| Th2 | S. Durand.
"Reduction of the Energy Consumption in Embedded Electronic Devices with Low Control Computational Cost".
Ph.D. thesis.
NeCS team (INRIA Grenoble Rhône-Alpes, GIPSA-lab), Grenoble University.
Grenoble, France.
January 2011.
Supervised by: Jury committee: - M. Alamir (CNRS, GIPSA-lab, Grenoble, France), president of the jury
- P. Boucher (Supelec, Gif-sur-Yvette, France), reviewer
- M. Heemels (TUe, Eindhoven, The Netherlands), reviewer
- A. Cela (ESIEE, Noisy le Grand, France), member
- J.F. Guerrero-Castellanos (Facultad de Ciencias de la Electrónica, BUAP, Puebla, Mexico), member
- S. Lesecq (CEA-Leti, Grenoble, France), member
- L. Fesquet (CIS group, TIMA, Grenoble, France), invited
Abstract - Thesis reportAbstract:The demand of electronic components in all embedded and miniaturized applications encourages to develop low-cost components, in term of energy consumption and computational resources. Actually, the power consumption can be reduced when decreasing the supply voltage and/or the clock frequency, but with the effect that the device runs more slowly in return. Nevertheless, a fast predictive control strategy allows to dynamically manage this tradeoff in order to minimize the energy consumption while ensuring good performance of the device. Furthermore, the proposals are highly robust to tackle variability which is a real problem in nanometric systems on chip. Some issues are also suggested in this thesis to reduce the control computational cost. Contrary to a time-triggered system where the controller calculates the control law at each (constant and periodic) sampling time, an event-based controller updates the control signal only when the measurement sufficiently changes. Such a paradigm hence calls for resources whenever they are indeed necessary, that is when required from a performance or stability point of view for instance. The idea is to soften the computational load by reducing the number of samples and consequently the CPU utilization. Some simulation and experimental results eventually validate the interest of such an approach. |
| Th1 | S. Durand.
"Fluid Modeling of the Request Treatment in a Database Server System to avoid Thrashing" (Modélisation du traitement des requêtes d'un serveur de base de données).
Master thesis.
Sardes team (INRIA Grenoble Rhône-Alpes, LIG), ESISAR (Grenoble-INP).
Grenoble, France.
June 2007.
Supervised by: Abstract - Thesis reportAbstract:The main goal of this training was to modelize the request treatment in a database server in order to reproduce the thrashing event which occurs when the system is overloaded. A fluid approach was used to establish a first simple model. Then, we determined the available capacity of the processor (analyzing the request treatment and parallelisation costs) and established the relation between the number of requests into the server and the output throughput. We finally reproduced a typical thrashing curve and a parametric identification allowed the model to fit with the real system (a postgreSQL database server and TPC-C client generator). At the end, we improved the model and gave some points to work on the future. |