10 research outputs found

    3rd EGEE User Forum

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    We have organized this book in a sequence of chapters, each chapter associated with an application or technical theme introduced by an overview of the contents, and a summary of the main conclusions coming from the Forum for the chapter topic. The first chapter gathers all the plenary session keynote addresses, and following this there is a sequence of chapters covering the application flavoured sessions. These are followed by chapters with the flavour of Computer Science and Grid Technology. The final chapter covers the important number of practical demonstrations and posters exhibited at the Forum. Much of the work presented has a direct link to specific areas of Science, and so we have created a Science Index, presented below. In addition, at the end of this book, we provide a complete list of the institutes and countries involved in the User Forum

    Advanced Simulation and Computing FY12-13 Implementation Plan, Volume 2, Revision 0.5

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    Development of a robot-based magnetic flux leakage inspection system

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    Surface cracking is one of the primary factors leading to failure of mechanical components. One of the most sensitive methods for surface or near surface crack detection is MFL inspection. Magnetic sensor based MFL inspection, MSI, has shown many advantageous over MPI and gives the opportunity for automated MFL inspection after its equivalent detectability to MPI is validated. A standard industrial robot is introduced and applied in this work as an automated solution for precise sensor guidance and a more accurate, flexible and efficient automatic MSI system is developed as an extension of the already existing automatic MFL inspection scheme at IZFP. Performance of the system is demonstrated by applying the system on different inspection situations of concern. The measurement results obtained validate the application of the system on the inspection.Oberflächenrisse sind eine der wichtigsten Faktoren, die zum Versagen von mechanischen Komponenten führen können. Eine der empfindlichsten Methoden für Überprüfung von Oberflächen auf Risse im Bereich der Werkstückoberfläche ist die magnetische Streuflussprüfung. Die auf dem Magnetsensor basierte magnetische Streuflussprüfung, MSI, hat viele Vorteile bei der praktischen Anwendung gegenüber MPI gezeigt und bietet die Möglichkeit zur automatisierten MFL mit dem Gegenwert der Validierung des MPI Verfahrens. In dieser Arbeit wird ein Standard-Industrieroboter vorgestellt, welcher für eine automatisierte Lösung zur Prüfungsdurchführung verwendet wird. So kann die präzise Sensorführung für ein genaues, flexibles und effizientes automatisches MSI-System gewährleistet werden. Das System dient auch als Erweiterung zu den bereits bestehenden automatischen MFL Prüfsystem besteht. Schließlich wird die Leistungsfähigkeit des Gesamtsystems durch die Anwendungen in unterschiedlichen Prüfsituationen demonstriert. Die erhaltenen Prüfergebnisse bestätigen die Anwendung des Systems als Grundlage für unterschiedliche Prüfaufgaben im mechanisierten Prüfbetrieb auch im Produktionsprozeß

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

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    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

    Numerical Study of Plasma-Assisted Aerodynamic Control for Hypersonic Vehicles.

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    Plasma actuators and various forms of volumetric energy deposition have received a good deal of research attention recently as a means of hypersonic flight control. Ground-based and flight experiments are extremely expensive and potentially dangerous, thus creating a need for computational tools capable of quickly and accurately modeling these devices and their effects on the flow-field. This thesis addresses these limitations by developing and incorporating several new features into an existing parallelized three-dimensional flow solver to accurately account for electromagnetic effects. A phenomenological heating model is developed and coupled to the fluid solver to investigate whether a practical level of pitch moment control can be achieved from volumetric energy deposition for a representative hypersonic vehicle. The results imply that the shape of the deposition volume does not have a significant effect on the flow structure, whereas the amount of energy deposited greatly influences the flow-field. The results suggest that these systems could be potential replacements for traditional mechanical flaps. While the phenomenological heating model sufficiently characterizes the downstream flow properties, it is a highly simplified physical model. To improve the physical fidelity and accuracy in the near-field, a three-dimensional magnetohydrodynamics (MHD) solver is developed and coupled to the fluid solver. This solver accurately computes the current density and electric field, and accounts for their effects on the flow-field. A particularly important parameter in the MHD solver is the electrical conductivity. Although several semi-empirical models exist in the literature, none provide generality across different flight regimes and gas compositions. Boltzmann's equation provides the necessary generality, but directly coupling a Boltzmann solver to a fluid solver is computationally prohibitive, even for a modern, multi-processor computing facility. A surrogate model of solutions to Boltzmann's equation is developed and coupled to the fluid solver to provide the accuracy and generality of the Boltzmann solver without the computational expense. With this accurate electrical conductivity module, the coupled MHD-fluid solver is used to investigate the effectiveness of a MHD-heat shield, a device that uses a magnet positioned near the bow of the vehicle to reduce the amount of heat transferred to the vehicle.Ph.D.Aerospace EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/75939/1/nbisek_1.pd

    Proceedings of the 8th Cologne-Twente Workshop on Graphs and Combinatorial Optimization

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    International audienceThe Cologne-Twente Workshop (CTW) on Graphs and Combinatorial Optimization started off as a series of workshops organized bi-annually by either Köln University or Twente University. As its importance grew over time, it re-centered its geographical focus by including northern Italy (CTW04 in Menaggio, on the lake Como and CTW08 in Gargnano, on the Garda lake). This year, CTW (in its eighth edition) will be staged in France for the first time: more precisely in the heart of Paris, at the Conservatoire National d’Arts et Métiers (CNAM), between 2nd and 4th June 2009, by a mixed organizing committee with members from LIX, Ecole Polytechnique and CEDRIC, CNAM

    Planetary Science Vision 2050 Workshop : February 27–28 and March 1, 2017, Washington, DC

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    This workshop is meant to provide NASA’s Planetary Science Division with a very long-range vision of what planetary science may look like in the future.Organizer, Lunar and Planetary Institute ; Conveners, James Green, NASA Planetary Science Division, Doris Daou, NASA Planetary Science Division ; Science Organizing Committee, Stephen Mackwell, Universities Space Research Association [and 14 others]PARTIAL CONTENTS: Exploration Missions to the Kuiper Belt and Oort Cloud--Future Mercury Exploration: Unique Science Opportunities from Our Solar System’s Innermost Planet--A Vision for Ice Giant Exploration--BAOBAB (Big and Outrageously Bold Asteroid Belt) Project--Asteroid Studies: A 35-Year Forecast--Sampling the Solar System: The Next Level of Understanding--A Ground Truth-Based Approach to Future Solar System Origins Research--Isotope Geochemistry for Comparative Planetology of Exoplanets--The Moon as a Laboratory for Biological Contamination Research--“Be Careful What You Wish For:” The Scientific, Practical, and Cultural Implications of Discovering Life in Our Solar System--The Importance of Particle Induced X-Ray Emission (PIXE) Analysis and Imaging to the Search for Life on the Ocean Worlds--Follow the (Outer Solar System) Water: Program Options to Explore Ocean Worlds--Analogies Among Current and Future Life Detection Missions and the Pharmaceutical/ Biomedical Industries--On Neuromorphic Architectures for Efficient, Robust, and Adaptable Autonomy in Life Detection and Other Deep Space Missions

    GSI Scientific Report 2009 [GSI Report 2010-1]

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    Displacement design response spectrum is an essential component for the currently-developing displacement-based seismic design and assessment procedures. This paper proposes a new and simple method for constructing displacement design response spectra on soft soil sites. The method takes into account modifications of the seismic waves by the soil layers, giving due considerations to factors such as the level of bedrock shaking, material non-linearity, seismic impedance contrast at the interface between soil and bedrock, and plasticity of the soil layers. The model is particularly suited to applications in regions with a paucity of recorded strong ground motion data, from which empirical models cannot be reliably developed
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