Collective and Single-particle Motion in Beyond Mean Field Approaches

We present a novel nuclear energy density functional method to calculate spectroscopic properties of atomic nuclei. Intrinsic nuclear quadrupole deformations and rotational frequencies are considered simultaneously as the degrees of freedom within a symmetry conserving configuration mixing framework. The present method allows the study of nuclear states with collective and single-particle character. We calculate the fascinating structure of the semi-magic 44S nucleus as a first application of the method, obtaining an excellent quantitative agreement both with the available experimental data and with state-of-the-art shell model calculations.Comment: 5 pages, 4 figures, accepted for publication in Phys. Rev. Let

Symmetry conserving configuration mixing description of odd mass nuclei

We present a self-consistent theory for the description of the spectroscopic properties of odd nuclei, which includes exact blocking, particle-number and angular-momentum projection, and configuration mixing. In our theory the pairing correlations are treated in a variation-after-projection approach and the triaxial deformation parameters are explicitly considered as generator coordinates. The angular-momentum and particle-number symmetries are exactly recovered. The use of the effective finite-range density-dependent Gogny force in the calculations provides an added value to the theoretical results. We apply the theory to the textbook example of Mg25 and, although this nucleus has been thoroughly studied in the past, we still provide a novel view of nuclear phenomena taking place in this nucleus. We obtain an overall good agreement with the known experimental energies and transition probabilities without any additional parameter such as effective charges. In particular, we clearly identify six bands, two of which we interpret as collective γ bandsThis work was supported by MINECO (Spain) under contract FPA2014-57196-C5-2-P

An approximation in symmetry conserving configuration mixing calculations

An approximation is proposed in Beyond mean field calculations to reduce the size of the grid subtended by the generator coordinates by one order of magnitude. We show the quality of the approximation calculating the excitation energies of the titanium isotopes and the E2 transition probabilitiesThis work was supported by the Spanish Ministerio de Economía y Competitividad under contracts FPA2011-29854-C04-04, FPA2014-57196-C5-2-P and BES-2012-05940

Distributed reinforcement learning in multi-agent decision systems

Proceeding of: 6th Ibero-American Conference on AI (IBERAMIA '98),Lisbon, Portugal, October 5–9, 1998Decision problems can be usually solved using systems that implement different paradigms. These systems may be integrated into a single distributed system, with the expectation of obtaining a group performance more satisfactory than individual performances. Such a distributed system is what we call a Multi Agent Decision System (MADES), a special kind of Multi Agent System, that integrates several heterogeneous autonomous decision systems (agents). A MADES must produce a single solution proposal for the problem instance it faces, despite the fact that its decision making is distributed, and every agent produces solution proposals according to its local view and to its idiosyncrasy. We present a distributed reinforcement algorithm for learning how to combine the decisions the agents make in a distributed way, into a single group decision (solution proposal).Publicad

A Distributed Solution to the PTE Problem

Proceeding of: AAAI Spring Symposium on Predictive Toxicology, AAAI Press, Stanford, March 1999A wide panoply of machine learning methods is available for application to the Predictive Toxicology Evaluation (PTE) problem. The authors have built four monolithic classification systems based on Tilde, Progol, C4.5 and naive bayesian classification. These systems have been trained using the PTE dataset, and their accuracy has been tested using the unseen PTE1 data set as test set. A Multi Agent Decision System (MADES) has been built using the aforementioned monolithic systems to build classification agents. The MADES was trained and tested with the same data sets used with the monolithic systems. Results show that the accuracy of the MADES improves the accuracies obtained by the monolithic systems. We believe that in most real world domains the combination of several approaches is stronger than the individuals. Introduction The Predictive Toxicology Evaluation (PTE) Challenge (Srinivasan et al. 1997) was devised by the Oxford University Computing Laboratory to test the suitability ...Publicad

Pesquisa neonatal

La pesquisa neonatal es un sistema preventivo de la salud pública dirigido a la detección de enfermedades inaparentes en el período neonatal cuyo cuadro clínico puede ser prevenido mediante su diagnóstico y tratamiento precoz a través de la determinación de marcadores bioquímicos, moleculares o funcionales en el recién nacido. El éxito de dichas acciones depende de su implementación bajo la forma de programas de implementación sistemática y continua.Facultad de Ciencias Exacta