Ohio Supercomputer Center Research Articles

Ambient Air Pollution Associated with Body Fat Percentages at Different Body Compartments: A Cohort Study of UK Biobank Participants.

Ambient Air Pollution Associated with Body Fat Percentages at Different Body Compartments: A Cohort Study of UK Biobank Participants.

Measuring the Welfare of Intermediaries

We investigate the welfare of intermediaries in oligopolistic markets where intermediaries offer additional services. We exploit the unique circumstance that in the empirical setting studied, outdoor advertising, consumers can purchase from manufacturers or intermediaries. Intermediaries provide additional services to the consumers and charge a margin for them. Intermediaries provide the following additional services: search services (information about products), purchase-aggregation services (access to quantity discounts), and consulting services. We specify an equilibrium model and structurally estimate it using market-level data. The demand includes consumers with costly search and channel-specific preferences. The supply includes two distribution channels. One features bargaining about wholesale prices between manufacturers and intermediaries and downstream price competition. The other is vertically integrated. We show how Google search data can be used to identify the search-cost parameters. We use the estimated model to simulate counterfactual scenarios where intermediaries do not offer additional services. We find that the three services considered provide value to consumers, with search playing a prominent role. Our analysis helps explain why intermediaries are ubiquitous in modern economies despite the double marginalization. This paper was accepted by Matthew Shum, marketing. Funding: The authors acknowledge the allocation of computing time from the Ohio Supercomputer Center [Grant PAS1350-2]. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001. This work was also supported by Fundação para a Ciência e a Tecnologia [Grant UIDB/00315/2020]. Supplemental Material: The data files and online appendix are available at https://doi.org/10.1287/mnsc.2021.4266 .

Database NORAD-Atomic-Data for Atomic Processes in Plasma

The online atomic database of NORAD-Atomic-Data, where NORAD stands for Nahar OSU Radiative, is part of the data sources of the two international collaborations of the Opacity Project (OP) and the Iron Project (IP). It contains large sets of parameters for the dominant atomic processes in astrophysical plasmas, such as, (i) photo-excitation, (ii) photoionization, (iii) electron–ion recombination, (iv) electron–impact excitations. The atomic parameters correspond to tables of energy levels, level-specific total photoionization cross-sections, partial photoionization cross-sections of all bound states for leaving the residual ion in the ground state, partial cross-sections of the ground state for leaving the ion in various excited states, total level-specific electron–ion recombination rate coefficients that include both the radiative and dielectronic recombination, total recombination rate coefficients summed from contributions of an infinite number of recombined states, total photo-recombination cross-sections and rates with respect to photoelectron energy, transition probabilities, lifetimes, collision strengths. The database was created after the first two atomic databases, TOPbase under the OP and TIPbase under the IP. Hence the contents of NORAD-Atomic-Data are either new or from repeated calculations using a much larger wave function expansion making the data more complete. The results have been obtained from the R-matrix method using the close-coupling approximation developed under the OP and IP, and from atomic structure calculations using the program SUPERSTRUCTURE. They have been compared with available published results which have been obtained theoretically and experimentally, and are expected to be of high accuracy in general. All computations were carried out using the computational facilities at the Ohio Supercomputer Center (OSC) starting in 1990. At present it contains atomic data for 154 atomic species, 98 of which are lighter atomic species with nuclear charge Z ≤ 28 and 56 are heavier ones with Z > 28. New data are added with publications.

Corrigendum: Twisted Baskets

In their Communication the authors made a mistake in acknowledging the funding agency. The authors apologize for the mistake. The correct Acknowledgement should read as follows: The experimental portion of this work was financially supported with funds obtained from the U.S. National Science Foundation (CHE-1305179). The computational portion was financially supported with funds obtained from the Department of Defense, Defense Threat Reduction Agency (HDTRA1-11-1-0042). Computational support from the Ohio Supercomputer Center is gratefully acknowledged. E.D. is grateful for the predoctoral fellowship received from the Turkish National Science Foundation (TUBITAK).

Battery Life Estimation in PHEV Applications: A Monte Carlo Simulation Study

With the onset of the electrification of vehicles, battery life estimation has become a very important issue in the design and commercialization of vehicle electrification technologies. Designing and implementing algorithms to adequately predict battery life is essential for the wide-scale adoption of hybrid vehicles, i.e. both charge-sustaining electric vehicles (HEVs) and plug-in electric vehicles (PHEVs) and pure electric vehicles (EVs). In order to effectively design methods for predicting battery life, accurate and efficient modeling and simulation tools are required to support in the design, identification, and modeling of such methodologies and algorithms. In this paper, we will present a modeling and simulation tool that is intended to be used for battery life estimation in PHEV applications. The dynamic PHEV model is based on many years of development at The Ohio State University's Center for Automotive Research in Columbus OH. The focus of the paper is not so much on each individual vehicle component of the model, but on the design and implementation of the software model. In addition, we will present the design and implementation of parallelized Monte Carlo simulations completed on The Ohio Supercomputer Center using the software model. At the end of the paper, we will present some example results and metrics obtained from the simulation infrastructure that can be used for battery life estimation.

An MPI/GPU parallelization of an interior penalty discontinuous Galerkin time domain method for Maxwell's equations

In this paper we discuss our approach to the MPI/GPU implementation of an Interior Penalty Discontinuous Galerkin Time domain (IPDGTD) method to solve the time dependent Maxwell's equations. In our approach, we exploit the inherent DGTD parallelism and describe a combined MPI/GPU and local time stepping implementation. This combination is aimed at increasing efficiency and reducing computational time, especially for multiscale applications. The CUDA programming model was used, together with non‐blocking MPI calls to overlap communications across the network. A 10× speedup compared to CPU clusters is observed for double precision arithmetic. Finally, for p = 1 basis functions, a good scalability with parallelization efficiency of 85% for up to 40 GPUs and 80% for up to 160 CPU cores was achieved on the Ohio Supercomputer Center's Glenn cluster.

Enabling Data-Intensive Biomedical Science: Gaps, Opportunities, and Challenges

OMICS: A Journal of Integrative BiologyVol. 15, No. 4 Letters to the EditorEnabling Data-Intensive Biomedical Science: Gaps, Opportunities, and ChallengesDavid E. Hudak, Don Stredney, Prasad Calyam, Kevin Wohlever, Thomas Bitterman, Bradley Hittle, Thomas Kerwin, and Ashok KrishnamurthyDavid E. HudakSearch for more papers by this author, Don StredneySearch for more papers by this author, Prasad CalyamSearch for more papers by this author, Kevin WohleverSearch for more papers by this author, Thomas BittermanSearch for more papers by this author, Bradley HittleSearch for more papers by this author, Thomas KerwinSearch for more papers by this author, and Ashok KrishnamurthySearch for more papers by this authorPublished Online:8 Apr 2011https://doi.org/10.1089/omi.2011.0017AboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View articleFiguresReferencesRelatedDetails Volume 15Issue 4Apr 2011 InformationCopyright 2011, Mary Ann Liebert, Inc.To cite this article:David E. Hudak, Don Stredney, Prasad Calyam, Kevin Wohlever, Thomas Bitterman, Bradley Hittle, Thomas Kerwin, and Ashok Krishnamurthy.Enabling Data-Intensive Biomedical Science: Gaps, Opportunities, and Challenges.OMICS: A Journal of Integrative Biology.Apr 2011.231-233.http://doi.org/10.1089/omi.2011.0017Published in Volume: 15 Issue 4: April 8, 2011PDF download

A Computational Science IDE for HPC Systems: Design and Applications

Software engineering studies have shown that programmer productivity is improved through the use of computational science integrated development environments (or CSIDE, pronounced "sea side") such as MATLAB. Scientists often desire to use high-performance computing (HPC) systems to run their existing CSIDE scripts with large data sets. ParaM is a CSIDE distribution that provides parallel execution of MATLAB scripts on HPC systems at large shared computer centers. ParaM runs on a range of processor architectures (e.g., x86, x64, Itanium, PowerPC) and its MPI binding, known as bcMPI, supports a number of interconnect architectures (e.g., Myrinet and InfiniBand). On a cluster at Ohio Supercomputer Center, bcMPI with blocking communication has achieved 60% of the bandwidth of an equivalent C/MPI benchmark. In this paper, we describe goals and status for the ParaM project and the development of applications in signal and image processing that use ParaM.

Experimental analysis of a mass storage system

Mass storage systems (MSSs) play a key role in data-intensive parallel computing. Most contemporary MSSs are implemented as redundant arrays of independent/inexpensive disks (RAID) in which commodity disks are tied together with proprietary controller hardware. The performance of such systems can be difficult to predict because most internal details of the controller behavior are not public. We present a systematic method for empirically evaluating MSS performance by obtaining measurements on a series of RAID configurations of increasing size and complexity. We apply this methodology to a large MSS at Ohio Supercomputer Center that has 16 input/output processors, each connected to four 8 + 1 RAID5 units and provides 128 TB of storage (of which 116.8 TB are usable when formatted). Our methodology permits storage-system designers to evaluate empirically the performance of their systems with considerable confidence. Although we have carried out our experiments in the context of a specific system, our methodology is applicable to all large MSSs. The measurements obtained using our methods permit application programmers to be aware of the limits to the performance of their codes. Copyright © 2006 John Wiley & Sons, Ltd.

The coordination geometry of Np(VII) in alkaline solution.

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTThe Coordination Geometry of Np(VII) in Alkaline SolutionC. W. Williams, J.-P. Blaudeau, J. C. Sullivan, Mark R. Antonio, B. Bursten, and L. SoderholmView Author Information Chemistry Division, Argonne National Laboratory Argonne Illinois 60439 Ohio Supercomputer Center, ASC-HP 2435 West 5th St., B676, WPAFB, Ohio 45433 Department of Chemistry, The Ohio State University Columbus, Ohio 43210 Cite this: J. Am. Chem. Soc. 2001, 123, 18, 4346–4347Publication Date (Web):April 12, 2001Publication History Received25 September 2000Published online12 April 2001Published inissue 1 May 2001https://doi.org/10.1021/ja005640gCopyright © 2001 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views475Altmetric-Citations57LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (31 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Group theory,Ions,Ligands,Mathematical methods,Oxygen Get e-Alerts

Distributed Numerical Weather Prediction via Satellite

Abstract This paper describes a recent undertaking in distributed numerical weather prediction via high data rate networks. The governing project involved the operation of a coupled mesoscale modeling system on widely separated supercomputers, and experiments and demonstrations were performed to explore both long-distance and local-area operation of the system. Connectivity was provided either by NASA's Advanced Communications Technology Satellite (ACTS) or by a terrestrial Asynchronous Transfer Mode (ATM) network. The modeling system was built around the Fifth-Generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (PSU–NCAR MM5) and consisted of the MM5, an ocean circulation model, and a surface wave model. The primary experiments and demonstrations utilized ACTS to link supercomputers at both NCAR in Boulder, Colorado, and at the Ohio Supercomputer Center in Columbus, Ohio. Other experiments and demonstrations utilized an ATM network to link supercomputers runn...

A nationwide parallel computing environment

article Free AccessA nationwide parallel computing environment Authors: Ken Kennedy Rice Univ., Houston, TX Rice Univ., Houston, TXView Profile , Charles F. Bender Ohio Supercomputer Center, Columbus Ohio Supercomputer Center, ColumbusView Profile , John W. D. Connolly Univ. of Kentucky, Lexington Univ. of Kentucky, LexingtonView Profile , John L. Hennessy Stanford Univ., Stanford, CA Stanford Univ., Stanford, CAView Profile , Mary K. Vernon Univ. of Wisconsin, Madison Univ. of Wisconsin, MadisonView Profile , Larry Smarr Univ. of Illinois at Urbana-Champaign, Urbana Univ. of Illinois at Urbana-Champaign, UrbanaView Profile Authors Info & Claims Communications of the ACMVolume 40Issue 11Nov. 1997 pp 62–72https://doi.org/10.1145/265684.265693Published:01 November 1997Publication History 17citation693DownloadsMetricsTotal Citations17Total Downloads693Last 12 Months29Last 6 weeks16 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Predicting the crystal structure of organic molecular materials

This paper describes a novel method for predicting the crystal structure of organic molecular materials which employs a series of successive approximations to focus on structures of high probability, without resorting to a brute force search and energy minimization of all possible structures. The problem of multiple local minima is overcome by assuming that the crystal structure is closely packed, thereby eliminating 217 of the 230 possible space groups. Configurations within the 13 remaining space groups are searched by rotating the reference molecule about Cartesian axes in rotational increments of 15°. Initial energy minimization is performed using (6–12) Lennard–Jones pair potentials to produce a set of closely packed structures. The structures are then refined with the introduction of a Coulombic potential calculated using molecular multipole moments. This method has successfully located local minima which correspond to the observed crystal structures of several saturated and unsaturated hydro-C atoms with no a priori information provided. For large polycyclic aromatic hydrocarbons, additional refinements of the energy calculations are required to distinguish the experimental structure from a small number of closely packed structures. Our methodology for a priori crystal structure prediction represents the most efficient algorithm presented to date, in a field where the first successes have only been described within the past year and have been few and far between. Since our algorithm is capable of locating a large number of reasonable structures with similar energy in a short period of time, and is more likely to locate a minimum corresponding to the experimental structure, our program provides a superior framework to determine the level of theory required to calculate the intermolecular potential. For all but highly asymmetric hydrocarbons, however, distinguishing the observed structure from a large number of highly probable structures requires more rigorously calculated intermolecular interactions than pair potentials, plus an ad hoc electrostatic potential, and is thus beyond the scope of this paper. All calculations were performed on the Ohio Supercomputer Center's Cray Y-MP.

Performance Attributes for Code and Workload Analysis On Cray X-Mp and Y-Mp Systems

A Performance Analysis Tools (PAT) report implement ing hpm and perftrace software, installed under UNICOS on CRAY X-MP and Y-MP systems, was de signed at the Ohio Supercomputer Center. The report presents a concise summary of code performance characteristics using 28 performance attributes grouped into four categories: operations and instruc tions, scalar to vector load balance, memory utilization, and input/output utilization. Demonstrated applications of this performance metric include code performance analysis in a case study, workload analysis for a 24- code sample, and performance comparison of CRAY X-MP and Y-MP processors. The analysis of the case study shows that a precise performance assessment was possible using this metric without the necessity of source code analysis. Measurements with the 24-code sample established realistic performance ranges in the metric and were also used to compare performance of CRAY X-MP and Y-MP models. Although the clock pe riod on the Y-MP was reduced by 29% relative to the X-MP, increases of 52% were observed in instruction fetch rates and vector MFLOPS, with a corresponding rise of 39% in computational intensity.

Physics of forced unsteady flow for a NACA 0015 airfoil undergoing constant-rate pitch-up motion**This research is supported, in part, by AFOSR Grant No. 90-0249, and by the Ohio Supercomputer Center Grant No. PES080.

The unsteady Navier-Stokes (NS) analysis of Osswald, Ghia and Ghia in velocity-vorticity variables is modified to study the dynamic stall phenomenon for a NACA 0015 airfoil undergoing constant Ω0 pitch-up maneuvers at Reynolds number Re = 10 000 and 45000. The use of third-order accurate biased upwind differencing for the nonlinear convective terms in the vorticity transport equation removes the spurious oscillations observed in the earlier studies by the authors for these values of Re. The fully implicit and vectorized ADI-BGE method of the authors is used to solve the unsteady NS equations. Instantaneous inertial surface vorticity, which is an invariant of the choice of reference frame selected, is employed to determine the location of separation of the boundary-layer flow on the suction surface; also a separation bubble embedded within the boundary layer is observed for both cases somewhere between the leading edge and the quarter-chord point. Primary, secondary, tertiary and quarternary vortices have been observed before the dynamic-stall vortex evolves and gathers its maximum strength.

Simulation of dynamic stall phenomenon using unsteady Navier-Stokes equations

A non-inertial body-fixed generalized coordinate frame is employed to develop an unsteady Navier-Stokes (NS) analysis for arbitrary maneuvering bodies. A fully implicit direct numerical simulation (DNS) methodology is implemented for the solution of the governing equations. A velocity-vorticity (disturbance stream function - vorticity in 2-D) formulation is shown to simplify both the theoretical and numerical analysis of maneuvering flight when compared with the primitive-variable formulation. The resulting method is highly vectorizable and currently achieves a computational index of 6 micro-seconds per time step per mesh point using a single processor on the CRAY Y-MP 8 864 at the Ohio Supercomputer Center. Vectorization has been achieved satisfactorily, with the code currently performing in the range of 130–180 Mflops. The rapid pitch-up maneuver of a NACA 0015 airfoil is wxamined at Re=1000 and Re=10 000, with particular emphasis being placed on the development and evolution of the dynamic stall vortex.

Research At the Ohio Supercomputer Center

Research At the Ohio Supercomputer Center