Scientific and Technical Aerospace Reports Volume 38 July 28, 2000

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set for wing tip vortex flow solutions (2.5 million grid points). It is shown that high data compression ratio can be achieved (around 50:1 ratio) in both vector and scalar data set. Author Data Compression; Image Resolution; Unstructured Grids (Mathematics); Wavelet Analysis; Computerized Simulation 20000064611 NASA Glenn Research Center, Cleveland, OH USA NPSS on NASA’s IPG: Using CORBA and Globus to Coordinate Multidisciplinary Aeroscience Applications Lopez, Isaac, NASA Glenn Research Center, USA; Follen, Gregory J., NASA Glenn Research Center, USA; Gutierrez, Richard, NASA Glenn Research Center, USA; Naiman, Cynthia G., NASA Glenn Research Center, USA; Foster, Ian, Argonne National Lab., USA; Ginsburg, Brian, Argonne National Lab., USA; Larsson, Olle, Argonne National Lab., USA; Martin, Stuart, Argonne National Lab., USA; Tuecke, Steven, Argonne National Lab., USA; Woodford, David, Argonne National Lab., USA; February 2000; In English; See also 20000064579; No Copyright; Abstract Only; Available from CASI only as part of the entire parent document Within NASA’s High Performance Computing and Communication (HPCC) program, the NASA Glenn Research Center is developing an environment for the analysis/design of aircraft engines called the Numerical Propulsion System Simulation (NPSS). The vision for NPSS is to create a ”numerical test cell” enabling full engine simulations overnight on cost-effective computing platforms. to this end, NPSS integrates multiple disciplines such as aerodynamics, structures, and heat transfer and supports ”numerical zooming” between O-dimensional to 1-, 2-, and 3-dimensional component engine codes. In order to facilitate the timely and cost-effective capture of complex physical processes, NPSS uses object-oriented technologies such as C++ objects to encapsulate individual engine components and CORBA ORBs for object communication and deployment across heterogeneous computing platforms. Recently, the HPCC program has initiated a concept called the Information Power Grid (IPG), a virtual computing environment that integrates computers and other resources at different sites. IPG implements a range of Grid services such as resource discovery, scheduling, security, instrumentation, and data access, many of which are provided by the Globus toolkit. IPG facilities have the potential to benefit NPSS considerably. For example, NPSS should in principle be able to use Grid services to discover dynamically and then co-schedule the resources required for a particular engine simulation, rather than relying on manual placement of ORBs as at present. Grid services can also be used to initiate simulation components on parallel computers (MPPs) and to address inter-site security issues that currently hinder the coupling of components across multiple sites. These considerations led NASA Glenn and Globus project personnel to formulate a collaborative project designed to evaluate whether and how benefits such as those just listed can be achieved in practice. This project involves firstly development of the basic techniques required to achieve co-existence of commodity object technologies and Grid technologies; and secondly the evaluation of these techniques in the context of NPSS-oriented challenge problems. The work on basic techniques seeks to understand how ”commodity” technologies (CORBA, DCOM, Excel, etc.) can be used in concert with specialized ”Grid” technologies (for security, MPP scheduling, etc.). In principle, this coordinated use should be straightforward because of the Globus and IPG philosophy of providing low-level Grid mechanisms that can be used to implement a wide variety of application-level programming models. (Globus technologies have previously been used to implement Grid-enabled message-passing libraries, collaborative environments, and parameter study tools, among others.) Results obtained to date are encouraging: we have successfully demonstrated a CORBA to Globus resource manager gateway that allows the use of CORBA RPCs to control submission and execution of programs on workstations and MPPs; a gateway from the CORBA Trader service to the Grid information service; and a preliminary integration of CORBA and Grid security mechanisms. The two challenge problems that we consider are the following: 1) Desktop-controlled parameter study. Here, an Excel spreadsheet is used to define and control a CFD parameter study, via a CORBA interface to a high throughput broker that runs individual cases on different IPG resources. 2) Aviation safety. Here, about 100 near real time jobs running NPSS need to be submitted, run and data returned in near real time. Evaluation will address such issues as time to port, execution time, potential scalability of simulation, and reliability of resources. The full paper will present the following information: 1. A detailed analysis of the requirements that NPSS applications place on IPG. 2. A description of the techniques used to meet these requirements via the coordinated use of CORBA and Globus. 3. A description of results obtained to date in the first two challenge problems. Author Computerized Simulation; Object-Oriented Programming; Software Engineering; Computer Systems Design; Graphical User Interface 164
20000064615 NASA Ames Research Center, Moffett Field, CA USA Performance Assessment of OVERFLOW on Distributed Computing Environment Djomehri, M. Jahed, MRJ Technology Solutions, USA; Rizk, Yehia M., NASA Ames Research Center, USA; Welcome to the NASA High Performance Computing and Communications Computational Aerosciences (CAS) Workshop 2000; February 2000; In English; See also 20000064579; No Copyright; Abstract Only; Available from CASI only as part of the entire parent document The aerodynamic computer code, OVERFLOW, with a multi-zone overset grid feature, has been parallelized to enhance its performance on distributed and shared memory paradigms. Practical application benchmarks have been set to assess the efficiency of code’s parallelism on high-performance architectures. The code’s performance has also been experimented with in the context of the distributed computing paradigm on distant computer resources using the Information Power Grid (IPG) toolkit, Globus. Two parallel versions of the code, namely OVERFLOW-MPI and -MLP, have developed around the natural coarse grained parallelism inherent in a multi-zonal domain decomposition paradigm. The algorithm invokes a strategy that forms a number of groups, each consisting of a zone, a cluster of zones and/or a partition of a large zone. Each group can be thought of as a process with one or multithreads assigned to it and that all groups run in parallel. The -MPI version of the code uses explicit message-passing based on the standard MPI library for sending and receiving interzonal boundary data across processors. The -MLP version employs no message-passing paradigm; the boundary data is transferred through the shared memory. The -MPI code is suited for both distributed and shared memory architectures, while the -MLP code can only be used on shared memory platforms. The IPG applications are implemented by the -MPI code using the Globus toolkit. While a computational task is distributed across multiple computer resources, the parallelism can be explored on each resource alone. Performance studies are achieved with some practical aerodynamic problems with complex geometries, consisting of 2.5 up to 33 million grid points and a large number of zonal blocks. The computations were executed primarily on SGI Origin 2000 multiprocessors and on the Cray T3E. OVERFLOW’s IPG applications are carried out on NASA homogeneous metacomputing machines located at three sites, Ames, Langley and Glenn. Plans for the future will exploit the distributed parallel computing capability on various homogeneous and heterogeneous resources and large scale benchmarks. Alternative IPG toolkits will be used along with sophisticated zonal grouping strategies to minimize the communication time across the computer resources. Author Algorithms; Computer Programs; Multiprocessing (Computers); Parallel Processing (Computers); Distributed Processing; Computer Systems Design; Software Engineering 20000064616 NASA Goddard Space Flight Center, Greenbelt, MD USA Performance of an Optimized Eta Model Code on the Cray T3E and a Network of PCs Kouatchou, Jules, NASA Goddard Space Flight Center, USA; Rancic, Miodrag, NASA Goddard Space Flight Center, USA; Geiger, Jim, NASA Goddard Space Flight Center, USA; February 2000; In English; See also 20000064579; No Copyright; Abstract Only; Available from CASI only as part of the entire parent document In the year 2001, NASA will launch the satellite TRIANA that will be the first Earth observing mission to provide a continuous, full disk view of the sunlit Earth. As a part of the HPCC Program at NASA GSFC, we have started a project whose objectives are to develop and implement a 3D cloud data assimilation system, by combining TRIANA measurements with model simulation, and to produce accurate statistics of global cloud coverage as an important element of the Earth’s climate. For simulation of the atmosphere within this project we are using the NCEP/NOAA operational Eta model. In order to compare TRIANA and the Eta model data on approximately the same grid without significant downscaling, the Eta model will be integrated at a resolution of about 15 km. The integration domain (from -70 to +70 deg in latitude and 150 deg in longitude) will cover most of the sunlit Earth disc and will continuously rotate around the globe following TRIANA. The cloud data assimilation is supposed to run and produce 3D clouds on a near real-time basis. Such a numerical setup and integration design is very ambitious and computationally demanding. Thus, though the Eta model code has been very carefully developed and its computational efficiency has been systematically polished during the years of operational implementation at NCEP, the current MPI version may still have problems with memory and efficiency for the TRIANA simulations. Within this work, we optimize a parallel version of the Eta model code on a Cray T3E and a network of PCs (theHIVE) in order to improve its overall efficiency. Our optimization procedure consists of introducing dynamically allocated arrays to reduce the size of static memory, and optimizing on a single processor by splitting loops to limit the number of streams. All the presented results are derived using an integration domain centered at the equator, with a size of 60 x 60 deg, and with horizontal resolutions of 1/2 and 1/3 deg, respectively. In accompanying charts we report the elapsed time, the speedup and the Mflops as a function of the number of processors for the non-optimized version of the code on the T3E and theHIVE. The large amount of communication required for model integration explains its poor performance on theHIVE. Our initial implementation of the dynamic memory allocation has contributed to about 12% reduction of memory but has introduced a 3% overhead in computing time. This overhead was removed by performing loop splitting in some of the high demanding subroutines. When the Eta code is fully optimized in order to meet the memory requirement for TRIANA simulations, a non-neglige- 165
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Scientific and Technical Aerospace
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Introduction Scientific and Technic
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Subject Divisions Table of Contents
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ground equipment and systems. For a
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Subject Categories of the Division
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48 Oceanography 139 Includes the ph
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72 Atomic and Molecular Physics 191
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Document Availability Information T
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Avail: NASA Public Document Rooms.
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NASA CASI Price Tables — Effectiv
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ALABAMA AUBURN UNIV. AT MONTGOMERY
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20000061433 Pisa Univ., Dipartiment
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English; 34th; 34th Thermophysics C
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ciency of the generated derivative
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20000063509 NASA Glenn Research Cen
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05 AIRCRAFT DESIGN, TESTING AND PER
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A long tradition of aerodynamic des
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sonic and transonic cases will be p
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20000061449 British Aerospace Publi
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20000064593 NASA Langley Research C
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performance required for a proposed
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ment cost and create better product
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tion (NPSS), is focused on the inte
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surface measurement techniques used
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with emphasis on the search for lin
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20000063520 NASA Kennedy Space Cent
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primary issues for it’s adaptatio
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Footage shows the night vertical ta
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necessary for ignition modeling, or
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engine lifetime, and high power ope
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24 COMPOSITE MATERIALS ��
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ments. For the screening of liner m
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formation of a neutral, fluorescent
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20000065655 Ames Lab., IA USA Funda
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This is a second Triennial Conferen
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of completely charged PSSNa solutio
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20000064100 NASA Langley Research C
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Spacecraft in low Earth orbit (LEO)
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Pressure gradients, i.e. pressure h
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agreed that the NO(sub x) levels co
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tectural approach to extending the
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20000064078 Physics and Electronics
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20000064925 Institute for Human Fac
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20000066607 Institute for Human Fac
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20000062455 National Inst. of Stand
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Added Analysis (Risk Reduction); 6)
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shipboard electrical power generati
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20000067664 Jet Propulsion Lab., Ca
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other, The theoretical framework go
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figures compare the lift and pitchi
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ment phase demonstrate desired feat
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esolution mode with resolving power
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to track 1% or 0.5% changes was hig
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20000067643 NASA Marshall Space Fli
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37 MECHANICAL ENGINEERING ��
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solver based on overset grid techno
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20000067659 NASA Marshall Space Fli
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20000064621 Rensselaer Polytechnic
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that for a specific example of a be
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km x 1000 km). As with the nearly c
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20000064527 Analytical Imaging and
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20000064533 Austin State Univ., Dep
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20000064539 California Univ., Inst.
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20000064547 Jet Propulsion Lab., Ca
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in Yellowstone National Park. We ar
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Page 145 and 146: 20000064912 New Energy and Industri
Page 147 and 148: and discusses the issues and resear
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Page 153 and 154: 7.6, while the 1926 events appear t
Page 155 and 156: We investigate the compositional di
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Page 159 and 160: This report presents the Applied Me
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Page 163 and 164: 51 LIFE SCIENCES (GENERAL) Includes
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Page 169 and 170: during 50% (SD 4%) of the breathing
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Page 183 and 184: 85 dB amplifier design evolved by o
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82 DOCUMENTATION AND INFORMATION SC
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ecoming almost too cumbersome to be
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physical world. These are the two p
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with WFPC2 data. Tests of HSTphot
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A brief description is given of the
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20000064070 NASA Ames Research Cent
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gas, show variations that have rema
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egy, called Power In that would all
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20000064089 Smithsonian Astrophysic
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A ABERRATION, 143, 198 ABRASION, 22
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COMPRESSIBLE FLOW, 83 COMPRESSION L
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FATIGUE (MATERIALS), 50, 93, 96 FAT
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LASING, 90 LATE STARS, 224 LATITUDE
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PATCH ANTENNAS, 74 PATHOLOGY, 98 PA
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SPACE PLATFORMS, 38 SPACE PROBES, 2
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WIND PROFILES, 137 WIND TUNNEL TEST
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Brown, Andy, 38 Brown, April S., 20
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Grosvenor, C. A., 70 Grosvenor, J.
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Lu, Gui-Ying, 50 Lugg, Desmond J.,
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Robertson, Tony, 39 Robinson, Jeffr
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Warner, J. D., 63 Warren, James, 16
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