Article

Software for Distributed Systems - The EMI Product Portfolio

January 2012

Authors:

Forschungszentrum Jülich

Alberto Di Meglio

CERN

Enhancing the performance of scientific workflow execution in e-science environments by harnessing the standards based parameter sweep model

Article

Jul 2013

Certain scientific use cases possess complex requirements to have Grid jobs executed in collections where the jobs' request contains only some variation in different parts. These scenarios can easily be tackled by a single job request which abstract this variation and can represent the same collection. The Open Grid Forum (OGF) standards community modeled this requirement through the Job Submission and Description Language (JSDL) Parameter Sweep specification, which takes a modular approach to handle different variations of parameter sweeps (e.g. document and file sweep). In this paper we present the UNICORE server environment implementing this specification build upon its existing JSDL implementation. We also demonstrate the application of UNICORE's parameter sweep extension for optimizing job executions, which are submitted as a sub-activity of a Taverna based scientific workflow. Further we validate our approach by analyzing performance of the workflow with and without using the parameter sweep extension.

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Conference Paper

Software for Distributed Systems - The EMI Product Portfolio

December 2012

Conference Paper

Common mode current measurements and radiated emissions from long cable systems

September 1990

M.A. Wright

Given the size and complexity of the installations which are being measured, currently applied standards are of limited value in assessing their performance. Common mode current measurements for emissions offer an acceptable solution to an otherwise difficult problem. The degree of equivalence between the results quoted suggest that these alternative methods may prove the basis for a standard in ... [Show full abstract] their own right which will alleviate many of the problems associated with the measurements of large distributed systems. The experimental uncertainty estimates show that common mode current measurements are in excellent agreement with the CISPR 22 type radiated measurements. These measurements only consider emissions on the system cabling and do not consider direct board radiation. The author concludes that the most effective test procedure would include the measurement of both radiated field and conducted common mode signals when determining the compliance of a system containing large lengths of cable

Conference Paper

Distributed System for Query Processing with Grid Authentication

June 2014

When using Grid resources, usually a specific type of middleware is deployed. For example the European infrastructure is based on EMI-GLite and GLOBUS. The deployment of this middleware enforces a number of limitations concerning the OS, libraries and software packages. On the other hand the typical Grid middleware does not provide elasticity in the way Cloud services do. In our system we propose ... [Show full abstract] an entirely Java-based solution designed with elasticity in mind, providing distributed processing of queries from a single endpoint. The system is lightweight and easy to deploy on Cloud resourced and depends only on a few EMI packages. In this paper we describe the architecture and workflow of the system, providing benchmarks which show the effectiveness of our solution during processing of queries related to monitoring computational jobs in the Grid, using a distributed Cassandra database.

Article

Grid-Interface Bidirectional Converter for Residential DC Distribution Systems—Part 2: AC and DC Int...

April 2013 · IEEE Transactions on Power Electronics

With the emerging installations of multitype renewable energy sources and energy storage elements, the dc electronic distribution systems in residential houses/buildings (dc nanogrid) are becoming an alternative future system solution, achieving a zero net-energy consumption and optimized power management. One of the critical components in such a dc system is the grid-interface bidirectional ... [Show full abstract] ac–dc power converter, namely the energy control center. Besides, the basic power conversion function, the system interface solution in grid-interface converter is important to successfully interconnect the ac and dc systems as well as fulfill the power quality and EMI regulation codes on both dc and ac sides. This paper presents a complete discussion of several aspects of system interface design for the grid-interface converter under both single-phase and three-phase system conditions. A passive plus active filter solution is proposed to accomplish the common-mode-related noises minimization as well as a dramatic reduction of the converter system volume.

Conference Paper

Consideration of inrush current on DC distribution system

September 2012

In recent years, 380Vdc distribution systems have been expected to be one of the energy saving solutions for telecommunication buildings and data centers. However, DC distribution systems have various problems. In this paper, We report the results of an investigation of inrush current, including current size, effects and testing methods, as one problem in the construction and operation of 380Vdc ... [Show full abstract] power distribution circuit.