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Goldmann, Andrew ; Humphries, Larry L. ; Cardoni, Jeffrey ; Gauntt, Randall O.
Humphries, Larry L.
Proposed for publication in Reliability Engineering and System Safety.
Hansen, Clifford
Cardoni, Jeffrey
Littlewood, David J. ; Tikare, Veena
Denman, Matthew R. ; Ames, Arlo
%22Combustion and Flame%22
Knupp, Patrick K. ; Day, David M.
Knepper, Robert A. ; Reeves, Robert V. ; Adams, David P.
Gwinn, Kenneth W.
Burton, Andrew R.
Ward, Donald K. ; Wong, Bryan M. ; Doty, F.P. ; Zimmerman, Jonathan A. ; Cruz-Campa, Jose L. ; Nielson, Gregory N.
Cheng, Shengfeng
Mackinnon, Robert J. ; Leigh, Christi ; Hansen, Francis D.
Bixler, Nathan E.
Furnish, Michael D. ; Alexander, Charles S. ; Reinhart, William D. ; Brown, Justin L.
Briggs, Timothy ; Bryan, Gregory'
Radtke, Gregg A. ; Musson, Lawrence C. ; Cartwright, Keith
Hammond, Simon
Silling, Stewart
Olivier, Stephen L.
Olivier, Stephen L.
Proposed for publication in Proceedings of the National Academy of Sciences of the United States of America .
Boslough, Mark
Bignell, John
Bignell, John ; Jones, Christopher A. ; Pickering, Susan Y.
Tandon, Rajan
McClanahan, Richard M.
Salloum, Maher ; Gharagozloo, Patricia E. ; Shugard, Andrew D.
Sun, Waiching
Lu, Wei-Yang ; Song, Bo
Lu, Wei-Yang ; Jin, Helena
Moore, Jacqueline K.
Hill, Roger R.
Doerfler, Douglas W.
Hill, Roger R.
Littlewood, David J. ; Mish, Kyran D. ; Pierson, Kendall H.
Rajan, Mahesh ; Doerfler, Douglas W. ; Lin, Paul T. ; Hammond, Simon ; Barrett, Richard F. ; Vaughan, Courtenay T.
Proposed for publication in Human Factors: The Journal of Human Factors and Ergonomics Society.
Abbott, Robert G. ; Haass, Michael J.
Phillips, Jesse
Tewell, Craig R. ; Reyna, David R.
Mueller, Charles J.
Humphries, Larry L.
Ruffing, Anne R.
Bacon, Larry D. ; Mar, Alan ; Vigliano, David J. ; Zeek, Erik C.
Meagher, Robert M.
Leigh, Christi
Chambers, Robert S. ; Tandon, Rajan ; Stavig, Mark E. ; Antoun, Bonnie R. ; Emery, John M.
Moreland, Kenneth D.
Moreland, Kenneth D.
Von White II, Gregory ; Wichhart, Derek ; Bernstein, Robert
Heitman, Lili A.A. ; Bignell, John ; Pickering, Susan Y.
Rowland, Scott F.
Chee, Chelsea
Gallis, Michael A. ; Torczynski, John R.
Spoerke, Erik D. ; Wheeler, Jill S. ; Gough, Dara ; Bachand, George D.
Gill, Walter ; Donaldson, Burl
Reyna, David R.
Schollmeier, Marius
Phinney, Leslie ; Spletzer, Matthew ; Baker, Michael S. ; Serrano, Justin R.
Thayer, Rachel C.
Kaplar, Robert
Rouson, Damian R.
Goldmann, Andrew ; Humphries, Larry L. ; Cardoni, Jeffrey ; Gauntt, Randall O.
Timlin, Jerilyn A.
Timlin, Jerilyn A.
Erickson, Lindsay ; Noble, David R.
Allerman, A.A.
Cardoni, Jeffrey
Chen, Qiushi ; Lu, Wei-Yang
Ostien, Jakob T. ; Foulk, James W. ; Mota, Alejandro ; Chen, Qiushi ; Sun, Waiching
Sun, Waiching
Sun, Waiching ; Ostien, Jakob T.
Reeves, Robert V. ; Rodriguez, Marko A. ; Jones, Eric
Goldmann, Andrew ; Humphries, Larry L. ; Cardoni, Jeffrey ; Gauntt, Randall O.
Humphries, Larry L.
Beyeler, Walter E. ; Kelic, Andjelka ; Aamir, Munaf S.
Phillips, Jesse
Womble, David E.
Templeton, J.A.
Erikson, William W. ; Cooper, Marcia ; Hobbs, Michael L. ; Kaneshige, Michael ; Oliver, Michael S. ; Snedigar, Shane
Stockman, Christine T.
Hirschfeld, Deidre A.
Swift, Peter
Proposed for publication in Reliability Engineering and System Safety.
Swift, Peter ; Knowles, Mary K. ; Mcneish, Jerry ; Hansen, Clifford ; Mackinnon, Robert J. ; Sevougian, Stephen D.
Hill, Roger R.
Hansen, Clifford ; Luketa-Hanlin, Amanda
One year of power output was simulated at one-minute intervals for each of fourteen hypothetical utility-scale photovoltaic power plants and for the aggregate power output from a large number of distribution-connected photovoltaic systems. For utility-scale plants, the simulation first constructs one-year time series of global horizontal irradiance at one-minute intervals at each plant location, and a performance model translates irradiance and weather information to AC output power. Distribution-connected photovoltaic systems comprise a variety of system configurations: residential-scale rooftop systems at various tilts; commercial-scale flat-roof mounted systems; and commercial-scale ground-mounted tracked systems. For distribution-connected PV systems, the simulation estimates the time series of spatially-averaged irradiance for the region containing the systems, and the performance model is employed to estimate power aggregate power from all systems. The simulation results are validated by comparing statistics for the time series of irradiance with statistics for measured irradiance within the region.
Mandadapu, Kranthi K. ; Templeton, J.A. ; Lee, Jonathan W.
Littlewood, David J. ; Bignell, John ; Tikare, Veena
Proposed for publication in Journal of the Electrochemical Society.
Brennecka, Geoff ; Brumbach, Michael T. ; Apblett, Christopher A. ; Ihlefeld, Jon F. ; Small, Leo J.
Barrett, Brian ; Brightwell, Ronald B. ; Hemmert, Karl S.
Silva-Monroy, Cesar A.
Phinney, Leslie
Guildenbecher, Daniel ; Reu, P.L.
Coker, Eric N. ; Van Swol, Frank B. ; Gill, Walter ; Donaldson, Burl
Moore, Thomas ; Finley, Patrick D. ; Glass Jr., Robert J. ; Hammer, Ryan
Outkin, Alexander V.
Ratzel, Arthur C.
Bacon, Larry D. ; Walker, Michael J. ; Zeek, Erik C.
Beechem, Thomas E. ; Ohta, Taisuke
Ellis, Abraham
El Gabaly, Farid
El Gabaly, Farid
Hattar, Khalid M. ; Buchheit, Thomas E. ; Lu, Ping ; Clark, Blythe C.
Lucas, Greg ; Bixler, Nathan E. ; Lipinski, Ronald
Sullivan, John P.
Miller, Christopher H. ; Burnett, Louann C.
Burnett, Louann C.
Miller, Christopher H.
De Luna, Raul D.
Kim, Iltai
Modine, Normand A.
Clausen, Jonathan ; Roberts, Scott A.
Brewer, Jerry ; Chang, Jeannette ; Simms, Tina C. ; Kvam, Jacques K. ; Pugh, Matthew O.
McWherter-Payne, Mary A.
Boyce, Brad L.
Burnett, Louann C.
Burnett, Louann C.
Thompson, Kyle
Quintana, Enrico C. ; Thompson, Kyle
Reeves, Robert V. ; Jones, Eric ; Adams, David P.
Burnett, Louann C.
Rajasekhara, Shreyas
Proposed for publication in Modelling and Simulation in Materials Science and Engineering.
Weinberger, C.R.
Proposed for publication in Journal of Nuclear Materials.
Hattar, Khalid M.
Resnick, Paul
Reliability Engineering and System Safety
Helton, Jon C.; Hansen, Clifford ; Sallaberry, Cedric J.
Reliability Engineering and System Safety
Weirs, V.G.; Kamm, James R. ; Swiler, Laura P. ; Tarantola, Stefano; Ratto, Marco; Adams, Brian M. ; Rider, William J. ; Eldred, Michael
Sensitivity analysis is comprised of techniques to quantify the effects of the input variables on a set of outputs. In particular, sensitivity indices can be used to infer which input parameters most significantly affect the results of a computational model. With continually increasing computing power, sensitivity analysis has become an important technique by which to understand the behavior of large-scale computer simulations. Many sensitivity analysis methods rely on sampling from distributions of the inputs. Such sampling-based methods can be computationally expensive, requiring many evaluations of the simulation; in this case, the Sobol method provides an easy and accurate way to compute variance-based measures, provided a sufficient number of model evaluations are available. As an alternative, meta-modeling approaches have been devised to approximate the response surface and estimate various measures of sensitivity. In this work, we consider a variety of sensitivity analysis methods, including different sampling strategies, different meta-models, and different ways of evaluating variance-based sensitivity indices. The problem we consider is the 1-D Riemann problem. By a careful choice of inputs, discontinuous solutions are obtained, leading to discontinuous response surfaces; such surfaces can be particularly problematic for meta-modeling approaches. The goal of this study is to compare the estimated sensitivity indices with exact values and to evaluate the convergence of these estimates with increasing samples sizes and under an increasing number of meta-model evaluations. © 2011 Elsevier Ltd. All rights reserved.
EAMTA 2012 - Proceedings of the Argentine School of Micro-Nanoelectronics, Technology and Applications 2012
Hulin, Kevin J. ; Hu, Yalin
Formal verification techniques such as model checking (MC) and theorem proving (TP) have found increasingly widespread use in the design of critical digital systems as a means to ensure their functional correctness. However, both MC and TP have their limitations. TP generally requires non-trivial human intervention, and MC is limited by the state explosion problem. The situation for MC is especially daunting for systems with large data components. In these cases, it is common to rely on a model abstraction to make MC feasible. Unfortunately, this may also add inaccuracies to the verification process, rendering it invalid. In this paper, we build upon current research and propose a hybrid verification approach that leverages the automation of MC and the logical soundness of TP to build a highly automated, high confidence verification system. We perform a preliminary investigation of the effectiveness of this method by verifying a random access memory (RAM) model. We also discuss how the lessons learned in this case study can be extended and implemented in a robust verification system to verify other similar systems. © 2012 EDIUNS.
Mcconnell, Paul E. ; Maheras, Steven J.; Best, Ralph E.; Ross, Steven B.; Buxton, Kenneth A.; England, Jeffery L.
The Blue Ribbon Commission on America's Nuclear Future identified removal of stranded used nuclear fuel at shutdown sites as a priority so that these sites may be completely decommissioned and put to other beneficial uses (BRC 2012). In this report, a preliminary evaluation of removing used nuclear fuel from nine shutdown sites was conducted. The shutdown sites included Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, and Zion. At these sites a total of 7649 used nuclear fuel assemblies and a total of 2813.2 metric tons heavy metal (MTHM) of used nuclear fuel are contained in 248 storage canisters. In addition, 11 canisters containing greater-than-Class C (GTCC) low-level radioactive waste are stored at these sites.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Hoefler, Torsten; Dinan, James; Buntinas, Darius; Balaji, Pavan; Barrett, Brian W.; Brightwell, Ronald B. ; Gropp, William; Kale, Vivek; Thakur, Rajeev
Hybrid parallel programming with MPI for internode communication in conjunction with a shared-memory programming model to manage intranode parallelism has become a dominant approach to scalable parallel programming. While this model provides a great deal of flexibility and performance potential, it saddles programmers with the complexity of utilizing two parallel programming systems in the same application. We introduce an MPI-integrated shared-memory programming model that is incorporated into MPI through a small extension to the one-sided communication interface. We discuss the integration of this interface with the upcoming MPI 3.0 one-sided semantics and describe solutions for providing portable and efficient data sharing, atomic operations, and memory consistency. We describe an implementation of the new interface in the MPICH2 and Open MPI implementations and demonstrate an average performance improvement of 40% to the communication component of a five-point stencil solver. © 2012 Springer-Verlag.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Barrett, Brian W.; Brightwell, Ronald B. ; Underwood, Keith D.
Message passing paradigms provide for many to one messaging patterns that result in receive side resource exhaustion. Traditionally, MPI implementations layered over the Portals network programming interface provided a large default unexpected receive buffer space, the user was expected to configure the buffer size to the application demand, and the application was aborted when the buffer space was overrun. The Portals 4 design provides a set of primitives for implementing scalable resource exhaustion recovery without negatively impacting normal operation. A resource exhaustion recovery protocol for MPI implementations is presented, as well as performance results for an Open MPI implementation of the protocol. © 2012 Springer-Verlag.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Lofstead, Jay; Dayal, Jai
Current scientific workflows consist of generally several components either integrated in situ or as completely independent, asynchronous components using centralized storage as an interface. Neither of these approaches are likely to scale well into Exascale. Instead, separate applications and services will be launched using online communication to link these components of the scientific discovery process. Our experiences with coupling multiple, independent MPI applications, each with separate processing phases, exposes limitations preventing use of some of the optimized mechanisms within the MPI standard. In this regard, we have identified two shortcomings with current MPI implementations. First, MPI intercommunicators offer a mechanism to communicate across application boundaries, but do not address the impact this operating mode has on possible programming models for each separate application. Second, MPI-Probe offers a way to interleave both local messaging and remote messages, but has limitations as MPI-Bcast and other collective calls are not supported by MPI-Probe thus limiting use of optimize collective calls in this operating mode. © 2012 Springer-Verlag.
ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
Anderson, Hyrum S.; Parrish, Nathan; Tsukida, Kristi; Gupta, Maya R.
Early classification of time series is important in time-sensitive applications. An approach is presented for early classification using generative classifiers with the dual objectives of providing a class label as early as possible while guaranteeing with high probability that the early class matches the class that would be assigned to a longer time series. We give a specific algorithm for early quadratic discriminant analysis (QDA), and demonstrate that this classifier meets the requirement of reliable early classification. © 2012 IEEE.
ACM International Conference Proceeding Series
Sun, Weibin; Ricci, Robert; Curry, Matthew L.
Many storage systems include computationally expensive components. Examples include encryption for confidentiality, checksums for integrity, and error correcting codes for reliability. As storage systems become larger, faster, and serve more clients, the demands placed on their computational components increase and they can become performance bottlenecks. Many of these computational tasks are inherently parallel: they can be run independently for different blocks, files, or I/O requests. This makes them a good fit for GPUs, a class of processor designed specifically for high degrees of parallelism: consumer-grade GPUs have hundreds of cores and are capable of running hundreds of thousands of concurrent threads. However, because the software frameworks built for GPUs have been designed primarily for the long-running, data-intensive workloads seen in graphics or high-performance computing, they are not well-suited to the needs of storage systems. In this paper, we present GPUstore, a framework for integrating GPU computing into storage systems. GPUstore is designed to match the programming models already used these systems. We have prototyped GPUstore in the Linux kernel and demonstrate its use in three storage subsystems: file-level encryption, block-level encryption, and RAID 6 data recovery. Comparing our GPU-accelerated drivers with the mature CPU-based implementations in the Linux kernel, we show performance improvements of up to an order of magnitude. © 2012 ACM.
Proceedings of the IEEE RAS and EMBS International Conference on Biomedical Robotics and Biomechatronics
Lincoln, Lucas S.; Bamberg, Stacy J.Morris; Parsons, Erin; Salisbury, Curt M. ; Wheeler, Jason
Measurement of the ground reaction force vector is important in clinical gait analysis and biomechanics research, for example to enable inverse dynamic calculations. Instrumented insoles allow biomechanical data to be collected outside of the motion analysis laboratory in many environments. However, current insole-based approaches typically measure only the vertical component of the reaction force and the plantar center of pressure. This work describes the development and evaluation of a silicone insole capable of measuring the complete three dimensional reaction force vector. The insole is optically based and low-cost with no complex manufacturing requirements. Accuracy over five nominal gait trails is shown to be on the order of 10% of the force range, with mean errors of 10.7 N in the shear directions and 68.1 N in normal. The insole can provide a simple mobile platform that allows kinetic gait data to be collected in many environments while minimally affecting the wearer's gait. © 2012 IEEE.
Optics Letters
Biberman, Aleksandr; Shaw, Michael J.; Timurdogan, Erman; Wright, Jeremy B. ; Watts, Michael R.
We experimentally demonstrate silicon ring resonators with internal quality factors of Q0 = 2.2 × 107, corresponding to record 2.7 dB/m propagation losses. Importantly, we show that these propagation losses are limited by bend loss, indicating that the propagation loss limit for silicon has not yet been reached. © 2012 Optical Society of America.
Conference Proceedings of the Society for Experimental Mechanics Series
Reu, P.L. ; Miller, Timothy J.
Uncertainty quantification (UQ) equations have been derived for predicting matching uncertainty in two-dimensional image correlation a priori. These equations include terms that represent the image noise and image contrast. Researchers at the University of South Carolina have extended previous 1D work to calculate matching errors in 2D. These 2D equations have been coded into a Sandia National Laboratories UQ software package to predict the uncertainty for DIC images. This paper presents those equations and the resulting error surfaces for trial speckle images. Comparison of the UQ results with experimentally subpixel-shifted images is also discussed. ©2010 Society for Experimental Mechanics Inc.
Macromolecules
Hall, Lisa M.; Stevens, Mark J. ; Frischknecht, Amalie L.
Ion-containing polymers have potential as single-ion conducting battery electrolyte materials. Their conductivity is often too low for such applications due to the low dielectric polymer backbone and resulting strong aggregation of ions. We simulate coarse-grained ionomer melts (with explicit counterions) of various polymer architectures to understand the effect of polymer connectivity on the dynamics. We report on the polymer and counterion dynamics as a function of periodically or randomly spaced charged groups, which can be placed in the backbone or pendant to it. The spacer length is also varied. The simulations reveal the mechanism of ion transport, the coupling between counterion and polymer dynamics, and the dependence of the ion dynamics on polymer architecture. Within the ionic aggregrates, ion dynamics is rather fluid and relatively fast. The larger scale dynamics (time and length) depends strongly on the large scale morphology of the ionomer. Systems with percolated clusters have faster counterion diffusion than systems with isolated clusters. In the systems with isolated clusters counterions diffuse through the combination, rearrangement, and separation of neighboring clusters. In this process, counterions move from one cluster to another without ever being separated from a cluster. In percolated systems, the counterions can move similarly without the need for the merging of clusters. Thus, the ion diffusion does not involve a hopping process. The dynamics also depends significantly on the details of the polymer architecture beyond the aggregate morphology. Adding randomness in spacing of the charges can either increase or decrease the ion diffusion, depending on the specific type of random sequence. © 2012 American Chemical Society.
Multiscale Modeling and Simulation
Ganis, Benjamin; Pencheva, Gergina; Wheeler, Mary F.; Wildey, Tim; Yotov, Ivan
We present an efficient approach for preconditioning systems arising in multiphase flow in a parallel domain decomposition framework known as the mortar mixed finite element method. Subdomains are coupled together with appropriate interface conditions using mortar finite elements. These conditions are enforced using an inexact Newton-Krylov method, which traditionally required the solution of nonlinear subdomain problems on each interface iteration. A new preconditioner is formed by constructing a multiscale basis on each subdomain for a fixed Jacobian and time step. This basis contains the solutions of nonlinear subdomain problems for each degree of freedom in the mortar space and is applied using an efficient linear combination. Numerical experiments demonstrate the relative computational savings of recomputing the multiscale preconditioner sparingly throughout the simulation versus the traditional approach. © 2012 Society for Industrial and Applied Mathematics.
Small
Aaron, Jesse S. ; Carson, Bryan ; Timlin, Jerilyn A.
Many membrane receptors are recruited to specific cell surface domains to form nanoscale clusters upon ligand activation. This step appears to be necessary to initiate cell signaling, including pathways in innate immune system activation. However, virulent pathogens such as Yersinia pestis (the causative agent of plague) are known to evade innate immune detection, in contrast to similar microbes (such as Escherichia coli) that elicit a robust response. This disparity has been partly attributed to the structure of lipopolysaccharides (LPS) on the bacterial cell wall, which are recognized by the innate immune receptor TLR4. It is hypothesized that nanoscale differences exist between the spatial clustering of TLR4 upon binding of LPS derived from Y. pestis and E. coli. Although optical imaging can provide exquisite details of the spatial organization of biomolecules, there is a mismatch between the scale at which receptor clustering occurs (<300 nm) and the optical diffraction limit (>400 nm). The last decade has seen the emergence of super-resolution imaging methods that effectively break the optical diffraction barrier to yield truly nanoscale information in intact biological samples. This study reports the first visualizations of TLR4 distributions on intact cells at image resolutions of <30 nm using a novel, dual-color stochastic optical reconstruction microscopy (STORM) technique. This methodology permits distinction between receptors containing bound LPS from those without at the nanoscale. Importantly, it is also shown that LPS derived from immunostimulatory bacteria result in significantly higher LPS-TLR4 cluster sizes and a nearly twofold greater ligand/receptor colocalization as compared to immunoevading LPS. A dual-color stochastic optical reconstruction microscopy technique is employed to gain insight into the nanoscale organization of the innate immune system receptor TLR4. Data indicate significant changes in TLR4 clustering behavior within the cell membrane in response to immunostimulatory and immunoevading bacterial antigens, thereby shedding light on virulence mechanisms of highly pathogenic microbes such as Yersinia pestis. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
SPEEDAM 2012 - 21st International Symposium on Power Electronics, Electrical Drives, Automation and Motion
Williams, Joseph ; Wilson, David G. ; Robinett, Rush D.
SPEEDAM 2012 - 21st International Symposium on Power Electronics, Electrical Drives, Automation and Motion
Heath, Matthew; Vosters, Gregory; Parker, Gordon; Weaver, Wayne; Wilson, David G.; Robinett, Rush D.
Microgrids with significant renewable penetration will likely require storage devices to maintain a stable bus voltage due to the stochastic behavior of renewable sources and grid loads. The distribution and frequency response characteristics of the storage are two important variables when designing these types of microgrids. For example, storage can be distributed at renewable sources located centrally on a common bus, or a combination thereof. Storage devices will need to compensate for both long and short period disturbances such as the changing output of a photovoltaic (PV) array and the switching of large loads. Simulation results indicate that a cost function based on bus voltage stability is suitable for computing optimal converter capacitances when the load contains cyclic transients. © 2012 IEEE.
SPEEDAM 2012 - 21st International Symposium on Power Electronics, Electrical Drives, Automation and Motion
Bordeau, K.; Parker, G.; Vosters, G.; Weaver, W.; Kelly, J.; Wilson, D.G.; Robinett, Rush D.
This paper explores the effect of a distributed control system for the charging of plug-in hybrid electric vehicles utilizing an agent-based approach in a smart grid. The vehicles are regarded as additional loads in addition to a primary forecasted load and use information transfer with the grid to make their charging decisions. MATLAB was used as the simulation tool to design the control strategy and simulate its effect on a power grid. The findings of this study are that the charging behavior and peak loads on the grid can be reduced by use of this distributed control strategy. © 2012 IEEE.
Proceedings of the 2012 IEEE 26th International Parallel and Distributed Processing Symposium, IPDPS 2012
Rajamanickam, Sivasankaran ; Boman, Erik G. ; Heroux, Michael A.
Proceedings of the 2012 IEEE 26th International Parallel and Distributed Processing Symposium, IPDPS 2012
Azad, Ariful; Halappanavar, Mahantesh; Rajamanickam, Sivasankaran ; Boman, Erik G. ; Khan, Arif; Pothen, Alex
We design, implement, and evaluate algorithms for computing a matching of maximum cardinality in a bipartite graph on multicore and massively multithreaded computers. As computers with larger numbers of slower cores dominate the commodity processor market, the design of multithreaded algorithms to solve large matching problems becomes a necessity. Recent work on serial algorithms for the matching problem has shown that their performance is sensitive to the order in which the vertices are processed for matching. In a multithreaded environment, imposing a serial order in which vertices are considered for matching would lead to loss of concurrency and performance. But this raises the question: Would parallel matching algorithms on multithreaded machines improve performance over a serial algorithm? We answer this question in the affirmative. We report efficient multithreaded implementations of three classes of algorithms based on their manner of searching for augmenting paths: breadth-first-search, depth-first-search, and a combination of both. The Karp-Sipser initialization algorithm is used to make the parallel algorithms practical. We report extensive results and insights using three shared-memory platforms (a 48-core AMD Opteron, a 32-coreIntel Nehalem, and a 128-processor Cray XMT) on a representative set of real-world and synthetic graphs. To the best of our knowledge, this is the first study of augmentation-based parallel algorithms for bipartite cardinality matching that demonstrates good speedups on multithreaded shared memory multiprocessors. © 2012 IEEE.
Proceedings - Electronic Components and Technology Conference
Chu, Dahwey ; Rohwer, Lauren E.S.
A high density 2-D integration process that involves linking multiple die along their edges using a linear array of solder bridges was explored. Solder bridging is a versatile approach that is compatible with a range of interconnect geometries and metallizations. We have demonstrated this approach using copper plated nodules that were fabricated on the surface of the die and extend beyond the edge of the die. These nodules were 25 microns (μm) thick with 10, 20, and 50 μm widths. The formation of solder bridges was accomplished using immersion soldering, where the entire part was dipped into a molten solder bath. Due to surface energy effects, the solder selectively wets and flows along all wettable metal surfaces to form a strong solder bond. The solder can even flow across gaps (15 microns). © 2012 IEEE.
Proceedings - Electronic Components and Technology Conference
Chu, Dahwey; Rohwer, Lauren E.S.
A high density 2-D integration process that involves linking multiple die along their edges using a linear array of solder bridges was explored. Solder bridging is a versatile approach that is compatible with a range of interconnect geometries and metallizations. We have demonstrated this approach using copper plated nodules that were fabricated on the surface of the die and extend beyond the edge of the die. These nodules were 25 microns (μm) thick with 10, 20, and 50 μm widths. The formation of solder bridges was accomplished using immersion soldering, where the entire part was dipped into a molten solder bath. Due to surface energy effects, the solder selectively wets and flows along all wettable metal surfaces to form a strong solder bond. The solder can even flow across gaps (15 microns). © 2012 IEEE.
Proceedings - Electronic Components and Technology Conference
Palmer, Jeremy ; Chu, Dahwey ; Fang, Lu
Extended service life plastic ball grid array (PBGA) packaging with Au ball wire bonding and die-side electroless nickel electroless palladium immersion gold (ENEPIG) surface finish is in development. Post-microfabrication ENEPIG plating is proposed for the extended service life PBGA application to reduce the risk of brittle failure of wire bonds with Au-Al intermetallics over decades of exposure to thermal extremes in the field. An experimental study was undertaken to measure wire bond strength in PBGA samples with ENEPIG plating and varying die and substrate surface preparation. Liquid-phase immersion surface treatment with alkanethiol-based self-assembled monolayers (SAMs) was investigated as an alternative to argon plasma cleaning. Wire bond pull and shear force measurements per MIL-STD-883 were performed on four groups of PBGA samples with prescribed combinations of ENEPIG plating, plasma cleaning and SAM surface treatment. Results reveal that average wire bond pull and shear force in ENEPIG-plated samples exceed six grams force in all cases and are consistent with that of non-plated samples for constant bonding parameters. Surface treatment yields a measurable increase in wire bond strength relative to untreated samples, and ENEPIG-plated samples that receive plasma cleaning exhibit 23% greater average wire bond pull force relative to plated samples treated with SAMs. Wire bond strength was lower in samples where greater ENEPIG surface roughness was observed, consistent with data from the literature. The outcome supports the importance of surface cleaning for robust wire bonds, and suggests that in the context of strength, ENEPIG plating is compatible with the legacy Au ball-on-Al pad thermosonic wire bonding process. © 2012 IEEE.
Proceedings - Electronic Components and Technology Conference
Brocato, Robert W. ; Brocato, Terisse B. ; Wendt, Joel R. ; Sanchez, Carlos A. ; Stotts, Larry G.
Surface acoustic wave (SAW) devices are used as sensing elements in the best performing portable chemical detectors. The SAW device, with a selectively absorbing chemical coating, serves as a mass sensor which preferentially responds to various chemical exposures. To obtain the highest performance, a number of criteria must be optimized, including SAW microwave insertion loss, impedance matching, electrode design configuration, RF shielding, chemically absorbent coating area, electronic measurement approach, and microfluidic packaging. A properly optimized system can be sensitive to chemical exposures the parts-per-trillion range. We report on a design optimization approach consisting of multiple comparison experiments made with competing designs. © 2012 IEEE.
Combustion and Flame
Kearney, Sean P.; Pierce, Flint
We report experimental observations of extremely large, 10-100μm, soot aggregates in a blended methanol/toluene fueled turbulent pool fire, which are believed to be the first observation of " superaggregates" in a turbulent flame. Laser-induced incandescence images of soot volume concentration, at the center of the fire plume and at a height within the active flaming region, reveal the appearance of large-scale particle-like features across a broad range of apparent volume fraction, which emit at an intensity that is comparable with that of the laser-heated soot particles. We argue that the features in the incandescence images result from very large soot aggregates. This observation is supported by scanning electron microscope imaging of extracted soot that reveals large soot structures composed of much smaller chains of individual primary particles. Analysis of the soot aggregate structure from the electron-microscope images reveals a 1.8 fractal dimension at micron scales, comparable with commonly reported soot aggregate sizes from hydrocarbon flames. At larger scales of 10s of microns, comparable with the total aggregate size, a larger volume-filling fractal dimension of 2.5-2.6 is observed. This type of fractal structure is consistent with reported, but apparently rare, observations of soot superaggregates in heavily sooting laboratory laminar diffusion flames, but is encountered in the much larger meter-scale pool fire at much lower soot volume concentrations. © 2012 The Combustion Institute.
Chansoria, Monika
India and China display a peculiar case of “constrained cooperation” 50 years after their border war, with convergence of economic interests tending to overlook strategic differences. While China acknowledges sharing an interest in a peaceful and stable South Asia, it perceives strengthened Indo-US ties as an attempt to enlist New Delhi as a counterweight to China or as part of a containment strategy against it. The Chinese realists are subdivided into “offensive”/“defensive” and “hard”/“soft” camps; each believes that the state has to build its own strength. The hard-power realists argue for strengthening national power–particularly the military and economic dimensions, while soft-power realism emphasizes diplomacy and cultural power. The “offensive realists” argue that China should use its newly built military, economic, and diplomatic influence to coerce others toward the ends China desires. A range of CBMs between India and China that could reduce frictions and establish common ground are discussed.
Villa, Daniel L. ; Passell, Howard ; Malczynski, Leonard A. ; Ballantine, Marissa D.
Resilience is a quality that allows human systems to rebound from shocks, such as droughts or famines, floods, conflict events, and others. Human resilience is tightly coupled to human ecology, including population dynamics, resource availability, and resource consumption. The Human Resilience Index (HRI) and Modeling (HRIM) Project provides a set of tools that help explore the links among human ecological conditions, human resilience, and conflict. The HRIM allows users to simulate future scenarios and mitigation strategies. Historic calculations using the HRI show numerous times and places where declining HRI values have corresponded to instability and conflict, supporting the hypothesis that poor human ecological conditions can contribute to conflict. Seven indicators are used to calculate the HRI: population growth rate, population density, caloric intake per capita, renewable fresh water per capita, arable land per capita, median age, and population health (including infant and child mortality and life expectancy). The HRIM provides a set of tools for evaluating alternative mitigation strategies to help improve human ecological conditions, increase resilience to shocks, and reduce the threat of instability and conflict.
Brown, Theresa J. ; Villa, Daniel L. ; Tidwell, Vincent C. ; Kalinina, Elena A. ; Parks, Mancel J. ; Boslough, Mark
Climate change, through drought, flooding, storms, heat waves, and melting Arctic ice, affects the production and flow of resource within and among geographical regions. The interactions among governments, populations, and sectors of the economy require integrated assessment based on risk, through uncertainty quantification (UQ). This project evaluated the capabilities with Sandia National Laboratories to perform such integrated analyses, as they relate to (inter)national security. The combining of the UQ results from climate models with hydrological and economic/infrastructure impact modeling appears to offer the best capability for national security risk assessments.
Journal of Computational Physics
Scovazzi, Guglielmo S.
Review of Scientific Instruments
Gomez, Matthew R. ; Rochau, G.A. ; Bailey, James E. ; Dunham, G.S. ; Kernaghan, Matthew D. ; Gard, P.; Robertson, G.K. ; Owen, A.C.; Argo, Jeffrey W. ; Nielsen, D.S. ; Lake, Patrick
The pinned optically aligned diagnostic dock (PODD) is a multi-configuration diagnostic platform designed to measure x-ray emission on the Z facility. The PODD houses two plasma emission acquisition (PEA) systems, which are aligned with a set of precision machined pins. The PEA systems are modular, allowing a single diagnostic housing to support several different diagnostics. The PEA configurations fielded to date include both time-resolved and time-integrated, 1D spatially resolving, elliptical crystal spectrometers, and time-integrated, 1D spatially resolving, convex crystal spectrometers. Additional proposed configurations include time-resolved, monochromatic mirrored pinhole imagers and arrays of filtered x-ray diodes, diamond photo-conducting diode detectors, and bolometers. The versatility of the PODD system will allow the diagnostic configuration of the Z facility to be changed without significantly adding to the turn-around time of the machine. Additionally, the PODD has been designed to allow instrument setup to be completed entirely off-line, leaving only a refined alignment process to be performed just prior to a shot, which is a significant improvement over the instrument the PODD replaces. Example data collected with the PODD are presented. © 2012 American Institute of Physics.
Review of Scientific Instruments
Olson, Richard E. ; Hicks, D.G.; Meezan, N.B.; Koch, J.A.; Landen, O.L.
A technique for comparing simulation results directly with radiograph data from backlit capsule implosion experiments will be discussed. Forward Abel transforms are applied to the kappa*rho profiles of the simulation. These provide the transmission ratio (optical depth) profiles of the simulation. Gaussian and top hat blurs are applied to the simulated transmission ratio profiles in order to account for the motion blurring and imaging slit resolution of the experimental measurement. Comparisons between the simulated transmission ratios and the radiograph data lineouts are iterated until a reasonable backlighter profile is obtained. This backlighter profile is combined with the blurred, simulated transmission ratios to obtain simulated intensity profiles that can be directly compared with the radiograph data. Examples will be shown from recent convergent ablation (backlit implosion) experiments at the NIF. © 2012 American Institute of Physics.
Combustion and Flame
Shaddix, Christopher R.
Cipiti, Benjamin B. ; Flores, Gregg
Dicker, Deanna M.
Weinberger, C.R.
Knowlton, Robert G. ; Finley, Patrick D. ; Ramsey Jr., James L.
Leach, Janice ; Torres, Teresa M.
Hardin, Ernest
Fleetwood, James D. ; Hall, Aaron ; Mccloskey, James F.
Chow, James G.
Doerschuk, Peter C.
Lofstead, Gerald F.
Staten, Matthew L.
Clark, Brett W.
Moore, Jacqueline K.
Proposed for publication in IEEE Computer Magazine.
Moreland, Kenneth D.
Proposed for publication in PNAS.
Seagle, Christopher T.
Lamb, Joshua ; Orendorff, Christopher
Lim, Hojun ; Weinberger, C.R. ; Battaile, Corbett C. ; Buchheit, Thomas E. ; Holm, Elizabeth A.
Tran, Hy ; Mertes, Rick
Brown, Arthur ; Puskar, J.D. ; San Marchi, Chris
Williams, Janet L.
Crozier, Paul ; Boerner, Jeremiah J. ; Hopkins, Matthew M. ; Moore, Christopher H. ; Musson, Lawrence C.
Ho, Clifford K.
Proposed for publication in Computers & Chemical Engineering.
Watson, Jean-Paul
Dominguez, Dean
Argibay, Nicolas ; Dugger, Michael T. ; Brumbach, Michael T. ; Prasad, Somuri V.
Bacon, Larry D. ; Williams, Jeffery T. ; Turner, C.D. ; Walker, Michael J. ; Zeek, Erik C.
Wang, Yifeng ; Rodriguez, Mark A. ; Brady, Patrick V. ; Swift, Peter ; Newton, Clay S.
Meeks, Jason M.
Reno, John L. ; Hargett, Terry
Michaels, Jeremy
Musculus, Mark P.B.
Stevens, Jeffrey ; Shul, Randy J.
Cruz-Campa, Jose L. ; Nielson, Gregory N. ; Zhou, Xiaowang ; Ward, Donald K. ; Sanchez, Carlos A. ; Aguirre, Brandon A. ; Lu, Ping ; Rye, Michael J. ; Spoerke, Erik D. ; Chan, Calvin
Ohta, Taisuke
Musculus, Mark P.B.
Ho, Clifford K.
Ho, Clifford K. ; Sment, Jeremy N.I. ; Moya, Adam ; Ghanbari, Cheryl M.
Ho, Clifford K. ; Hartley, James Y. ; Sims, Cianan ; Sment, Jeremy N.I.
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