Modern Grid middleware is built around components providing basic functionality, such as data storage, authentication, security, job management, resource monitoring and reservation. In this paper we ...describe the Computing Resource Execution and Management (CREAM) service. CREAM provides a Web service-based job execution and management capability for Grid systems; in particular, it is being used within the gLite middleware. CREAM exposes a Web service interface allowing conforming clients to submit and manage computational jobs to a Local Resource Management System. We developed a special component, called ICE (Interface to CREAM Environment) to integrate CREAM in gLite. ICE transfers job submissions and cancellations from the Workload Management System, allowing users to manage CREAM jobs from the gLite User Interface. This paper describes some recent studies aimed at assessing the performance and reliability of CREAM and ICE; those tests have been performed as part of the acceptance tests for integration of CREAM and ICE in gLite. We also discuss recent work towards enhancing CREAM with a BES and JSDL compliant interface.
People involved in modular projects need to improve the build software process, planning the correct execution order and detecting circular dependencies. The lack of suitable tools may cause delays ...in the development, deployment and maintenance of the software. Experience in such projects has shown that the use of version control and build systems is not able to support the development of the software efficiently, due to a large number of errors each of which causes the breaking of the build process. Common causes of errors are for example the adoption of new libraries, libraries incompatibility, the extension of the current project in order to support new software modules. In this paper, we describe a possible solution implemented in ETICS, an integrated infrastructure for the automated configuration, build and test of Grid and distributed software. ETICS has defined meta-data software abstractions, from which it is possible to download, build and test software projects, setting for instance dependencies, environment variables and properties. Furthermore, the meta-data information is managed by ETICS reflecting the version control system philosophy, because of the existence of a meta-data repository and the handling of a list of operations, such as check out and commit. All the information related to a specific software are stored in the repository only when they are considered to be correct. By means of this solution, we introduce a sort of flexibility inside the ETICS system, allowing users to work accordingly to their needs. Moreover, by introducing this functionality, ETICS will be a version control system like for the management of the meta-data.
First level trigger using pixel detector for the CMS experiment D’Alfonso, M.; Ambroglini, F.; Bagliesi, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2007, Letnik:
570, Številka:
2
Journal Article
Recenzirano
A proposal for a pixel-based Level 1 trigger for the Super-LHC is presented. The trigger is based on fast track reconstruction using the full pixel granularity exploiting a readout which connects ...different layers in specific trigger towers. The trigger will implement the current CMS high level trigger functionality in a novel concept of intelligent detector. A possible layout is discussed and implications on data links are evaluated.
First performance studies of a pixel-based trigger in the CMS experiment Pioppi, M.; Ambroglini, F.; Bagliesi, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2007, Letnik:
570, Številka:
2
Journal Article
Recenzirano
An important tool for the discovery of new physics at LHC is the design of a low level trigger with an high power of background rejection. The contribution of pixel detector to the lowest level ...trigger at CMS is studied focusing on low-energy jet identification, matching the information from calorimeters and pixel detector. In addition, primary vertex algorithms are investigated. The performances are evaluated in terms of, respectively, QCD rejection and multihadronic jets final states efficiency.
Solar radiation is a dominant driver of snowmelt dynamics and streamflow generation in alpine catchments. A better understanding of how solar radiation patterns affect the hydrologic response is ...needed to assess when calibrated temperature‐index models are likely to be spatially transferable for ecohydrological applications. We induce different solar radiation patterns in a Swiss Alpine catchment through virtual rotations of the digital elevation model. Streamflow simulations are performed at different spatial scales through a spatially explicit hydrological model coupled to a physically based snow model. Results highlight that the effects of solar radiation patterns on the hydrologic response are scale dependent, i.e., significant at small scales with predominant aspects and weak at larger scales where aspects become uncorrelated and orientation differences average out. Such scale dependence proves relevant for the spatial transferability of a temperature‐index model, whose calibrated degree‐day factors are stable to different solar radiation patterns for catchment sizes larger than the aspect correlation scale.
Key Points
Solar radiation patterns have scale‐dependent effects on streamflow generation
The control is exerted by catchment size as opposed to aspect correlation scale
The scale dependence affects the spatial transferability of degree‐day factors
Snow cover maps provide information of great practical interest for hydrologic purposes: when combined with point values of snow water equivalent (SWE), they enable estimation of the regional snow ...resource. In this context, Earth observation satellites are an interesting tool for evaluating large scale snow distribution and extension. MODIS (MODerate resolution Imaging Spectroradiometer on board Terra and Aqua satellites) daily Snow Covered Area product has been widely tested and proved to be appropriate for hydrologic applications. However, within a daily map the presence of cloud cover can hide the ground, thus obstructing snow detection. Here, we consider MODIS binary products for daily snow mapping over the Po River basin. Ten years (2003-2012) of MOD10A1 and MYD10A1 snow maps have been analysed and processed with the support of a 500 m resolution Digital Elevation Model (DEM). We first investigate the issue of cloud obstruction, highlighting its dependence on altitude and season. Snow maps seem to suffer the influence of overcast conditions mainly in mountain and during the melting period. Thus, cloud cover highly influences those areas where snow detection is regarded with more interest. In spring, the average percentages of area lying beneath clouds are in the order of 70%, for altitudes over 1000 m a.s.l. Then, starting from previous studies, we propose a cloud removal procedure and we apply it to a wide area, characterized by high geomorphological heterogeneity such as the Po River basin. In conceiving the new procedure, our first target was to preserve the daily temporal resolution of the product. Regional snow and land lines were estimated for detecting snow cover dependence on elevation. In cases when there was not enough information on the same day within the cloud-free areas, we used temporal filters with the aim of reproducing the micro-cycles which characterize the transition altitudes, where snow does not stand continually over the entire winter. In the validation stage, the proposed procedure was compared against others, showing improvements in the performance for our case study. The accuracy is assessed by applying the procedure to clear-sky maps masked with additional cloud cover. The average value is higher than 95% considering 40 days chosen over all seasons. The procedure also has advantages in terms of input data and computational effort requirements.
A recent study by Bojowald and Paily M. Bojowald and G. M. Paily, Phys. Rev. D 87, 044044 (2013). provided a path toward the identification of an effective quantum-spacetime picture of loop quantum ...gravity, applicable in the “Minkowski regime,” the regime where the large-scale (coarse-grained) spacetime metric is flat. A pivotal role in the analysis is played by loop-quantum-gravity-based modifications to the hypersurface deformation algebra, which leave a trace in the Minkowski regime. We here show that the symmetry-algebra results reported by Bojowald and Paily are consistent with a description of spacetime in the Minkowski regime given in terms of the κ-Minkowski noncommutative spacetime, whose relevance for the study of the quantum-gravity problem had already been proposed for independent reasons.
In this paper, a fast and effective CFD-based automatic loop for optimization of rotorcraft components is presented. The automatic loop is strictly designed around an innovative Multi Objective ...Evolutionary Algorithm (MOEA) developed at University of Padua, namely the GeDEA-II. This algorithm allows performing multi-objective, multi-point optimization works in a fast and robust way. It combines novel crossover and mutation operators when compared to other state-of-the-art MOEA. Recent papers show its excellent performance when tested on state-of-the-art problems. In order to test the performance of this algorithm, two test cases are presented, each having peculiar characteristics making them even harder to solve. Test cases regard the aerodynamic shape optimization of ERICA components, that is an innovative tilt-rotor concept conceived and designed recently. The first problem regards the single-objective, multi-constrained aerodynamic optimization of the ERICA tilt-rotor cockpit region. The second one is a multi-objective multi-constrained optimization of the ERICA landing gear sponsons. Results demonstrate the effectiveness of this automatic optimization loop in tackling real-world engineering problems.
Two-photon resonant excitation of the biexciton-exciton cascade in a quantum dot generates highly polarization-entangled photon pairs in a near-deterministic way. However, the ultimate level of ...achievable entanglement is still debated. Here, we observe the impact of the laser-induced ac-Stark effect on the quantum dot emission spectra and on entanglement. For increasing pulse-duration-to-lifetime ratios and pump powers, decreasing values of concurrence are recorded. Nonetheless, additional contributions are still required to fully account for the observed below-unity concurrence.
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