer that utilizes symmetric broadcast networks (SBN) as the underlying communication pattern, with a goal to providing a global view of system loads across processors. Experiments on, an SP2 and an Origin2000 demonstrate the portability of our approach which achieves superb load balance at the cost of minimal extra overhead.
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.
Dick, Jonathan J; Nundy, Shantanu; Solomon, Marla C; Bishop, Keisha N; Chin, Marshall H; Peek, Monica E
2011-09-01
We pilot-tested a text message-based diabetes care program in an urban African-American population in which automated text messages were sent to participants with personalized medication, foot care, and appointment reminders and text messages were received from participants on adherence. Eighteen patients participated in a 4-week pilot study. Baseline surveys collected data about demographics, historical cell phone usage, and adherence to core diabetes care measures. Exit interview surveys (using close-coded and open-ended questions) were administered to patients at the end of the program. A 1-month follow-up interview was conducted surveying patients on perceived self-efficacy. Wilcoxon signed-rank tests were used to compare baseline survey responses about self-management activities to those at the pilot's end and at 1-month follow-up. Eighteen urban African-American participants completed the pilot study. The average age was 55 and the average number of years with diabetes was 8. Half the participants were initially uncomfortable with text messaging. Example messages include "Did you take your diabetes medications today" and "How many times did you check your feet for wounds this week?" Participants averaged 220 text messages with the system, responded to messages 80% of the time, and on average responded within 6 minutes. Participants strongly agreed that text messaging was easy to perform and helped with diabetes self-care. Missed medication doses decreased from 1.6 per week to 0.6 (p = .003). Patient confidence in diabetes self-management was significantly increased during and 1 month after the pilot (p = .002, p = .008). Text messaging may be a feasible and useful approach to improve diabetes self-management in urban African Americans. © 2011 Diabetes Technology Society.
Performance issues for domain-oriented time-driven distributed simulations
NASA Technical Reports Server (NTRS)
Nicol, David M.
1987-01-01
It has long been recognized that simulations form an interesting and important class of computations that may benefit from distributed or parallel processing. Since the point of parallel processing is improved performance, the recent proliferation of multiprocessors requires that we consider the performance issues that naturally arise when attempting to implement a distributed simulation. Three such issues are: (1) the problem of mapping the simulation onto the architecture, (2) the possibilities for performing redundant computation in order to reduce communication, and (3) the avoidance of deadlock due to distributed contention for message-buffer space. These issues are discussed in the context of a battlefield simulation implemented on a medium-scale multiprocessor message-passing architecture.
Parallel integer sorting with medium and fine-scale parallelism
NASA Technical Reports Server (NTRS)
Dagum, Leonardo
1993-01-01
Two new parallel integer sorting algorithms, queue-sort and barrel-sort, are presented and analyzed in detail. These algorithms do not have optimal parallel complexity, yet they show very good performance in practice. Queue-sort designed for fine-scale parallel architectures which allow the queueing of multiple messages to the same destination. Barrel-sort is designed for medium-scale parallel architectures with a high message passing overhead. The performance results from the implementation of queue-sort on a Connection Machine CM-2 and barrel-sort on a 128 processor iPSC/860 are given. The two implementations are found to be comparable in performance but not as good as a fully vectorized bucket sort on the Cray YMP.
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.
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.
Pope, J Paige; Pelletier, Luc; Guertin, Camille
2018-09-01
Health promotion programs represent a salient means through which physical activity promoters can cultivate positive health behavior change and maintenance. The messages communicated within these programs serve as an essential component as they are often used to convey valuable information, resources, or tools that facilitate health behavior initiation and sustained engagement. Identifying the most effective way to communicate health promotion information is, therefore, of considerable importance to ensuring that people not only attend to these messages, but also connect with and internalize the information conveyed within them. This paper was written to (1) summarize and evaluate the most prominent reviewed research approaches of message framing and tailoring to message design; and (2) offer a comprehensive messaging strategy to promote sustained health behavior change. A review of the literature demonstrated that a messaging strategy that has consistently led to healthy behavior change has yet to be identified. Furthermore, scholars have articulated that a multi-theoretical approach that places emphasis on facilitating motivation and healthy behavior change needs to be employed. Thus, this paper proposes and provides recommendations for employing the Comprehensive Messaging Strategy for Sustained Behavior Change (CMSSBC), which advocates tailoring messages to peoples' stage of change and framing them to focus on self-determined motives and intrinsic goals.
NASA Astrophysics Data System (ADS)
Gregg, C. E.; Johnston, D. M.; Ricthie, L.; Meinhold, S.; Johnson, V.; Scott, C.; Farnham, C.; Houghton, B. F.; Horan, J.; Gill, D.
2012-12-01
Improving the quality and effectiveness of tsunami warning messages and the TsunamiReady community preparedness program of the US National Oceanic and Atmospheric Administration, National Weather Service's (NWS), Tsunami Program are two key objectives of a three year project (Award NA10NWS4670015) to help integrate social science into the NWS' Tsunami Program and improve the preparedness of member states and territories of the National Tsunami Hazard Mitigation Program (NTHMP). Research was conducted in collaboration with state and local emergency managers. Based on findings from 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), and upon review of research literature on behavioral response to warnings, we developed a warning message metric to help guide revisions to tsunami warning messages issued by the NWS' West Coast/Alaska Tsunami Warning Center, Alaska and Pacific Tsunami Warning Center, Hawaii. The metric incorporates factors that predict response to warning information, which are divided into categories of Message Content, Style, Order and Formatting and Receiver Characteristics. A message is evaluated by cross-referencing the message with the meaning of metric factors and assigning a maximum score of one point per factor. Findings are then used to guide revisions of the message until the characteristics of each factor are met. From focus groups that gathered information on the usefulness and achievability of tsunami preparedness actions, we developed recommendations for revisions to the proposed draft guidelines of the TsunamiReady Improvement Program. Proposed key revisions include the incorporation of community vulnerability to distant (far-field) versus local (near-field) tsunamis as a primary determinant of mandatory actions, rather than community population. Our team continues to work with NWS personnel, including a NWS Tsunami Warning Improvement Team, and the focus group participants to finalize and pilot test prototype warning products and the draft TsunamiReady guidelines.
Thakkar, Jay; Barry, Tony; Thiagalingam, Aravinda; Redfern, Julie; McEwan, Alistair L; Rodgers, Anthony
2016-01-01
Background Mobile health (mHealth) has huge potential to deliver preventative health services. However, there is paucity of literature on theoretical constructs, technical, practical, and regulatory considerations that enable delivery of such services. Objectives The objective of this study was to outline the key considerations in the development of a text message-based mHealth program; thus providing broad recommendations and guidance to future researchers designing similar programs. Methods We describe the key considerations in designing the intervention with respect to functionality, technical infrastructure, data management, software components, regulatory requirements, and operationalization. We also illustrate some of the potential issues and decision points utilizing our experience of developing text message (short message service, SMS) management systems to support 2 large randomized controlled trials: TEXT messages to improve MEDication adherence & Secondary prevention (TEXTMEDS) and Tobacco, EXercise and dieT MEssages (TEXT ME). Results The steps identified in the development process were: (1) background research and development of the text message bank based on scientific evidence and disease-specific guidelines, (2) pilot testing with target audience and incorporating feedback, (3) software-hardware customization to enable delivery of complex personalized programs using prespecified algorithms, and (4) legal and regulatory considerations. Additional considerations in developing text message management systems include: balancing the use of customized versus preexisting software systems, the level of automation versus need for human inputs, monitoring, ensuring data security, interface flexibility, and the ability for upscaling. Conclusions A merging of expertise in clinical and behavioral sciences, health and research data management systems, software engineering, and mobile phone regulatory requirements is essential to develop a platform to deliver and manage support programs to hundreds of participants simultaneously as in TEXT ME and TEXTMEDS trials. This research provides broad principles that may assist other researchers in developing mHealth programs. PMID:27847350
Thakkar, Jay; Barry, Tony; Thiagalingam, Aravinda; Redfern, Julie; McEwan, Alistair L; Rodgers, Anthony; Chow, Clara K
2016-11-15
Mobile health (mHealth) has huge potential to deliver preventative health services. However, there is paucity of literature on theoretical constructs, technical, practical, and regulatory considerations that enable delivery of such services. The objective of this study was to outline the key considerations in the development of a text message-based mHealth program; thus providing broad recommendations and guidance to future researchers designing similar programs. We describe the key considerations in designing the intervention with respect to functionality, technical infrastructure, data management, software components, regulatory requirements, and operationalization. We also illustrate some of the potential issues and decision points utilizing our experience of developing text message (short message service, SMS) management systems to support 2 large randomized controlled trials: TEXT messages to improve MEDication adherence & Secondary prevention (TEXTMEDS) and Tobacco, EXercise and dieT MEssages (TEXT ME). The steps identified in the development process were: (1) background research and development of the text message bank based on scientific evidence and disease-specific guidelines, (2) pilot testing with target audience and incorporating feedback, (3) software-hardware customization to enable delivery of complex personalized programs using prespecified algorithms, and (4) legal and regulatory considerations. Additional considerations in developing text message management systems include: balancing the use of customized versus preexisting software systems, the level of automation versus need for human inputs, monitoring, ensuring data security, interface flexibility, and the ability for upscaling. A merging of expertise in clinical and behavioral sciences, health and research data management systems, software engineering, and mobile phone regulatory requirements is essential to develop a platform to deliver and manage support programs to hundreds of participants simultaneously as in TEXT ME and TEXTMEDS trials. This research provides broad principles that may assist other researchers in developing mHealth programs. ©Jay Thakkar, Tony Barry, Aravinda Thiagalingam, Julie Redfern, Alistair L McEwan, Anthony Rodgers, Clara K Chow. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 15.11.2016.
Nature and Impact of Alcohol Messages in a Youth-Oriented Television Series
Russell, Cristel Antonia; Russell, Dale W.; Grube, Joel W.
2008-01-01
This research contributes to the extant literature on television influence by pairing a stimulus-side approach documenting how information is presented within a TV series with a response-side assessment of whether connectedness and exposure to a series influence the processing of that information differently depending on its format. The inquiry focuses on the nature and impact of messages about alcohol contained within a youth oriented TV program. The findings indicate that the recall and perception of the more overt negative messages increase with exposure and that receptiveness to the subtle and less remembered positive messages increases with levels of program connectedness. Highly connected viewers are both more receptive to and in greater agreement with the underlying positive alcohol message communicated in the series. PMID:21113396
Nature and Impact of Alcohol Messages in a Youth-Oriented Television Series.
Russell, Cristel Antonia; Russell, Dale W; Grube, Joel W
2009-01-01
This research contributes to the extant literature on television influence by pairing a stimulus-side approach documenting how information is presented within a TV series with a response-side assessment of whether connectedness and exposure to a series influence the processing of that information differently depending on its format. The inquiry focuses on the nature and impact of messages about alcohol contained within a youth oriented TV program. The findings indicate that the recall and perception of the more overt negative messages increase with exposure and that receptiveness to the subtle and less remembered positive messages increases with levels of program connectedness. Highly connected viewers are both more receptive to and in greater agreement with the underlying positive alcohol message communicated in the series.
Engineered cell-cell communication via DNA messaging
2012-01-01
Background Evolution has selected for organisms that benefit from genetically encoded cell-cell communication. Engineers have begun to repurpose elements of natural communication systems to realize programmed pattern formation and coordinate other population-level behaviors. However, existing engineered systems rely on system-specific small molecules to send molecular messages among cells. Thus, the information transmission capacity of current engineered biological communication systems is physically limited by specific biomolecules that are capable of sending only a single message, typically “regulate transcription.” Results We have engineered a cell-cell communication platform using bacteriophage M13 gene products to autonomously package and deliver heterologous DNA messages of varying lengths and encoded functions. We demonstrate the decoupling of messages from a common communication channel via the autonomous transmission of various arbitrary genetic messages. Further, we increase the range of engineered DNA messaging across semisolid media by linking message transmission or receipt to active cellular chemotaxis. Conclusions We demonstrate decoupling of a communication channel from message transmission within engineered biological systems via the autonomous targeted transduction of user-specified heterologous DNA messages. We also demonstrate that bacteriophage M13 particle production and message transduction occurs among chemotactic bacteria. We use chemotaxis to improve the range of DNA messaging, increasing both transmission distance and communication bit rates relative to existing small molecule-based communication systems. We postulate that integration of different engineered cell-cell communication platforms will allow for more complex spatial programming of dynamic cellular consortia. PMID:22958599
1991-11-29
inter,:reted in ways not intended; the percepLion of subliminal messages is based on demographic characteristics and subculture influence; and...receiver and sender, and must be dealt with accordingly. For instance, if the sender of the message must compete with a louder auditory stimulus, this...these themes. Hoijer concluded that television programs do stimulate thought processes, and there is a connection between the contents 18 of the program
DICE: An Object Oriented Programming Environment for Cooperative Engineering Design
1989-03-20
environment called PARMENIDES /FRULEKIT; PARMENIDES /FRULEKIT supports programming in frames and rules and was developed in LISP at Carnegie-Mellon...the domain of building design and construction. The Blackboard in DICEY-BUILDER is represented as frames in PARMENIDES , while the KMs are implemented... PARMENIDES fo rart omat format d a b C /envelope BLACKBOAR D machine to machine (’BLACKBOARD l m message f il transfer message p read •d message format J
Walkosz, Barbara J; Buller, David B; Andersen, Peter A; Scott, Michael D; Dignan, Mark B; Cutter, Gary R; Liu, Xia; Maloy, Julie A
2014-09-01
Go Sun Smart is a theory-based health communication program designed to influence sun-protection behaviors of employees and guests at high-altitude ski areas to reduce skin cancer risk. The effects of Go Sun Smart, in a Phase IV dissemination randomized posttest-only trial, on sun-protection behaviors of ski area guests are reported. Program use was assessed by on-site observation and guest message exposure, and sun protection was measured in intercept surveys at ski areas. Dissemination strategy-enhanced versus basic-was not significantly related to sun safety practices. Additional analyses examined the relation between message exposure and guests' sun safety practices. Ski areas displaying at least 6 Go Sun Smart materials in guest-only areas and 9 Go Sun Smart materials throughout the area increased guests' message exposure. Higher message exposure within the high-use ski areas was associated with improved sun protection by guests but not within the low-use ski areas. The authors underscore the importance of program implementation and message exposure on the success of evidence-based health communication efforts applied industrywide.
Lancioni, Giulio E; Singh, Nirbhay N; O'Reilly, Mark F; Sigafoos, Jeff; Oliva, Doretta; Buonocunto, Francesca; Sacco, Valentina; D'Amico, Fiora; Navarro, Jorge; Lanzilotti, Crocifissa; De Tommaso, Marina; Megna, Marisa
2014-01-01
Interventions for post-coma persons, who have emerged from a minimally conscious state but present with extensive neuro-motor impairment and lack of or minimal verbal skills, need to promote occupation and communication through the use of assistive technology. These two studies were aimed at assessing two technology-aided programs to promote leisure engagement and communication for three post-coma participants with multiple disabilities. Study I assessed a program to allow a woman and a man with extensive neuro-motor impairment and lack of speech to switch on music and videos, make requests to caregivers, and send messages to (communicate with) relevant partners and receive messages from those partners. Study II assessed a program to allow a post-coma woman with extensive motor impairment and reduced verbal behavior to activate music, videos and requests, send and receive messages, and make telephone calls. Data showed that both programs were successful. The participants of Study I managed leisure engagement, requests, as well as text messaging. The participant of Study II showed consistent leisure engagement, text messaging, and telephone calls. Assistive technology can be profitably used to provide post-coma persons with multiple disabilities relevant leisure and communication opportunities.
Prescott, Tonya L; Espelage, Dorothy L
2016-01-01
Background Bullying is a significant public health issue among middle school-aged youth. Current prevention programs have only a moderate impact. Cell phone text messaging technology (mHealth) can potentially overcome existing challenges, particularly those that are structural (e.g., limited time that teachers can devote to non-educational topics). To date, the description of the development of empirically-based mHealth-delivered bullying prevention programs are lacking in the literature. Objective To describe the development of BullyDown, a text messaging-based bullying prevention program for middle school students, guided by the Social-Emotional Learning model. Methods We implemented five activities over a 12-month period: (1) national focus groups (n=37 youth) to gather acceptability of program components; (2) development of content; (3) a national Content Advisory Team (n=9 youth) to confirm content tone; and (4) an internal team test of software functionality followed by a beta test (n=22 youth) to confirm the enrollment protocol and the feasibility and acceptability of the program. Results Recruitment experiences suggested that Facebook advertising was less efficient than using a recruitment firm to recruit youth nationally, and recruiting within schools for the pilot test was feasible. Feedback from the Content Advisory Team suggests a preference for 2-4 brief text messages per day. Beta test findings suggest that BullyDown is both feasible and acceptable: 100% of youth completed the follow-up survey, 86% of whom liked the program. Conclusions Text messaging appears to be a feasible and acceptable delivery method for bullying prevention programming delivered to middle school students. PMID:27296471
Ybarra, Michele L; Prescott, Tonya L; Espelage, Dorothy L
2016-06-13
Bullying is a significant public health issue among middle school-aged youth. Current prevention programs have only a moderate impact. Cell phone text messaging technology (mHealth) can potentially overcome existing challenges, particularly those that are structural (e.g., limited time that teachers can devote to non-educational topics). To date, the description of the development of empirically-based mHealth-delivered bullying prevention programs are lacking in the literature. To describe the development of BullyDown, a text messaging-based bullying prevention program for middle school students, guided by the Social-Emotional Learning model. We implemented five activities over a 12-month period: (1) national focus groups (n=37 youth) to gather acceptability of program components; (2) development of content; (3) a national Content Advisory Team (n=9 youth) to confirm content tone; and (4) an internal team test of software functionality followed by a beta test (n=22 youth) to confirm the enrollment protocol and the feasibility and acceptability of the program. Recruitment experiences suggested that Facebook advertising was less efficient than using a recruitment firm to recruit youth nationally, and recruiting within schools for the pilot test was feasible. Feedback from the Content Advisory Team suggests a preference for 2-4 brief text messages per day. Beta test findings suggest that BullyDown is both feasible and acceptable: 100% of youth completed the follow-up survey, 86% of whom liked the program. Text messaging appears to be a feasible and acceptable delivery method for bullying prevention programming delivered to middle school students.
Using dual-phase message signs to display airline information : technical summary.
DOT National Transportation Integrated Search
2010-01-01
Changeable Message Signs are electronic traffic signs that can be programmed to display : important messages that vary according to current roadway conditions, including the : presence of traffic congestion and accidents. CMSs can also be used to dis...
Practical Formal Verification of MPI and Thread Programs
NASA Astrophysics Data System (ADS)
Gopalakrishnan, Ganesh; Kirby, Robert M.
Large-scale simulation codes in science and engineering are written using the Message Passing Interface (MPI). Shared memory threads are widely used directly, or to implement higher level programming abstractions. Traditional debugging methods for MPI or thread programs are incapable of providing useful formal guarantees about coverage. They get bogged down in the sheer number of interleavings (schedules), often missing shallow bugs. In this tutorial we will introduce two practical formal verification tools: ISP (for MPI C programs) and Inspect (for Pthread C programs). Unlike other formal verification tools, ISP and Inspect run directly on user source codes (much like a debugger). They pursue only the relevant set of process interleavings, using our own customized Dynamic Partial Order Reduction algorithms. For a given test harness, DPOR allows these tools to guarantee the absence of deadlocks, instrumented MPI object leaks and communication races (using ISP), and shared memory races (using Inspect). ISP and Inspect have been used to verify large pieces of code: in excess of 10,000 lines of MPI/C for ISP in under 5 seconds, and about 5,000 lines of Pthread/C code in a few hours (and much faster with the use of a cluster or by exploiting special cases such as symmetry) for Inspect. We will also demonstrate the Microsoft Visual Studio and Eclipse Parallel Tools Platform integrations of ISP (these will be available on the LiveCD).
Methodologies and Tools for Tuning Parallel Programs: 80% Art, 20% Science, and 10% Luck
NASA Technical Reports Server (NTRS)
Yan, Jerry C.; Bailey, David (Technical Monitor)
1996-01-01
The need for computing power has forced a migration from serial computation on a single processor to parallel processing on multiprocessors. However, without effective means to monitor (and analyze) program execution, tuning the performance of parallel programs becomes exponentially difficult as program complexity and machine size increase. In the past few years, the ubiquitous introduction of performance tuning tools from various supercomputer vendors (Intel's ParAide, TMC's PRISM, CRI's Apprentice, and Convex's CXtrace) seems to indicate the maturity of performance instrumentation/monitor/tuning technologies and vendors'/customers' recognition of their importance. However, a few important questions remain: What kind of performance bottlenecks can these tools detect (or correct)? How time consuming is the performance tuning process? What are some important technical issues that remain to be tackled in this area? This workshop reviews the fundamental concepts involved in analyzing and improving the performance of parallel and heterogeneous message-passing programs. Several alternative strategies will be contrasted, and for each we will describe how currently available tuning tools (e.g. AIMS, ParAide, PRISM, Apprentice, CXtrace, ATExpert, Pablo, IPS-2) can be used to facilitate the process. We will characterize the effectiveness of the tools and methodologies based on actual user experiences at NASA Ames Research Center. Finally, we will discuss their limitations and outline recent approaches taken by vendors and the research community to address them.
Commanding and Controlling Satellite Clusters (IEEE Intelligent Systems, November/December 2000)
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 .
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.
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.
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.
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.
Dhamodharan, Udaya Suriya Raj Kumar; Vayanaperumal, Rajamani
2015-01-01
Wireless sensor networks are highly indispensable for securing network protection. Highly critical attacks of various kinds have been documented in wireless sensor network till now by many researchers. The Sybil attack is a massive destructive attack against the sensor network where numerous genuine identities with forged identities are used for getting an illegal entry into a network. Discerning the Sybil attack, sinkhole, and wormhole attack while multicasting is a tremendous job in wireless sensor network. Basically a Sybil attack means a node which pretends its identity to other nodes. Communication to an illegal node results in data loss and becomes dangerous in the network. The existing method Random Password Comparison has only a scheme which just verifies the node identities by analyzing the neighbors. A survey was done on a Sybil attack with the objective of resolving this problem. The survey has proposed a combined CAM-PVM (compare and match-position verification method) with MAP (message authentication and passing) for detecting, eliminating, and eventually preventing the entry of Sybil nodes in the network. We propose a scheme of assuring security for wireless sensor network, to deal with attacks of these kinds in unicasting and multicasting. PMID:26236773
Streaming data analytics via message passing with application to graph algorithms
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
Everybody Brush! Consumer Satisfaction with a Tooth Decay Prevention Program.
Cunha-Cruz, Joana; Huebner, Colleen E; Ludwig, Sharity; Dysert, Jeanne; Mitchell, Melissa; Allen, Gary; Shirtcliff, R Mike; Scott, JoAnna M; Milgrom, Peter
2017-01-01
Twice-daily caregiver-supervised toothbrushing with fluoridated toothpaste is an effective and widely recommended strategy to prevent tooth decay in children. Qualitative research suggests that low-income caregivers know the recommendation but would benefit from toothbrushing supplies and advice about how to introduce this health behavior especially as the child becomes older and asserts autonomy to do it "myself." Our objective is to assess consumer satisfaction with the evidence-based theory-informed campaign and usefulness of materials that were home delivered. The focus of the evaluation was families with children <36 months of age because of the high incidence of disease in this population. A dental care organization designed and implemented Everybody Brush! in three counties of Central Oregon. Participants were families of Medicaid-insured children <21 years of age. Participants were randomly assigned to one of the three study groups: test (supplies, voice/printed messages, telephone support), active (supplies), and a waitlist control. Program materials were in English and Spanish. Caregivers of children <36 months were interviewed at the beginning and end of the program. A total of 83,148 toothbrushing kits were mailed to 21,743 families. In addition, 93,766 printed messages and 110,367 recorded messages were sent to half of the families. Caregivers were highly satisfied. On a global rating scale from 0 to 10 (worst to best program possible), they rated the program 9.5 on average (median: 10, SD 0.9). On a scale from 0 to 10 (not at all to very useful), mean ratings for usefulness of the toothbrushing supplies was 9.5 (SD = 1.5), for the printed postcard messages was 7.2 (SD 3.6), and for the voice telephone messages was 6.5 (SD 3.9). A dental care organization carried out a complex community intervention designed to address excess tooth decay among low-income children. Caregivers were highly satisfied with the Everybody Brush! program and toothbrushing supplies were considered the most useful, followed by printed messages. Voice telephone messages were rated least useful. Further evaluation of the impact of the program on toothbrushing behavior and dental-care utilization is underway.
Krieger, Janice L.; Coveleski, Samantha; Hecht, Michael L.; Miller-Day, Michelle; Graham, John W.; Pettigrew, Jonathan; Kootsikas, Allison
2014-01-01
Recent technological advances have increased the interest and ability of lay audiences to create messages; however, the feasibility of incorporating lay multimedia messages into health campaigns has seldom been examined. Drawing on the principle of cultural grounding and narrative engagement theory, this article seeks to examine what types of messages adolescents believe are most effective in persuading their peers to resist substance use and to provide empirical data on the extent to which audience-generated intervention messages are consistent with the associated campaign philosophy and branding. Data for the current study are prevention messages created by students as part of a four-lesson substance use prevention “booster” program delivered to eighth-grade students in 20 rural schools in Pennsylvania and Ohio during 2010–2011. Content analysis results indicate that didactic message strategies were more common in audience-generated messages than narrative strategies, although strategy was somewhat dependent on the medium used. Two of the most common strategies that adolescents used to persuade peers not to use substances were negative consequences and identity appeals, and messages varied in the degree to which they were consistent with the theoretical underpinnings and program philosophy of the prevention campaign. Implications of the current study for understanding the social construction of substance use prevention messages among adolescents and incorporating audience-generated messages in health communication campaigns are discussed. PMID:23980520
Krieger, Janice L; Coveleski, Samantha; Hecht, Michael L; Miller-Day, Michelle; Graham, John W; Pettigrew, Jonathan; Kootsikas, Allison
2013-01-01
Recent technological advances have increased the interest and ability of lay audiences to create messages; however, the feasibility of incorporating lay multimedia messages into health campaigns has seldom been examined. Drawing on the principle of cultural grounding and narrative engagement theory, this article seeks to examine what types of messages adolescents believe are most effective in persuading their peers to resist substance use and to provide empirical data on the extent to which audience-generated intervention messages are consistent with the associated campaign philosophy and branding. Data for the current study are prevention messages created by students as part of a four-lesson substance use prevention "booster" program delivered to eighth-grade students in 20 rural schools in Pennsylvania and Ohio during 2010-2011. Content analysis results indicate that didactic message strategies were more common in audience-generated messages than narrative strategies, although strategy was somewhat dependent on the medium used. Two of the most common strategies that adolescents used to persuade peers not to use substances were negative consequences and identity appeals, and messages varied in the degree to which they were consistent with the theoretical underpinnings and program philosophy of the prevention campaign. Implications of the current study for understanding the social construction of substance use prevention messages among adolescents and incorporating audience-generated messages in health communication campaigns are discussed.
Effect of Outreach Messages on Medicaid Enrollment
Stillson, Christian; Rosin, Roy; Cahill, Rachel; Kruger, Evelyne; Grande, David
2017-01-01
Objectives. To measure the impact of different outreach messages on health insurance enrollment among Medicaid-eligible adults. Methods. Between March 2015 and April 2016, we conducted a series of experiments using mail-based outreach that encouraged individuals to enroll in Pennsylvania’s expanded Medicaid program. Recipients were randomized to receive 1 of 4 different messages describing the benefits of health insurance. The primary outcome was the response rate to each letter. Results. We mailed outreach letters to 32 993 adults in Philadelphia. Messages that emphasized the dental benefits of insurance were significantly more likely to result in a response than messages emphasizing the health benefits (odds ratio = 1.33; 95% confidence interval = 1.10, 1.61). Conclusions. Medicaid enrollment outreach messages that emphasized the dental benefits of insurance were more effective than those that emphasized the health-related benefits. Public Health Implications. Although the structure and eligibility of the Medicaid program are likely to change, testing and identifying successful outreach and enrollment strategies remains important. Outreach messages that emphasize dental benefits may be more effective at motivating enrollment among individuals of low socioeconomic status. PMID:28661816
Squiers, Linda; Brown, Derick; Parvanta, Sarah; Dolina, Suzanne; Kelly, Bridget; Dever, Jill; Southwell, Brian G; Sanders, Amy; Augustson, Erik
2016-06-27
Text messaging (short message service, SMS) has been shown to be effective in delivering interventions for various diseases and health conditions, including smoking cessation. While there are many published studies regarding smoking cessation text messaging interventions, most do not provide details about the study's operational methods. As a result, there is a gap in our understanding of how best to design studies of smoking cessation text messaging programs. The purpose of this paper is to detail the operational methods used to conduct a randomized trial comparing three different versions of the National Cancer Institute's SmokefreeText (SFTXT) program, designed for smokers 18 to 29 years of age. We detail our methods for recruiting participants from the Internet, reducing fraud, conducting online data collection, and retaining panel study participants. Participants were recruited through website advertisements and market research online panels. Screening questions established eligibility for the study (eg, 18 to 29 years of age, current smoker). Antifraud measures screened out participants who could not meet the study requirements. After completing a baseline survey, participants were randomized to one of three study arms, which varied by type and timing of text message delivery. The study offered US $20 gift cards as incentives to complete each of four follow-up surveys. Automated email reminders were sent at designated intervals to increase response rates. Researchers also provided telephone reminders to those who had not completed the survey after multiple email reminders. We calculated participation rates across study arms and compared the final sample characteristics to the Current Population Survey to examine generalizability. Recruitment methods drove 153,936 unique visitors to the SFTXT Study landing page and 27,360 began the screener. Based on the screening questions, 15,462 out of 27,360 responders (56.51%) were eligible to participate. Of the 15,462 who were eligible, 9486 passed the antifraud measures that were implemented; however, 3882 failed to verify their email addresses or cell phone numbers, leaving 5604 who were invited to complete the baseline survey. Of the 5604 who were invited, 4432 completed the baseline survey, but only 4027 were retained for analysis because 405 did not receive the intervention. Although antifraud measures helped to catch participants who failed study requirements and could have biased the data collected, it is possible that the email and cell phone verification check excluded some potentially eligible participants from the study. Future research should explore ways to implement verification methods without risking the loss of so many potential participants. Clinical Trials.gov NCT01885052; https://clinicaltrials.gov/ct2/show/NCT01885052; (Archived by WebCite at http://www.webcitation.org/6iWzcmFdw).
Brown, Derick; Parvanta, Sarah; Dolina, Suzanne; Kelly, Bridget; Dever, Jill; Southwell, Brian G; Sanders, Amy; Augustson, Erik
2016-01-01
Background Text messaging (short message service, SMS) has been shown to be effective in delivering interventions for various diseases and health conditions, including smoking cessation. While there are many published studies regarding smoking cessation text messaging interventions, most do not provide details about the study’s operational methods. As a result, there is a gap in our understanding of how best to design studies of smoking cessation text messaging programs. Objective The purpose of this paper is to detail the operational methods used to conduct a randomized trial comparing three different versions of the National Cancer Institute’s SmokefreeText (SFTXT) program, designed for smokers 18 to 29 years of age. We detail our methods for recruiting participants from the Internet, reducing fraud, conducting online data collection, and retaining panel study participants. Methods Participants were recruited through website advertisements and market research online panels. Screening questions established eligibility for the study (eg, 18 to 29 years of age, current smoker). Antifraud measures screened out participants who could not meet the study requirements. After completing a baseline survey, participants were randomized to one of three study arms, which varied by type and timing of text message delivery. The study offered US $20 gift cards as incentives to complete each of four follow-up surveys. Automated email reminders were sent at designated intervals to increase response rates. Researchers also provided telephone reminders to those who had not completed the survey after multiple email reminders. We calculated participation rates across study arms and compared the final sample characteristics to the Current Population Survey to examine generalizability. Results Recruitment methods drove 153,936 unique visitors to the SFTXT Study landing page and 27,360 began the screener. Based on the screening questions, 15,462 out of 27,360 responders (56.51%) were eligible to participate. Of the 15,462 who were eligible, 9486 passed the antifraud measures that were implemented; however, 3882 failed to verify their email addresses or cell phone numbers, leaving 5604 who were invited to complete the baseline survey. Of the 5604 who were invited, 4432 completed the baseline survey, but only 4027 were retained for analysis because 405 did not receive the intervention. Conclusions Although antifraud measures helped to catch participants who failed study requirements and could have biased the data collected, it is possible that the email and cell phone verification check excluded some potentially eligible participants from the study. Future research should explore ways to implement verification methods without risking the loss of so many potential participants. ClinicalTrial Clinical Trials.gov NCT01885052; https://clinicaltrials.gov/ct2/show/NCT01885052; (Archived by WebCite at http://www.webcitation.org/6iWzcmFdw) PMID:27349898
Parallel, Distributed Scripting with Python
DOE Office of Scientific and Technical Information (OSTI.GOV)
Miller, P J
2002-05-24
Parallel computers used to be, for the most part, one-of-a-kind systems which were extremely difficult to program portably. With SMP architectures, the advent of the POSIX thread API and OpenMP gave developers ways to portably exploit on-the-box shared memory parallelism. Since these architectures didn't scale cost-effectively, distributed memory clusters were developed. The associated MPI message passing libraries gave these systems a portable paradigm too. Having programmers effectively use this paradigm is a somewhat different question. Distributed data has to be explicitly transported via the messaging system in order for it to be useful. In high level languages, the MPI librarymore » gives access to data distribution routines in C, C++, and FORTRAN. But we need more than that. Many reasonable and common tasks are best done in (or as extensions to) scripting languages. Consider sysadm tools such as password crackers, file purgers, etc ... These are simple to write in a scripting language such as Python (an open source, portable, and freely available interpreter). But these tasks beg to be done in parallel. Consider the a password checker that checks an encrypted password against a 25,000 word dictionary. This can take around 10 seconds in Python (6 seconds in C). It is trivial to parallelize if you can distribute the information and co-ordinate the work.« less
Case Study of the Denver Regional Transportation District Eco Pass Program
DOT National Transportation Integrated Search
1993-11-01
This report documents the Denver Regional Transportation District (RTD) Eco Pass Program and evaluates its impacts. The Eco Pass is an annual, unlimited-use photo identification pass covering transportation on all RTD transit routes. Employers in the...
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.
Message Design Guidelines For Screen-Based Programs.
ERIC Educational Resources Information Center
Rimar, G. I.
1996-01-01
Effective message design for screen-based computer or video instructional programs requires knowledge from many disciplines. Evaluates current conventions and suggests a new set of guidelines for screen-based designers. Discusses screen layout, highlighting and cueing, text font and style, text positioning, color, and graphical user interfaces for…
Applications of Multi-Channel Safety Authentication Protocols in Wireless Networks.
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.
Bad News Has Wings: Dread Risk Mediates Social Amplification in Risk Communication.
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.
Prokhorov, Alexander V; Machado, Tamara C; Calabro, Karen S; Vanderwater, Elizabeth A; Vidrine, Damon J; Pasch, Keryn P; Marani, Salma K; Buchberg, Meredith; Wagh, Aditya; Russell, Sophia C; Czerniak, Katarzyna W; Botello, Gabrielle C; Dobbins, Mackenzie H; Khalil, Georges E; Perry, Cheryl L
2017-01-31
Engaging young adults for the purpose of communicating health risks associated with nicotine and tobacco use can be challenging since they comprise a population heavily targeted with appealing marketing by the evolving tobacco industry. The Food and Drug Administration seeks novel ways to effectively communicate risks to warn about using these products. This paper describes the first step in developing a text messaging program delivered by smartphones that manipulate three messaging characteristics (i.e., depth, framing, and appeal). Perceptions of community college students were described after previewing text messages designed to inform about risks of using conventional and new tobacco products. Thirty-one tobacco users and nonusers, aged 18-25 participated in five focus discussions held on two community college campuses. Attendees reviewed prototype messages and contributed feedback about text message structure and content. Qualitative data were coded and analyzed using NVivo Version 10. Most participants were female and two-thirds were ethnic minorities. A variety of conventional and new tobacco products in the past month were used by a third of participants. Three identified domains were derived from the qualitative data. These included perceived risks of using tobacco products, receptivity to message content, and logistical feedback regarding the future message campaign. Overall, participants found the messages to be interesting and appropriate. A gap in awareness of the risks of using new tobacco products was revealed. Feedback on the prototype messages was incorporated into message revisions. These findings provided preliminary confirmation that the forthcoming messaging program will be appealing to young adults.
Ramsingh, R; Mills, C J
1997-01-01
The objective of this paper is to assess the impact of the 1994 Workshop on Public Education Messages for Reducing Health Risks from Ultraviolet Radiation (UVR). The target audience was any organization in Canada doing education on the health risks of UVR. A mailed survey with telephone follow-up was distributed to 130 addresses, including workshop participants, recipients of the workshop report and 40 local public health units. The response rate was 62%. Public health messages from the workshop served as an added impetus or helped to initiate activities around UVR in approximately 40% of organizations over the two years since the workshop. The public health messages were used directly in programming by approximately 38% of all organizations responding. However, looking at those who had previously seen the messages, 61% used them directly in programming. Forty percent of those sampled had never seen a copy of the messages. The results suggest the need for improved dissemination of consensus statements.
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…
The Hidden Messages of Secondary Reading Programs: What Students Learn vs. What Teachers Teach.
ERIC Educational Resources Information Center
Battraw, Judith L.
Hidden messages are part of the culture of reading at any school, particularly at the secondary level. In many schools, the overt message that reading is essential to success on state-mandated tests and in society is jeopardized due to hidden messages about the nature of the reading process and the place of reading in everyday life. A qualitative…
Information and the Origin of Qualia
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
Harnessing the power of advertising to prevent childhood obesity.
Bell, Andrew Colin; Wolfenden, Luke; Sutherland, Rachel; Coggan, Lucy; Young, Kylie; Fitzgerald, Michael; Hodder, Rebecca; Orr, Neil; Milat, Andrew J; Wiggers, John
2013-10-04
Social marketing integrates communication campaigns with behavioural and environmental change strategies. Childhood obesity programs could benefit significantly from social marketing but communication campaigns on this issue tend to be stand-alone. A large-scale multi-setting child obesity prevention program was implemented in the Hunter New England (HNE) region of New South Wales (NSW), Australia from 2005-2010. The program included a series of communication campaigns promoting the program and its key messages: drinking water; getting physically active and; eating more vegetables and fruit. Pre-post telephone surveys (n = 9) were undertaken to evaluate awareness of the campaigns among parents of children aged 2-15 years using repeat cross-sections of randomly selected cohorts. A total of 1,367 parents (HNE = 748, NSW = 619) participated. At each survey post baseline, HNE parents were significantly more likely to have seen, read or heard about the program and its messages in the media than parents in the remainder of the state (p < 0.001). Further, there was a significant increase in awareness of the program and each of its messages over time in HNE compared to no change over time in NSW (p < 0.001). Awareness was significantly higher (p < 0.05) in HNE compared to NSW after each specific campaign (except the vegetable one) and significantly higher awareness levels were sustained for each campaign until the end of the program. At the end of the program participants without a tertiary education were significantly more likely (p = 0.04) to be aware of the brand campaign (31%) than those with (20%) but there were no other statistically significant socio-demographic differences in awareness. The Good for Kids communication campaigns increased and maintained awareness of childhood obesity prevention messages. Moreover, messages were delivered equitably to diverse socio-demographic groups within the region.
ERIC Educational Resources Information Center
Linnehan, Frank
2004-01-01
Using a pre- and post-test design, this study examined the relation of an adult's credibility and message frequency to the beliefs of female high school students participating in a job-shadowing program. Hypotheses were based on the Elaboration Likelihood Model of attitude formation and change. Findings indicate that credibility of the adult…
ERIC Educational Resources Information Center
Suffoletto, Brian; Merrill, Jennifer E.; Chung, Tammy; Kristan, Jeffrey; Vanek, Marian; Clark, Duncan B.
2016-01-01
Objective: To evaluate a text message (SMS) program as a booster to an in-person alcohol intervention with mandated college students. Participants: Undergraduates (N = 224; 46% female) who violated an on-campus alcohol policy over a 2-semester period in 2014. Methods: The SMS program sent drinking-related queries each Thursday and Sunday and…
Kolodziejczyk, Julia K; Norman, Gregory J; Barrera-Ng, Angelica; Dillon, Lindsay; Marshall, Simon; Arredondo, Elva; Rock, Cheryl L; Raab, Fred; Griswold, William G; Sullivan, Mark; Patrick, Kevin
2013-11-06
Little is known about the feasibility and acceptability of tailored text message based weight loss programs for English and Spanish-language speakers. This pilot study evaluated the feasibility, acceptability, and estimated impact of a tailored text message based weight loss program for English and Spanish-language speakers. The purpose of this pilot study was to inform the development of a full-scale randomized trial. There were 20 overweight or obese participants (mean age 40.10, SD 8.05; 8/20, 40% male; 9/20, 45% Spanish-speakers) that were recruited in San Diego, California, from March to May 2011 and evaluated in a one-group pre/post clinical trial. For 8 weeks, participants received and responded to 3-5 text messages daily sent from a fully automated text messaging system. They also received printed weight loss materials and brief 10-15 minute weekly counseling calls. To estimate the impact of the program, the primary outcome was weight (kg) measured during face-to-face measurement visits by trained research staff. Pre and post differences in weight were analyzed with a one-way repeated measures analysis of variance. Differences by language preference at both time points were analyzed with t tests. Body mass index and weight management behaviors also were examined. Feasibility and acceptability were determined by recruitment success, adherence (ie, percentage of replies to interactive text messages and attrition), and participant satisfaction. Participants who completed the final assessment (N=18) decreased body weight by 1.85 kg (F1,17=10.80, P=.004, CI∆ 0.66-3.03, η(2)=0.39). At both time points, there were no differences in weight by language preference. Participants responded to 88.04% (986/1120) of interactive text messages, attrition rate was 10% (2/20), and 94% (19/20) of participants reported satisfaction with the program. This fully automated text message based weight program was feasible with English and Spanish-speakers and may have promoted modest weight loss over an 8-week period. Clinicaltrials.gov NCT01171586; http://clinicaltrials.gov/ct2/show/NCT01171586 (Archived by WebCite at http://www.webcitation.org/6Ksr6dl7n).
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.
Development of a Culturally Tailored Text Message Maternal Health Program: TextMATCH
Whittaker, Robyn; Bartley, Hannah; Connor, Augusta; Chen, Ruyan; Ross, Mairead; McCool, Judith
2017-01-01
Background Mobile phones are increasingly being used to deliver health information and health services globally. Mobile health (mHealth) interventions may be well-suited for minority groups with greater barriers to accessing traditional health services. However, little has been written about the process of culturally adapting interventions for multiple ethnic and cultural minorities within a population. Objective This study describes the process of developing a culturally tailored text message-based maternal health program (TextMATCH: Text for MATernal and Child Health) for Māori, Pacific, Asian, and South Asian families living in New Zealand. We report on engagement and acceptability of the TextMATCH program. Methods Program data was examined to describe engagement with the program 18 months after implementation. Telephone interviews were conducted with a sample of participants who consented to provide feedback on acceptability and relevance of the program. Results A total of 1404 participants enrolled in TextMATCH over 18 months, with 18.52% (260) actively opting out at some point (after 0 to 17 months of messages). It was found that 356 (70.9%) of the 502 eligible participants actively switched from the initial pregnancy program to the baby program after delivery. Phone interviews were conducted with 29 participants including 6 who had withdrawn (duration of program from 3 to 16 months). Only 2 participants reported that the program was not useful, with the remainder rating the usefulness of messages positively (average 4.24 out of 5). All participants stated that the messages were relevant, culturally appropriate, and easy to understand. Most were happy with the specific advice and the language options provided. Conclusions We have demonstrated the importance of an intensive approach to the development of a culturally adapted and tailored mHealth program for multiple different cultural minority groups within our population. PMID:28428159
Clandestine Message Passing in Virtual Environments
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
ERIC Educational Resources Information Center
FitzGerald Murphy, Maggie
2016-01-01
Despite the fact that over fifty years have passed since its publication, Stuart Hall's article "The Supply of Demand" (1960), is remarkably relevant today. The central message that society must not be blinded by "prosperity" such that it no longer envisions and demands a better world is especially pertinent in light of the…
The Guardian. Volume 9, Number 3, Winter 2007
2007-01-01
message correctly. Muslims will ultimately determine whether the ideology of al Qaeda, its affiliates, franchisees , and fellow travelers represents...opined that the effort would not work or would not pass the cost– benefit comparison. Others wanted to develop comprehensive NATO doctrine to guide...full BAT capability, the access-control benefits of BAT/HIIDE are a significant improvement to overall ISAF force protection, even in stand-alone mode
PETSc Users Manual Revision 3.7
DOE Office of Scientific and Technical Information (OSTI.GOV)
Balay, Satish; Abhyankar, S.; Adams, M.
This manual describes the use of PETSc for the numerical solution of partial differential equations and related problems on high-performance computers. The Portable, Extensible Toolkit for Scientific Computation (PETSc) is a suite of data structures and routines that provide the building blocks for the implementation of large-scale application codes on parallel (and serial) computers. PETSc uses the MPI standard for all message-passing communication.
PETSc Users Manual Revision 3.8
DOE Office of Scientific and Technical Information (OSTI.GOV)
Balay, S.; Abhyankar, S.; Adams, M.
This manual describes the use of PETSc for the numerical solution of partial differential equations and related problems on high-performance computers. The Portable, Extensible Toolkit for Scientific Computation (PETSc) is a suite of data structures and routines that provide the building blocks for the implementation of large-scale application codes on parallel (and serial) computers. PETSc uses the MPI standard for all message-passing communication.
Diagnosing the Causes and Severity of One-sided Message Contention
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tallent, Nathan R.; Vishnu, Abhinav; van Dam, Hubertus
Two trends suggest network contention for one-sided messages is poised to become a performance problem that concerns application developers: an increased interest in one-sided programming models and a rising ratio of hardware threads to network injection bandwidth. Unfortunately, it is difficult to reason about network contention and one-sided messages because one-sided tasks can either decrease or increase contention. We present effective and portable techniques for diagnosing the causes and severity of one-sided message contention. To detect that a message is affected by contention, we maintain statistics representing instantaneous (non-local) network resource demand. Using lightweight measurement and modeling, we identify themore » portion of a message's latency that is due to contention and whether contention occurs at the initiator or target. We attribute these metrics to program statements in their full static and dynamic context. We characterize contention for an important computational chemistry benchmark on InfiniBand, Cray Aries, and IBM Blue Gene/Q interconnects. We pinpoint the sources of contention, estimate their severity, and show that when message delivery time deviates from an ideal model, there are other messages contending for the same network links. With a small change to the benchmark, we reduce contention up to 50% and improve total runtime as much as 20%.« less
Falcone, John L; Middleton, Donald B
2013-01-01
The Accreditation Council for Graduate Medical Education (ACGME) sets residency performance standards for the American Board of Family Medicine Certification Examination. This study aims are to describe the compliance of residency programs with ACGME standards and to determine whether residency pass rates depend on program size and location. In this retrospective cohort study, residency performance from 2007 to 2011 was compared with the ACGME performance standards. Simple linear regression was performed to see whether program pass rates were dependent on program size. Regional differences in performance were compared with χ(2) tests, using an α level of 0.05. Of 429 total residency programs, there were 205 (47.8%) that violate ACGME performance standards. Linear regression showed that program pass rates were positively correlated and dependent on program size (P < .001). The median pass rate per state was 86.4% (interquartile range, 82.0-90.8. χ(2) Tests showed that states in the West performed higher than the other 3 US Census Bureau Regions (all P < .001). Approximately half of the family medicine training programs do not meet the ACGME examination performance standards. Pass rates are associated with residency program size, and regional variation occurs. These findings have the potential to affect ACGME policy and residency program application patterns.
McNeill, Marjorie H
2009-01-01
The purpose of this research study was to determine whether the administration of a comprehensive examination before graduation increases the percentage of students passing the Registered Health Information Administrator certification examination. A t-test for independent means yielded a statistically significant difference between the Registered Health Information Administrator certification examination pass rates of health information administration programs that administer a comprehensive examination and programs that do not administer a comprehensive examination. Programs with a high certification examination pass rate do not require a comprehensive examination when compared with those programs with a lower pass rate. It is concluded that health information administration faculty at the local level should perform program self-analysis to improve student progress toward achievement of learning outcomes and entry-level competencies.
Audience reactions and receptivity to HIV prevention message concepts for people living with HIV.
Uhrig, Jennifer D; Bann, Carla M; Wasserman, Jill; Guenther-Grey, Carolyn; Eroğlu, Doğan
2010-04-01
This study measured audience reactions and receptivity to five draft HIV prevention messages developed for people living with HIV (PLWH) to inform future HIV message choice and audience targeting decisions. Our premise was that message concepts that receive wide audience appeal constitute a strong starting point for designing future HIV prevention messages, program activities, and health communication and marketing campaigns for PLWH. The majority of participants indicated agreement with evaluative statements that expressed favorable attitudes toward all five of the message concepts we evaluated. Participants gave the lowest approval to the message promoting sero-sorting. Sociodemographic characteristics played less of a role in predicting differences in message perceptions than attitudes, beliefs and sexual behavior. The general appeal for these messages is encouraging given that messages were expressed in plain text without the support of other creative elements that are commonly used in message execution. These results confirm the utility of systematic efforts to generate and screen message concepts prior to large-scale testing.
Secret Message Decryption: Group Consulting Projects Using Matrices and Linear Programming
ERIC Educational Resources Information Center
Gurski, Katharine F.
2009-01-01
We describe two short group projects for finite mathematics students that incorporate matrices and linear programming into fictional consulting requests presented as a letter to the students. The students are required to use mathematics to decrypt secret messages in one project involving matrix multiplication and inversion. The second project…
Making the Connection: Some People, Programs and Ideas Highlighted by Adult Learners Week 2001.
ERIC Educational Resources Information Center
Cross, John; Della, Jennie
This document profiles selected people, programs, and ideas highlighted by Australia's Adult Learners Week 2001 and begins with these papers: "Adult Learners Week: A National Celebration" (Ned Dennis); "A Message from the Adult Learners Week Patron" (Peter Hollingworth); "A Message of Support from the Prime Minister of…
LeFevre, Amnesty E; Mohan, Diwakar; Hutchful, David; Jennings, Larissa; Mehl, Garrett; Labrique, Alain; Romano, Karen; Moorthy, Anitha
2017-03-14
Despite the growing use of technology in the health sector, little evidence is available on the technological performance of mobile health programs nor on the willingness of target users to utilize these technologies as intended (behavioral performance). In this case study of the Mobile Technology for Health (MOTECH) program in Ghana, we assess the platform's effectiveness in delivering messages, along with user response across sites in five districts from 2011 to 2014. MOTECH is comprised of "Client Data Application" (CDA) which allows providers to digitize and track service delivery information for women and infants and "Mobile Midwife" (MM) which sends automated educational voice messages to the mobile phones of pregnant and postpartum women. Using a naturalist study design, we draw upon system generated data to evaluate message delivery, client engagement, and provider responsiveness to MOTECH over time and by level of facility. A total of 7,370 women were enrolled in MM during pregnancy and 14,867 women were enrolled postpa1rtum. While providers were able to register and upload patient-level health information using CDA, the majority of these uploads occurred in Community-based facilities versus Health Centers. For MM, 25% or less of expected messages were received by pregnant women, despite the majority (>77%) owning a private mobile phone. While over 80% of messages received by pregnant women were listened to, postpartum rates of listening declined over time. Only 25% of pregnant women received and listened to at least 1 first trimester message. By 6-12 months postpartum, less than 6% of enrolled women were exposed to at least one message. Caution should be exercised in assuming that digital health programs perform as intended. Evaluations should measure the technological, behavioral, health systems, and/or community factors which may lead to breaks in the impact pathway and influence findings on effectiveness. The MOTECH platform's technological limitations in 'pushing' out voice messages highlights the need for more timely use of data to mitigate delivery challenges and improve exposure to health information. Alternative message delivery channels (USSD or SMS) could improve the platform's ability to deliver messages but may not be appropriate for illiterate users. Not applicable.
McDonald, P W
1999-06-01
Attempts to reduce the prevalence of smoking through quit-smoking programs have been unsuccessful because they have not attracted large numbers of smokers to participate in them. An analytic review of the literature was conducted to identify potential communication variables that might enhance recruitment for community-based quit-smoking programs. Recruitment was defined as the number of smokers who enroll in a quit-smoking program divided by the estimated number of smokers in the target population. Thirty-three publications reporting the results of 40 recruitment campaigns were located. The median recruitment rate was 2.0%. Logistic regression was used to examine the effect of six variables on recruitment rate: the type of program sponsor, the type of program, program costs, use of participation incentives, whether messages were segmented by stage of change, and the type of channel used to send messages. The only significant predictor of recruitment rate was channel type (i.e., the method used to deliver a message). Studies that used interactive recruitment channels (telephone, interpersonal communication) were 66.5 times more effective than those using passive recruitment strategies (mass media, direct mail). Results examining the segmentation of messages by stage of change on recruitment were inconclusive. Results suggest that researchers and practitioners interested in population-based smoking cessation programs should pay more attention to recruitment methods. The use of interpersonal channels has been underused and appears to be particularly promising for improving the population impact of quit-smoking programs.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tsugane, Keisuke; Boku, Taisuke; Murai, Hitoshi
Recently, the Partitioned Global Address Space (PGAS) parallel programming model has emerged as a usable distributed memory programming model. XcalableMP (XMP) is a PGAS parallel programming language that extends base languages such as C and Fortran with directives in OpenMP-like style. XMP supports a global-view model that allows programmers to define global data and to map them to a set of processors, which execute the distributed global data as a single thread. In XMP, the concept of a coarray is also employed for local-view programming. In this study, we port Gyrokinetic Toroidal Code - Princeton (GTC-P), which is a three-dimensionalmore » gyrokinetic PIC code developed at Princeton University to study the microturbulence phenomenon in magnetically confined fusion plasmas, to XMP as an example of hybrid memory model coding with the global-view and local-view programming models. In local-view programming, the coarray notation is simple and intuitive compared with Message Passing Interface (MPI) programming while the performance is comparable to that of the MPI version. Thus, because the global-view programming model is suitable for expressing the data parallelism for a field of grid space data, we implement a hybrid-view version using a global-view programming model to compute the field and a local-view programming model to compute the movement of particles. Finally, the performance is degraded by 20% compared with the original MPI version, but the hybrid-view version facilitates more natural data expression for static grid space data (in the global-view model) and dynamic particle data (in the local-view model), and it also increases the readability of the code for higher productivity.« less
Tsugane, Keisuke; Boku, Taisuke; Murai, Hitoshi; ...
2016-06-01
Recently, the Partitioned Global Address Space (PGAS) parallel programming model has emerged as a usable distributed memory programming model. XcalableMP (XMP) is a PGAS parallel programming language that extends base languages such as C and Fortran with directives in OpenMP-like style. XMP supports a global-view model that allows programmers to define global data and to map them to a set of processors, which execute the distributed global data as a single thread. In XMP, the concept of a coarray is also employed for local-view programming. In this study, we port Gyrokinetic Toroidal Code - Princeton (GTC-P), which is a three-dimensionalmore » gyrokinetic PIC code developed at Princeton University to study the microturbulence phenomenon in magnetically confined fusion plasmas, to XMP as an example of hybrid memory model coding with the global-view and local-view programming models. In local-view programming, the coarray notation is simple and intuitive compared with Message Passing Interface (MPI) programming while the performance is comparable to that of the MPI version. Thus, because the global-view programming model is suitable for expressing the data parallelism for a field of grid space data, we implement a hybrid-view version using a global-view programming model to compute the field and a local-view programming model to compute the movement of particles. Finally, the performance is degraded by 20% compared with the original MPI version, but the hybrid-view version facilitates more natural data expression for static grid space data (in the global-view model) and dynamic particle data (in the local-view model), and it also increases the readability of the code for higher productivity.« less
The effect of Medicaid wage pass-through programs on the wages of direct care workers.
Baughman, Reagan A; Smith, Kristin
2010-05-01
Despite growing demand for nursing and home health care as the US population ages, compensation levels in the low-skill nursing labor market that provides the bulk of long-term care remain quite low. The challenge facing providers of long-term care is that Medicaid reimbursement rates for nursing home and home health care severely restrict the wage growth that is necessary to attract workers, resulting in high turnover and labor shortages. Almost half of US states have responded by enacting "pass-through" provisions in their Medicaid programs, channeling additional long-term care funding directly to compensation of lower-skill nursing workers. We test the effect of Medicaid wage pass-through programs on hourly wages for direct care workers. We estimate several specifications of wage models using employment data from the 1996 and 2001 panels of the Survey of Income and Program Participation for nursing, home health, and personal care aides. The effect of pass-through programs is identified by an indicator variable for states with programs; 20 states adopted pass-throughs during the sample period. Workers in states with pass-through programs earn as much as 12% more per hour than workers in other states after those programs are implemented. Medicaid wage pass-through programs appear to be a viable policy option for raising compensation levels of direct care workers, with an eye toward improving recruitment and retention in long-term care settings.
Colletti, Thomas P; Salisbury, Helen; Hertelendy, Attila J; Tseng, Tina
2016-03-01
This study was conducted to examine the relationship between physician assistant (PA) educational program length and PA programs' 5-year average Physician Assistant National Certifying Examination (PANCE) first-time pass rates. This was a retrospective correlational study that analyzed previously collected data from a nonprobability purposive sample of accredited PA program Web sites. Master's level PA programs (n = 108) in the United States with published average PANCE scores for 5 consecutive classes were included. Provisional and probationary programs were excluded (n = 4). Study data were not normally distributed per the Kolmogorov-Smirnov test, P = .00. There was no relationship between program length and PANCE pass rates, ρ (108) = -0.04, P = .68. Further analyses examining a possible relationship between program phase length (didactic and clinical) and PANCE pass rates also demonstrated no differences (ρ [107] = -0.05, P = .60 and ρ [107] = 0.02, P = .80, respectively). The results of this study suggest that shorter length PA programs perform similarly to longer programs in preparing students to pass the PANCE. In light of rapid expansion of PA educational programs, educators may want to consider these findings when planning the length of study for new and established programs.
Considerations for Community-Based mHealth Initiatives: Insights From Three Beacon Communities
2013-01-01
Mobile health (mHealth) is gaining widespread attention for its potential to engage patients in their health and health care in their daily lives. Emerging evidence suggests that mHealth interventions can be used effectively to support behavior change, but numerous challenges remain when implementing these programs at the community level. This paper provides an overview of considerations when implementing community-based mHealth initiatives, based on the experiences of three Beacon Communities across the United States that have launched text messaging (short message service, SMS) pilot programs aimed at diabetes risk reduction and disease management. The paper addresses lessons learned and suggests strategies to overcome challenges related to developing text message content, conducting marketing and outreach, enrolling participants, engaging providers, evaluating program effectiveness, and sustaining and scaling the programs. PMID:24128406
2014-01-01
Background The huge quantity of data produced in Biomedical research needs sophisticated algorithmic methodologies for its storage, analysis, and processing. High Performance Computing (HPC) appears as a magic bullet in this challenge. However, several hard to solve parallelization and load balancing problems arise in this context. Here we discuss the HPC-oriented implementation of a general purpose learning algorithm, originally conceived for DNA analysis and recently extended to treat uncertainty on data (U-BRAIN). The U-BRAIN algorithm is a learning algorithm that finds a Boolean formula in disjunctive normal form (DNF), of approximately minimum complexity, that is consistent with a set of data (instances) which may have missing bits. The conjunctive terms of the formula are computed in an iterative way by identifying, from the given data, a family of sets of conditions that must be satisfied by all the positive instances and violated by all the negative ones; such conditions allow the computation of a set of coefficients (relevances) for each attribute (literal), that form a probability distribution, allowing the selection of the term literals. The great versatility that characterizes it, makes U-BRAIN applicable in many of the fields in which there are data to be analyzed. However the memory and the execution time required by the running are of O(n3) and of O(n5) order, respectively, and so, the algorithm is unaffordable for huge data sets. Results We find mathematical and programming solutions able to lead us towards the implementation of the algorithm U-BRAIN on parallel computers. First we give a Dynamic Programming model of the U-BRAIN algorithm, then we minimize the representation of the relevances. When the data are of great size we are forced to use the mass memory, and depending on where the data are actually stored, the access times can be quite different. According to the evaluation of algorithmic efficiency based on the Disk Model, in order to reduce the costs of the communications between different memories (RAM, Cache, Mass, Virtual) and to achieve efficient I/O performance, we design a mass storage structure able to access its data with a high degree of temporal and spatial locality. Then we develop a parallel implementation of the algorithm. We model it as a SPMD system together to a Message-Passing Programming Paradigm. Here, we adopt the high-level message-passing systems MPI (Message Passing Interface) in the version for the Java programming language, MPJ. The parallel processing is organized into four stages: partitioning, communication, agglomeration and mapping. The decomposition of the U-BRAIN algorithm determines the necessity of a communication protocol design among the processors involved. Efficient synchronization design is also discussed. Conclusions In the context of a collaboration between public and private institutions, the parallel model of U-BRAIN has been implemented and tested on the INTEL XEON E7xxx and E5xxx family of the CRESCO structure of Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), developed in the framework of the European Grid Infrastructure (EGI), a series of efforts to provide access to high-throughput computing resources across Europe using grid computing techniques. The implementation is able to minimize both the memory space and the execution time. The test data used in this study are IPDATA (Irvine Primate splice- junction DATA set), a subset of HS3D (Homo Sapiens Splice Sites Dataset) and a subset of COSMIC (the Catalogue of Somatic Mutations in Cancer). The execution time and the speed-up on IPDATA reach the best values within about 90 processors. Then the parallelization advantage is balanced by the greater cost of non-local communications between the processors. A similar behaviour is evident on HS3D, but at a greater number of processors, so evidencing the direct relationship between data size and parallelization gain. This behaviour is confirmed on COSMIC. Overall, the results obtained show that the parallel version is up to 30 times faster than the serial one. PMID:25077818
D'Angelo, Gianni; Rampone, Salvatore
2014-01-01
The huge quantity of data produced in Biomedical research needs sophisticated algorithmic methodologies for its storage, analysis, and processing. High Performance Computing (HPC) appears as a magic bullet in this challenge. However, several hard to solve parallelization and load balancing problems arise in this context. Here we discuss the HPC-oriented implementation of a general purpose learning algorithm, originally conceived for DNA analysis and recently extended to treat uncertainty on data (U-BRAIN). The U-BRAIN algorithm is a learning algorithm that finds a Boolean formula in disjunctive normal form (DNF), of approximately minimum complexity, that is consistent with a set of data (instances) which may have missing bits. The conjunctive terms of the formula are computed in an iterative way by identifying, from the given data, a family of sets of conditions that must be satisfied by all the positive instances and violated by all the negative ones; such conditions allow the computation of a set of coefficients (relevances) for each attribute (literal), that form a probability distribution, allowing the selection of the term literals. The great versatility that characterizes it, makes U-BRAIN applicable in many of the fields in which there are data to be analyzed. However the memory and the execution time required by the running are of O(n(3)) and of O(n(5)) order, respectively, and so, the algorithm is unaffordable for huge data sets. We find mathematical and programming solutions able to lead us towards the implementation of the algorithm U-BRAIN on parallel computers. First we give a Dynamic Programming model of the U-BRAIN algorithm, then we minimize the representation of the relevances. When the data are of great size we are forced to use the mass memory, and depending on where the data are actually stored, the access times can be quite different. According to the evaluation of algorithmic efficiency based on the Disk Model, in order to reduce the costs of the communications between different memories (RAM, Cache, Mass, Virtual) and to achieve efficient I/O performance, we design a mass storage structure able to access its data with a high degree of temporal and spatial locality. Then we develop a parallel implementation of the algorithm. We model it as a SPMD system together to a Message-Passing Programming Paradigm. Here, we adopt the high-level message-passing systems MPI (Message Passing Interface) in the version for the Java programming language, MPJ. The parallel processing is organized into four stages: partitioning, communication, agglomeration and mapping. The decomposition of the U-BRAIN algorithm determines the necessity of a communication protocol design among the processors involved. Efficient synchronization design is also discussed. In the context of a collaboration between public and private institutions, the parallel model of U-BRAIN has been implemented and tested on the INTEL XEON E7xxx and E5xxx family of the CRESCO structure of Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), developed in the framework of the European Grid Infrastructure (EGI), a series of efforts to provide access to high-throughput computing resources across Europe using grid computing techniques. The implementation is able to minimize both the memory space and the execution time. The test data used in this study are IPDATA (Irvine Primate splice- junction DATA set), a subset of HS3D (Homo Sapiens Splice Sites Dataset) and a subset of COSMIC (the Catalogue of Somatic Mutations in Cancer). The execution time and the speed-up on IPDATA reach the best values within about 90 processors. Then the parallelization advantage is balanced by the greater cost of non-local communications between the processors. A similar behaviour is evident on HS3D, but at a greater number of processors, so evidencing the direct relationship between data size and parallelization gain. This behaviour is confirmed on COSMIC. Overall, the results obtained show that the parallel version is up to 30 times faster than the serial one.
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).
Cremers, Henricus-Paul; Mercken, Liesbeth; Candel, Math; de Vries, Hein; Oenema, Anke
2015-03-09
Smoking prevalence rates among Dutch children increase rapidly after they transit to secondary school, in particular among children with a low socioeconomic status (SES). Web-based, computer-tailored programs supplemented with prompt messages may be able to empower children to prevent them from starting to smoke when they transit to secondary school. The main aim of this study is to evaluate whether computer-tailored feedback messages, with and without prompt messages, are effective in decreasing children's smoking intentions and smoking behavior after 12 and 25 months of follow-up. Data were gathered at baseline (T0), and after 12 months (T1) and 25 months (T2) of follow-up of a smoking prevention intervention program called Fun without Smokes. A total of 162 schools were randomly allocated to a no-intervention control group, an intervention prompt group, or an intervention no-prompt group. A total of 3213 children aged 10 to 12 years old participated in the study and completed a Web-based questionnaire assessing their smoking intention, smoking behavior, and sociocognitive factors, such as attitude, social influence, and self-efficacy, related to smoking. After completion, children in the intervention groups received computer-tailored feedback messages in their own email inbox and those messages could be accessed on the intervention website. Children in the prompt group received prompt messages, via email and short message service (SMS) text messaging, to stimulate them to reuse the intervention website with nonsmoking content. Multilevel logistic regression analyses were performed using multiple imputations to assess the program effects on smoking intention and smoking behavior at T1 and T2. A total of 3213 children participated in the Fun without Smokes study at T0. Between T0 and T1 a total of 1067 children out of the original 3213 (33.21%) dropped out of the study. Between T0 and T2 the number of children that did not participate in the final measurement was 1730 out of the original 3213 (53.84%). No significant program effects were observed for any of the intervention groups compared to the control group at T1 for the intention to engage in smoking-prompt, OR 0.67 (95% CI 0.30-1.50), no-prompt, OR 0.76 (95% CI 0.34-1.67)-or for smoking behavior-prompt, OR 1.13 (95% CI 0.13-9.98), no-prompt, OR 0.50 (95% CI 0.04-5.59). Similar nonsignificant program effects were found at T2 for the intention to start smoking-prompt, OR 0.78 (95% CI 0.26-2.32), no-prompt, OR 1.31 (95% CI 0.45-3.82)-and smoking behavior-prompt, OR 0.53 (95% CI 0.12-2.47), no-prompt, OR 1.01 (95% CI 0.24-4.21). This study showed that the Web-based, computer-tailored feedback messages with and without prompt messages were not effective in modifying children's smoking intentions and smoking behavior as compared to no information. Future smoking prevention interventions are recommended to start closer to the age of actual smoking uptake. Furthermore, future studies on Web-based, computer-tailored smoking prevention programs should focus on assessing and controlling exposure to the educational content and the response to the prompt messages. Netherlands Trial Register NTR3116; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=3116 (Archived by WebCite at http://www.webcitation.org/6O0wQYuPI).
Multistakeholder Perspectives on Maternal Text Messaging Intervention in Uganda: Qualitative Study.
Ilozumba, Onaedo; Dieleman, Marjolein; Van Belle, Sara; Mukuru, Moses; Bardají, Azucena; Broerse, Jacqueline Ew
2018-05-10
Despite continued interest in the use of mobile health for improving maternal health outcomes, there have been limited attempts to identify relevant program theories. This study had two aims: first, to explicate the assumptions of program designers, which we call the program theory and second, to contrast this program theory with empirical data to gain a better understanding of mechanisms, facilitators, and barriers related to the program outcomes. To achieve the aforementioned objectives, we conducted a retrospective qualitative study of a text messaging (short message service) platform geared at improving individual maternal health outcomes in Uganda. Through interviews with program designers (n=3), we elicited 3 main designers' assumptions and explored these against data from qualitative interviews with primary beneficiaries (n=26; 15 women and 11 men) and health service providers (n=6), as well as 6 focus group discussions with village health team members (n=50) who were all involved in the program. Our study results highlighted that while the program designers' assumptions were appropriate, additional mechanisms and contextual factors, such as the importance of incentives for village health team members, mobile phone ownership, and health system factors should have been considered. Our results indicate that text messages could be an effective part of a more comprehensive maternal health program when context and system barriers are identified and addressed in the program theories. ©Onaedo Ilozumba, Marjolein Dieleman, Sara Van Belle, Moses Mukuru, Azucena Bardají, Jacqueline EW Broerse. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 10.05.2018.
Run-time scheduling and execution of loops on message passing machines
NASA Technical Reports Server (NTRS)
Crowley, Kay; Saltz, Joel; Mirchandaney, Ravi; Berryman, Harry
1989-01-01
Sparse system solvers and general purpose codes for solving partial differential equations are examples of the many types of problems whose irregularity can result in poor performance on distributed memory machines. Often, the data structures used in these problems are very flexible. Crucial details concerning loop dependences are encoded in these structures rather than being explicitly represented in the program. Good methods for parallelizing and partitioning these types of problems require assignment of computations in rather arbitrary ways. Naive implementations of programs on distributed memory machines requiring general loop partitions can be extremely inefficient. Instead, the scheduling mechanism needs to capture the data reference patterns of the loops in order to partition the problem. First, the indices assigned to each processor must be locally numbered. Next, it is necessary to precompute what information is needed by each processor at various points in the computation. The precomputed information is then used to generate an execution template designed to carry out the computation, communication, and partitioning of data, in an optimized manner. The design is presented for a general preprocessor and schedule executer, the structures of which do not vary, even though the details of the computation and of the type of information are problem dependent.
Run-time scheduling and execution of loops on message passing machines
NASA Technical Reports Server (NTRS)
Saltz, Joel; Crowley, Kathleen; Mirchandaney, Ravi; Berryman, Harry
1990-01-01
Sparse system solvers and general purpose codes for solving partial differential equations are examples of the many types of problems whose irregularity can result in poor performance on distributed memory machines. Often, the data structures used in these problems are very flexible. Crucial details concerning loop dependences are encoded in these structures rather than being explicitly represented in the program. Good methods for parallelizing and partitioning these types of problems require assignment of computations in rather arbitrary ways. Naive implementations of programs on distributed memory machines requiring general loop partitions can be extremely inefficient. Instead, the scheduling mechanism needs to capture the data reference patterns of the loops in order to partition the problem. First, the indices assigned to each processor must be locally numbered. Next, it is necessary to precompute what information is needed by each processor at various points in the computation. The precomputed information is then used to generate an execution template designed to carry out the computation, communication, and partitioning of data, in an optimized manner. The design is presented for a general preprocessor and schedule executer, the structures of which do not vary, even though the details of the computation and of the type of information are problem dependent.
Progress in Computational Simulation of Earthquakes
NASA Technical Reports Server (NTRS)
Donnellan, Andrea; Parker, Jay; Lyzenga, Gregory; Judd, Michele; Li, P. Peggy; Norton, Charles; Tisdale, Edwin; Granat, Robert
2006-01-01
GeoFEST(P) is a computer program written for use in the QuakeSim project, which is devoted to development and improvement of means of computational simulation of earthquakes. GeoFEST(P) models interacting earthquake fault systems from the fault-nucleation to the tectonic scale. The development of GeoFEST( P) has involved coupling of two programs: GeoFEST and the Pyramid Adaptive Mesh Refinement Library. GeoFEST is a message-passing-interface-parallel code that utilizes a finite-element technique to simulate evolution of stress, fault slip, and plastic/elastic deformation in realistic materials like those of faulted regions of the crust of the Earth. The products of such simulations are synthetic observable time-dependent surface deformations on time scales from days to decades. Pyramid Adaptive Mesh Refinement Library is a software library that facilitates the generation of computational meshes for solving physical problems. In an application of GeoFEST(P), a computational grid can be dynamically adapted as stress grows on a fault. Simulations on workstations using a few tens of thousands of stress and displacement finite elements can now be expanded to multiple millions of elements with greater than 98-percent scaled efficiency on over many hundreds of parallel processors (see figure).
Parallel Ray Tracing Using the Message Passing Interface
2007-09-01
software is available for lens design and for general optical systems modeling. It tends to be designed to run on a single processor and can be very...Cameron, Senior Member, IEEE Abstract—Ray-tracing software is available for lens design and for general optical systems modeling. It tends to be designed to...National Aeronautics and Space Administration (NASA), optical ray tracing, parallel computing, parallel pro- cessing, prime numbers, ray tracing
Control Transfer in Operating System Kernels
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
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:
Performance Analysis and Optimization of the Winnow Secret Key Reconciliation Protocol
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
Best bang for your buck: GPU nodes for GROMACS biomolecular simulations
Páll, Szilárd; Fechner, Martin; Esztermann, Ansgar; de Groot, Bert L.; Grubmüller, Helmut
2015-01-01
The molecular dynamics simulation package GROMACS runs efficiently on a wide variety of hardware from commodity workstations to high performance computing clusters. Hardware features are well‐exploited with a combination of single instruction multiple data, multithreading, and message passing interface (MPI)‐based single program multiple data/multiple program multiple data parallelism while graphics processing units (GPUs) can be used as accelerators to compute interactions off‐loaded from the CPU. Here, we evaluate which hardware produces trajectories with GROMACS 4.6 or 5.0 in the most economical way. We have assembled and benchmarked compute nodes with various CPU/GPU combinations to identify optimal compositions in terms of raw trajectory production rate, performance‐to‐price ratio, energy efficiency, and several other criteria. Although hardware prices are naturally subject to trends and fluctuations, general tendencies are clearly visible. Adding any type of GPU significantly boosts a node's simulation performance. For inexpensive consumer‐class GPUs this improvement equally reflects in the performance‐to‐price ratio. Although memory issues in consumer‐class GPUs could pass unnoticed as these cards do not support error checking and correction memory, unreliable GPUs can be sorted out with memory checking tools. Apart from the obvious determinants for cost‐efficiency like hardware expenses and raw performance, the energy consumption of a node is a major cost factor. Over the typical hardware lifetime until replacement of a few years, the costs for electrical power and cooling can become larger than the costs of the hardware itself. Taking that into account, nodes with a well‐balanced ratio of CPU and consumer‐class GPU resources produce the maximum amount of GROMACS trajectory over their lifetime. © 2015 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:26238484
Best bang for your buck: GPU nodes for GROMACS biomolecular simulations.
Kutzner, Carsten; Páll, Szilárd; Fechner, Martin; Esztermann, Ansgar; de Groot, Bert L; Grubmüller, Helmut
2015-10-05
The molecular dynamics simulation package GROMACS runs efficiently on a wide variety of hardware from commodity workstations to high performance computing clusters. Hardware features are well-exploited with a combination of single instruction multiple data, multithreading, and message passing interface (MPI)-based single program multiple data/multiple program multiple data parallelism while graphics processing units (GPUs) can be used as accelerators to compute interactions off-loaded from the CPU. Here, we evaluate which hardware produces trajectories with GROMACS 4.6 or 5.0 in the most economical way. We have assembled and benchmarked compute nodes with various CPU/GPU combinations to identify optimal compositions in terms of raw trajectory production rate, performance-to-price ratio, energy efficiency, and several other criteria. Although hardware prices are naturally subject to trends and fluctuations, general tendencies are clearly visible. Adding any type of GPU significantly boosts a node's simulation performance. For inexpensive consumer-class GPUs this improvement equally reflects in the performance-to-price ratio. Although memory issues in consumer-class GPUs could pass unnoticed as these cards do not support error checking and correction memory, unreliable GPUs can be sorted out with memory checking tools. Apart from the obvious determinants for cost-efficiency like hardware expenses and raw performance, the energy consumption of a node is a major cost factor. Over the typical hardware lifetime until replacement of a few years, the costs for electrical power and cooling can become larger than the costs of the hardware itself. Taking that into account, nodes with a well-balanced ratio of CPU and consumer-class GPU resources produce the maximum amount of GROMACS trajectory over their lifetime. © 2015 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.
A distributed Clips implementation: dClips
NASA Technical Reports Server (NTRS)
Li, Y. Philip
1993-01-01
A distributed version of the Clips language, dClips, was implemented on top of two existing generic distributed messaging systems to show that: (1) it is easy to create a coarse-grained parallel programming environment out of an existing language if a high level messaging system is used; and (2) the computing model of a parallel programming environment can be changed easily if we change the underlying messaging system. dClips processes were first connected with a simple master-slave model. A client-server model with intercommunicating agents was later implemented. The concept of service broker is being investigated.
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.
Tofler, A; Chapman, S
2003-12-01
Epidemiological studies and reports on smoking and health published in the 1950s and 1960s threatened the tobacco industry worldwide, which acted to reassure smokers and counteract mounting evidence that smoking posed a serious risk to smokers' health. To document the use of tobacco retailers (1) as a conduit to pass messages of reassurance onto smokers, and (2) to recruit youth and women into smoking. Review of an extensive collection of Australian tobacco retail trade journals (1950-1978) for articles consistent with the industry's efforts to counter messages about smoking and health, and how to attract non-smokers, particularly youth and women. The main arguments advanced in the journals included the notion that air pollution and other substances cause cancer, that "statistics" did not constitute proof in the tobacco health scare, and that the industry was committed to research into the causes of cancer and into developing a "safer" cigarette. Numerous articles designed to be reiterated to customers were published, arguing against the link between tobacco and ill health. Tobacco retailers, salesmen and retail trade organisations played a significant role in dissembling the tobacco health nexus. Tobacco retail journals may be an important component in tobacco industry misinformation strategies.
A Bayesian Model for Highly Accelerated Phase-Contrast MRI
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
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.
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
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.
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.
Plasma Physics Calculations on a Parallel Macintosh Cluster
NASA Astrophysics Data System (ADS)
Decyk, Viktor; Dauger, Dean; Kokelaar, Pieter
2000-03-01
We have constructed a parallel cluster consisting of 16 Apple Macintosh G3 computers running the MacOS, and achieved very good performance on numerically intensive, parallel plasma particle-in-cell simulations. A subset of the MPI message-passing library was implemented in Fortran77 and C. This library enabled us to port code, without modification, from other parallel processors to the Macintosh cluster. For large problems where message packets are large and relatively few in number, performance of 50-150 MFlops/node is possible, depending on the problem. This is fast enough that 3D calculations can be routinely done. Unlike Unix-based clusters, no special expertise in operating systems is required to build and run the cluster. Full details are available on our web site: http://exodus.physics.ucla.edu/appleseed/.
Plasma Physics Calculations on a Parallel Macintosh Cluster
NASA Astrophysics Data System (ADS)
Decyk, Viktor K.; Dauger, Dean E.; Kokelaar, Pieter R.
We have constructed a parallel cluster consisting of 16 Apple Macintosh G3 computers running the MacOS, and achieved very good performance on numerically intensive, parallel plasma particle-in-cell simulations. A subset of the MPI message-passing library was implemented in Fortran77 and C. This library enabled us to port code, without modification, from other parallel processors to the Macintosh cluster. For large problems where message packets are large and relatively few in number, performance of 50-150 Mflops/node is possible, depending on the problem. This is fast enough that 3D calculations can be routinely done. Unlike Unix-based clusters, no special expertise in operating systems is required to build and run the cluster. Full details are available on our web site: http://exodus.physics.ucla.edu/appleseed/.
Impact of Online Summer Mathematics Bridge Program on Placement Scores and Pass Rates
ERIC Educational Resources Information Center
Frost, Jodi L.; Dreher, J. P.
2017-01-01
An online four-week summer mathematics bridge program was implemented at a Midwest university with historically low pass rates in College Algebra and Remedial Mathematics. Students who completed the four week program significantly increased their mathematics placement exam scores. These students also had a higher pass rate in their initial college…
Supporting Beacon and Event-Driven Messages in Vehicular Platoons through Token-Based Strategies
Uhlemann, Elisabeth
2018-01-01
Timely and reliable inter-vehicle communications is a critical requirement to support traffic safety applications, such as vehicle platooning. Furthermore, low-delay communications allow the platoon to react quickly to unexpected events. In this scope, having a predictable and highly effective medium access control (MAC) method is of utmost importance. However, the currently available IEEE 802.11p technology is unable to adequately address these challenges. In this paper, we propose a MAC method especially adapted to platoons, able to transmit beacons within the required time constraints, but with a higher reliability level than IEEE 802.11p, while concurrently enabling efficient dissemination of event-driven messages. The protocol circulates the token within the platoon not in a round-robin fashion, but based on beacon data age, i.e., the time that has passed since the previous collection of status information, thereby automatically offering repeated beacon transmission opportunities for increased reliability. In addition, we propose three different methods for supporting event-driven messages co-existing with beacons. Analysis and simulation results in single and multi-hop scenarios showed that, by providing non-competitive channel access and frequent retransmission opportunities, our protocol can offer beacon delivery within one beacon generation interval while fulfilling the requirements on low-delay dissemination of event-driven messages for traffic safety applications. PMID:29570676
Supporting Beacon and Event-Driven Messages in Vehicular Platoons through Token-Based Strategies.
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.
Assessing clarity of message communication for mandated USEPA drinking water quality reports.
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.
The Physical Therapy and Society Summit (PASS) Meeting: observations and opportunities.
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.
ERIC Educational Resources Information Center
Bauer, Stephanie; Okon, Eberhard; Meermann, Rolf; Kordy, Hans
2012-01-01
Objective: Given the lack of maintenance interventions for eating disorders, a program delivered via the short message service (SMS) and text messaging was developed to support patients after their discharge from inpatient treatment. Method: The efficacy of the intervention was studied in a randomized controlled trial. Additionally, its impact on…
Spelling for Writing: Student Activity Book. Level 5.
ERIC Educational Resources Information Center
Peet, Howard
The Level 5 activity book is designed to help children learn that writing messages and stories will help them see the value of learning to spell. The workbook's program is based on the ideas that accurate spelling contributes to the clarity of written messages; spelling accuracy shows attention to detail, sending a positive message to teachers and…
NASA Technical Reports Server (NTRS)
Allen, C. P.; Martin, C. F.
1977-01-01
The SEAHT program is designed to process multiple passes of altimeter data with intersecting ground tracks, with the estimation of corrections for orbital errors to each pass such that the data has the best overall agreement at the crossover points. Orbit error for each pass is modeled as a polynomial in time, with optional orders of 0, 1, or 2. One or more passes may be constrained in the adjustment process, thus allowing passes with the best orbits to provide the overall level and orientation of the estimated sea surface heights. Intersections which disagree by more than an input edit level are not used in the error parameter estimation. In the program implementation, passes are grouped into South-North passes and North-South passes, with the North-South passes partitioned out for the estimation of orbit error parameters. Computer core utilization is thus dependent on the number of parameters estimated for the set of South-North arcs, but is independent on the number of North-South passes. Estimated corrections for each pass are applied to the data at its input data rate and an output tape is written which contains the corrected data.
Harnessing the power of advertising to prevent childhood obesity
2013-01-01
Background Social marketing integrates communication campaigns with behavioural and environmental change strategies. Childhood obesity programs could benefit significantly from social marketing but communication campaigns on this issue tend to be stand-alone. Methods A large-scale multi-setting child obesity prevention program was implemented in the Hunter New England (HNE) region of New South Wales (NSW), Australia from 2005–2010. The program included a series of communication campaigns promoting the program and its key messages: drinking water; getting physically active and; eating more vegetables and fruit. Pre-post telephone surveys (n = 9) were undertaken to evaluate awareness of the campaigns among parents of children aged 2–15 years using repeat cross-sections of randomly selected cohorts. A total of 1,367 parents (HNE = 748, NSW = 619) participated. Results At each survey post baseline, HNE parents were significantly more likely to have seen, read or heard about the program and its messages in the media than parents in the remainder of the state (p < 0.001). Further, there was a significant increase in awareness of the program and each of its messages over time in HNE compared to no change over time in NSW (p < 0.001). Awareness was significantly higher (p < 0.05) in HNE compared to NSW after each specific campaign (except the vegetable one) and significantly higher awareness levels were sustained for each campaign until the end of the program. At the end of the program participants without a tertiary education were significantly more likely (p = 0.04) to be aware of the brand campaign (31%) than those with (20%) but there were no other statistically significant socio-demographic differences in awareness. Conclusions The Good for Kids communication campaigns increased and maintained awareness of childhood obesity prevention messages. Moreover, messages were delivered equitably to diverse socio-demographic groups within the region. PMID:24090174
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
Evaluation of a new parallel numerical parameter optimization algorithm for a dynamical system
NASA Astrophysics Data System (ADS)
Duran, Ahmet; Tuncel, Mehmet
2016-10-01
It is important to have a scalable parallel numerical parameter optimization algorithm for a dynamical system used in financial applications where time limitation is crucial. We use Message Passing Interface parallel programming and present such a new parallel algorithm for parameter estimation. For example, we apply the algorithm to the asset flow differential equations that have been developed and analyzed since 1989 (see [3-6] and references contained therein). We achieved speed-up for some time series to run up to 512 cores (see [10]). Unlike [10], we consider more extensive financial market situations, for example, in presence of low volatility, high volatility and stock market price at a discount/premium to its net asset value with varying magnitude, in this work. Moreover, we evaluated the convergence of the model parameter vector, the nonlinear least squares error and maximum improvement factor to quantify the success of the optimization process depending on the number of initial parameter vectors.
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.
NASA Astrophysics Data System (ADS)
Rizki, Permata Nur Miftahur; Lee, Heezin; Lee, Minsu; Oh, Sangyoon
2017-01-01
With the rapid advance of remote sensing technology, the amount of three-dimensional point-cloud data has increased extraordinarily, requiring faster processing in the construction of digital elevation models. There have been several attempts to accelerate the computation using parallel methods; however, little attention has been given to investigating different approaches for selecting the most suited parallel programming model for a given computing environment. We present our findings and insights identified by implementing three popular high-performance parallel approaches (message passing interface, MapReduce, and GPGPU) on time demanding but accurate kriging interpolation. The performances of the approaches are compared by varying the size of the grid and input data. In our empirical experiment, we demonstrate the significant acceleration by all three approaches compared to a C-implemented sequential-processing method. In addition, we also discuss the pros and cons of each method in terms of usability, complexity infrastructure, and platform limitation to give readers a better understanding of utilizing those parallel approaches for gridding purposes.
Efficient Parallelization of a Dynamic Unstructured Application on the Tera MTA
NASA Technical Reports Server (NTRS)
Oliker, Leonid; Biswas, Rupak
1999-01-01
The success of parallel computing in solving real-life computationally-intensive problems relies on their efficient mapping and execution on large-scale multiprocessor architectures. Many important applications are both unstructured and dynamic in nature, making their efficient parallel implementation a daunting task. This paper presents the parallelization of a dynamic unstructured mesh adaptation algorithm using three popular programming paradigms on three leading supercomputers. We examine an MPI message-passing implementation on the Cray T3E and the SGI Origin2OOO, a shared-memory implementation using cache coherent nonuniform memory access (CC-NUMA) of the Origin2OOO, and a multi-threaded version on the newly-released Tera Multi-threaded Architecture (MTA). We compare several critical factors of this parallel code development, including runtime, scalability, programmability, and memory overhead. Our overall results demonstrate that multi-threaded systems offer tremendous potential for quickly and efficiently solving some of the most challenging real-life problems on parallel computers.
Performance Evaluation of Communication Software Systems for Distributed Computing
NASA Technical Reports Server (NTRS)
Fatoohi, Rod
1996-01-01
In recent years there has been an increasing interest in object-oriented distributed computing since it is better quipped to deal with complex systems while providing extensibility, maintainability, and reusability. At the same time, several new high-speed network technologies have emerged for local and wide area networks. However, the performance of networking software is not improving as fast as the networking hardware and the workstation microprocessors. This paper gives an overview and evaluates the performance of the Common Object Request Broker Architecture (CORBA) standard in a distributed computing environment at NASA Ames Research Center. The environment consists of two testbeds of SGI workstations connected by four networks: Ethernet, FDDI, HiPPI, and ATM. The performance results for three communication software systems are presented, analyzed and compared. These systems are: BSD socket programming interface, IONA's Orbix, an implementation of the CORBA specification, and the PVM message passing library. The results show that high-level communication interfaces, such as CORBA and PVM, can achieve reasonable performance under certain conditions.
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.
Design and implementation of a hybrid MPI-CUDA model for the Smith-Waterman algorithm.
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.
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.
Performance Characteristics of the Multi-Zone NAS Parallel Benchmarks
NASA Technical Reports Server (NTRS)
Jin, Haoqiang; VanderWijngaart, Rob F.
2003-01-01
We describe a new suite of computational benchmarks that models applications featuring multiple levels of parallelism. Such parallelism is often available in realistic flow computations on systems of grids, but had not previously been captured in bench-marks. The new suite, named NPB Multi-Zone, is extended from the NAS Parallel Benchmarks suite, and involves solving the application benchmarks LU, BT and SP on collections of loosely coupled discretization meshes. The solutions on the meshes are updated independently, but after each time step they exchange boundary value information. This strategy provides relatively easily exploitable coarse-grain parallelism between meshes. Three reference implementations are available: one serial, one hybrid using the Message Passing Interface (MPI) and OpenMP, and another hybrid using a shared memory multi-level programming model (SMP+OpenMP). We examine the effectiveness of hybrid parallelization paradigms in these implementations on three different parallel computers. We also use an empirical formula to investigate the performance characteristics of the multi-zone benchmarks.
Fernandes, Natália Maria da Silva; Bastos, Marcus Gomes; Oliveira, Nivalda A C de; Costa, Alex do Vale; Bernardino, Heder Soares
2015-01-01
The focus in the treatment of CKD is to prevent its progression through optimal medical control. The large number of patients with CKD has pressed nephrologists to assess more patients into ever-smaller periods of consultation. The use of light technologies as a promising form of health care. The internet offers the opportunity to manipulate the doctor in his professional contact with the user. To develop a web system to attend the patients with CKD not on dialysis and clinically stable stages at distance. Developed a system using the Java language, MySQL database and PrimeFaces framework; available on a Glassfish application server. The initial access is performed by the nephrologist, which registers the patients with their personal information and access data. After being registered, the patient (or family doctor) can enter the data of your query and these will be following, passed on to the nephrologist for evaluation. The form with the data of interest is pre-determined, but there is possibility to add free-form information. The system enables, in addition, there is exchange of messages between doctors and patients. In addition, users receive messages via e-mail alerting them of their duties. Confidentiality is guaranteed by individual passwords for doctors and patients. This tool will enable to increase the coverage area of nephrologists, reduce costs and bring the patient to the primary care physician, using the Family Health Program as an interface between the patient and the nephrology secondary care.
ERIC Educational Resources Information Center
Child Research Service, Inc., New York, NY.
A total of 687 children, aged 7 through 11, was interviewed in fall, 1974 to determine the extent to which the Harlem Globetrotters Popcorn Machine television programs communicated "pro-social" messages to its audience. Viewers of four different episodes of the Globetrotters were questioned about the program they had seen. Among the…
JMS Proxy and C/C++ Client SDK
NASA Technical Reports Server (NTRS)
Wolgast, Paul; Pechkam, Paul
2007-01-01
JMS Proxy and C/C++ Client SDK (JMS signifies "Java messaging service" and "SDK" signifies "software development kit") is a software package for developing interfaces that enable legacy programs (here denoted "clients") written in the C and C++ languages to communicate with each other via a JMS broker. This package consists of two main components: the JMS proxy server component and the client C library SDK component. The JMS proxy server component implements a native Java process that receives and responds to requests from clients. This component can run on any computer that supports Java and a JMS client. The client C library SDK component is used to develop a JMS client program running in each affected C or C++ environment, without need for running a Java virtual machine in the affected computer. A C client program developed by use of this SDK has most of the quality-of-service characteristics of standard Java-based client programs, including the following: Durable subscriptions; Asynchronous message receipt; Such standard JMS message qualities as "TimeToLive," "Message Properties," and "DeliveryMode" (as the quoted terms are defined in previously published JMS documentation); and Automatic reconnection of a JMS proxy to a restarted JMS broker.
The data acquisition system for the Anglo-Australian Observatory 2-degree field project
NASA Technical Reports Server (NTRS)
Shortridge, K.; Farrell, T. J.; Bailey, J.
1992-01-01
The Anglo-Australian Observatory (AAO) is building a system that will provide a two-degree field of view at prime focus. A robot positioner will be used to locate up to 400 optical fibers at pre-determined positions in this field. While observations are being made using one set of 400 fibers, the robot will be positioning a second set of fibers in a background field that can be moved in to replace the first when the telescope is moved to a new position. The fibers feed two spectrographs each with a 1024 square CCD detector. The software system being produced to control this involves Vaxes for overall control and data recording, UNIX workstations for fiber configuration calculations and on-line data reduction, and VME systems running VxWorks for real-time control of critical parts such as the positioner robot. The system has to be able to interact with the observatory's present data acquisition systems, which use the ADAM system. As yet, the real-time parts of ADAM have not been ported to Unix, and so we are having to produce a smaller-scale system that is similar but inherently distributed (which ADAM is not). We are using this system as a testbed for ideas that we hope may eventually influence an ADAM II system. The system we are producing is based on a message system that is designed to be able to handle inter-process and inter-processor messages of any length, efficiently, and without ever requiring a task to block (i.e., be unresponsive to 'cancel' messages, enquiry messages), other than when deliberately waiting for external input - all of which will be through such messages. The essential requirement is that a message 'send' operation should never be able to block. The messages will be hierarchical, self-defining, machine-independent data structures. This allows us to provide very simple monitoring of messages for diagnostic purposes, and allows general purpose interface programs to be written without needing to share precise byte by byte message format definitions. Programs in this system have interfaces defined simply in terms of named actions and their parameters. Real-time control programs are required to be able to handle a number of such actions concurrently; data reduction programs will normally only need to handle one action at a time ('process an image', 'display a spectrum', etc).
Perspectives on communication problems in the English-speaking Caribbean.
Okwesa, B A
1984-03-01
The Caribbean is experiencing a host of serious socioeconomic problems that prevent the majority of the population from realizing and maintaining a satisfactory standard of living. Food and Nutrition Surveys of some countries identified a lack of information on health, food, and nutrition as a primary reason for the prevalence of malnutrition, infectious diseases, and nutrition related diseases. "Misinformation" creates an often insurmountable barrier to effective communication between source and receiver, in this case the health, food, and nutrition sector and the wider community. Misinformation occurs when the message is either incorrect, incomplete, inconsistent with other messages in the same program, or contradictory. This element of "misinformation" can negate the effectiveness of the message and an entire communication program. Some examples are cited which show that in programs aimed at effecting change in attitude or behavior it is essential to ensure that messages are clearly communicated to avoid misunderstanding and the right infrastructure is in place for the innovation proposed by the message to be carried out. In the Jamaica Nutrition Education Program (JNEP) were used to communicate the messages. Evaluation revealed that health staff were providing incorrect and contradictory advice about breastfeeding, which showed that they lacked basic information on the subject. In Barbados, despite an intensified health education campaign, face to face instruction in the clinics, and extensive use of the Caribbean Food and Nutrition Institute (CFNI) Breastfeeding Package as well as other locally developed materials, a marked decline in breastfeeding was recorded over the 1969-81 survey period. Misinformation and misunderstanding among mothers were identified as the key reasons for the failure of breastfeeding. In relation to the decline in breaastfeeding and incorrect weaning practices, mass media was implicated as luring mothers away from natural feeding methods towards the use of expensive imported products. A 1976 CFNI meeting established strong linkages between mass media and nutrition personnel and was the factor most responsible for the selection of an advertising/marketing approach as the chief component of the mass media strategy. In sum, there is more to communication than mere information transfer. Effective communication can produce/create the right climate for change to occur. The nature of the message is an important determining factor in attitude and behavior change, and the message must fit the intended audience. The medium of the message must be appropriate, culturally relevant, familiar and liked.
Earthquake Analysis (EA) Software for The Earthquake Observatories
NASA Astrophysics Data System (ADS)
Yanik, K.; Tezel, T.
2009-04-01
There are many software that can used for observe the seismic signals and locate the earthquakes, but some of them commercial and has technical support. For this reason, many seismological observatories developed and use their own seismological software packets which are convenient with their seismological network. In this study, we introduce our software which has some capabilities that it can read seismic signals and process and locate the earthquakes. This software is used by the General Directorate of Disaster Affairs Earthquake Research Department Seismology Division (here after ERD) and will improve according to the new requirements. ERD network consist of 87 seismic stations that 63 of them were equipped with 24 bite digital Guralp CMG-3T, 16 of them with analogue short period S-13-Geometrics and 8 of them 24 bite digital short period S-13j-DR-24 Geometrics seismometers. Data is transmitted with satellite from broadband stations, whereas leased line used from short period stations. Daily data archive capacity is 4 GB. In big networks, it is very important that observe the seismic signals and locate the earthquakes as soon as possible. This is possible, if they use software which was developed considering their network properties. When we started to develop a software for big networks as our, we recognized some realities that all known seismic format data should be read without any convert process, observing of the only selected stations and do this on the map directly, add seismic files with import command, establishing relation between P and S phase readings and location solutions, store in database and entering to the program with user name and password. In this way, we can prevent data disorder and repeated phase readings. There are many advantages, when data store on the database proxies. These advantages are easy access to data from anywhere using ethernet, publish the bulletin and catalogues using website, easily sending of short message (sms) and e-mail, data reading from anywhere that has ethernet connection and store the results in same centre. The Earthqukae Analysis (EA) program was developed considering above facilities. Microsoft Visual Basic 6.0 and Microsoft GDI tools were used as a basement for program development. EA program can image five different seismic formats (gcf, suds, seisan, sac, nanometrics-y) without any conversion and use all seismic process facilities that are filtering (band-pass, low-pass, high-pass), fast fourier transform, offset adjustment etc.
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.
Thakkar, Jay; Redfern, Julie; Khan, Ehsan; Atkins, Emily; Ha, Jeffrey; Vo, Kha; Thiagalingam, Aravinda; Chow, Clara K
2018-05-23
The 'Tobacco, Exercise and Diet Messages' (TEXT ME) study was a 6-month, single-centre randomised clinical trial (RCT) that found a text message support program improved levels of cardiovascular risk factors in patients with coronary heart disease (CHD). The current analyses examined whether receipt of text messages influenced participants' engagement with conventional healthcare resources. The TEXT ME study database (N=710) was linked with routinely collected health department databases. Number of doctor consultations, investigations and cardiac medication prescriptions in the two study groups were compared. The most frequently accessed health service was consultations with a General Practitioner (mean 7.1, s.d. 5.4). The numbers of medical consultations, biochemical tests or cardiac-specific investigations were similar between the study groups. There was at least one prescription registered for statin, ACEI/ARBs and β-blockers in 79, 66 and 50% of patients respectively, with similar refill rates in both the study groups. The study identified TEXT ME text messaging program did not increase use of Medicare Benefits Schedule (MBS) and Pharmaceutical Benefits Scheme (PBS) captured healthcare services. The observed benefits of TEXT ME reflect direct effects of intervention independent of conventional healthcare resource engagement.
SMS Security System on Mobile Devices Using Tiny Encryption Algorithm
NASA Astrophysics Data System (ADS)
Novelan, M. S.; Husein, A. M.; Harahap, M.; Aisyah, S.
2018-04-01
The development of telecommunications technology is so rapid has given such great benefits. With the telecommunication technology, distance and time no longer be a significant obstacle. One of the results of telecommunications technology that is well known is the Short Message Service. In this study developed an application on the mobile phone to modify the SMS message into ciphertext so that the information content of the SMS is not known by others. SMS delivery system for encrypting messages into ciphertext using a key that is entered by the sender then sends to the destination number. SMS reception system to decrypt it to others via SMS without the fear of information from these messages will be known by others. The method used in the system encrypt and decrypt the message is the algorithm Tiny Encryption Algorithm and implemented using the Java programming language. JDK 1.7 as the Java programming language ciphertext into plaintext using the key entered by the receiver and displays the original message to the recipient. This application can be used by someone who wants to send a confidential information and the Java compiler. Eclipse, a Java SDK and the Android SDK as a Java source code editor.
Development of targeted messages to promote smoking cessation among construction trade workers
Strickland, J. R.; Smock, N.; Casey, C.; Poor, T.; Kreuter, M. W.; Evanoff, B. A.
2015-01-01
Blue-collar workers, particularly those in the construction trades, are more likely to smoke and have less success in quitting when compared with white-collar workers. Little is known about health communication strategies that might influence this priority population. This article describes our formative work to develop targeted messages to increase participation in an existing smoking cessation program among construction workers. Using an iterative and sequential mixed-methods approach, we explored the culture, health attitudes and smoking behaviors of unionized construction workers. We used focus group and survey data to inform message development, and applied audience segmentation methods to identify potential subgroups. Among 144 current smokers, 65% reported wanting to quit smoking in the next 6 months and only 15% had heard of a union-sponsored smoking cessation program, despite widespread advertising. We tested 12 message concepts and 26 images with the target audience to evaluate perceived relevance and effectiveness. Participants responded most favorably to messages and images that emphasized family and work, although responses varied by audience segments based on age and parental status. This study is an important step towards integrating the culture of a high-risk group into targeted messages to increase participation in smoking cessation activities. PMID:25231165
DOT National Transportation Integrated Search
2014-04-01
The University Transportation Research Center Region 2 supported a study entitled Connections Beyond Campus: An Evaluation of the Niagara Frontier Transportation : Authority University at Buffalo Transit Pass Program. Unlimited Access t...
Whittaker, Robyn; Maddison, Ralph; McRobbie, Hayden; Bullen, Chris; Denny, Simon; Dorey, Enid; Ellis-Pegler, Mary; van Rooyen, Jaco; Rodgers, Anthony
2008-11-25
While most young people who smoke want to quit, few access cessation support services. Mobile phone-based cessation programs are ideal for young people: mobile phones are the most common means of peer communication, and messages can be delivered in an anonymous manner, anywhere, anytime. Following the success of our text messaging smoking cessation program, we developed an innovative multimedia mobile phone smoking cessation intervention. The aim of the study was to develop and pilot test a youth-oriented multimedia smoking cessation intervention delivered solely by mobile phone. Development included creating content and building the technology platform. Content development was overseen by an expert group who advised on youth development principles, observational learning (from social cognitive theory), effective smoking cessation interventions, and social marketing. Young people participated in three content development phases (consultation via focus groups and an online survey, content pre-testing, and selection of role models). Video and text messages were then developed, incorporating the findings from this research. Information technology systems were established to support the delivery of the multimedia messages by mobile phone. A pilot study using an abbreviated 4-week program of video and text content tested the reliability of the systems and the acceptability of the intervention. Approximately 180 young people participated in the consultation phase. There was a high priority placed on music for relaxation (75%) and an interest in interacting with others in the program (40% would read messages, 36% would read a blog). Findings from the pre-testing phase (n = 41) included the importance of selecting "real" and "honest" role models with believable stories, and an interest in animations (37%). Of the 15 participants who took part in the pilot study, 13 (87%) were available for follow-up interviews at 4 weeks: 12 participants liked the program or liked it most of the time and found the role model to be believable; 7 liked the role model video messages (5 were unsure); 8 used the extra assistance for cravings; and 9 were happy with two messages per day. Nine participants (60%) stopped smoking during the program. Some technical challenges were encountered during the pilot study. A multimedia mobile phone smoking cessation program is technically feasible, and the content developed is appropriate for this medium and is acceptable to our target population. These results have informed the design of a 6-month intervention currently being evaluated for its effectiveness in increasing smoking cessation rates in young people.
Maddison, Ralph; McRobbie, Hayden; Bullen, Chris; Denny, Simon; Dorey, Enid; Ellis-Pegler, Mary; van Rooyen, Jaco; Rodgers, Anthony
2008-01-01
Background While most young people who smoke want to quit, few access cessation support services. Mobile phone–based cessation programs are ideal for young people: mobile phones are the most common means of peer communication, and messages can be delivered in an anonymous manner, anywhere, anytime. Following the success of our text messaging smoking cessation program, we developed an innovative multimedia mobile phone smoking cessation intervention. Objective The aim of the study was to develop and pilot test a youth-oriented multimedia smoking cessation intervention delivered solely by mobile phone. Methods Development included creating content and building the technology platform. Content development was overseen by an expert group who advised on youth development principles, observational learning (from social cognitive theory), effective smoking cessation interventions, and social marketing. Young people participated in three content development phases (consultation via focus groups and an online survey, content pre-testing, and selection of role models). Video and text messages were then developed, incorporating the findings from this research. Information technology systems were established to support the delivery of the multimedia messages by mobile phone. A pilot study using an abbreviated 4-week program of video and text content tested the reliability of the systems and the acceptability of the intervention. Results Approximately 180 young people participated in the consultation phase. There was a high priority placed on music for relaxation (75%) and an interest in interacting with others in the program (40% would read messages, 36% would read a blog). Findings from the pre-testing phase (n = 41) included the importance of selecting “real” and “honest” role models with believable stories, and an interest in animations (37%). Of the 15 participants who took part in the pilot study, 13 (87%) were available for follow-up interviews at 4 weeks: 12 participants liked the program or liked it most of the time and found the role model to be believable; 7 liked the role model video messages (5 were unsure); 8 used the extra assistance for cravings; and 9 were happy with two messages per day. Nine participants (60%) stopped smoking during the program. Some technical challenges were encountered during the pilot study. Conclusions A multimedia mobile phone smoking cessation program is technically feasible, and the content developed is appropriate for this medium and is acceptable to our target population. These results have informed the design of a 6-month intervention currently being evaluated for its effectiveness in increasing smoking cessation rates in young people. PMID:19033148
A Parallel Workload Model and its Implications for Processor Allocation
1996-11-01
with SEV or AVG, both of which can tolerate c = 0.4 { 0.6 before their performance deteriorates signi cantly. On the other hand, Setia [10] has...Sanjeev. K Setia . The interaction between memory allocation and adaptive partitioning in message-passing multicomputers. In IPPS Workshop on Job...Scheduling Strategies for Parallel Processing, pages 89{99, 1995. [11] Sanjeev K. Setia and Satish K. Tripathi. An analysis of several processor
Parallel deterministic neutronics with AMR in 3D
DOE Office of Scientific and Technical Information (OSTI.GOV)
Clouse, C.; Ferguson, J.; Hendrickson, C.
1997-12-31
AMTRAN, a three dimensional Sn neutronics code with adaptive mesh refinement (AMR) has been parallelized over spatial domains and energy groups and runs on the Meiko CS-2 with MPI message passing. Block refined AMR is used with linear finite element representations for the fluxes, which allows for a straight forward interpretation of fluxes at block interfaces with zoning differences. The load balancing algorithm assumes 8 spatial domains, which minimizes idle time among processors.
NASA Astrophysics Data System (ADS)
Cardall, Christian Y.; Budiardja, Reuben D.
2017-05-01
GenASiS Basics provides Fortran 2003 classes furnishing extensible object-oriented utilitarian functionality for large-scale physics simulations on distributed memory supercomputers. This functionality includes physical units and constants; display to the screen or standard output device; message passing; I/O to disk; and runtime parameter management and usage statistics. This revision -Version 2 of Basics - makes mostly minor additions to functionality and includes some simplifying name changes.
An HLA-Based Approach to Quantify Achievable Performance for Tactical Edge Applications
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
Indirect exposure to a family planning mass media campaign in Nepal.
Boulay, Marc; Storey, J Douglas; Sood, Suruchi
2002-01-01
It is often noted that some individuals become aware of a mass media program's messages through discussions with other individuals. However, the extent to which indirect exposure occurs, and its influence on behavior, are somewhat unclear. This study examines the role of indirect exposure in extending the reach of a family planning mass media campaign in Nepal. Sociometric data, gathered from nearly all women between the ages of 15 and 49 years living in six villages in Dang District, Nepal (N = 667), assessed indirect exposure to the radio program. Indirect exposure was extensive; half of all respondents were indirectly exposed to the program's messages and the overall reach of the program increased from 50% to 75% when indirect exposure was considered. Members of community groups had higher levels of direct exposure to the radio program and more extensive and diverse social networks, allowing them to serve as a conduit for these messages into the wider community. While direct exposure to the radio program appeared to influence family planning knowledge, indirect exposure was more strongly associated with contraceptive use. These findings suggest that program evaluations that ignore indirect exposure underestimate the impact of a mass media program on behavior.
Thrul, Johannes; Mendel, Judith A; Simmens, Samuel J; Abroms, Lorien C
2018-05-18
Text messaging interventions have shown promise in helping people quit smoking. Texting programs periodically survey participants about their smoking status. This study examined the consistency of participant self-reported smoking between external surveys and internal program text message assessments. Participants in Text2Quit program were surveyed about their past 7-day smoking at one, three, and six months post-enrollment using different survey modes (external surveys and internal program text message assessments) and responses were compared for consistency. The first set of analyses was conducted for participants responding on both modes (n = 45 at one month; n = 50 at three months; n = 42 at six months). Additional analyses, assuming missing = smoking, were conducted with the full sample of 262 smokers (68.7% female, mean age = 35.8 years) and compared to saliva-confirmed abstinence rates. Participants responding to both modes consistently reported smoking status at one (88.9%), three (88.0%) and six (88.1%) months post-enrollment, with fair to substantial levels of agreement (one month: κ = 0.24; three months: κ = 0.63; six months: κ = 0.66). Participants responding to both modes reported high rates of abstinence. In missing = smoking analyses, significant differences in abstinence rates reported across modes were detected at each timepoint (one month: external = 30.5%, internal = 16.4%; three months: external = 33.2%, internal = 16.0%; six months: external = 31.7%, internal = 12.2%; all p < .001). Moderate levels of agreement were found between the two modes. At 6 months, abstinence rates obtained via internal data were closer to those biochemically verified (15.7%) compared to external surveys. Results provide initial support for the use of internal program assessments in text messaging programs with missing = smoking assumptions in order to gather outcome data on smoking behavior. Copyright © 2018 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
Story, Mary; Faulkner, Patricia
1990-01-01
Identifies and analyzes messages related to food and eating behavior as presented on prime time television programing and commercials. Finds that food references occur an average of 4.8 times per 30 minutes and that over half of all food references were for low nutrient beverages and sweets, which is inconsistent with healthy dietary guidelines.…
ERIC Educational Resources Information Center
Cania, Lisa M.
1989-01-01
A communications audit, analyzed programs and publications at St. Lawrence University, audience by audience, message by message, and month by month. The ways St. Lawrence integrated themes into major projects as well as into small details is discussed. (MLW)
Optimal message log reclamation for independent checkpointing
NASA Technical Reports Server (NTRS)
Wang, Yi-Min; Fuchs, W. Kent
1993-01-01
Independent (uncoordinated) check pointing for parallel and distributed systems allows maximum process autonomy but suffers from possible domino effects and the associated storage space overhead for maintaining multiple checkpoints and message logs. In most research on check pointing and recovery, it was assumed that only the checkpoints and message logs older than the global recovery line can be discarded. It is shown how recovery line transformation and decomposition can be applied to the problem of efficiently identifying all discardable message logs, thereby achieving optimal garbage collection. Communication trace-driven simulation for several parallel programs is used to show the benefits of the proposed algorithm for message log reclamation.
Mullin, Sandra; Prasad, Vinayak; Kaur, Jagdish; Turk, Tahir
2011-08-01
Antitobacco mass media campaigns have had good success at changing knowledge, attitudes, and behaviors with respect to smoking in high-income countries provided they are sustained. Mass media campaigns should be a critical component of tobacco control programs in low- and lower-middle-income countries. Mounting evidence shows that graphic campaigns and those that evoke negative emotions run over long periods of time have achieved the most influence. These types of campaigns are now being implemented in low- and middle-income countries. The authors provide 3 case studies of first-ever graphic warning mass media campaigns in China, India, and Russia, 3 priority high-burden countries in the global Bloomberg Initiative to Reduce Tobacco Use. In each of these countries, message testing of core messages provided confidence in messages, and evaluations demonstrated message uptake. The authors argue that given the initial success of these campaigns, governments in low- and middle-income countries should consider resourcing and sustaining these interventions as key components of their tobacco control strategies and programs.
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
Corporate social marketing: message design to recruit program participants.
Black, David R; Blue, Carolyn L; Coster, Daniel C; Chrysler, Lisa M
2002-01-01
To identify variables for a corporate social marketing (SM) health message based on the 4 Ps of SM in order to recruit future participants to an existing national, commercial, self-administered weight-loss program. A systematically evaluated, author-developed, 310-response survey was administered to a random sample of 270 respondents. A previously established research plan was used to empirically identify the audience segments and the "marketing mix" appropriate for the total sample and each segment. Tangible product, pertaining to the unique program features, should be emphasized rather than positive core product and outcome expectation related to use of the program.
Lewis, I; White, K M; Ho, B; Elliott, B; Watson, B
2017-06-01
In Australia, young drivers aged 17-25 years comprise 13% of the population yet account for 22% of all road deaths with young males over-represented in such trauma. Speeding represents a major contributing factor and advertising campaigns have long focused on promoting anti-speeding messages in the effort to reduce drivers' speeds. Positioned within a larger program of research aimed at developing, piloting, and evaluating a range of theoretically-informed anti-speeding messages, the current study reports results relating to the final phase of the research, the evaluation. Six messages were devised in accordance with the guiding framework, the Step approach to Message Design and Testing ([SatMDT]; Lewis et al., 2016) and based on the findings emerging from earlier qualitative and quantitative studies within the program of research. N=938 licensed drivers (n=455 males, 48%) aged 17-62 years completed an online survey. To ensure a controlled test of the persuasiveness of the message content, the messages were presented in an audio-based format and thus were devoid of potential confounds, such as images. The messages sought to address a particular belief (i.e., behavioural, normative, control) and to focus either on emphasising the positive aspects which make speeding less likely or challenging the negative aspects which make speeding more likely. Thus, key to this evaluation was to test the persuasiveness of the message content in terms of the particular belief and focus it was addressing. Participants were randomly assigned to either the Control condition (i.e., no exposure to a message) or the Intervention condition (i.e., exposed to one of the six messages presented as an audio-recorded message within the survey). Persuasiveness was assessed via a range of outcome measures including both direct (i.e., third-person perceptions, message rejection) as well as indirect measures (i.e., intentions, willingness to speed). Age, gender, and message type were independent variables (IVs), together with issue involvement as a covariate (or IV) in the study's analyses. Overall, positive persuasive effects, and a relative absence of any negative, dissuasive effects, were found for two messages, Glass Cars and The Lift. These messages addressed the same salient belief, control beliefs, with the former emphasising the factors which discourage speeding and the latter message challenging those factors which encourage speeding. The implications of the findings are discussed in terms of the insights they offer for the key content of future anti-speeding messages. Copyright © 2017 Elsevier Ltd. All rights reserved.
Lim, Megan S C; Gold, Judy; Bowring, Anna L; Pedrana, Alisa E; Hellard, Margaret E
2015-05-01
In 2009, the Australian Government's National Sexually Transmitted Infection Prevention Program launched a multi-million dollar sexual health campaign targeting young people. We assessed campaign recognition among a community sample of young people. Individuals aged 16-29 years self-completed a questionnaire at a music festival. Participants were asked whether they recognised the campaign image and attempted to match the correct campaign message. Recognition of two concurrent campaigns, GlaxoSmithKline's The Facts genital herpes campaign (targeting young women) and the Drama Downunder campaign (targeting gay men) were assessed simultaneously. Among 471 participants, just 29% recognised the National Sexually Transmitted Infection Prevention Program campaign. This compared to 52% recognising The Facts and 27% recognising Drama Downunder. Of 134 who recognised the National Sexually Transmitted Infection Prevention Program campaign, 27% correctly recalled the campaign messages compared to 61% of those recognising the Facts campaign, and 25% of those recognising the Drama Downunder campaign. There was no difference in National Sexually Transmitted Infection Prevention Program campaign recognition by gender or age. Campaign recognition and message recall of the National Sexually Transmitted Infection Prevention Program campaign was comparatively low. Future mass media sexual health campaigns targeting young people can aim for higher recognition and recall rates than that achieved by the National Sexually Transmitted Infection Prevention Program campaign. Alternative distribution channels and message styles should be considered to increase these rates. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
Covington, Kyle; McCallum, Christine; Engelhard, Chalee; Landry, Michel D; Cook, Chad
2016-01-01
The rising cost of health professions education is well documented and a growing concern among educators; however, little is known about the implications of resource investment on student success. The objective of this study was to determine whether programs with higher National Physical Therapist Exam (NPTE) pass rates invested significantly more on programmatic resources. This observational study used data from the Commission on Accreditation in Physical Therapy Education's (CAPTE) Annual Accreditation Report including all accredited physical therapist programs from the United States who graduated physical therapist students in 2011. Resource expenditures were recorded as both raw and as an index variable (resources per student). Descriptive statistics and comparisons (using chi-square and t-tests) among programs with <100% and 100% pass rates were analyzed from 2009-2011. An ANCOVA was used to determine differences in raw resource expenditures and resource expenditures per student. There were no differences in raw resource expenditures between programs with <100% and 100% pass rates. Programs with 100% pass rates were provided more resource expenditures per student for personnel, overall budget, and core faculty. The results of this study suggest programs with 100% pass rates invested significantly more per student for selected resources.
Patterson, Paul Daniel; Moore, Charity G; Weaver, Matthew D; Buysse, Daniel J; Suffoletto, Brian P; Callaway, Clifton W; Yealy, Donald M
2014-06-21
Mental and physical fatigue while at work is common among emergency medical services (EMS) shift workers. Extended shifts (for example 24 hours) and excessive amounts of overtime work increase the likelihood of negative safety outcomes and pose a challenge for EMS fatigue-risk management. Text message-based interventions are a potentially high-impact, low-cost platform for sleep and fatigue assessment and distributing information to workers at risk of negative safety outcomes related to sleep behaviors and fatigue. We will conduct a pilot randomized trial with a convenience sample of adult EMS workers recruited from across the United States using a single study website. Participants will be allocated to one of two possible arms for a 90-day study period. The intervention arm will involve text message assessments of sleepiness, fatigue, and difficulty with concentration at the beginning, during, and end of scheduled shifts. Intervention subjects reporting high levels of sleepiness or fatigue will receive one of four randomly selected intervention messages promoting behavior change during shiftwork. Control subjects will receive assessment only text messages. We aim to determine the performance characteristics of a text messaging tool for the delivery of a sleep and fatigue intervention. We seek to determine if a text messaging program with tailored intervention messages is effective at reducing perceived sleepiness and/or fatigue among emergency medicine clinician shift workers. Additional aims include testing whether a theory-based behavioral intervention, delivered by text message, changes 'alertness behaviors'. The SleepTrackTXT pilot trial could provide evidence of compliance and effectiveness that would support rapid widespread expansion in one of two forms: 1) a stand-alone program in the form of a tailored/individualized sleep monitoring and fatigue reduction support service for EMS workers; or 2) an add-on to a multi-component fatigue risk management program led and maintained by employers or by safety and risk management services. Clinicaltrials.gov NCT02063737, Registered on 10 January 2014.
2014-01-01
Background Mental and physical fatigue while at work is common among emergency medical services (EMS) shift workers. Extended shifts (for example 24 hours) and excessive amounts of overtime work increase the likelihood of negative safety outcomes and pose a challenge for EMS fatigue-risk management. Text message-based interventions are a potentially high-impact, low-cost platform for sleep and fatigue assessment and distributing information to workers at risk of negative safety outcomes related to sleep behaviors and fatigue. Methods/Design We will conduct a pilot randomized trial with a convenience sample of adult EMS workers recruited from across the United States using a single study website. Participants will be allocated to one of two possible arms for a 90-day study period. The intervention arm will involve text message assessments of sleepiness, fatigue, and difficulty with concentration at the beginning, during, and end of scheduled shifts. Intervention subjects reporting high levels of sleepiness or fatigue will receive one of four randomly selected intervention messages promoting behavior change during shiftwork. Control subjects will receive assessment only text messages. We aim to determine the performance characteristics of a text messaging tool for the delivery of a sleep and fatigue intervention. We seek to determine if a text messaging program with tailored intervention messages is effective at reducing perceived sleepiness and/or fatigue among emergency medicine clinician shift workers. Additional aims include testing whether a theory-based behavioral intervention, delivered by text message, changes ‘alertness behaviors’. Discussion The SleepTrackTXT pilot trial could provide evidence of compliance and effectiveness that would support rapid widespread expansion in one of two forms: 1) a stand-alone program in the form of a tailored/individualized sleep monitoring and fatigue reduction support service for EMS workers; or 2) an add-on to a multi-component fatigue risk management program led and maintained by employers or by safety and risk management services. Trial Registration Clinicaltrials.gov NCT02063737, Registered on 10 January 2014 PMID:24952387
Li, Ye; Wang, Wei; van Velthoven, Michelle Helena; Chen, Li; Car, Josip; Rudan, Igor; Zhang, Yanfeng; Wu, Qiong; Du, Xiaozhen; Scherpbier, Robert W
2013-12-04
An effective data collection method is crucial for high quality monitoring of health interventions. The traditional face-to-face data collection method is labor intensive, expensive, and time consuming. With the rapid increase of mobile phone subscribers, text messaging has the potential to be used for evaluation of population health interventions in rural China. The objective of this study was to explore the feasibility of using text messaging as a data collection tool to monitor an infant feeding intervention program. Participants were caregivers of children aged 0 to 23 months in rural China who participated in an infant feeding health education program. We used the test-retest method. First, we collected data with a text messaging survey and then with a face-to-face survey for 2 periods of 3 days. We compared the response rate, data agreement, costs, and participants' acceptability of the two methods. Also, we interviewed participants to explore their reasons for not responding to the text messages and the reasons for disagreement in the two methods. In addition, we evaluated the most appropriate time during the day for sending text messages. We included 258 participants; 99 (38.4%) participated in the text messaging survey and 177 (68.6%) in the face-to-face survey. Compared with the face-to-face survey, the text messaging survey had much lower response rates to at least one question (38.4% vs 68.6%) and to all 7 questions (27.9% vs 67.4%) with moderate data agreement (most kappa values between .5 and .75, the intraclass correlation coefficients between .53 to .72). Participants who took part in both surveys gave the same acceptability rating for both methods (median 4.0 for both on a 5-point scale, 1=disliked very much and 5=liked very much). The costs per questionnaire for the text messaging method were much lower than the costs for the face-to-face method: ¥19.7 (US $3.13) versus ¥33.9 (US $5.39) for all questionnaires, and ¥27.1 (US $4.31) versus ¥34.4 (US $5.47) for completed questionnaires. The main reasons for not replying were that participants did not receive text messages, they were too busy to reply, or they did not see text messages in time. The main reasons for disagreement in responses were that participants forgot their answers in the text messaging survey and that they changed their minds. We found that participants were more likely to reply to text messages immediately during 2 time periods: 8 AM to 3 PM and 8 PM to 9 PM. The text messaging method had reasonable data agreement and low cost, but a low response rate. Further research is needed to evaluate effectiveness of measures that can increase the response rate, especially in collecting longitudinal data by text messaging.
van Velthoven, Michelle Helena; Chen, Li; Car, Josip; Rudan, Igor; Wu, Qiong; Du, Xiaozhen; Scherpbier, Robert W
2013-01-01
Background An effective data collection method is crucial for high quality monitoring of health interventions. The traditional face-to-face data collection method is labor intensive, expensive, and time consuming. With the rapid increase of mobile phone subscribers, text messaging has the potential to be used for evaluation of population health interventions in rural China. Objective The objective of this study was to explore the feasibility of using text messaging as a data collection tool to monitor an infant feeding intervention program. Methods Participants were caregivers of children aged 0 to 23 months in rural China who participated in an infant feeding health education program. We used the test-retest method. First, we collected data with a text messaging survey and then with a face-to-face survey for 2 periods of 3 days. We compared the response rate, data agreement, costs, and participants’ acceptability of the two methods. Also, we interviewed participants to explore their reasons for not responding to the text messages and the reasons for disagreement in the two methods. In addition, we evaluated the most appropriate time during the day for sending text messages. Results We included 258 participants; 99 (38.4%) participated in the text messaging survey and 177 (68.6%) in the face-to-face survey. Compared with the face-to-face survey, the text messaging survey had much lower response rates to at least one question (38.4% vs 68.6%) and to all 7 questions (27.9% vs 67.4%) with moderate data agreement (most kappa values between .5 and .75, the intraclass correlation coefficients between .53 to .72). Participants who took part in both surveys gave the same acceptability rating for both methods (median 4.0 for both on a 5-point scale, 1=disliked very much and 5=liked very much). The costs per questionnaire for the text messaging method were much lower than the costs for the face-to-face method: ¥19.7 (US $3.13) versus ¥33.9 (US $5.39) for all questionnaires, and ¥27.1 (US $4.31) versus ¥34.4 (US $5.47) for completed questionnaires. The main reasons for not replying were that participants did not receive text messages, they were too busy to reply, or they did not see text messages in time. The main reasons for disagreement in responses were that participants forgot their answers in the text messaging survey and that they changed their minds. We found that participants were more likely to reply to text messages immediately during 2 time periods: 8 AM to 3 PM and 8 PM to 9 PM. Conclusions The text messaging method had reasonable data agreement and low cost, but a low response rate. Further research is needed to evaluate effectiveness of measures that can increase the response rate, especially in collecting longitudinal data by text messaging. PMID:24305514
Distributed Processor/Memory Architectures Design Program
1975-02-01
Event Scheduling Plo 31 Globat LAl Message Input Event Sicheduling Fhou ..... ............... 106 32 It tc Iata Representation...298 138 GEX LEX Scheduling Phlmophy ....... ...................... 300 139 Executive Comirol Herarchy... Scheduler Subroutine lnterrelatiomhips . ..... ................. 312 145 Task Scheduler Message Scatuer. . ...... ....................... 315 146
Oh, Sohee; Steinhubl, Steven; Kim, Sohye; Bae, Woo Kyung; Han, Jong Soo; Kim, Jeong-Hyun; Lee, Keehyuck; Kim, Mi Jin
2015-01-01
Background Worksite nutrition and physical activity interventions are important to help overweight and obese employees lose weight, but costs and insufficient sustained motivation prevent the majority of these programs from succeeding. Tailored text messaging in aiding weight management has been effective in several studies, but no studies have evaluated the effect of a tailored text message service on weight loss in a worksite health promotion program. Objective We studied the efficacy of a tailored text-messaging intervention for obese male participants in a worksite weight loss program of 6 months duration. Methods The study was an unblinded, randomized controlled trial. Men with a body mass index greater than 25 kg/m2 were recruited from the Korea District Heating Corporation, the Korea Expressway Corporation, and the Korea Gas Corporation. The participants were identified by nurse managers. Participants were randomly allocated to 1 of the following 2 groups for 24 weeks: (1) intervention group, which received tailored text message reminders every other day plus 4 offline education sessions and brief counseling with monthly weight check by nurses for weight control over 6 months and (2) control group, which received the 4 offline education sessions and brief counseling with monthly weight check by nurses about weight control over 6 months. The primary outcome was the difference in weight loss at 6 months. A mixed-model repeated-measures analysis was performed to evaluate the effect of the intervention group’s weight loss compared with the control group. Results A total of 205 obese men were randomized into either the intervention (n=104) or the control group (n=101). At the end of 6 months, the intervention group (n=63) had lost 1.71 kg (95% CI –2.53 to –0.88) and the control group (n=59) had lost 1.56 kg (95% CI –2.45 to –0.66); the difference between the 2 groups was not significant (mean difference –0.15, 95% CI –1.36 to 1.07). At the end of the study, 60% (34/57) of the intervention group rated the message program as helpful for weight control and 46% (26/57) would recommend the text message service to their friends. Conclusions Tailored text message reminders did not have a significant effect on weight loss in obese men as part of a worksite weight loss program. Trial Registration International Standard Randomized Controlled Trial Number (ISRCTN): 39629189; http://www.isrctn.com/ISRCTN39629189?q=39629189&filters=&sort=&offset=1&totalResults=1&page=1&pageSize=10&searchType=basic-search (Archived by WebCite at http://www.webcitation.org/6VsFkwJH6). PMID:25648325
Tuning collective communication for Partitioned Global Address Space programming models
Nishtala, Rajesh; Zheng, Yili; Hargrove, Paul H.; ...
2011-06-12
Partitioned Global Address Space (PGAS) languages offer programmers the convenience of a shared memory programming style combined with locality control necessary to run on large-scale distributed memory systems. Even within a PGAS language programmers often need to perform global communication operations such as broadcasts or reductions, which are best performed as collective operations in which a group of threads work together to perform the operation. In this study we consider the problem of implementing collective communication within PGAS languages and explore some of the design trade-offs in both the interface and implementation. In particular, PGAS collectives have semantic issues thatmore » are different than in send–receive style message passing programs, and different implementation approaches that take advantage of the one-sided communication style in these languages. We present an implementation framework for PGAS collectives as part of the GASNet communication layer, which supports shared memory, distributed memory and hybrids. The framework supports a broad set of algorithms for each collective, over which the implementation may be automatically tuned. In conclusion, we demonstrate the benefit of optimized GASNet collectives using application benchmarks written in UPC, and demonstrate that the GASNet collectives can deliver scalable performance on a variety of state-of-the-art parallel machines including a Cray XT4, an IBM BlueGene/P, and a Sun Constellation system with InfiniBand interconnect.« less
NavP: Structured and Multithreaded Distributed Parallel Programming
NASA Technical Reports Server (NTRS)
Pan, Lei
2007-01-01
We present Navigational Programming (NavP) -- a distributed parallel programming methodology based on the principles of migrating computations and multithreading. The four major steps of NavP are: (1) Distribute the data using the data communication pattern in a given algorithm; (2) Insert navigational commands for the computation to migrate and follow large-sized distributed data; (3) Cut the sequential migrating thread and construct a mobile pipeline; and (4) Loop back for refinement. NavP is significantly different from the current prevailing Message Passing (MP) approach. The advantages of NavP include: (1) NavP is structured distributed programming and it does not change the code structure of an original algorithm. This is in sharp contrast to MP as MP implementations in general do not resemble the original sequential code; (2) NavP implementations are always competitive with the best MPI implementations in terms of performance. Approaches such as DSM or HPF have failed to deliver satisfying performance as of today in contrast, even if they are relatively easy to use compared to MP; (3) NavP provides incremental parallelization, which is beyond the reach of MP; and (4) NavP is a unifying approach that allows us to exploit both fine- (multithreading on shared memory) and coarse- (pipelined tasks on distributed memory) grained parallelism. This is in contrast to the currently popular hybrid use of MP+OpenMP, which is known to be complex to use. We present experimental results that demonstrate the effectiveness of NavP.
ERIC Educational Resources Information Center
Arpan, Laura M.; Barooah, Prabir; Subramany, Rahul
2015-01-01
This study examined building occupants' responses associated with an occupant-based energy-efficiency pilot in a university building. The influence of occupants' values and norms as well as effects of two educational message frames (descriptive vs. moral norms cues) on program support were tested. Occupants' personal moral norm to conserve energy…
Kong, Jung-Hyeon; Ha, Yeongmi
2013-08-01
This study was done to identify effects of a smoking cessation program including telephone counseling and text messaging using stages of change for outpatients who have had a myocardial infarction (MI). This research was a quasi-experimental design with a nonequivalent control group pretest-posttest. The participants were 48 outpatients (experimental group=24, control group=24) recruited from one university hospital. They were randomly assigned to one of two groups: (a) an experimental group with telephone counseling (once a week) and text messaging (five times a week) using stages of change, and (b) a control group with traditional telephone counseling (once a month). Efficacy of the intervention was measured by comparing the two groups on smoking-related variables at 3 weeks and 12 weeks. At the 3-week and 12-week measurements, there were significant differences between the experimental and control groups on smoking cessation self-efficacy (p<.001), nicotine dependence (p<.001), CO levels (p<.001), and smoking cessation rates (p<.001). The results indicate that the smoking cessation program including telephone counseling and text messaging using stages of change is effective for outpatients after a MI. Further attention should be paid to the intensity of the smoking cessation program and periods for long-term follow-up.
Social capital and health: civic engagement, community size, and recall of health messages.
Viswanath, Kasisomayajula; Randolph Steele, Whitney; Finnegan, John R
2006-08-01
We explored the effects of community integration and pluralism on recall of cardiovascular disease health information messages. With 1980-1983 data from the Minnesota Heart Health Program, we examined whether ties to community groups were associated with recall of health messages, and whether this relation was modified by size and degree of differentiation of the community. A higher level of civic engagement through ties to community groups was associated with better recall of health messages. Ties to community groups independently contributed to better message recall even after control for gender, education, and other variables. The moderating role of community size was non-significant but intriguing. Community group membership could increase exposure to health messages, providing a critical pathway for social capital to influence health promotion and, thus, public health outcomes.
Give Me a Like: How HIV/AIDS Nonprofit Organizations Can Engage Their Audience on Facebook.
Huang, Yu-Chao; Lin, Yi-Pin; Saxton, Gregory D
2016-12-01
With the rapid proliferation and adoption of social media among healthcare professionals and organizations, social media-based HIV/AIDS intervention programs have become increasingly popular. However, the question of the effectiveness of the HIV/AIDS messages disseminated on social media has received scant attention in the literature. The current study applies content analysis to examine the relationship between Facebook messaging strategies employed by 110 HIV/AIDS nonprofit organizations and audience reactions in the form of liking, commenting, and sharing behavior. The results reveal that HIV/AIDS nonprofit organizations often use informational messages as one-way communication with their audience instead of dialogic interactions. Some specific types of messages, such as medication-focused messages, engender better audience engagement; in contrast, event-related messages and call-to-action messages appear to translate into lower corresponding audience reactions. The findings provide guidance to HIV/AIDS organizations in developing effective social media communication strategies.
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.
The amplification of risk in experimental diffusion chains.
Moussaïd, Mehdi; Brighton, Henry; Gaissmaier, Wolfgang
2015-05-05
Understanding how people form and revise their perception of risk is central to designing efficient risk communication methods, eliciting risk awareness, and avoiding unnecessary anxiety among the public. However, public responses to hazardous events such as climate change, contagious outbreaks, and terrorist threats are complex and difficult-to-anticipate phenomena. Although many psychological factors influencing risk perception have been identified in the past, it remains unclear how perceptions of risk change when propagated from one person to another and what impact the repeated social transmission of perceived risk has at the population scale. Here, we study the social dynamics of risk perception by analyzing how messages detailing the benefits and harms of a controversial antibacterial agent undergo change when passed from one person to the next in 10-subject experimental diffusion chains. Our analyses show that when messages are propagated through the diffusion chains, they tend to become shorter, gradually inaccurate, and increasingly dissimilar between chains. In contrast, the perception of risk is propagated with higher fidelity due to participants manipulating messages to fit their preconceptions, thereby influencing the judgments of subsequent participants. Computer simulations implementing this simple influence mechanism show that small judgment biases tend to become more extreme, even when the injected message contradicts preconceived risk judgments. Our results provide quantitative insights into the social amplification of risk perception, and can help policy makers better anticipate and manage the public response to emerging threats.
The amplification of risk in experimental diffusion chains
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
Mercken, Liesbeth; Candel, Math; de Vries, Hein; Oenema, Anke
2015-01-01
Background Smoking prevalence rates among Dutch children increase rapidly after they transit to secondary school, in particular among children with a low socioeconomic status (SES). Web-based, computer-tailored programs supplemented with prompt messages may be able to empower children to prevent them from starting to smoke when they transit to secondary school. Objective The main aim of this study is to evaluate whether computer-tailored feedback messages, with and without prompt messages, are effective in decreasing children’s smoking intentions and smoking behavior after 12 and 25 months of follow-up. Methods Data were gathered at baseline (T0), and after 12 months (T1) and 25 months (T2) of follow-up of a smoking prevention intervention program called Fun without Smokes. A total of 162 schools were randomly allocated to a no-intervention control group, an intervention prompt group, or an intervention no-prompt group. A total of 3213 children aged 10 to 12 years old participated in the study and completed a Web-based questionnaire assessing their smoking intention, smoking behavior, and sociocognitive factors, such as attitude, social influence, and self-efficacy, related to smoking. After completion, children in the intervention groups received computer-tailored feedback messages in their own email inbox and those messages could be accessed on the intervention website. Children in the prompt group received prompt messages, via email and short message service (SMS) text messaging, to stimulate them to reuse the intervention website with nonsmoking content. Multilevel logistic regression analyses were performed using multiple imputations to assess the program effects on smoking intention and smoking behavior at T1 and T2. Results A total of 3213 children participated in the Fun without Smokes study at T0. Between T0 and T1 a total of 1067 children out of the original 3213 (33.21%) dropped out of the study. Between T0 and T2 the number of children that did not participate in the final measurement was 1730 out of the original 3213 (53.84%). No significant program effects were observed for any of the intervention groups compared to the control group at T1 for the intention to engage in smoking—prompt, OR 0.67 (95% CI 0.30-1.50), no-prompt, OR 0.76 (95% CI 0.34-1.67)—or for smoking behavior—prompt, OR 1.13 (95% CI 0.13-9.98), no-prompt, OR 0.50 (95% CI 0.04-5.59). Similar nonsignificant program effects were found at T2 for the intention to start smoking—prompt, OR 0.78 (95% CI 0.26-2.32), no-prompt, OR 1.31 (95% CI 0.45-3.82)—and smoking behavior—prompt, OR 0.53 (95% CI 0.12-2.47), no-prompt, OR 1.01 (95% CI 0.24-4.21). Conclusions This study showed that the Web-based, computer-tailored feedback messages with and without prompt messages were not effective in modifying children’s smoking intentions and smoking behavior as compared to no information. Future smoking prevention interventions are recommended to start closer to the age of actual smoking uptake. Furthermore, future studies on Web-based, computer-tailored smoking prevention programs should focus on assessing and controlling exposure to the educational content and the response to the prompt messages. Trial Registration Netherlands Trial Register NTR3116; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=3116 (Archived by WebCite at http://www.webcitation.org/6O0wQYuPI). PMID:25759248
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.
Temporal Proof Methodologies for Real-Time Systems,
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