Liste des mémoires soutenus pendant la période 2008-2010

Liste des mémoires soutenus pendant la période 2008-201

Constants of motion and the conformal anti - de Sitter algebra in (2+1)-Dimensional Gravity

Constants of motion are calculated for 2+1 dimensional gravity with topology R x T^2 and negative cosmological constant. Certain linear combinations of them satisfy the anti - de Sitter algebra so(2,2) in either ADM or holonomy variables. Quantisation is straightforward in terms of the holonomy parameters. On inclusion of the Hamiltonian three new global constants are derived and the quantum algebra extends to that of the conformal algebra so(2,3). The modular group appears as a discrete subgroup of the conformal group. Its quantum action is generated by these conserved quantities.Comment: 22 pages, Plain Tex, No Figure

Legitimizing the Educational Experience in the context of the Didactic Methodology

The didactic methodology reminds of the idea of an efficient functioning of the education process. In this way, the systemic perspective of the didactic methodology illustrates the way in which the educational experience transposed at the level of the teaching-learning-evaluating activity. Thus, the didactic courses of action initiated in the context of the educational reality emphasize an image that legitimizes the experience of learning itself in general. Therefore, from a pragmatic perspective, the didactic methodology represents a transposition of the educational strategies in relevant learning situations and adequate (self) training actions.didactic activity, educational methodology, didactic methodology, didactic technology, educational experience

Can Manipulators Mislead Prediction Market Observers?

We study experimental markets where privately informed traders exchange simple assets, and where uninformed third parties are asked to forecast the values of these assets, guided only by market prices. Although prices only partially aggregate information, they significantly improve the forecasts of third parties. In a second treatment, a portion of traders are given preferences over the forecasts made by observers. Although we find evidence that these traders attempt to manipulate prices in order to influence the beliefs of observers, we find no evidence that observers make less accurate forecasts as a result.

Preparing Black and Latino Young Men for College and Careers: A Description of the Schools and Strategies in NYC's Expanded Success Initiative

The Expanded Success Initiative (ESI) provides funding and technical support to 40 relatively successful New York City high schools to help them improve college and career readiness among black and Latino male students. This preliminary report describes key components and strategies of ESI and begins to look at factors that might influence the potential to apply ESI more broadly

EEG source connectivity to localize the seizure onset zone in patients with drug resistant epilepsy

Visual inspection of the EEG to determine the seizure onset zone (SOZ) in the context of the presurgical evaluation in epilepsy is time-consuming and often challenging or impossible. We offer an approach that uses EEG source imaging (ESI) in combination with functional connectivity analysis (FC) to localize the SOZ from ictal EEG. Ictal low-density-scalp EEG from 111 seizures in 27 patients who were rendered-seizure free after surgery was analyzed. For every seizure, ESI (LORETA) was applied on an artifact-free epoch selected around the seizure onset. Additionally, FC was applied on the reconstructed sources. We estimated the SOZ in two ways: (i)the source with highest power after ESI and (ii)the source with the most outgoing connections after ESI and FC. For both approaches, the distance between the estimated SOZ and the resected zone (RZ) of the patient were calculated. Using ESI alone, the SOZ was estimated inside the RZ in 31% of the seizures and within 10mm from the border of the RZ in 42%. For 18.5% of the patients, all seizures were estimated within 10mm of the RZ. Using ESI and FC, 72% of the seizures were estimated inside the RZ, and 94% within 10mm. For 85% of the patients, all seizures were estimated within 10mm of the RZ. FC provided a significant added value to ESI alone (p<0.001). ESI combined with subsequent FC is able to localize the SOZ in a non-invasive way with high accuracy. Therefore it could be a valuable tool in the presurgical evaluation of epilepsy