69 research outputs found
Phase-TA: Periodicity Detection and Characterization for HPC Applications
International audienceThe world of High-Performance Computing (HPC) currently stands on the edge of the ExaScale. The supercomputers are growing ever more powerful, requiring power-efficient components and ever smarter tool-suites to operate them. One of the key features of those frameworks will be their ability to monitor and predict the behavior of executed applications to optimize resources utilization, and abide by the operating constraints, notably on power consumption. In this context, this article presents Phase-TA, an offline tool which detects and characterizes the inherent periodicities of iterative HPC applications, with no prior knowledge of the latter. To do so, it analyzes the evolution of several performance counters at the scale of the compute node, and infers patterns representing the identified periodicities. As a result, Phase-TA offers a nonintrusive mean to gain insights on the processor use associated with an application, and paves the way to predicting its behavior. Phase-TA was tested on a panel of 3 applications and benchmarks from the supercomputing field: HPCG, NEMO, and OpenFoam. For all of them, periodicities, accountable for on average 78% of their execution time, were detected and represented by accurate patterns. Furthermore, it was demonstrated that there is no need to analyze the whole profile of an application to precisely characterize its periodic behaviors. Indeed, an extract of the aforementioned profile is enough for Phase-TA to infer representative patterns on-the-fly, opening the way to energyefficiency optimization through Dynamic Voltage-Frequency Scaling (DVFS)
Very low-temperature epitaxial growth of Mn5Ge3 and Mn5Ge3C0.2 films on Ge(111) using molecular beam epitaxy
International audienceC-doped Mn5Ge3 compound is ferromagnetic at temperature up to 430 K. Hence it is a potential spin injector into group-IV semiconductors. Segregation and diffusion of Mn at the Mn5Ge3 /Ge interface could severely hinder the efficiency of the spin injection. To avoid these two phenomena we investigate the growth of Mn5Ge3 and C-doped Mn5Ge3 films on Ge(111) substrates by molecular beam epitaxy at room-temperature. The reactive deposition epitaxy method is used to deposit these films. Reflection high energy electron diffraction, X-ray diffraction analysis, transmission electron microscopy and atomic force microscopy indicate that the crystalline quality is very high. Magnetic characterizations by superconducting quantum interference device and ferromagnetic resonance reinforce the structural analysis results on the thin films quality
Loss of microRNA-7a2 induces hypogonadotropic hypogonadism and infertility
MicroRNAs (miRNAs) are negative modulators of gene expression that fine-tune numerous biological processes. miRNA loss-of-function rarely results in highly penetrant phenotypes, but rather, influences cellular responses to physiologic and pathophysiologic stresses. Here, we have reported that a single member of the evolutionarily conserved miR-7 family, miR7a2, is essential for normal pituitary development and hypothalamic-pituitary-gonadal (HPG) function in adulthood. Genetic deletion of mir-7a2 causes infertility, with low levels of gonadotropic and sex steroid hormones, small testes or ovaries, impaired spermatogenesis, and lack of ovulation in male and female mice, respectively. We found that miR-7a2 is highly expressed in the pituitary, where it suppresses golgi glycoprotein 1 (GLG1) expression and downstream bone morphogenetic protein 4 (BMP4) signaling and also reduces expression of the prostaglandin F2a receptor negative regulator (PTGFRN), an inhibitor of prostaglandin signaling and follicle-stimulating hormone (FSH) and luteinizing hormone (LH) secretion. Our results reveal that miR-7a2 critically regulates sexual maturation and reproductive function by interconnecting miR-7 genomic circuits that regulate FSH and LH synthesis and secretion through their effects on pituitary prostaglandin and BMP4 signaling
Personalized bacteriophage therapy outcomes for 100 consecutive cases:a multicentre, multinational, retrospective observational study
In contrast to the many reports of successful real-world cases of personalized bacteriophage therapy (BT), randomized controlled trials of non-personalized bacteriophage products have not produced the expected results. Here we present the outcomes of a retrospective observational analysis of the first 100 consecutive cases of personalized BT of difficult-to-treat infections facilitated by a Belgian consortium in 35 hospitals, 29 cities and 12 countries during the period from 1 January 2008 to 30 April 2022. We assessed how often personalized BT produced a positive clinical outcome (general efficacy) and performed a regression analysis to identify functional relationships. The most common indications were lower respiratory tract, skin and soft tissue, and bone infections, and involved combinations of 26 bacteriophages and 6 defined bacteriophage cocktails, individually selected and sometimes pre-adapted to target the causative bacterial pathogens. Clinical improvement and eradication of the targeted bacteria were reported for 77.2% and 61.3% of infections, respectively. In our dataset of 100 cases, eradication was 70% less probable when no concomitant antibiotics were used (odds ratio = 0.3; 95% confidence interval = 0.127â0.749). In vivo selection of bacteriophage resistance and in vitro bacteriophageâantibiotic synergy were documented in 43.8% (7/16 patients) and 90% (9/10) of evaluated patients, respectively. We observed a combination of antibiotic re-sensitization and reduced virulence in bacteriophage-resistant bacterial isolates that emerged during BT. Bacteriophage immune neutralization was observed in 38.5% (5/13) of screened patients. Fifteen adverse events were reported, including seven non-serious adverse drug reactions suspected to be linked to BT. While our analysis is limited by the uncontrolled nature of these data, it indicates that BT can be effective in combination with antibiotics and can inform the design of future controlled clinical trials. BT100 study, ClinicalTrials.gov registration: NCT05498363.</p
Approches statiques et dynamiques pour l'optimisation de la consommation énergétique des applications de calcul à hautes performances
The High Performance Computing (HPC) field is a crucial issue, for both industry andacademics: from astrophysics to meteorology, passing by materials chemistry, fromAirbus to Total, passing by Pfizer. Computational sciences have become essential, andthis dependence implies a neverending urge for more computational power.At the time of writing, all the actors of the HPC field redouble their efforts to reach theExaScale: 10^18 operations on floating point numbers per second. Nevertheless, contraryto the previous milestones (e.g. the PetaScale), the computational power achieved by asupercomputer is not the only key performance indicator. Indeed, the first assessment ofthe electrical power consumed by an exaflopic system were way too high to be acceptable,from both economic and ecological points of view. Consequently, numerous research anddevelopment efforts aiming at making supercomputer more energy-efficient were initiatedduring the last decade.That is precisely the main topic of the work presented by this manuscript, whichincludes significant contributions to Bull Dynamic Power Optimizer (BDPO), and theconception, development, and experimental validation of Phase - Temporality Analyser(Phase-TA).BDPO is a dynamic reconfiguration tool, that is to say a daemon executed in parallel ofan HPC application, which changes the functioning frequency of the cores of the CPUs tothe workload the latter are executing. It has the distinctive feature of being completelyagnostic of both the aforementioned executed application and its execution environment,while requiring no specific configuration from the user. Using BDPO induces a 15% decreaseof the energy consumption associated with the execution of the two applications NEMO andHPCG, while maintaining the associated performance degradation under 4%.Phase-TA is designed to analyse the profile of an iterative HPC application, notablythose produced by BDPO. It detects the locally periodic behaviours, and caracterises themby infering representative patterns for the associated periodicities. What motivated thedevelopment of Phase-TA was the possibility to build a relevant and reliable predictionof the future behaviour of the executed application, so as to make the reconfigurationsperformed by BDPO more efficient. It was experimentally shown that the patterns inferredby Phase-TA are relevant representations of the periodicities featured by HPC applications,and that those periodicities are accountable for a significant part (i.e. more than twothirds) of the execution time of the aformentioned applications. Finally, the performancesof Phase-TA make it suitable for on-the-fly analysis of the profile of HPC applications.Le domaine du calcul aÌ hautes performances est un enjeu industriel et acadeÌmique crucial : de lâastrophysique aÌ la meÌteÌorologie en passant par la chimie des mateÌriaux, dâAirbus aÌ Total, en passant par Pfizer. Les sciences numeÌriques leurs sont devenues indispensables, et cette deÌpendance se traduit par un besoin pour toujours plus de puissance de calcul. Au moment de lâeÌcriture de ce manuscrit, tous les acteurs du calcul aÌ hautes performances redoublent dâeffort pour atteindre lâExaScale : 10^18 opeÌrations sur nombres aÌ virgule flottante par seconde. NeÌanmoins, contrairement au passage des preÌceÌdents jalons (e.g. le PetaScale), la puissance de calcul atteinte par un supercalculateur nâest pas la seule grandeur dâinteÌreÌt. En effet, les premieÌres estimations de la puissance eÌlectrique consommeÌe par un systeÌme exaflopique eÌtaient bien trop eÌleveÌes pour eÌtre acceptables, aussi bien du point de vue eÌconomique quâeÌcologique. En conseÌquence, de nombreux efforts de recherche et de deÌveloppement visant aÌ reÌduire la consommation eÌnergeÌtique des supercalculateurs ont vu le jour. Câest preÌciseÌment le theÌme central des travaux preÌsenteÌs par ce manuscrit, qui incluentdes contributions significatives aÌ Bull Dynamic Power Optimizer (BDPO), ainsi que la conception, le deÌveloppement, et la validation expeÌrimentale de Phase - Temporality Analyser (Phase-TA). BDPO est un outil de reconfiguration dynamique, câest-aÌ-dire un daemon exeÌcuteÌ en paralleÌle dâune application de calcul intensif, qui adapte la freÌquence des cĆurs de calcul aÌ la charge de travail que ces derniers exeÌcutent. Il a la particulariteÌ dâeÌtre compleÌtement agnostique de ladite application, ainsi que du support dâexeÌcution, tout en ne requeÌrant aucune configuration de la part de lâutilisateur. Lâutilisation de BDPO permet de reÌduire lâeÌnergie consommeÌe associeÌe aÌ lâexeÌcution des applications NEMO et HPCG dâenviron 15%, tout en maintenant la deÌgradation de performance associeÌe sous les 4%. Phase-TA est un outil dâanalyse du profil dâune application iteÌrative de calcul intensif, notamment ceux produits par BDPO. Il deÌtecte les comportements localement peÌriodiques, et les caracteÌrise en construisant des motifs repreÌsentatifs des peÌriodiciteÌs associeÌes. Ce qui a motiveÌ le deÌveloppement de Phase-TA est de pouvoir fournir aÌ BDPO une preÌdiction pertinente et fiable du comportement aÌ venir de lâapplication exeÌcuteÌe, de sorte aÌ ameÌliorer lâefficaciteÌ des reconfigurations quâil opeÌre. Il a eÌteÌ montreÌ expeÌrimentalement que les motifs construits par Phase-TA sont des repreÌsentations pertinentes des peÌriodiciteÌs exhibeÌes par les applications de calcul intensif, et quâune part significative (i.e. plus de deux tiers) du temps dâexeÌcution de ces dernieÌres leur est imputable. Enfin, les performances de Phase-TApermettent dâenvisager son utilisation pendant lâexeÌcution dâune application de calcul intensif
Static and dynamic approaches for the optimization of the energy consumption associated with applications of the High Performance Computing (HPC) field
Le domaine du calcul aÌ hautes performances est un enjeu industriel et acadeÌmique crucial : de lâastrophysique aÌ la meÌteÌorologie en passant par la chimie des mateÌriaux, dâAirbus aÌ Total, en passant par Pfizer. Les sciences numeÌriques leurs sont devenues indispensables, et cette deÌpendance se traduit par un besoin pour toujours plus de puissance de calcul. Au moment de lâeÌcriture de ce manuscrit, tous les acteurs du calcul aÌ hautes performances redoublent dâeffort pour atteindre lâExaScale : 10^18 opeÌrations sur nombres aÌ virgule flottante par seconde. NeÌanmoins, contrairement au passage des preÌceÌdents jalons (e.g. le PetaScale), la puissance de calcul atteinte par un supercalculateur nâest pas la seule grandeur dâinteÌreÌt. En effet, les premieÌres estimations de la puissance eÌlectrique consommeÌe par un systeÌme exaflopique eÌtaient bien trop eÌleveÌes pour eÌtre acceptables, aussi bien du point de vue eÌconomique quâeÌcologique. En conseÌquence, de nombreux efforts de recherche et de deÌveloppement visant aÌ reÌduire la consommation eÌnergeÌtique des supercalculateurs ont vu le jour. Câest preÌciseÌment le theÌme central des travaux preÌsenteÌs par ce manuscrit, qui incluentdes contributions significatives aÌ Bull Dynamic Power Optimizer (BDPO), ainsi que la conception, le deÌveloppement, et la validation expeÌrimentale de Phase - Temporality Analyser (Phase-TA). BDPO est un outil de reconfiguration dynamique, câest-aÌ-dire un daemon exeÌcuteÌ en paralleÌle dâune application de calcul intensif, qui adapte la freÌquence des cĆurs de calcul aÌ la charge de travail que ces derniers exeÌcutent. Il a la particulariteÌ dâeÌtre compleÌtement agnostique de ladite application, ainsi que du support dâexeÌcution, tout en ne requeÌrant aucune configuration de la part de lâutilisateur. Lâutilisation de BDPO permet de reÌduire lâeÌnergie consommeÌe associeÌe aÌ lâexeÌcution des applications NEMO et HPCG dâenviron 15%, tout en maintenant la deÌgradation de performance associeÌe sous les 4%. Phase-TA est un outil dâanalyse du profil dâune application iteÌrative de calcul intensif, notamment ceux produits par BDPO. Il deÌtecte les comportements localement peÌriodiques, et les caracteÌrise en construisant des motifs repreÌsentatifs des peÌriodiciteÌs associeÌes. Ce qui a motiveÌ le deÌveloppement de Phase-TA est de pouvoir fournir aÌ BDPO une preÌdiction pertinente et fiable du comportement aÌ venir de lâapplication exeÌcuteÌe, de sorte aÌ ameÌliorer lâefficaciteÌ des reconfigurations quâil opeÌre. Il a eÌteÌ montreÌ expeÌrimentalement que les motifs construits par Phase-TA sont des repreÌsentations pertinentes des peÌriodiciteÌs exhibeÌes par les applications de calcul intensif, et quâune part significative (i.e. plus de deux tiers) du temps dâexeÌcution de ces dernieÌres leur est imputable. Enfin, les performances de Phase-TApermettent dâenvisager son utilisation pendant lâexeÌcution dâune application de calcul intensif.The High Performance Computing (HPC) field is a crucial issue, for both industry andacademics: from astrophysics to meteorology, passing by materials chemistry, fromAirbus to Total, passing by Pfizer. Computational sciences have become essential, andthis dependence implies a neverending urge for more computational power.At the time of writing, all the actors of the HPC field redouble their efforts to reach theExaScale: 10^18 operations on floating point numbers per second. Nevertheless, contraryto the previous milestones (e.g. the PetaScale), the computational power achieved by asupercomputer is not the only key performance indicator. Indeed, the first assessment ofthe electrical power consumed by an exaflopic system were way too high to be acceptable,from both economic and ecological points of view. Consequently, numerous research anddevelopment efforts aiming at making supercomputer more energy-efficient were initiatedduring the last decade.That is precisely the main topic of the work presented by this manuscript, whichincludes significant contributions to Bull Dynamic Power Optimizer (BDPO), and theconception, development, and experimental validation of Phase - Temporality Analyser(Phase-TA).BDPO is a dynamic reconfiguration tool, that is to say a daemon executed in parallel ofan HPC application, which changes the functioning frequency of the cores of the CPUs tothe workload the latter are executing. It has the distinctive feature of being completelyagnostic of both the aforementioned executed application and its execution environment,while requiring no specific configuration from the user. Using BDPO induces a 15% decreaseof the energy consumption associated with the execution of the two applications NEMO andHPCG, while maintaining the associated performance degradation under 4%.Phase-TA is designed to analyse the profile of an iterative HPC application, notablythose produced by BDPO. It detects the locally periodic behaviours, and caracterises themby infering representative patterns for the associated periodicities. What motivated thedevelopment of Phase-TA was the possibility to build a relevant and reliable predictionof the future behaviour of the executed application, so as to make the reconfigurationsperformed by BDPO more efficient. It was experimentally shown that the patterns inferredby Phase-TA are relevant representations of the periodicities featured by HPC applications,and that those periodicities are accountable for a significant part (i.e. more than twothirds) of the execution time of the aformentioned applications. Finally, the performancesof Phase-TA make it suitable for on-the-fly analysis of the profile of HPC applications
Approches statiques et dynamiques pour l'optimisation de la consommation énergétique des applications de calcul à hautes performances
The High Performance Computing (HPC) field is a crucial issue, for both industry andacademics: from astrophysics to meteorology, passing by materials chemistry, fromAirbus to Total, passing by Pfizer. Computational sciences have become essential, andthis dependence implies a neverending urge for more computational power.At the time of writing, all the actors of the HPC field redouble their efforts to reach theExaScale: 10^18 operations on floating point numbers per second. Nevertheless, contraryto the previous milestones (e.g. the PetaScale), the computational power achieved by asupercomputer is not the only key performance indicator. Indeed, the first assessment ofthe electrical power consumed by an exaflopic system were way too high to be acceptable,from both economic and ecological points of view. Consequently, numerous research anddevelopment efforts aiming at making supercomputer more energy-efficient were initiatedduring the last decade.That is precisely the main topic of the work presented by this manuscript, whichincludes significant contributions to Bull Dynamic Power Optimizer (BDPO), and theconception, development, and experimental validation of Phase - Temporality Analyser(Phase-TA).BDPO is a dynamic reconfiguration tool, that is to say a daemon executed in parallel ofan HPC application, which changes the functioning frequency of the cores of the CPUs tothe workload the latter are executing. It has the distinctive feature of being completelyagnostic of both the aforementioned executed application and its execution environment,while requiring no specific configuration from the user. Using BDPO induces a 15% decreaseof the energy consumption associated with the execution of the two applications NEMO andHPCG, while maintaining the associated performance degradation under 4%.Phase-TA is designed to analyse the profile of an iterative HPC application, notablythose produced by BDPO. It detects the locally periodic behaviours, and caracterises themby infering representative patterns for the associated periodicities. What motivated thedevelopment of Phase-TA was the possibility to build a relevant and reliable predictionof the future behaviour of the executed application, so as to make the reconfigurationsperformed by BDPO more efficient. It was experimentally shown that the patterns inferredby Phase-TA are relevant representations of the periodicities featured by HPC applications,and that those periodicities are accountable for a significant part (i.e. more than twothirds) of the execution time of the aformentioned applications. Finally, the performancesof Phase-TA make it suitable for on-the-fly analysis of the profile of HPC applications.Le domaine du calcul aÌ hautes performances est un enjeu industriel et acadeÌmique crucial : de lâastrophysique aÌ la meÌteÌorologie en passant par la chimie des mateÌriaux, dâAirbus aÌ Total, en passant par Pfizer. Les sciences numeÌriques leurs sont devenues indispensables, et cette deÌpendance se traduit par un besoin pour toujours plus de puissance de calcul. Au moment de lâeÌcriture de ce manuscrit, tous les acteurs du calcul aÌ hautes performances redoublent dâeffort pour atteindre lâExaScale : 10^18 opeÌrations sur nombres aÌ virgule flottante par seconde. NeÌanmoins, contrairement au passage des preÌceÌdents jalons (e.g. le PetaScale), la puissance de calcul atteinte par un supercalculateur nâest pas la seule grandeur dâinteÌreÌt. En effet, les premieÌres estimations de la puissance eÌlectrique consommeÌe par un systeÌme exaflopique eÌtaient bien trop eÌleveÌes pour eÌtre acceptables, aussi bien du point de vue eÌconomique quâeÌcologique. En conseÌquence, de nombreux efforts de recherche et de deÌveloppement visant aÌ reÌduire la consommation eÌnergeÌtique des supercalculateurs ont vu le jour. Câest preÌciseÌment le theÌme central des travaux preÌsenteÌs par ce manuscrit, qui incluentdes contributions significatives aÌ Bull Dynamic Power Optimizer (BDPO), ainsi que la conception, le deÌveloppement, et la validation expeÌrimentale de Phase - Temporality Analyser (Phase-TA). BDPO est un outil de reconfiguration dynamique, câest-aÌ-dire un daemon exeÌcuteÌ en paralleÌle dâune application de calcul intensif, qui adapte la freÌquence des cĆurs de calcul aÌ la charge de travail que ces derniers exeÌcutent. Il a la particulariteÌ dâeÌtre compleÌtement agnostique de ladite application, ainsi que du support dâexeÌcution, tout en ne requeÌrant aucune configuration de la part de lâutilisateur. Lâutilisation de BDPO permet de reÌduire lâeÌnergie consommeÌe associeÌe aÌ lâexeÌcution des applications NEMO et HPCG dâenviron 15%, tout en maintenant la deÌgradation de performance associeÌe sous les 4%. Phase-TA est un outil dâanalyse du profil dâune application iteÌrative de calcul intensif, notamment ceux produits par BDPO. Il deÌtecte les comportements localement peÌriodiques, et les caracteÌrise en construisant des motifs repreÌsentatifs des peÌriodiciteÌs associeÌes. Ce qui a motiveÌ le deÌveloppement de Phase-TA est de pouvoir fournir aÌ BDPO une preÌdiction pertinente et fiable du comportement aÌ venir de lâapplication exeÌcuteÌe, de sorte aÌ ameÌliorer lâefficaciteÌ des reconfigurations quâil opeÌre. Il a eÌteÌ montreÌ expeÌrimentalement que les motifs construits par Phase-TA sont des repreÌsentations pertinentes des peÌriodiciteÌs exhibeÌes par les applications de calcul intensif, et quâune part significative (i.e. plus de deux tiers) du temps dâexeÌcution de ces dernieÌres leur est imputable. Enfin, les performances de Phase-TApermettent dâenvisager son utilisation pendant lâexeÌcution dâune application de calcul intensif
Approches statiques et dynamiques pour l'optimisation de la consommation énergétique des applications de calcul à hautes performances
The High Performance Computing (HPC) field is a crucial issue, for both industry andacademics: from astrophysics to meteorology, passing by materials chemistry, fromAirbus to Total, passing by Pfizer. Computational sciences have become essential, andthis dependence implies a neverending urge for more computational power.At the time of writing, all the actors of the HPC field redouble their efforts to reach theExaScale: 10^18 operations on floating point numbers per second. Nevertheless, contraryto the previous milestones (e.g. the PetaScale), the computational power achieved by asupercomputer is not the only key performance indicator. Indeed, the first assessment ofthe electrical power consumed by an exaflopic system were way too high to be acceptable,from both economic and ecological points of view. Consequently, numerous research anddevelopment efforts aiming at making supercomputer more energy-efficient were initiatedduring the last decade.That is precisely the main topic of the work presented by this manuscript, whichincludes significant contributions to Bull Dynamic Power Optimizer (BDPO), and theconception, development, and experimental validation of Phase - Temporality Analyser(Phase-TA).BDPO is a dynamic reconfiguration tool, that is to say a daemon executed in parallel ofan HPC application, which changes the functioning frequency of the cores of the CPUs tothe workload the latter are executing. It has the distinctive feature of being completelyagnostic of both the aforementioned executed application and its execution environment,while requiring no specific configuration from the user. Using BDPO induces a 15% decreaseof the energy consumption associated with the execution of the two applications NEMO andHPCG, while maintaining the associated performance degradation under 4%.Phase-TA is designed to analyse the profile of an iterative HPC application, notablythose produced by BDPO. It detects the locally periodic behaviours, and caracterises themby infering representative patterns for the associated periodicities. What motivated thedevelopment of Phase-TA was the possibility to build a relevant and reliable predictionof the future behaviour of the executed application, so as to make the reconfigurationsperformed by BDPO more efficient. It was experimentally shown that the patterns inferredby Phase-TA are relevant representations of the periodicities featured by HPC applications,and that those periodicities are accountable for a significant part (i.e. more than twothirds) of the execution time of the aformentioned applications. Finally, the performancesof Phase-TA make it suitable for on-the-fly analysis of the profile of HPC applications.Le domaine du calcul aÌ hautes performances est un enjeu industriel et acadeÌmique crucial : de lâastrophysique aÌ la meÌteÌorologie en passant par la chimie des mateÌriaux, dâAirbus aÌ Total, en passant par Pfizer. Les sciences numeÌriques leurs sont devenues indispensables, et cette deÌpendance se traduit par un besoin pour toujours plus de puissance de calcul. Au moment de lâeÌcriture de ce manuscrit, tous les acteurs du calcul aÌ hautes performances redoublent dâeffort pour atteindre lâExaScale : 10^18 opeÌrations sur nombres aÌ virgule flottante par seconde. NeÌanmoins, contrairement au passage des preÌceÌdents jalons (e.g. le PetaScale), la puissance de calcul atteinte par un supercalculateur nâest pas la seule grandeur dâinteÌreÌt. En effet, les premieÌres estimations de la puissance eÌlectrique consommeÌe par un systeÌme exaflopique eÌtaient bien trop eÌleveÌes pour eÌtre acceptables, aussi bien du point de vue eÌconomique quâeÌcologique. En conseÌquence, de nombreux efforts de recherche et de deÌveloppement visant aÌ reÌduire la consommation eÌnergeÌtique des supercalculateurs ont vu le jour. Câest preÌciseÌment le theÌme central des travaux preÌsenteÌs par ce manuscrit, qui incluentdes contributions significatives aÌ Bull Dynamic Power Optimizer (BDPO), ainsi que la conception, le deÌveloppement, et la validation expeÌrimentale de Phase - Temporality Analyser (Phase-TA). BDPO est un outil de reconfiguration dynamique, câest-aÌ-dire un daemon exeÌcuteÌ en paralleÌle dâune application de calcul intensif, qui adapte la freÌquence des cĆurs de calcul aÌ la charge de travail que ces derniers exeÌcutent. Il a la particulariteÌ dâeÌtre compleÌtement agnostique de ladite application, ainsi que du support dâexeÌcution, tout en ne requeÌrant aucune configuration de la part de lâutilisateur. Lâutilisation de BDPO permet de reÌduire lâeÌnergie consommeÌe associeÌe aÌ lâexeÌcution des applications NEMO et HPCG dâenviron 15%, tout en maintenant la deÌgradation de performance associeÌe sous les 4%. Phase-TA est un outil dâanalyse du profil dâune application iteÌrative de calcul intensif, notamment ceux produits par BDPO. Il deÌtecte les comportements localement peÌriodiques, et les caracteÌrise en construisant des motifs repreÌsentatifs des peÌriodiciteÌs associeÌes. Ce qui a motiveÌ le deÌveloppement de Phase-TA est de pouvoir fournir aÌ BDPO une preÌdiction pertinente et fiable du comportement aÌ venir de lâapplication exeÌcuteÌe, de sorte aÌ ameÌliorer lâefficaciteÌ des reconfigurations quâil opeÌre. Il a eÌteÌ montreÌ expeÌrimentalement que les motifs construits par Phase-TA sont des repreÌsentations pertinentes des peÌriodiciteÌs exhibeÌes par les applications de calcul intensif, et quâune part significative (i.e. plus de deux tiers) du temps dâexeÌcution de ces dernieÌres leur est imputable. Enfin, les performances de Phase-TApermettent dâenvisager son utilisation pendant lâexeÌcution dâune application de calcul intensif
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