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Duncan Brown

Publications and source records attributed to Duncan Brown.

6 recordsLinked to original sources

Reproducibility of the First Image of a Black Hole in the Galaxy M87 from the Event Horizon Telescope (EHT) Collaboration

This paper presents an interdisciplinary effort aiming to develop and share sustainable knowledge necessary to analyze, understand, and use published scientific results to advance reproducibility in multi-messenger astrophysics. Specifically, we target the breakthrough work associated with the generation of the first image of a black hole, called M87. The image was computed by the Event Horizon Telescope Collaboration. Based on the artifacts made available by EHT, we deliver documentation, code, and a computational environment to reproduce the first image of a black hole. Our deliverables support new discovery in multi-messenger astrophysics by providing all the necessary tools for generalizing methods and findings from the EHT use case. Challenges encountered during the reproducibility of EHT results are reported. The result of our effort is an open-source, containerized software package that enables the public to reproduce the first image of a black hole in the galaxy M87.

astro-ph.IM

SciTokens: Demonstrating Capability-Based Access to Remote Scientific Data using HTCondor

The management of security credentials (e.g., passwords, secret keys) for computational science workflows is a burden for scientists and information security officers. Problems with credentials (e.g., expiration, privilege mismatch) cause workflows to fail to fetch needed input data or store valuable scientific results, distracting scientists from their research by requiring them to diagnose the problems, re-run their computations, and wait longer for their results. SciTokens introduces a capabilities-based authorization infrastructure for distributed scientific computing, to help scientists manage their security credentials more reliably and securely. SciTokens uses IETF-standard OAuth JSON Web Tokens for capability-based secure access to remote scientific data. These access tokens convey the specific authorizations needed by the workflows, rather than general-purpose authentication impersonation credentials, to address the risks of scientific workflows running on distributed infrastructure including NSF resources (e.g., LIGO Data Grid, Open Science Grid, XSEDE) and public clouds (e.g., Amazon Web Services, Google Cloud, Microsoft Azure). By improving the interoperability and security of scientific workflows, SciTokens 1) enables use of distributed computing for scientific domains that require greater data protection and 2) enables use of more widely distributed computing resources by reducing the risk of credential abuse on remote systems. In this extended abstract, we present the results over the past year of our open source implementation of the SciTokens model and its deployment in the Open Science Grid, including new OAuth support added in the HTCondor 8.8 release series.

cs.DC

Applicability study of the PRIMAD model to LIGO gravitational wave search workflows

The PRIMAD model with its six components (i.e., Platform, Research Objective, Implementation, Methods, Actors, and Data), provides an abstract taxonomy to represent computational experiments and enforce reproducibility by design. In this paper, we assess the model applicability to a set of Laser Interferometer Gravitational-Wave Observatory (LIGO) workflows from literature sources (i.e., published papers). Our work outlines potentials and limits of the model in terms of its abstraction levels and application process.

cs.DC

SciTokens: Capability-Based Secure Access to Remote Scientific Data

The management of security credentials (e.g., passwords, secret keys) for computational science workflows is a burden for scientists and information security officers. Problems with credentials (e.g., expiration, privilege mismatch) cause workflows to fail to fetch needed input data or store valuable scientific results, distracting scientists from their research by requiring them to diagnose the problems, re-run their computations, and wait longer for their results. In this paper, we introduce SciTokens, open source software to help scientists manage their security credentials more reliably and securely. We describe the SciTokens system architecture, design, and implementation addressing use cases from the Laser Interferometer Gravitational-Wave Observatory (LIGO) Scientific Collaboration and the Large Synoptic Survey Telescope (LSST) projects. We also present our integration with widely-used software that supports distributed scientific computing, including HTCondor, CVMFS, and XrootD. SciTokens uses IETF-standard OAuth tokens for capability-based secure access to remote scientific data. The access tokens convey the specific authorizations needed by the workflows, rather than general-purpose authentication impersonation credentials, to address the risks of scientific workflows running on distributed infrastructure including NSF resources (e.g., LIGO Data Grid, Open Science Grid, XSEDE) and public clouds (e.g., Amazon Web Services, Google Cloud, Microsoft Azure). By improving the interoperability and security of scientific workflows, SciTokens 1) enables use of distributed computing for scientific domains that require greater data protection and 2) enables use of more widely distributed computing resources by reducing the risk of credential abuse on remote systems.

cs.DC

Search for $WH \to \ell νb\bar{b}$ Final States at the Tevatron

Latest results are presented in the search for low mass standard model Higgs production in association with a $W$ boson, based on large luminosity data samples collected at the CDF and D0 Experiments at the Fermilab Tevatron $p\bar{p}$ collider. The selection of event samples containing an isolated lepton, an imbalance in transverse energy in the events, and either one or two reconstructed jets consistent with having evolved from a $b$-quark, provides statistically independent data samples to search for $q\bar{q}\rightarrow WH$ candidates. Expected and observed upper limits are derived for the product of the $WH$ production cross section and branching ratios and are reported in units of the standard model prediction. The observed (expected) upper limits for a Higgs mass $M_{H}=115 ~\rm GeV$ are factors 2.65 (2.6) and 4.6 (3.5) above the standard model prediction for the CDF and D0 searches, respectively.

hep-ex

Hadronic Final States

In this summary we give a concise overview of the experimental and theoretical results, which were presented during the QCD and Hadronic Final State Working Group sessions at the DIS 2007 workshop.

hep-ph