Pre-scission neutron multiplicity associated with the dynamical process in superheavy mass region

The fusion-fission process accompanied by neutron emission is studied in the superheavy-mass region on the basis of the fluctuation-dissipation model combined with a statistical model. The calculation of the trajectory or the shape evolution in the deformation space of the nucleus with neutron emission is performed. Each process (quasi-fission, fusion-fission, and deep quasi-fission processes) has a characteristic travelling time from the point of contact of colliding nuclei to the scission point. These dynamical aspects of the whole process are discussed in terms of the pre-scission neutron multiplicity, which depends on the time spent on each process. We have presented the details of the characteristics of our model calculation in the reactions $^{48}$Ca+$^{208}$Pb and $^{48}$Ca+$^{244}$Pu, and shown how the structure of the distribution of pre-scission neutron multiplicity depends on the incident energy.Comment: 19 pages, 12 figures, Accepted for publication in J. Phys.

Un campo redefinido como parte de la ciudad

¿Era lo que se construyó en La Linière, en la localidad de Grand-Synthe (en el norte de Francia), un campo de refugiados tradicional o un nuevo tipo de distrito urbano

Analysis of fusion-fission dynamics by pre-scission neutron emission in 58^{58}Ni+208^{208}Pb

We analyzed the experimental data of the pre-scission neutron multiplicity in connection with fission fragments in the reaction $^{58}$Ni+$^{208}$Pb at the incident energy corresponding to the excitation energy of compound nucleus $E^{*}$=185.9 MeV, which was performed by D\'{e}MoN group. The relation between the pre-scission neutron multiplicity and each reaction process having different reaction time is investigated. In order to study the fusion-fission process accompanied by neutron emission, the fluctuation-dissipation model combined with a statistical model is employed. It is found that the fusion-fission process and the quasi-fission process are clearly distinguished in correlation with the pre-scission neutron multiplicity.Comment: 11 figure

Integrating collaborative tagging and emergent semantics for image retrieval

Trabajo presentado al Workshop de la 15th International World Wide Conference (WWW) celebrado en Edinburgh (Scotland) del 22 al 23 de mayo de 2006.In this paper, we investigate the combination of collaborative tagging and emergent semantics for improved data navigation and search. We propose to use visual features in addition to tags provided by users in order to discover new relationships between data. We show that our method is able to overcome some of the problems involved in navigating databases using tags only, such as synonymy or different languages, spelling mistakes, homonymy, or missing tags. On the other hand, image search based on visual features can be simplified substantially by the use of tags. We present technical details of our prototype system and show some preliminary results.This research was carried out and funded by the Sony Computer Science Laboratory in Paris with additional funding from the EU FET project ECAgents (IST-2003-1940) through the Sony Computer Science Laboratory in Paris.N

Continual Learning with Deep Streaming Regularized Discriminant Analysis

Continual learning is increasingly sought after in real world machine learning applications, as it enables learning in a more human-like manner. Conventional machine learning approaches fail to achieve this, as incrementally updating the model with non-identically distributed data leads to catastrophic forgetting, where existing representations are overwritten. Although traditional continual learning methods have mostly focused on batch learning, which involves learning from large collections of labeled data sequentially, this approach is not well-suited for real-world applications where we would like new data to be integrated directly. This necessitates a paradigm shift towards streaming learning. In this paper, we propose a streaming version of regularized discriminant analysis as a solution to this challenge. We combine our algorithm with a convolutional neural network and demonstrate that it outperforms both batch learning and existing streaming learning algorithms on the ImageNet ILSVRC-2012 dataset

Quasifission and fusion-fission in massive nuclei reactions. Comparison of reactions leading to the Z=120 element

The yields of evaporation residues, fusion-fission and quasifission fragments in the $^{48}$Ca+$^{144,154}$Sm and $^{16}$O+$^{186}$W reactions are analyzed in the framework of the combined theoretical method based on the dinuclear system concept and advanced statistical model. The measured yields of evaporation residues for the $^{48}$Ca+$^{154}$Sm reaction can be well reproduced. The measured yields of fission fragments are decomposed into contributions coming from fusion-fission, quasifission, and fast-fission. The decrease in the measured yield of quasifission fragments in $^{48}$Ca+$^{154}$Sm at the large collision energies and the lack of quasifission fragments in the $^{48}$Ca+$^{144}$Sm reaction are explained by the overlap in mass-angle distributions of the quasifission and fusion-fission fragments. The investigation of the optimal conditions for the synthesis of the new element $Z$=120 ($A$=302) show that the $^{54}$Cr+$^{248}$Cm reaction is preferable in comparison with the $^{58}$Fe+$^{244}$Pu and $^{64}$Ni+$^{238}$U reactions because the excitation function of the evaporation residues of the former reaction is some orders of magnitude larger than that for the last two reactions.Comment: 27 pages, 12 figures, submitted to Phys. Rev.

Le permaculteur et son robot : les microfermes et la gouvernance des nouvelles technologies

Les licences libres sont généralement considérées comme une garantie suffisante contre les risques que peuvent présenter les outils non libres. Les œuvres intellectuelles couvertes par ces licences font partie des biens communs informationnels. L’argument principal de ce texte est que ces licences ne sont pas suffisantes pour assurer un équilibre entre les concepteurs des technologies et les utilisateurs finaux. Dans ce texte, nous nous intéressons particulièrement à l’agriculture. Dans ce domaine, nous assistons aujourd’hui à une intégration entre les TIC, l’intelligence artificielle et la robotique. L’impact qu’auront ces systèmes est difficile à évaluer. Pour accompagner l’introduction des nouvelles technologies, nous suggérons de prendre en compte un autre commun : celui des pratiques agricoles. Nous proposons d’encadrer l’introduction des nouvelles technologies agricoles par des systèmes participatifs de garantie tels que mis en place par des labels participatifs.Free and Open Source licenses are generally considered a sufficient guarantee against the risks of closed-source technologies. The tools protected by open licenses belong to what is called the knowledge Commons. The main argument of this text is that these licenses are insufficient to ensure a balance between the producers of new technologies and their users. We focus on the case of agriculture. This field is currently witnessing a fast integration of ICT, artificial intelligence and robotics, and the impact of these changes is hard to predict. However, to assist with the introduction of these new technologies and manage their impact, we propose using Participative Systems of Guarantee, such as those employed by existing participative quality labels.Las licencias de software libres o de software de código abierto son consideradas generalmente como una garantía suficiente contra los riesgos que podrían presentar las herramientas no libres. Las obras intelectuales cubiertas por estas licencias forman parte de los bienes comunes informacionales. El argumento principal de este texto es que las licencias no son suficientes para asegurar un equilibrio entre los diseñadores de tecnologías y los usuarios finales. Se basa particularmente en la agricultura, en donde hoy se asiste a una integración de las TIC, la inteligencia artificial y la robótica. Resulta muy difícil evaluar el impacto futuro de estos sistemas. Para acompañar la introducción de nuevas tecnologías, se sugiere tomar en cuenta otro bien común : las prácticas agrícolas. Finalmente se encuadran las nuevas tecnologías agrícolas con Sistemas Participativos de Garantía, como los sistemas establecidos por los labels participativos

Citizen noise pollution monitoring

Trabajo presentado a la 10th Annual International Conference on Digital Government Research: Social Networks: Making Connections between Citizens, Data and Government, celebrada en Puebla (México) del 17 al 21 de mayo de 2009.In this paper we present a new approach to monitor noise pollution involving citizens and built upon the notions of participatory sensing and citizen science. We enable citizens to measure their personal exposure to noise in their everyday environment by using GPS-equipped mobile phones as noise sensors. The geo-localised measures and user-generated meta-data can be automatically sent and shared online with the public to contribute to the collective noise mapping of cities. Our prototype, called NoiseTube, can be found online.This work was partially supported by the EU under contract IST- 34721 (TAGora). The TAGora project is funded by the Future and Emerging Technologies program (IST-FET) of the European Commission. Matthias Stevens is a Research Assistant of the Fund for Scientific Research, Flanders (Aspirant van het Fonds Wetenschappelijk Onderzoek - Vlaanderen).Peer reviewe

Intrinsic motivation and episodic memories for robot exploration of high-dimensional sensory spaces

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer überregionalen Konsortiallizenz frei zugänglich.This work presents an architecture that generates curiosity-driven goal-directed exploration behaviours for an image sensor of a microfarming robot. A combination of deep neural networks for offline unsupervised learning of low-dimensional features from images and of online learning of shallow neural networks representing the inverse and forward kinematics of the system have been used. The artificial curiosity system assigns interest values to a set of pre-defined goals and drives the exploration towards those that are expected to maximise the learning progress. We propose the integration of an episodic memory in intrinsic motivation systems to face catastrophic forgetting issues, typically experienced when performing online updates of artificial neural networks. Our results show that adopting an episodic memory system not only prevents the computational models from quickly forgetting knowledge that has been previously acquired but also provides new avenues for modulating the balance between plasticity and stability of the models.H2020 Marie Skłodowska-Curie Actionshttps://doi.org/10.13039/100010665Horizon 2020 Framework Programmehttps://doi.org/10.13039/100010661Peer Reviewe