2009 DoD High Performance Computing Modernization Program Users Group Conference最新文献

{"title":"A Migration-Based Parallel Programming Model with Architectural Support Structures","authors":"Megan Vance","doi":"10.1109/HPCMP-UGC.2009.77","DOIUrl":"https://doi.org/10.1109/HPCMP-UGC.2009.77","url":null,"abstract":"This paper introduces a new parallel programming model motivated by: 1) the concept that computation should move to, and execute near, the global data which it accesses, 2) a set of extended memory semantics to provide fine-grained global synchronization, 3) architectural support for fast lightweight thread creation/destruction/migration, and 4) the need for a high performance language to provide the programmer with transparency to the generated code while protecting them from making low-level errors. Using pseudocode examples, we compare this new model to several other high performance languages: Chapel, Fortress, and UPC, in terms of 1) expressibility of parallel structures, 2) facility in synchronizing communication to avoid race conditions, and 3) ability to diagnose/resolve possible performance issues that result from the mapping of these structures to hardware and system software. The new model, combined with appropriate architectural support, provides equal potential for expressibility and safety while giving the programmer more direct insight into the code that ultimately executes.","PeriodicalId":268639,"journal":{"name":"2009 DoD High Performance Computing Modernization Program Users Group Conference","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116964057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Implicit LES Computations with Applications to Micro Air Vehicles","authors":"R. Gordnier, M. Visbal","doi":"10.1109/HPCMP-UGC.2009.16","DOIUrl":"https://doi.org/10.1109/HPCMP-UGC.2009.16","url":null,"abstract":"Implicit large eddy simulation (ILES) computations have been performed for canonical model problems associated with flexible, flapping-wing micro air vehicles. This computationally intensive approach, which is able to directly model laminar/transitional/turbulent flowfields, requires the use of the best high performance computational platforms available. Computations are first performed for an SD7003 airfoil section at ? o=4° plunging with reduced frequency k=3.93 and amplitude ho=0.05. For Rec=4×104, the dynamic-stall vortex system is laminar at inception, but experiences an abrupt breakdown associated with the onset of spanwise instability effects. The aerodynamics solver is then coupled with a nonlinear finite element solver to compute the flow over a flexible membrane wing. A description of the unsteady fluid/structure interaction for ?=14° is presented indicating a close coupling between the unsteady flow behavior and the structural response. Good agreement of the computed results with available experimental measurements is shown for both problems considered.","PeriodicalId":268639,"journal":{"name":"2009 DoD High Performance Computing Modernization Program Users Group Conference","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126587019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SSH-Enabled ParaView","authors":"Joel P. Martin, R. Vickery, S. Ziegeler, Richard C. Angelini","doi":"10.1109/HPCMP-UGC.2009.63","DOIUrl":"https://doi.org/10.1109/HPCMP-UGC.2009.63","url":null,"abstract":"ParaView is a very powerful visualization tool used by many in the Department of Defense (DoD) high performance computing (HPC) community. It is both fast and flexible. It performs well on a user’s desktop, but it can also scale to take advantage of clusters and large shared memory machines. Recently, ParaView has been adapted to run on the Linux clusters at the US Army Research Laboratory DoD Supercomputing Resource Center (ARL DSRC) using the Load Sharing Facility (LSF) batch queues. This method makes heavy use of Secure Shell (SSH) port forwarding to move data between the cluster nodes and the user’s desktop. The method is fast, convenient, and secure. Unfortunately, not everyone can use SSH port forwarding. For example, some users may not have access to servers that allow port-forwarded traffic. Also, there are users that are specifically banned from initiating a port forward from their desktop. To solve this problem, we have developed a version of ParaView that does not use TCP/IP sockets between the client and the server. Instead, the data is passed through the SSH standard in/out. If the user wishes to use a batch queue, a helper script handles the communication between the login node and the nodes that are allocated to the user. This paper describes the implementation of an SSHenabled ParaView. It then empirically compares our version to various other methods of running ParaView in the DoD HPC environment. Finally, it helps guide HPC users to determine the method that best fits their needs. This work benefits the DoD HPC community by making ParaView client/server available to users that have been previously unable to use it.","PeriodicalId":268639,"journal":{"name":"2009 DoD High Performance Computing Modernization Program Users Group Conference","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115319654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three-Dimensional Computation of Focused Beam Propagation through Multiple Biological Cells","authors":"M. Starosta, A. Dunn, R. Thomas","doi":"10.1117/12.809433","DOIUrl":"https://doi.org/10.1117/12.809433","url":null,"abstract":"A massively parallel finite difference time domain method was used to compute scattering of a focused optical beam by multiple heterogeneous biological cells. A perfectly matched layer boundary condition and the scattered-field-only method were utilized in the simulation to increase accuracy and computational efficiency. A fifth-order approximation to the focused Gaussian beam was used for the incident field. A parametric study was performed to determine scattering effects of varying cellular fine structure, such as nuclear refractive index, organelle volume density, cellular shape and the cell membrane on the point spread function (PSF) of the beam. It was found that two-photon PSF is largely unaffected by increasing numbers of scatterers within cells, while two-photon excitation signal strength is dependent on both beam focal depth and the density of scatterers in tissue.","PeriodicalId":268639,"journal":{"name":"2009 DoD High Performance Computing Modernization Program Users Group Conference","volume":"2011 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114745712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Virtual Prototyping of Directed Energy Weapons","authors":"M. Bettencourt, K. Cartwright, T. Fleming, A. Greenwood, J. Keisling, M. Lambrecht, N. Lockwood, P. Mardahl","doi":"10.1109/DOD.HPCMP.UGC.2008.34","DOIUrl":"https://doi.org/10.1109/DOD.HPCMP.UGC.2008.34","url":null,"abstract":"This paper reports on RF sources that have been virtually prototyped with the Improved Concurrent Electromagnetic Particle-in-Cell (ICEPIC) code. ICEPIC simulates from first principles (Maxwell’s equations and Lorenz’s force law) the electrodynamics and charged particle dynamics of the RF-producing part of the system. Our simulations focus on two classes of Lband sources: giga-watt, 100ns length pulse sources and 100s of kilo-watt long pulse sources (>100 milliseconds). Such simulations require enormous computational resources. These simulations successfully expose undesirable features of these sources and help us to suggest improvements.","PeriodicalId":268639,"journal":{"name":"2009 DoD High Performance Computing Modernization Program Users Group Conference","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126239743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct Quantum Mechanical Simulations of Shocked Energetic Materials Supporting Future Force Insensitive Munitions (IM) Requirements","authors":"W. Mattson, R. Balu, B. Rice","doi":"10.1109/DOD.HPCMP.UGC.2008.11","DOIUrl":"https://doi.org/10.1109/DOD.HPCMP.UGC.2008.11","url":null,"abstract":"Quantum mechanical calculations based on Density Functional Theory (DFT) are used to study dynamic behavior of shocked energetic materials. In this work, we present results of quantum molecular dynamics simulations of shocked pentaerythritol tetranitrate, a conventional high explosive, and the polymeric cubic gauche phase of nitrogen (cg-N), proposed as an environmentally acceptable energetic alternative to conventional explosive formulations. All calculations are performed with the DFT code CP2K. These simulations represent the leading edge of DFT simulation in both system size and simulation time with over 4,000 atoms and up to ten thousand time steps utilizing as many as 512 processors per run.","PeriodicalId":268639,"journal":{"name":"2009 DoD High Performance Computing Modernization Program Users Group Conference","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123435726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated Analysis of Scramjet Flowpath with Innovative Inlets","authors":"D. Gaitonde, H. Ebrahimi","doi":"10.1109/HPCMP-UGC.2007.44","DOIUrl":"https://doi.org/10.1109/HPCMP-UGC.2007.44","url":null,"abstract":"An overview is presented of fundamental and practical insights obtained on scramjet flowpaths during a three year Challenge Project utilizing high fidelity methodologies and advanced post-processing techniques. Simulations are employed to analyze the principal phenomena, including inlet distortion, fuel-air mixing, ignition and thrust generation at freestream Mach numbers between 6 and 8. In addition to guiding the evolution and execution of high-speed ground and flight experiments, the discovery objective of the project identifies trends and suggests optimization strategies for rapid response and kinetic kill hypersonic vehicles. Three inlet designs are considered, including the traditional rectangular cross-section configuration and two streamline traced variants denoted Scoop and Jaws, each attached to a corresponding cavity-based flame-holding combustor. The simulations reveal the characteristic distortion signature of each design. Parametric analyses provide insight into major performance issues, including the effects of distortion on combustion, injector port configurations and gaseous versus liquid (multi-phase) injection of simple and complex fuels. Some results are consistent with intuition: for example, streamwisestaggered and spanwise-interlaced injectors enhance diffusive mixing. Other findings are not intuitive and point to competing constraints. Injection strategies that enhance cavity circulation, or disturb the shear layer emanating from the step are superior. Numerical issues are also explored to understand the effect of chemistry model fidelity (frozen versus finite-rate kinetics of increasing complexity) and turbulence closure (Reynolds-Averaged Navier-Stokes and Large-Eddy Simulation [LES]). Small scales resolved with the superior LES method are essential in understanding the unsteady shock dynamics and ignition delay time.","PeriodicalId":268639,"journal":{"name":"2009 DoD High Performance Computing Modernization Program Users Group Conference","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132665599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of Energetic Ionic Liquids","authors":"J. Boatz, G. Voth, M. Gordon, S. Hammes‐Schiffer","doi":"10.1109/DOD.HPCMP.UGC.2008.57","DOIUrl":"https://doi.org/10.1109/DOD.HPCMP.UGC.2008.57","url":null,"abstract":"An essential need of the US Air Force is the discovery, development, and fielding of new, energetic materials for advanced chemical propulsion in space and missile applications. Some of the key factors driving the requirement for new chemical propellants include: (a) improved performance in terms of increased specific impulse and density, (b) reduced sensitivity to external stimuli such as impact, friction, shock, and electrostatic discharge, and (c) mitigation of environmental and toxicological hazards (and the resulting costs) associated with currently used propellants. A class of compounds, which can potentially meet these requirements is known as ionic liquids (ILs), which are chemical salts with unusually low melting points. The physical and chemical properties of ILs render them useful for many purposes, most notably as environmentally benign (“green”) solvents/reaction media but also as catalysts, electrolytes, etc. From a Department of Defense (DoD) perspective, ILs are being explored as new propellants, explosives, and munitions. The Air Force, in particular, is interested in ILs as potential replacements for currently used monopropellants such as hydrazine—which is carcinogenic, highly toxic, and has relatively modest performance characteristics. In contrast, many ILs have superior densities and specific impulses as well as significantly reduced sensitivity and toxicity characteristics. Furthermore, their properties can be carefully tuned via the choice of the component ions. The overall objective of the Design of Energetic Ionic Liquids Challenge Project is to address several key technical issues and challenges associated with the characterization, design, and development of ILs as new monopropellants. Among these, for example, are a fundamental understanding of the (in)stability of ILs, the intrinsic nature of the short- and long-range structure and interactions between the component ions, and identification of the key steps in the initial stages of decomposition and combustion. A hierarchy of computational approaches is employed, including atomistic, high-level quantum chemical methods applied to individual ions and ion clusters, condensed phase atomistic molecular dynamics simulations utilizing polarizable force fields, and mesoscale-level simulations of bulk ionic liquids based upon multiscale coarse graining techniques.","PeriodicalId":268639,"journal":{"name":"2009 DoD High Performance Computing Modernization Program Users Group Conference","volume":"125 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132248211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polynitrogen/Nanoaluminum Surface Interactions","authors":"J. A. Boatz, D. Sorescu","doi":"10.1109/HPCMP-UGC.2007.60","DOIUrl":"https://doi.org/10.1109/HPCMP-UGC.2007.60","url":null,"abstract":"First-principles density functional theory (DFT) calculations using the generalized gradient approximation (GGA) have been used to expand the analysis of the adsorption properties of polynitrogen and high nitrogen compounds on Al(111) and AlN(0001) surfaces. The electron-ion interaction has been described using ultrasoft (PAW) pseudopotentials in the case of Al (AlN). All calculations have been done using the PW91 generalized gradient approximation. In the case of Al, the calculations employ periodic slab models with 4 layers, ranging in size from (4×4) to (6×6) surface unit cells, and containing up to 144 Al atoms. For AlN, slab models with (2×2) and (3×3) unit cells and with 8 and 4 dual AlN layers, respectively, have been considered. Complementary quantum chemical calculations, utilizing DFT and second-order perturbation theory methods, of the ground state potential energy surfaces of the corresponding polynitrogen/high nitrogen species in the absence of the aluminum surface also have been performed. Previous results obtained in the first two years of this Challenge Project, related to adsorption properties of all nitrogen Nx(x=1-6,8-12) compounds or of non-substituted and mono-substituted triazenes have been extended to the case of high nitrogen heterocycle systems. Specifically, we have considered representative six-membered P-N-C heterocycles containing azide ligands on the C and P atoms such as C2N15P, CN18P2 and N21P3 systems. Additionally, we extended our analysis by including compounds containing the nitrogen rich CN7 - anion (i.e., the energetic salts NH4 +CN7 -, N2H5 +CN7 -, and CN4H7 +CN7 -) and heterocyclic-based ionic systems (C2N3H4 +- NO3 -) for which direct optimizations and ab initio molecular dynamics simulations have been performed. Finally, the interaction properties of atomic and molecular oxygen and of other energetic species like nitromethane (CH3NO2) with AlN(0001) and AlN(000 1 ) surfaces have been analyzed. For these systems the individual bonding mechanism involving either nondissociative (molecular) or dissociative processes has been determined, depending on both the molecular orientation and the surface sites involved. The binding energies were found to be highly sensitive to the specific adsorbed species and its local configuration. Dissociation processes were also found to be highly exothermic.","PeriodicalId":268639,"journal":{"name":"2009 DoD High Performance Computing Modernization Program Users Group Conference","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133568086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ocean Wave Prediction Using Large-Scale Phase-Resolved Computations","authors":"Wenting Xiao, Yuming Liu, D. Yue","doi":"10.1109/HPCMP-UGC.2009.46","DOIUrl":"https://doi.org/10.1109/HPCMP-UGC.2009.46","url":null,"abstract":"A direct phase-resolved simulation tool for large-scale nonlinear ocean wavefield evolution, which is named SNOW, has been developed. Unlike the phase-averaged model, it solves the primitive Euler equation and preserves the phases of the wavefield during its nonlinear evolution. Therefore, the detailed descriptions of the free surface and the kinematics of the wavefield are obtained. To provide realistic and representative wavefields for ship motion analyses, we have computed an ensemble of three-dimensional (3D) wavefields (of typical domain size of O(103~4) km2) based on initial JONSWAP spectra. The statistical properties of the synthetic wavefields are computed and compared with theory and experimental measurements to study long-time sea spectrum evolution. SNOW simulations have been used to identify and characterize the occurrence statistics and dynamical properties of extreme wave events. We confirm that linear theory significantly under predicts the probability of large rogue wave events, especially for sea states with narrow spectra bandwidth and narrow directional spreading angle. A new phase-resolved wave prediction capability, with the incorporation of multiple hybrid (satellite/radar/lidar/wave-probe) sensed wave data as initial input, for deterministic short time O(Tp) prediction of ocean waves in deep water close to real time in a region with relatively small scale (~O(1) km×O(1) km) for a single ship handling is also developed. The validity and efficacy of SNOW in reliably predicting nonlinear ocean wavefield evolution is demonstrated and verified.","PeriodicalId":268639,"journal":{"name":"2009 DoD High Performance Computing Modernization Program Users Group Conference","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128915719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}