The Experts below are selected from a list of 6163407 Experts worldwide ranked by ideXlab platform
P. Marchand - One of the best experts on this subject based on the ideXlab platform.
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Mesures hydrologiques par profileur à effet Doppler (aDcp) en France : application aux cours d'eau et aux réseaux urbains
La Houille Blanche - Revue internationale de l'eau, 2009Co-Authors: J. Le Coz, F. Larrarte, G. Saysset, G. Pierrefeu, J.f. Brochot, P. MarchandAbstract:Les profileurs acoustiques de vitesse par effet Doppler (aDcp, pour " acoustic Doppler current profiler ") sont de plus en plus utilisés pour le jaugeage des cours d'eau en France. Après un bref rappel du principe et de la mise en oeuvre de l'aDcp, les actions du groupe d'utilisateurs français (Groupe Doppler) sont présentées, en particulier concernant les incertitudes de mesure, le problème du fond mobile et le cas des profileurs fixes horizontaux (H-aDcp). Des essais prometteurs menés en réseaux d'assainissement urbains sont également décrits. / Acoustic Doppler current Profilers (aDcp) are increasingly used for gauging streams in France. After an overview of the principle of operation and deployment techniques, the efforts of the French user group (Groupe Doppler) are presented, in particular as regards measurement uncertainty, mobile-bed and fixed horizontal Profilers (H-aDcp). Promising tests conducted in urban drainage networks are also reported.
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Mesures hydrologiques par profileur à effet Doppler (aDcp) en France : application aux cours d'eau et aux réseaux urbains
2008Co-Authors: Jérôme Le Coz, F. Larrarte, G. Saysset, G. Pierrefeu, J.f. Brochot, P. MarchandAbstract:Les profileurs acoustiques de vitesse par effet Doppler (aDcp, pour « acoustic Doppler current profiler ») sont de plus en plus utilisés pour le jaugeage des cours d'eau en France. Après un bref rappel du principe et de la mise en oeuvre de l'aDcp, les actions du groupe d'utilisateurs français (Groupe Doppler) sont présentées, en particulier concernant les incertitudes de mesure, le problème du fond mobile et le cas des profileurs fixes horizontaux (H-aDcp). Des essais prometteurs menés en réseaux d'assainissement urbains sont également décrits.
M. R. Vitriü - One of the best experts on this subject based on the ideXlab platform.
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Transformation of Levantine Intermediate Water tracked by MEDARGO floats in the Western Mediterranean
Ocean Science, 2006Co-Authors: M. Emelianov, P.-m. Poulain, J. Font, C. Millot, A. Turiel, J. Solé, A. Juliü, M. R. VitriüAbstract:A clustering methodology is applied to investigate the thermohaline structure of Levantine Intermediate Water (LIW) in the western Mediterranean basin. Sixteen free-drifting hydrographic Profilers were deployed in the framework of the MFSTEP project (MEDARGO component) from September 2003. A total of 925 CTD profiles collected up to the beginning of February 2006 have been used in the analysis. The results are in good agreement with the general circulation scheme for intermediate waters in the basin and confirm the hypothesis about a "discrete-continuous" thermohaline structure of LIW.
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Transformation of Levantine Intermediate Water tracked by MedArgo floats in Western Mediterranean
Ocean Science Discussions, 2006Co-Authors: M. Emelianov, J. Font, A. Turiel, J. Solé, P. Poulain, A. Juliü, M. R. VitriüAbstract:A clustering methodology is applied to investigate the thermohaline structure of Levantine Intermediate Water (LIW) in the western Mediterranean basin. 16 free-drifting hydrographic Profilers were deployed in the framework of the MFSTEP project (MedArgo component) from September 2003. A total of 925 CTD profiles data collected until the beginning of February 2006 have been used in the analysis. The results are in good agreement with the general circulation scheme for intermediate waters in the basin and confirm the hypothesis about a "discrete-continuous" thermohaline structure of LIW.
Alexandre Bergel - One of the best experts on this subject based on the ideXlab platform.
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Performance Evolution Blueprint: Understanding the Impact of Software Evolution on Performance
2013Co-Authors: Juan Pablo Sandoval Alcocer, Alexandre Bergel, Stéphane Ducasse, Marcus DenkerAbstract:Understanding the root of a performance drop or improvement requires analyzing different program executions at a fine grain level. Such an analysis involves dedicated profiling and representation techniques. JProfiler and YourKit, two recognized code Profilers fail, on both providing adequate metrics and visual representations, conveying a false sense of the performance variation root. We propose performance evolution blueprint, a visual support to precisely compare multiple software executions. Our blueprint is offered by Rizel, a code profiler to efficiently explore performance of a set of benchmarks against multiple software revisions.
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counting messages as a proxy for average execution time in pharo
European Conference on Object-Oriented Programming, 2011Co-Authors: Alexandre BergelAbstract:Code Profilers are used to identify execution bottlenecks and understand the cause of a slowdown. Execution sampling is a monitoring technique commonly employed by code Profilers because of its low impact on execution. Regularly sampling the execution of an application estimates the amount of time the interpreter, hardware or software, spent in each method execution time. Nevertheless, this execution time estimation is highly sensitive to the execution environment, making it non reproductive, non-deterministic and not comparable across platforms. On our platform, we have observed that the number of messages sent per second remains within tight (±7%) bounds across a basket of 16 applications. Using principally the Pharo platform for experimentation, we show that such a proxy is stable, reproducible over multiple executions, profiles are comparable, even when obtained in different execution contexts. We have produced Compteur, a new code profiler that does not suffer from execution sampling limitations and have used it to extend the SUnit testing framework for execution comparison.
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ECOOP - Counting messages as a proxy for average execution time in pharo
Lecture Notes in Computer Science, 2011Co-Authors: Alexandre BergelAbstract:Code Profilers are used to identify execution bottlenecks and understand the cause of a slowdown. Execution sampling is a monitoring technique commonly employed by code Profilers because of its low impact on execution. Regularly sampling the execution of an application estimates the amount of time the interpreter, hardware or software, spent in each method execution time. Nevertheless, this execution time estimation is highly sensitive to the execution environment, making it non reproductive, non-deterministic and not comparable across platforms. On our platform, we have observed that the number of messages sent per second remains within tight (±7%) bounds across a basket of 16 applications. Using principally the Pharo platform for experimentation, we show that such a proxy is stable, reproducible over multiple executions, profiles are comparable, even when obtained in different execution contexts. We have produced Compteur, a new code profiler that does not suffer from execution sampling limitations and have used it to extend the SUnit testing framework for execution comparison.
J. Font - One of the best experts on this subject based on the ideXlab platform.
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MedArgo: a drifting profiler program in the Mediterranean Sea
Ocean Science, 2007Co-Authors: P.-m. Poulain, R. Barbanti, J. Font, A. Cruzado, C. Millot, I. Gertman, A. Griffa, Anne Molcard, V. Rupolo, S. Le BrasAbstract:In the framework of the EU-funded MFSTEP project, autonomous drifting Profilers were deployed throughout the Mediterranean Sea to collect temperature and salinity profile data and to measure subsurface currents. The realization of this profiler program in the Mediterranean, referred to as MedArgo, is described and assessed using data collected between June 2004 and December 2006 (including more than 2000 profiles). Recommendations are provided for the permanent future implementation of MedArgo in support of operational oceanography in the Mediterranean Sea. More than twenty drifting Profilers were deployed from research vessels and ships-of-opportunity in most areas of the Mediterranean. They were all programmed to execute 5-day cycles with a drift at a parking depth of 350 m and CTD profiles from either 700 or 2000 m up to the surface. They stayed at the sea surface for about 6 h to be localised by, and transmit the data to, the Argos satellite system. The temperature and salinity data obtained with pumped Sea-Bird CTD instruments were processed and made available to the scientific community and to operational users in near-real time using standard Argo protocols, and were assimilated into Mediterranean numerical forecasting models. In general, the cycling and sampling characteristics chosen for the MedArgo Profilers were found to be adequate for the Mediterranean. However, it is strongly advised to use GPS and global cellular phone telemetry or the future Argos bi-directional satellite system in order to avoid data compression and losses, for the continuation of the Mediterranean drifting profiler program.
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Transformation of Levantine Intermediate Water tracked by MEDARGO floats in the Western Mediterranean
Ocean Science, 2006Co-Authors: M. Emelianov, P.-m. Poulain, J. Font, C. Millot, A. Turiel, J. Solé, A. Juliü, M. R. VitriüAbstract:A clustering methodology is applied to investigate the thermohaline structure of Levantine Intermediate Water (LIW) in the western Mediterranean basin. Sixteen free-drifting hydrographic Profilers were deployed in the framework of the MFSTEP project (MEDARGO component) from September 2003. A total of 925 CTD profiles collected up to the beginning of February 2006 have been used in the analysis. The results are in good agreement with the general circulation scheme for intermediate waters in the basin and confirm the hypothesis about a "discrete-continuous" thermohaline structure of LIW.
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MEDARGO: A drifting profiler program in the Mediterranean Sea
Ocean Science Discussions, 2006Co-Authors: P.-m. Poulain, R. Barbanti, J. Font, A. Cruzado, C. Millot, I. Gertman, A. Griffa, Anne Molcard, V. Rupolo, S. Le BrasAbstract:In the framework of the EU-funded MFSTEP project, autonomous drifting Profilers were deployed throughout the Mediterranean Sea to collect temperature and salinity profile data and to measure subsurface currents. The realization of this profiler program in the Mediterranean, referred to as MEDARGO, is described and assessed using data collected between June 2004 and March 2006 (including more than 1500 profiles). Recommendations are provided for the permanent future implementation of MEDARGO in support of operational oceanography in the Mediterranean Sea. More than twenty drifting Profilers were deployed from research vessels and ships-of-opportunity in most areas of the Mediterranean. They were all programmed to execute 5-day cycles with drift at a neutral parking depth of 350 m and CTD profiles from either 700 or 2000 m up to the surface. They stayed at the sea surface for about 6 h to be localised by, and transmit the data to, the Argos satellite system. The temperature and salinity data obtained with pumped Sea-Bird CTD instruments were processed and made available to the scientific community and to operational users in near-real time using standard ARGO protocols, and were assimilated into Mediterranean numerical forecasting models. In general, the cycling and sampling characteristics chosen for the MEDARGO Profilers were found to be adequate for the Mediterranean. However, it is strongly advised to use GPS and global cellular phone telemetry or the future Argos bi-directional satellite system in order to avoid data compression and losses, for the continuation of the Mediterranean drifting profiler program.
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Transformation of Levantine Intermediate Water tracked by MedArgo floats in Western Mediterranean
Ocean Science Discussions, 2006Co-Authors: M. Emelianov, J. Font, A. Turiel, J. Solé, P. Poulain, A. Juliü, M. R. VitriüAbstract:A clustering methodology is applied to investigate the thermohaline structure of Levantine Intermediate Water (LIW) in the western Mediterranean basin. 16 free-drifting hydrographic Profilers were deployed in the framework of the MFSTEP project (MedArgo component) from September 2003. A total of 925 CTD profiles data collected until the beginning of February 2006 have been used in the analysis. The results are in good agreement with the general circulation scheme for intermediate waters in the basin and confirm the hypothesis about a "discrete-continuous" thermohaline structure of LIW.
V. Rupolo - One of the best experts on this subject based on the ideXlab platform.
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MedArgo: a drifting profiler program in the Mediterranean Sea
Ocean Science, 2007Co-Authors: P.-m. Poulain, R. Barbanti, J. Font, A. Cruzado, C. Millot, I. Gertman, A. Griffa, Anne Molcard, V. Rupolo, S. Le BrasAbstract:In the framework of the EU-funded MFSTEP project, autonomous drifting Profilers were deployed throughout the Mediterranean Sea to collect temperature and salinity profile data and to measure subsurface currents. The realization of this profiler program in the Mediterranean, referred to as MedArgo, is described and assessed using data collected between June 2004 and December 2006 (including more than 2000 profiles). Recommendations are provided for the permanent future implementation of MedArgo in support of operational oceanography in the Mediterranean Sea. More than twenty drifting Profilers were deployed from research vessels and ships-of-opportunity in most areas of the Mediterranean. They were all programmed to execute 5-day cycles with a drift at a parking depth of 350 m and CTD profiles from either 700 or 2000 m up to the surface. They stayed at the sea surface for about 6 h to be localised by, and transmit the data to, the Argos satellite system. The temperature and salinity data obtained with pumped Sea-Bird CTD instruments were processed and made available to the scientific community and to operational users in near-real time using standard Argo protocols, and were assimilated into Mediterranean numerical forecasting models. In general, the cycling and sampling characteristics chosen for the MedArgo Profilers were found to be adequate for the Mediterranean. However, it is strongly advised to use GPS and global cellular phone telemetry or the future Argos bi-directional satellite system in order to avoid data compression and losses, for the continuation of the Mediterranean drifting profiler program.
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Simulations of ARGO Profilers and of surface floating objects: applications in MFSTEP
Ocean Science, 2007Co-Authors: C. Pizzigalli, V. RupoloAbstract:In this work we describe part of the activities performed in the MFSTEP project by means of numerical simulations of ARGO Profilers and surface floating objects. Simulations of ARGO floats were used to define the optimal time cycling in order to maximize independent observations of vertical profiles of temperature and salinity and to minimize the error on the estimate of the velocity at the parking depth of the Profilers. Instead, the Mediterranean Forecasting System archive of Eulerian velocity field from 2000 to 2004 was used to build a related surface Lagrangian archive, systematically integrating numerical particles released and constrained to drift at surface. Here we use such Lagrangian archive to study the interannual variability of the surface Lagrangian transport in two key areas of the Western Mediterranean, also introducing an exponential decay in the particles concentration.
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MEDARGO: A drifting profiler program in the Mediterranean Sea
Ocean Science Discussions, 2006Co-Authors: P.-m. Poulain, R. Barbanti, J. Font, A. Cruzado, C. Millot, I. Gertman, A. Griffa, Anne Molcard, V. Rupolo, S. Le BrasAbstract:In the framework of the EU-funded MFSTEP project, autonomous drifting Profilers were deployed throughout the Mediterranean Sea to collect temperature and salinity profile data and to measure subsurface currents. The realization of this profiler program in the Mediterranean, referred to as MEDARGO, is described and assessed using data collected between June 2004 and March 2006 (including more than 1500 profiles). Recommendations are provided for the permanent future implementation of MEDARGO in support of operational oceanography in the Mediterranean Sea. More than twenty drifting Profilers were deployed from research vessels and ships-of-opportunity in most areas of the Mediterranean. They were all programmed to execute 5-day cycles with drift at a neutral parking depth of 350 m and CTD profiles from either 700 or 2000 m up to the surface. They stayed at the sea surface for about 6 h to be localised by, and transmit the data to, the Argos satellite system. The temperature and salinity data obtained with pumped Sea-Bird CTD instruments were processed and made available to the scientific community and to operational users in near-real time using standard ARGO protocols, and were assimilated into Mediterranean numerical forecasting models. In general, the cycling and sampling characteristics chosen for the MEDARGO Profilers were found to be adequate for the Mediterranean. However, it is strongly advised to use GPS and global cellular phone telemetry or the future Argos bi-directional satellite system in order to avoid data compression and losses, for the continuation of the Mediterranean drifting profiler program.
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Simulations of ARGO Profilers and of surface floating objects: applications in MFSTEP
Ocean Science Discussions, 2006Co-Authors: C. Pizzigalli, V. RupoloAbstract:In this work we describe part of the activities performed in the MFSTEP project by means of numerical simulations of ARGO Profilers and surface floating objects. Simulations of ARGO floats were used to define the optimal time cycling characteristics of the Profilers to maximize independent observations of vertical profiles of temperature and salinity and to minimize the error on the estimate of the velocity at the parking depth of the Profilers. Instead, the Mediterranean Forecasting System archive of Eulerian velocity field from 2000 to 2004 was used to build a related surface Lagrangian archive, systematically integrating numerical particles released and constrained to drift at surface. Such Lagrangian archive is then used to study the variability of the surface Lagrangian dispersion. Finally, as an example of a possible more realistic application, we estimated the interannual variability of the Lagrangian transport in two key areas of the Western Mediterranean also introducing an exponential decay in the particles concentration.
