22 research outputs found

    Metadata services on the Grid

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    We present an interface for metadata access on the Grid, designed to support flexible schema management, efficient retrieval of large result sets and to allow a broad range of implementations. We also describe an implementation of this interface, which supports a wide range of storage back-ends and two access protocols: SOAP and a TCP-streaming-based protocol. This interface and implementation have been selected as the official metadata components of the gLite-EGEE middleware. Finally, we present the results of extensive performance studies, where the two front-ends are compared to evaluate the cost of using SOAP as metadata access protocol.http://www.sciencedirect.com/science/article/B6TJM-4HRDX94-8/1/b801bfbc291fe7dad0af0e169eb4ec3

    A Search for Instantons at HERA

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    A search for QCD instanton (I) induced events in deep-inelastic scattering (DIS) at HERA is presented in the kinematic range of low x and low Q^2. After cutting into three characteristic variables for I-induced events yielding a maximum suppression of standard DIS background to the 0.1% level while still preserving 10% of the I-induced events, 549 data events are found while 363^{+22}_{-26} (CDM) and 435^{+36}_{-22} (MEPS) standard DIS events are expected. More events than expected by the standard DIS Monte Carlo models are found in the data. However, the systematic uncertainty between the two different models is of the order of the expected signal, so that a discovery of instantons can not be claimed. An outlook is given on the prospect to search for QCD instanton events using a discriminant based on range searching in the kinematical region Q^2\gtrsim100\GeV^2 where the I-theory makes safer predictions and the QCD Monte Carlos are expected to better describe the inclusive data.Comment: Invited talk given at the Ringberg Workshop on HERA Physics on June 19th, 2001 on behalf of the H1 collaboratio

    Bridging clinical information systems and grid middleware: a Medical Data Manager

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    International audienceThis paper describes the effort to deploy a Medical Data Management service on top of the EGEE grid infrastructure. The most widely accepted medical image stan- dard, DICOM, was developed for fulfilling clinical practice. It is implemented in most medical image acquisition and analysis devices. The EGEE middleware is us- ing the SRM standard for handling grid files. Our prototype is exposing an SRM compliant interface to the grid middleware, transforming on the fly SRM requests into DICOM transactions. The prototype ensures user identification, strict file ac- cess control and data protection through the use of relevant grid services. This Medical Data Manager is easing the access to medical databases needed for many medical data analysis applications deployed today. It offers a high level data man- agement service, compatible with clinical practices, which encourages the migration of medical applications towards grid infrastructures. A limited scale testbed has been deployed as a proof of concept of this new service. The service is expected to be put into production with the next EGEE middleware generation

    A Secure Grid Medical Data Manager Interfaced to the gLite Middleware

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    International audienceThe medical community is producing and manipulating a tremendous volume of digital data for which computerized archiving, processing and analysis is needed. Grid infrastructures are promising for dealing with challenges arising in computerized medicine but the manipulation of medical data on such infrastructures faces both the problem of interconnecting medical information systems to Grid middlewares and of preserving patients' privacy in a wide and distributed multi-user system. These constraints are often limiting the use of Grids for manipulating sensitive medical data. This paper describes our design of a medical data management system taking advantage of the advanced gLite data management services, developed in the context of the EGEE project, to fulfill the stringent needs of the medical community. It ensures medical data protection through strict data access control, anonymization and encryption. The multi-level access control provides the flexibility needed for imple! menting complex medical use-cases. Data anonymization prevents the exposure of most sensitive data to unauthorized users, and data encryption guarantees data protection even when it is stored at remote sites. Moreover, the developed prototype provides a Grid storage resource manager (SRM) interface to standard medical DICOM servers thereby enabling transparent access to medical data without interfering with medical practice

    Storage Resource Manager version 2.2: design, implementation, and testing experience

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    Storage Services are crucial components of the Worldwide LHC Computing Grid Infrastructure spanning more than 200 sites and serving computing and storage resources to the High Energy Physics LHC communities. Up to tens of Petabytes of data are collected every year by the four LHC experiments at CERN. To process these large data volumes it is important to establish a protocol and a very efficient interface to the various storage solutions adopted by the WLCG sites. In this work we report on the experience acquired during the definition of the Storage Resource Manager v2.2 protocol. In particular, we focus on the study performed to enhance the interface and make it suitable for use by the WLCG communities. At the moment 5 different storage solutions implement the SRM v2.2 interface: BeStMan (LBNL), CASTOR (CERN and RAL), dCache (DESY and FNAL), DPM (CERN), and StoRM (INFN and ICTP). After a detailed inside review of the protocol, various test suites have been written identifying the most effective set of tests: the S2 test suite from CERN and the SRM-Tester test suite from LBNL. Such test suites have helped verifying the consistency and coherence of the proposed protocol and validating existing implementations. We conclude our work describing the results achieved

    Search for Instanton-Induced Processes with the H1 Detector in Deep-Inelastic Electron-Proton Collisions at HERA

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    The first dedicated search for QCD instanton-induced processes is presented. Deep-inelastic scattering (DIS) data collected at the electron-proton collider HERA in a kinematical range defined by the DIS variables x > 0.001, 0.1 < y < 0.6 and Q2 < 100GeV2, and for a scattering angle of the electron of at least 156 degrees have been analysed. Several observables characterising the instanton hadronic final state are studied and combined to a powerful discriminant with the help of an innovative range searching algorithm. By cutting on the discriminant, a potentially instanton enriched region is found in the observable phase space. Given the accuracy of the standard DIS background models, no significant excess of events in this region is found, and a model independent limit on the instanton-induced cross-section of 221pb is calculated. A detailed study with different effective instanton sizes and distances can exclude a steep rise of the cross-section towards large instanton-sizes and small distances predicted by a naive extrapolation of instanton perturbation theory and is in accord with recent lattice calculations. Finally, the prospects of a search in the region Q2 > 100GeV2 are studied

    Performance comparison of the LCG2 and gLite file catalogues

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    When the Large Hadron Collider (LHC) begins operation at CERN in 2007 it will produce data in volumes never before seen. The LHC Computing Grid will provide the middleware necessary to distribute and analyse petabytes of this data. One of the critical factors in the smooth running of this system is the performance of the file catalogues which translate logical filenames into physical locations. We present a detailed study comparing the LCG project's catalogue with the gLite FiReMan catalogue developed in the EGEE project, covering performance and respective merits and shortcomings

    Security in distributed metadata catalogues

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    Catalogue services provide the discovery and location mechanisms that allow users and applications to locate data on Grids. Replication is a highly desirable feature in these services, since it provides the scalability and reliability required on large data Grids and is the basis for federating catalogues from different organizations. Grid catalogues are often used to store sensitive data and must have access control mechanisms to protect their data. Replication has to take this security policy into account, making sure that replicated information cannot be abused but allowing some flexibility such as selective replication for the sites depending on the level of trust in them. In this paper we discuss the security requirements and implications of several replication scenarios for Grid catalogues based on experiences gained within the EGEE project. Using the security infrastructure of the EGEE Grid as a basis, we then propose a security architecture for replicated Grid catalogues, which, among other features, supports partial and total replication of the security mechanisms on the master. The implementation of this architecture in the AMGA metadata catalogue of the EGEE project is then described including the application to a complex scenario in a biomedical application. Copyright (C) 2008 John Wiley & Sons, Ltd

    The European Patent Office and its handling of Computer Implemented Inventions

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    The speakers will introduce the activities of the European Patent Office, followed by a discussion on the patentability of CIIs. About the speakers Georg Weber is the Director at the EPO in Munich and Head of Directorate 1870. He is responsible for search, examination and opposition procedures in the technical areas of computer and network security, cryptography, computer arithmetic and mobile applications. His team comprises 70 patent examiners who are technical experts in these fields. Georg Weber joined the EPO in 1988 and is director since more than 10 years. He started his career in the office initially as a patent examiner and worked in different technical areas of chemistry and mechanics. Birger Koblitz is patent examiner at the EPO in Munich in the technical field of computer security. Before joining the office in 2009, he earned a PhD in Experimental Particle Physics from the University of Hamburg, and worked at CERN in the IT department supporting the experiments in their Grid Computing activities.</p
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