180,375 research outputs found
Gyrofluid simulations of collisionless reconnection in the presence of diamagnetic effects
No full textInternational audienceThe effects of the ion Larmor radius on magnetic reconnection are investigated by means of numerical simulations, with a Hamiltonian gyrofluid model. In the linear regime, it is found that ion diamagnetic effects decrease the growth rate of the dominant mode. Increasing ion temperature tends to make the magnetic islands propagate in the ion diamagnetic drift direction. In the nonlinear regime, diamagnetic effects reduce the final width of the island. Unlike the electron density, the guiding center density does not tend to distribute along separatrices and at high ion temperature, the electrostatic potential exhibits the superposition of a small scale structure, related to the electron density, and a large scale structure, related to the ion guiding-center density
I prelievi coattivi. Procedibilità, competenza ed attribuzione. Accelerazione dei processi. Interventi in materia di libertà personale
No full textil contributo riguarda le novità normative introdotte con la legge sull'omicidio stradale, con particolare riferimento all'introduzione dei prelievi coattivi di materiale biologico finalizzate all'accertamento dei reati di lesioni personali stradali e omicidio stradale. Vengono altresì analizzate le nuove disposizioni in materia di libertà personale riguardanti l'introduzione del potere di arresto in flagranza obbligatorio e facoltativo per i reati di nuova introduzione, come pure le disposizioni in tema di accelerazione delle indagini e dell'esercizio dell'azione penale per i reati in questione
Lo spirito del naturale e il sentimento del tempo
No full textSi tratta di una introduzione agli articoli pubblicati da Roberto Tassi sul quotidiano "La Repubblica", su cui Tassi ha scritto per una ventina d'anni, sino alla morte (1996) e si concentra sulle due linee tematiche principali affrontate da Tassi nella sua lettura delle arti visive: la natura e il tempo
Introduzione alla Finanza Matematica. Concetti di base, tassi e obbligazioni
No full textI principi fondamentali della Finanza Matematica. Leggi di capitalizzazione, tassi d'interesse, arbitraggi, obbligazioni, contratti a termin
Submarine gas burst at Panarea Island (southern Italy) on 3 November 2002: A magmatic versus hydrothermal episode
No full textOn 3 November 2002, fishermen observed the sudden appearance at the sea surface of three large whitish plumes 3 km offshore of Panarea Island (Aeolian Islands, southern Italy) caused by the uprising from the seafloor of huge columns of gas bubbles, mixed with sediments and colloidal sulfur. The degassing event partly superimposed an already existing gentle-degassing fumarolic field. Since 12 November 2002, a discontinuous geochemical monitoring program of these new discharging fluids have been carried out. The submarine emissions collected on November 2002 were an emulsion made by a CO2-dominated continuous gas phase with suspended sediments, colloidal sulfur, and water condensate microdroplets acidified by dissolution of compounds such as SO2, HCl, and HF. In the gas phase, light-unsaturated hydrocarbons also occurred, possibly related to relatively high temperature and oxidizing conditions due to local input of magmatic fluids at depth, whose occurrence was also supported by the relative high values of 3He/4He isotopic ratio (R/Rair = 4.62) with respect to previously measured values (R/R air < 4.2). The flux of the submarine emissions significantly decreased in a couple of months together with the almost complete disappearance of the magmatic chemical markers and the decrease of the helium isotopic ratio. Thus the most striking feature of the temporal and spatial evolution in the chemical and isotopic compositions of the submarine fumaroles was the relatively rapid restoration, since January 2003, of the precrisis conditions, i.e., typical of a stationary hydrothermal system. Copyright 2007 by the American Geophysical Union
A joint communication and computing resource management scheme for pervasive grid networks
No full textThe last years have been characterized by an increasing interest in the grid and cloud computing that allow the implementation of high performance computing structures in a distributed way by exploiting multiple processing resources. The presence of mobile terminals has extended the paradigm to the so called pervasive grid networks, where multiple heterogeneous devices are interconnected to form a distributed computing resource. In such a scenario, there is the need of efficient techniques for providing reliable wireless connections among network nodes. This paper deals with the proposal of a suitable resource management scheme relying on a routing algorithm able to perform jointly the resource discovery and task scheduling for implementing an efficient pervasive grid infrastructure in a wireless ad hoc scenario. The proposed solutions have been considered within two different parallelization processing schemes, and their effectiveness has been verified by resorting to computer simulations. Copyright (c) 2011 John Wiley & Sons, Ltd
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
A novel routing algorithm for mobile pervasive computing
No full textThe interest towards real-time computing has lead an even more interest in grid computing. While in the past the implementation of grid computing has been done on high performance computers, in the recent years there is an increasing interest in the pervasive grid scenarios, where multiple devices can be used for a distributed computing. The most challenging idea is to use mobile devices connected among them with wireless connections for setting up pervasive grid environments. In this context, it is a crucial problem the optimization of the routing algorithms among the processing nodes, in order to satisfy the performance requirements of a distributed computing. Aim of this paper is the design of specific routing algorithms for different pervasive grid applications with a particular attention to time sensitive scenarios
Reply to Dahlman et al. No association of reported functional protein tyrosine phosphatase 1B 3'UTR gene polymorphism with features of the metabolic syndrome in a Swedish population
No full text"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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