2,374 research outputs found
La Tubifera. Un secolo di lavoro
No full textLa mostra comprende un'esposizione di fotografie, materiali, documenti e filmati a cura di Fabrizio Benente, Roberto Frasca, Roberto Montanari, Carlo Staccini.
La mostra è stata promossa dall'Assessorato alla Cultura del Comune di Sestri Levante in concomitanza del percorso di apertura del Museo cittadino e nell'ambito delle rassegne "La Storia siete voi" e "Festival della Fotografia Una Penisola di Luce".
Il programma prevede l'inaugurazione della mostra e la sua illustrazione da parte dei curatori, anche con l'ausilio di un breve video
A conservative numerical method for a time fractional diffusion equation
No full textGeometric numerical integration, the branch of numerical analysis with the goal of finding approximate solutions of differential equations that preserve some structure of the continuous problem, is a well established field of research [5]. In particular, requiring that invariants or conservation laws are preserved, on one hand, applies on the approximations some constraints that are satisfied also by the exact solutions. On the other hand, it guarantees a better propagation of the error over long integration times [3].
In the last two decades, new techniques for finding conservation laws of fractional differential equations have been derived by suitably generalising methods for PDEs [4, 6]. However, the numerical preservation of conservation laws of time fractional differential
equations is a research topic still at an embryonic state. This talk deals with the numerical solution of diffusion equations in the form
D^α_t u = D^2_x K(u), α ∈ R,
where D_x is the partial derivative in space, K is an arbitrary regular function, and D^α_t
denotes the Riemann-Liouville fractional derivative of order α.
The proposed numerical method combines a finite difference scheme in space with a spectral time integrator and preserves discrete versions of the conservation laws of the original differential equation [1, 2].
The conservative and convergence properties of the proposed method are verified by the computational solution of some numerical experiments.
References
[1] K. Burrage, A. Cardone, R. D’Ambrosio, B. Paternoster. Numerical solution of time fractional diffusion systems. Appl. Numer. Math., 116 (2017), 82–94.
[2] A. Cardone, G. Frasca-Caccia. Numerical conservation laws of time fractional diffusion PDEs. arXiv.2203.01966, (2022).
[3] A. Dur ́an, J. M. Sanz-Serna. The numerical integration of relative equilibrium solutions. Geometric theory. Nonlinearity, 11, 1547–1567, (1998).
[4] G. S. F. Frederico, D. F. M. Torres. Fractional conservation laws in optimal control theory. Nonlinear Dyn., 53 (2008), 215–222.
[5] E. Hairer, C. Lubich, G. Wanner. Geometric Numerical Integration. Structure Preserving Algorithms for Ordinary Differential Equations, volume 31 of Springer Series in Computational Mathematics. Springer, Berlin, second edition, 2006.
[6] S. Y. Lukashchuk. Conservation laws for time-fractional subdiffusion and diffusionwave equations. Nonlinear Dyn., 80 (2015), 791–80
Dei "luoghi sdrucciolevoli", e di un testamento di nascita
No full textL'articolo affronta i temi della responsabilità e della sopravvivenza in due testi di Gabriele Frasca e di Dionys Mascol
Characterization of Neoparamoeba pemaquidensis strains: PCR-RFLP of the internal transcribed spacer region from the amoeba and endosymbiont
No full textNeoparamoeba pemaquidensis continues to be an ongoing problem for commercial finfish aquaculture and has also sporadically been associated with mass mortalities of commercially relevant marine invertebrates. Despite the ubiquity and importance of this amphizoic amoeba, our understanding of the biology as it applies to host range, pathogenicity, tissue tropism, and geographic distribution is severely lacking. This may stem from the inability of current diagnostic tests based on morphology, immunology, and molecular biology to differentiate strains at the subspecies level. In the present study, we developed a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method based on the internal transcribed spacer (ITS) region that can accurately differentiate amoeba strains of N. pemaquidensis. The investigation focused on the complications of the amoeba ITS microheterogeneity in the development of a subspecies marker and the use of the endosymbiont, Ichthyobodo necator related organism (IRO), ITS region as an alternative marker. The combination of host amoeba and endosymbiont ITS PCR-RFLP analyses was successfully used to correctly identify and characterize an N. pemaquidensis isolate from an outbreak of amoebic gill disease in Atlantic salmon Salmo salar from the west coast of North America (Washington State, USA).Charles G. B. Caraguel, Nathanaëlle Donay, Salvatore Frasca Jr., Charles J. O’Kelly, Richard J. Cawthorn Spencer J. Greenwoo
AUTO RAPPRESENTAZIONE DELLA COMUNITA' ITALO AMERICANA ATTRAVERSO LA MUSICA REGISTRATA NELLA PRIMA META' DEL NOVECENTO
No full textAltri luoghi, altri occhi. Immagini di un viaggio in Palestina
No full textUn viaggio in Palestina, tra luoghi storici, vita quotidiana e volti. immagini della campagna di ricerca 2013 a Sebastiya (Palestina). Mostra fotografica e istallazione digitale
COSNet: An R package for label prediction in unbalanced biological networks
No full textSeveral problems in computational biology and medicine are modeled as learning problems in graphs, where nodes represent the biological entities to be studied, e.g. proteins, and connections different kinds of relationships among them, e.g. protein-protein interactions. In this context, classes are usually characterized by a high imbalance, i.e. positive examples for a class are much less than those negative. Although several works studied this problem, no graph-based software designed to explicitly take into account the label imbalance in biological networks is available. We propose COSNet, an R package to serve this purpose. COSNet deals with the label imbalance problem by implementing a novel parametric model of Hopfield Network (HN), whose output levels and activation thresholds of neurons are parameters to be automatically learnt. Due to the quasi-linear time complexity, COSNet nicely scales when the number of instances is large, and application examples to challenging problems in biomedicine show the efficiency and the accuracy of the proposed library
Prediche per il nuovo millennio. Dall'Assedio delle ceneri
No full textLe prediche gesuitiche del XVII secolo riportate agli onori delle loro macchine teatrali
Per riflettere in tante trasparenze
No full textLa predica gesuitica del XVII secolo fra illuminotecnica e macchine sceniche
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