Andrew Joseph Dolgert

The CMS dataset bookkeeping service

The CMS Dataset Bookkeeping Service (DBS) has been developed to catalog all CMS event data from Monte Carlo and Detector sources. It provides the ability to identify MC or trigger source, track data provenance, construct datasets for analysis, and discover interesting data. CMS requires processing and analysis activities at various service levels and the DBS system provides support for localized processing or private analysis, as well as global access for CMS users at large. Catalog entries can be moved among the various service levels with a simple set of migration tools, thus forming a loose federation of databases. DBS is available to CMS users via a Python API, Command Line, and a Discovery web page interfaces. The system is built as a multi-tier web application with Java servlets running under Tomcat, with connections via JDBC to Oracle or MySQL database backends. Clients connect to the service through HTTP or HTTPS with authentication provided by GRID certificates and authorization through VOMS. DBS is an integral part of the overall CMS Data Management and Workflow Management systems.

Superheating fields of superconductors: Asymptotic analysis and numerical results

The superheated Meissner state in type-I superconductors is studied both analytically and numerically within the framework of Ginzburg-Landau theory. Using the method of matched asymptotic expansions we have developed a systematic expansion for the solutions of the Ginzburg-Landau equations in the limit of small {kappa}, and have determined the maximum superheating field {ital H}{sub sh} for the existence of the metastable, superheated Meissner state as an expansion in powers of {kappa}{sup 1/2}. Our numerical solutions of these equations agree quite well with the asymptotic solutions for {kappa}{lt}0.5. The same asymptotic methods are also used to study the stability of the solutions, as well as a modified version of the Ginzburg-Landau equations which incorporates nonlocal electrodynamics. Finally, we compare our numerical results for the superheating field for large {kappa} against recent asymptotic results for large {kappa}, and again find a close agreement. Our results demonstrate the efficacy of the method of matched asymptotic expansions for dealing with problems in inhomogeneous superconductivity involving boundary layers. {copyright} {ital 1996 The American Physical Society.}

Provenance in High-Energy Physics Workflows

The adoption of large-scale distributed computing presents new opportunities and challenges for the physicists analyzing data from the Large Hadron Collider experiments. With petabytes of data to manage, effective use of provenance is critical to understanding the results.

Nucleation and growth of the superconducting phase in the presence of a current

We study the localized stationary solutions of the one-dimensional time-dependent Ginzburg-Landau equations in the presence of a current. These threshold perturbations separate undercritical perturbations which return to the normal phase from overcritical perturbations which lead to the superconducting phase. Careful numerical work in the small-current limit shows that the amplitude of these solutions is exponentially small in the current; we provide an approximate analysis which captures this behavior. As the current is increased toward the stall current

A multi-dimensional view on information retrieval of CMS data

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Digital Material: A flexible atomistic simulation code

, the width of these solutions diverges, resulting in widely separated normal-superconducting interfaces. We map out numerically the dependence of

Data Location, Transfer and Bookkeeping in CMS

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Rapid web development using AJAX and Python

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Erratum: Superheating fields of superconductors: Asymptotic analysis and numerical results [Phys. Rev. B53, 5650 (1996)]

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Software methodologies for multiscale descriptions of defects, deformation and fracture

(a parameter characterizing the material) and use asymptotic analysis to derive the behaviors for large